We performed a multistage genome-wide association study of melanoma. In a discovery cohort of 1804 melanoma cases and 1026 controls, we identified loci at chromosomes 15q13.1 (HERC2/OCA2 region) and 16q24.3 (MC1R) regions that reached genome-wide significance within this study and also found strong evidence for genetic effects on susceptibility to melanoma from markers on chromosome 9p21.3 in the p16/ARF region and on chromosome 1q21.3 (ARNT/LASS2/ANXA9 region). The most significant single-nucleotide polymorphisms (SNPs) in the 15q13.1 locus (rs1129038 and rs12913832) lie within a genomic region that has profound effects on eye and skin color; notably, 50% of variability in eye color is associated with variation in the SNP rs12913832. Because eye and skin colors vary across European populations, we further evaluated the associations of the significant SNPs after carefully adjusting for European substructure. We also evaluated the top 10 most significant SNPs by using data from three other genome-wide scans. Additional in silico data provided replication of the findings from the most significant region on chromosome 1q21.3 rs7412746 (P = 6 × 10−10). Together, these data identified several candidate genes for additional studies to identify causal variants predisposing to increased risk for developing melanoma.
Clinical trials on adoptive T-cell therapy (ACT) using expanded tumor-infiltrating lymphocytes (TIL) have shown response rates of over 50% in refractory melanoma. However, little is known how clinical and pathologic features impact TIL outgrowth isolated from metastatic melanoma tumors.
We analyzed the impact of clinical and pathologic features on initial TIL outgrowth in 226 consecutive patients undergoing tumor resection. Successful initial TIL outgrowth was defined as ≥40 million viable lymphocytes harvested from all tumor fragments in a 5-week culture. To normalize for the different size of resected tumors and thus available tumor fragments, we divided the number of expanded TIL by the starting number of tumor fragments (TIL/fragment).
Overall, initial TIL outgrowth was successful in 62% of patients, with patients ≤30 years of age (94%; p=0.01) and female patients (71% vs. 57% for males; p=0.04) having the highest rate of success. Systemic therapy 30 days prior to tumor harvest negatively impacted initial TIL outgrowth compared to patients who never received systemic therapy (47% versus 71%, p=0.02). Biochemotherapy within 0–60 days of tumor harvest negatively impacted the initial TIL outgrowth with a success rate of only 16% (p<0.0001).
Parameters such as age, sex, and the type and timing of prior systemic therapy significantly affect the success rate of the initial TIL outgrowth from tumor fragments for ACT; these parameters may be helpful in selecting patients for melanoma ACT.
We and others have demonstrated that additional positive lymph nodes (LNs) are identified in only 8% to 33% of patients with melanoma who have positive sentinel LNs (SLNs) and undergo complete therapeutic LN dissection (cTLND). We sought to determine predictors of additional regional LN involvement in patients with positive SLNs.
Patients and Methods
Patients with clinically node-negative melanoma who underwent SLN biopsy (1991 to 2003) and had positive SLNs were identified. Clinicopathologic factors, including extent of microscopic disease within SLNs, were evaluated as potential predictors of positive non-SLNs.
Overall, 359 (16.3%) of the 2,203 patients identified had a positive SLN. Positive non-SLNs were identified in 48 (14.0%) of the 343 patients with positive SLNs who underwent cTLND. On univariate analysis, several measures of SLN microscopic tumor burden, one versus three or more SLNs harvested, tumor thickness more than 2 mm, age older than 50 years, and Clark level higher than III were predictive of positive non-SLNs; primary tumor ulceration and number of positive SLNs had no apparent impact. On multivariable logistic regression analysis, measures of SLN microscopic tumor burden were the most significant independent predictors of positive non-SLNs; tumor thickness more than 2 mm and number of SLNs harvested also predicted additional disease. A model was developed that stratified patients according to their risk for non-SLN involvement.
In melanoma patients with positive SLNs, SLN tumor burden, primary tumor thickness, and number of SLNs harvested may be useful in identifying a group at low risk for positive non-SLNs and be spared the potential morbidity of a cTLND.
Meta-analyses were performed to examine the utility of ultrasonography, computed tomography (CT), positron emission tomography (PET), and a combination of both (PET-CT) for the staging and surveillance of melanoma patients.
Patient-level data from 74 studies containing 10 528 patients (between January 1, 1990, and June, 30, 2009) were used to derive characteristics of the diagnostic tests used. Meta-analyses were conducted by use of Bayesian bivariate binomial models to estimate sensitivity and specificity. Diagnostic odds ratios [ie, true-positive results/false-negative results)/(false-positive results/true-negative results)] and their 95% credible intervals (CrIs) and positive predictive values were used as indicators of test performance.
Among the four imaging methods examined for the staging of regional lymph nodes, ultrasonography had the highest sensitivity (60%, 95% CrI = 33% to 83%), specificity (97%, 95% CrI = 88% to 99%), and diagnostic odds ratio (42, 95% CrI = 8.08 to 249.8). For staging of distant metastases, PET-CT had the highest sensitivity (80%, 95% CrI = 53% to 93%), specificity (87%, 95% CrI = 54% to 97%), and diagnostic odds ratio (25, 95% CrI = 3.58 to 198.7). Similar trends were observed for melanoma surveillance of lymph node involvement, with ultrasonography having the highest sensitivity (96%, 95% CrI = 85% to 99%), specificity (99%, 95% CrI = 95% to 100%), and diagnostic odds ratio (1675, 95% CrI = 226.6 to 15,920). For distant metastases, PET-CT had the highest sensitivity (86%, 95% CrI = 76% to 93%), specificity (91%, 95% CrI = 79% to 97%), and diagnostic odds ratio (67, 95% CrI = 20.42 to 229.7). Positive predictive values were likewise highest for ultrasonography in lymph node staging and for PET-CT in detecting distant metastases.
Among the compared modalities, ultrasonography was superior for detecting lymph node metastases, and PET-CT was superior for the detection of distant metastases in both the staging and surveillance of melanoma patients.
Matrix Metallopeptidase 1 (MMP1) is one of the interstitial collagens in the extracellular matrix metalloproteinase family and involved in tumor behaviors. However, there is no report on the role of genetic variation in MMP1 in risk of cutaneous melanoma (CM). We investigated the association between genotypes and haplotypes of seven reported MMP1 promoter polymorphisms (-1607 G ins/del, -839G>A, -755T>G, -519A>G, -422A>T, -340A>G, and -320T>C, genotyped by the TaqMan assay) and CM risk in 872 patients and 873 cancer-free controls. These seven polymorphisms were not in linkage disequilibrium among each other (r2 < 0.63). Compared to their common homozygous genotypes, the variant -519GG was associated with significantly decreased CM risk (adjusted odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.52-0.99), whereas variant -422TT and -320CC were associated with significantly increased CM risk (OR = 1.50, 95% CI = 1.11-2.03 and OR = 1.72, 95% CI = 1.05-2.81, respectively) after adjustment for age, sex, family history, and sun-exposure related risk factors. The number of risk alleles of these three polymorphisms was associated with CM risk in a dose- response manner (Ptrend = 0.0002). In the stratification analysis, we found that the associations of these polymorphisms with CM risk were modified by some of the risk factors. Furthermore, the haplotypes Gdel-A-G-A-T-G-T and G-G-G-A-T-A-T were associated with significantly increased CM risk (ORs = 1.56 and 2.13, 95% CIs = 1.02-2.38 and 1.22-3.70, respectively). These findings suggest that MMP1 promoter polymorphisms may individually or jointly play roles in the development of CM.
genotypes; haplotypes; genetic susceptibility; molecular epidemiology; skin neoplasms
We prospectively assessed the incidence, risk factors, and costs associated with wound complications and lymphedema in melanoma patients undergoing inguinal lymph node dissection (ILND).
Materials and Methods
A total of 53 melanoma patients were accrued to 2 trials (June 2005 to July 2008) that included prospective evaluations of postoperative complications; 30-day wound complications included infection, seroma, and/or dehiscence. There were 20 patients who underwent limb volume measurement and completed a 19-item lymphedema symptom assessment questionnaire preoperatively and 3 months postoperatively. A multivariate analysis was performed to evaluate potential risk factors for complications. A microcosting analysis was also performed to evaluate the direct costs associated with wound complications.
The 30-day wound complications were noted in 77.4% of patients. A BMI ≥ 30 (n = 28) increased the risk for wound complications (odds ratio [OR] = 11.4, 95% confidence interval [95%CI] 1.6–78.5, P = .01), while advanced nodal disease approached significance (OR = 9.0, 95%CI: 0.79–103.1, P = .08). Other risk factors, including diabetes, smoking, and the addition of a deep pelvic (iliac/obturator) dissection to ILND, were not significant. Of 20 patients, 9 (45%) developed limb volume change (LVC) ≥5% at 3 months, with associated mean symptom scores of 6.1 versus 4.6 for those without LVC. Costs for patients with wound complications were significantly higher than for those without wound complications.
Postoperative wound complications and early onset lymphedema occur frequently following ILND for melanoma. Obesity is an adverse risk factor for 30-day wound complications that can significantly increase postoperative costs, as is likely the case for advanced disease. Risk reduction practices and novel treatment approaches are needed to reduce postoperative morbidity.
Conditional survival (CS) has emerged as a clinically relevant measure of prognosis for cancer survivors. The objective of this analysis was to provide melanoma-specific CS estimates to help clinicians promote more informed patient decision-making.
Patients with melanoma and at least 5 years of follow-up were identified from the Surveillance Epidemiology and End Results (SEER) registry (1988–2000). Using the methods of Kaplan and Meier, stage-specific 5-year CS estimates were independently calculated for survivors for each year following diagnosis. Stage-specific multivariate Cox regression models including baseline survivor functions were used to calculate adjusted melanoma-specific CS for different subgroups of patients further stratified by age, gender, race, marital status, anatomic tumor location, and tumor histology.
Five-year CS estimates for stage I patients remained constant at 97% annually, while for patients with stages II, III and IV disease, 5-year CS estimates from time 0 (diagnosis) to 5 years improved from 72% to 86%, 51% to 87%, and 19% to 84%, respectively. Multivariate CS analysis revealed that differences in stages II through IV CS based on age, gender and race decreased over time.
Five-year melanoma-specific CS estimates improve dramatically over time for survivors with advanced stages of disease. These prognostic data are critical to patients for both treatment and non-treatment related life decisions.
melanoma; conditional survival; SEER
Caspase-8 (CASP8) and caspase-10 (CASP10) play key roles in regulating apoptosis, and functional polymorphisms of them may alter apoptosis and cancer risk. However, no reported studies have investigated the association between such polymorphisms and the risk of cutaneous melanoma (CM). In a hospital-based study of 805 non-Hispanic white patients with CM and 835 cancer-free age- sex- and ethnicity-matched controls, we genotyped three reported putatively functional polymorphisms of CASP8 and CASP10--CASP8 D302H (rs1045485:G>C), CASP8-652 6N del (rs3834129:–/CTTACT), and CASP10 I522L (rs13006529:A>T)--and assessed their associations with risk of CM and interactions with known risk factors for CM. We also calculated the false-positive-report probability (FPRP) for significant findings. CASP8 302H variant genotypes (DH: adjusted odds ratio [OR], 0.70 [95% confidence interval (CI), 0.50-0.98]; DH+HH: unadjusted OR, 0.78 [95% CI, 0.62-0.98]; FPRP, 0.79) and CASP8 -652 6N del variant genotypes (ins/del: OR, 0.74 [95% CI, 0.57-0.97]; ins/del+del/del: OR, 0.76 [95% CI, 0.61-0.95]; FPRP, 0.61) were associated with significantly lower CM risk than were the ins/ins genotypes. The CASP10 522L variant genotypes were not associated with significantly altered CM risk. Also, the D-del-I haplotype was associated with a significantly lower CM risk (OR, 0.52 [95% CI, 0.37-0.74]; FPRP, 0.116) than was the most common haplotype, D-ins-I. Furthermore, multivariate logistic regression analysis revealed that CASP8 D302H, CASP8 -652 6N del, and CASP10 I522L were independent risk factors for CM. Therefore, these CASP8 and CASP10 variant polymorphisms may be biomarkers for susceptibility to CM.
apoptosis; death pathway; genetic susceptibility; molecular epidemiology; skin cancer
In a hospital-based case-control study of 805 non-Hispanic whites with cutaneous melanoma and 841cancer-free age-, sex- and ethnicity-matched control subjects, three VDR polymorphisms (i.e., TaqI, BsmI, and FokI) were genotyped using blood samples collected between 1994 and 2006. We tested the hypothesis that the haplotypes and combined genotypes of these polymorphisms were associated with melanoma risk by interacting with known risk factors. Haplotypes t-B-F (adjusted odds ratio [OR], 0.52; 95 percent confidence interval [CI], 0.34–0.80) and t-B-f (adjusted OR, 0.51; CI, 0.27–0.94) were associated with a reduced risk when compared with T-b-f. The combined genotypes Tt+tt/Bb+BB/Ff+ff (adjusted OR, 0.69; CI, 0.52, 0.90) and Tt+tt/Bb+BB/FF (adjusted OR, 0.58; CI, 0.43, 0.78) were also associated with reduced risk, whereas the combined genotype TT/Bb+BB/Ff+ff genotype (adjusted OR, 2.35; CI, 1.13, 4.98) was associated with increased risk when compared with TT/bb/Ff+ff genotypes. On multivariate analysis, only the TaqI polymorphism was an independent risk factor, while the FokI polymorphism interacted with skin color (p = 0.029), moles (p = 0.017), and first-degree relatives with any cancer (p = 0.013) in modifying risk. Together, these findings suggest that VDR polymorphisms may directly effect or modify the risk associated with known melanoma risk factors. Larger, population-based studies are needed to replicate our findings.
case-control studies; vitamin D receptor; genetic polymorphisms; genotypes; melanoma
case-control study; cell cycle; DNA repair; genetic polymorphism; skin cancer
The objectives of this analysis were to compare various measures associated with lymph node (LN) dissection and to identify threshold values associated with disease-specific survival (DSS) outcomes in patients with melanoma.
Patients with node positive melanoma who underwent therapeutic LN dissection of the neck, axilla, and inguinal region were identified from the SEER database (1988–2005). We performed Cox multivariate analyses to determine the impact of the total number of LNs removed, number of negative LNs removed, and LN ratio on DSS. Multivariate cut-point analyses were conducted for each anatomic region to identify the threshold values associated with the largest improvement in DSS.
The LN ratio was significantly associated with DSS for all LN regions. The LN ratio thresholds resulting in the greatest difference in 5-year DSS were 0.07, 0.13, and 0.18 for neck, axillary, and inguinal regions, respectively, corresponding to 15, 8, and 6 LNs removed per positive node. After adjustment for other clinicopathologic factors, the hazard ratios (HRs) were 0.53 (95% confidence intervals (CIs), 0.40 to 0.71) in the neck, 0.52 (95% CI, 0.42 to 0.65) in the axillary, and 0.47 (95% CI, 0.36 to 0.61) in the inguinal regions for patients in whom the LN ratio threshold was met.
Among the prognostic factors examined, LN ratio was the best indicator of the extent of LN dissection, regardless of anatomic nodal region. These data provide evidence-based guidelines for defining adequate LN dissections in melanoma patients.
melanoma; lymphadenectomy; lymph node ratio; disease-specific survival
This study assessed the impact of closed suction drains and evaluated whether the intraoperative use of a fibrin sealant decreased time to drain removal and wound complications in melanoma patients undergoing inguino-femoral lymph node dissection.
A pilot study (n = 18) assessed the impact of a closed suction drain following inguino-femoral lymph node dissection. A single-institution, prospective trial was then performed in which patients were randomized to a group that received intraoperative application of a fibrin sealant following inguino-femoral lymph node dissection or to a control group that did not receive sealant.
The majority of the patients enrolled felt the drains caused moderate or severe discomfort and difficulties with activities of daily living. Thirty patients were then randomized; the median time to drain removal in the control group (n = 14) was 30 days (range, 13–74) compared to 29 days (range, 11–45) in the fibrin sealant group (n = 16; P = 0.6). Major and minor complications were similar in the two groups.
Postoperative closed suction drains were associated with major patient inconvenience. Applying a fibrin sealant at the time of inguino-femoral lymph node dissection in melanoma patients did not reduce the time to drain removal or postoperative morbidity. Alternative strategies are needed.
DNA repair pathway genes play an important role in maintaining genomic integrity and protecting against cancer development. This study aimed to identify novel SNPs in the DNA repair–related genes associated with melanoma risk from a genome-wide association study (GWAS).
A total of 8,422 SNPs from the 165 DNA repair–related genes were extracted from a GWAS of melanoma risk, including 494 cases and 5,628 controls from the Nurses’ Health Study (NHS) and the Health Professionals Follow-up Study (HPFS). We further replicated the top SNPs in a GWAS of melanoma risk from the MD Anderson Cancer Center (1,804 cases and 1,026 controls).
A total of 3 SNPs with P value < 0.001 were selected for in silico replication. One SNP was replicated: rs3902093 [A] in EXO1 promoter region (Pdiscovery = 6.6×10-4, Preplication = 0.039, Pjoint = 2.5×10-4; ORjoint = 0.80, 95% CI: 0.71, 0.90). This SNP was associated with the expression of the EXO1; carriers of the A allele showed lower expression (P = 0.002).
Our study found that a promoter region SNP in the editing and processing nucleases gene EXO1 was associated with decreased expression of EXO1 and decreased melanoma risk. Further studies are warranted to validate this association and to investigate the potential mechanisms.
Perineural invasion (PNI) is one of the established prognostic factors in pancreatic ductal adenocarcinoma (PDAC). However, the prognostic significance of PNI in patients with PDAC who received neoadjuvant therapy and pancreaticoduodenectomy (PD) is not clear. In this study, we performed detailed examination of neural invasion in PD specimens from 212 patients with PDAC who received neoadjuvant chemoradiation (treated group) and 60 untreated patients at our institution between January 1999 and December 2007. The frequency of PNI was higher in untreated group (80%, 48/60) than the treated group (58%, 123/212). For the 123 treated cases that were positive for PNI, extra-tumoral PNI, intra-tumoral PNI, intra-pancreatic PNI only, extra-pancreatic PNI, and intra-neural invasion were identified in 86 (69.9%), 37 (30.1%), 11 (8.9%), 112 (91.1%), and 35 (28.5%) respectively. Presence of PNI correlated with tumor size, margin status, lymph node metastasis, pathologic tumor and AJCC stages in the treated group. Tumor involvement of nerves >0.8 mm correlated with higher frequency of positive margin compared to those with PNI involving nerves ≤0.8 mm, but not with other clinicopathologic parameters and survival. In treated group, the presence of PNI or intra-neural invasion correlated significantly with shorter disease-free survival (DFS) and overall survival (OS) compared to those with no PNI or PNI only respectively. PNI was an independent prognostic factor for both DFS and OS in multivariate analysis. Our results showed that PNI plays an important role in the progression of PDAC and in predicting the prognosis in this group of patients.
pancreatic cancer; perineural invasion; intra-neural invasion; survival; prognosis
To verify circulating tumor cell (CTC) prognostic utility in stage IV resected melanoma patients in a prospective international phase III clinical trial.
Summary Background Data
Our studies of melanoma patients in phase II clinical trials demonstrated prognostic significance for CTCs in patients with AJCC stage IV melanoma. CTCs were assessed to determine prognostic utility in follow-up of disease-free stage IV patients pre- and during treatment.
After complete metastasectomy, patients were prospectively enrolled in a randomized trial of adjuvant therapy with a whole-cell melanoma vaccine plus Bacille Calmette-Guerin (BCG) vs. placebo plus BCG. Blood specimens obtained pretreatment (n=244) and during treatment (n=214) were evaluated by quantitative real-time reverse-transcriptase polymerase chain reaction (qPCR) for expression of MART-1, MAGE-A3 and PAX3 mRNA biomarkers. Univariate and multivariate Cox analyses examined CTC biomarker expression with respect to clinicopathological variables.
CTC biomarker(s) (≥1) was detected in 54% of patients pretreatment and in 86% of patients over the first 3 months. With a median follow-up of 21.9 months, 71% of patients recurred and 48% expired. CTC levels were not associated with known prognostic factors or treatment arm. In multivariate analysis, pretreatment CTC (>0 vs. 0 biomarker) status was significantly associated with disease-free survival (DFS) (HR 1.64, p=0.002) and overall survival (OS) (HR 1.53, p=0.028). Serial CTC (>0 vs. 0 biomarker) status was also significantly associated with DFS (HR 1.91, p=0.02) and OS (HR 2.57, p=0.012).
CTC assessment can provide prognostic discrimination before and during adjuvant treatment for resected stage IV melanoma patients. Study registration ID# NCT00052156.
Melanoma; Circulating Tumor Cells; Stage IV; Prognosis
Recent data showed that melanoma was more common among patients with Parkinson’s disease (PD) than individuals without PD and vice versa. It has been hypothesized that these two diseases may share common genetic and environmental risk factors.
We evaluated the association between single-nucleotide polymorphisms (SNPs) selected based on recent genome-wide association studies (GWAS) on PD risk and the risk of melanoma using 2,297 melanoma cases and 6,651 controls.
The PD SNP rs156429 in the chromosome 7p15 region was nominally associated with melanoma risk with p-value of 0.04, which was not significant after the Bonferroni correction for multiple comparisons. No association was observed between the remaining 31 PD SNPs and the risk of melanoma. The genetic score based on the number of PD risk allele was not associated with melanoma risk (odds ratio for the highest genetic score quartile (30–35) vs. the lowest (15–20), 1.13, 95% confidence interval, 0.47–2.70).
The PD SNPs identified in published GWAS do not appear to play an important role in melanoma development.
The PD susceptibility loci discovered by GWAS contribute little to the observed epidemiological association between the PD and melanoma.
Clonal mosaicism for large chromosomal anomalies (duplications, deletions and uniparental disomy) was detected using SNP microarray data from over 50,000 subjects recruited for genome-wide association studies. This detection method requires a relatively high frequency of cells (>5–10%) with the same abnormal karyotype (presumably of clonal origin) in the presence of normal cells. The frequency of detectable clonal mosaicism in peripheral blood is low (<0.5%) from birth until 50 years of age, after which it rises rapidly to 2–3% in the elderly. Many of the mosaic anomalies are characteristic of those found in hematological cancers and identify common deleted regions that pinpoint the locations of genes previously associated with hematological cancers. Although only 3% of subjects with detectable clonal mosaicism had any record of hematological cancer prior to DNA sampling, those without a prior diagnosis have an estimated 10-fold higher risk of a subsequent hematological cancer (95% confidence interval = 6–18).
We conducted a genome-wide association study on cutaneous basal cell carcinoma (BCC) among 2045 cases and 6013 controls of European ancestry, with follow-up replication in 1426 cases and 4845 controls. A non-synonymous SNP in the MC1R gene (rs1805007 encoding Arg151Cys substitution), a previously well-documented pigmentation gene, showed the strongest association with BCC risk in the discovery set (rs1805007[T]: OR (95% CI) for combined discovery set and replication set [1.55 (1.45–1.66); P= 4.3 × 10−17]. We identified that an SNP rs12210050 at 6p25 near the EXOC2 gene was associated with an increased risk of BCC [rs12210050[T]: combined OR (95% CI), 1.24 (1.17–1.31); P= 9.9 × 10−10]. In the locus on 13q32 near the UBAC2 gene encoding ubiquitin-associated domain-containing protein 2, we also identified a variant conferring susceptibility to BCC [rs7335046 [G]; combined OR (95% CI), 1.26 (1.18–1.34); P= 2.9 × 10−8]. We further evaluated the associations of these two novel SNPs (rs12210050 and rs7335046) with squamous cell carcinoma (SCC) risk as well as melanoma risk. We found that both variants, rs12210050[T] [OR (95% CI), 1.35 (1.16–1.57); P= 7.6 × 10−5] and rs7335046 [G] [OR (95% CI), 1.21 (1.02–1.44); P= 0.03], were associated with an increased risk of SCC. These two variants were not associated with melanoma risk. We conclude that 6p25 and 13q32 are novel loci conferring susceptibility to non-melanoma skin cancer.
Antibody 14G7 is protective against lethal Ebola virus challenge and recognizes a distinct linear epitope in the prominent mucin-like domain of the Ebola virus glycoprotein GP. The structure of 14G7 in complex with its linear peptide epitope has now been determined to 2.8 Å. The structure shows that this GP sequence forms a tandem β-hairpin structure that binds deeply into a cleft in the antibody-combining site. A key threonine at the apex of one turn is critical for antibody interaction and is conserved among all Ebola viruses. This work provides further insight into the mechanism of protection by antibodies that target the protruding, highly accessible mucin-like domain of Ebola virus and the structural framework for understanding and characterizing candidate immunotherapeutics.
This phase II trial was designed to assess the efficacy and safety of cetuximab, gemcitabine, and oxaliplatin followed by cetuximab, capecitabine, and radiation therapy in locally advanced pancreatic cancer (LAPC).
Patients and Methods
Treatment-naive eligible patients (n = 69) received intravenous gemcitabine (1,000 mg/m2) and oxaliplatin (100 mg/m2) every 2 weeks for four doses, followed by radiation (50.4 Gy to the gross tumor only) with concurrent capecitabine (825 mg/m2 twice daily on radiation treatment days). Cetuximab (500 mg/m2) was started on day 1 of chemotherapy and was continued every 2 weeks during chemotherapy and chemoradiotherapy. Diagnostic cytology specimens were immunostained for Smad4(Dpc4) expression.
Median overall survival time was 19.2 months (95% CI, 14.2 to 24.2 months), and 1-year, 2-year, and 4-year actuarial overall survival rates were 66.0%, 25.02%, and 11.3%, respectively. Acneiform rash correlated with improved survival (P = .001), but initial CA19-9, borderline resectable initial stage, and surgical resection (n = 7) did not. The 1-year and 2-year radiographic local progression rates were 22.8% and 61.0%, respectively. The worst acute toxic effects were GI toxicity (32% and 10% for grades 2 and 3, respectively); fatigue (26% and 6% for grades 2 and 3, respectively); sensory neuropathy (9% and 1% for grades 2 and 3, respectively); and acneiform rash (54% and 3% for grades 2 and 3, respectively). Smad4(Dpc4) expression correlated with a local rather than a distant dominant pattern of disease progression (P = .016).
This regimen appears effective and has acceptable toxicity. The primary end point (1-year overall survival rate > 45%) was met, with encouraging survival duration. Smad4(Dpc4) immunostaining correlated with the pattern of disease progression. Prospective validation of Smad4(Dpc4) expression in cytology specimens as a predictive biomarker is warranted and may lead to personalized treatment strategies for patients with localized pancreatic cancer.
We conducted a genome-wide association study on the number of melanocytic nevi reported by 9136 individuals of European ancestry, with follow-up replication in 3581 individuals. We identified the nidogen 1 (NID1) gene on 1q42 associated with nevus count (two linked single nucleotide polymorphisms with r2 > 0.9: rs3768080 A allele associated with reduced count, P = 6.5 × 10−8; and rs10754833 T allele associated with reduced count, P = 1.5 × 10−7). We further determined that the rs10754833 [T] was associated with a decreased melanoma risk in 2368 melanoma cases and 7432 controls [for CT genotype: odds ratio (OR) = 0.86, 95% confidence interval (CI) = 0.75–0.99, P = 0.04; for TT genotype: OR = 0.84, 95% CI = 0.71–0.98, P = 0.03]. Expression level of the NID1 locus was 2-fold higher for the rs10754833 T allele carriers than that with the CC genotype (P = 0.017) in the 87 HapMap CEU cell lines. The NID1 gene is a biologically plausible locus for nevogenesis and melanoma development, with decreased expression levels of NID1 in benign nevi (P = 3.5 × 10−6) and in primary melanoma (P = 4.6 × 10−4) compared with the normal skin.
The rationale for and outcomes associated with the use of adjuvant and neoadjuvant therapy for resectable and borderline resectable cancer of the pancreatic head and uncinate process are reviewed.
After completing this course, the reader will be able to:
Explain the rationale for the use of adjuvant and neoadjuvant chemoradiation and/or chemotherapy in the treatment of patients with potentially resectable pancreatic cancer.Describe the limitations of prior prospective, randomized trials of adjuvant therapy strategies and the clinical implications of these limitations.Compare modern strategies for the multidisciplinary management of potentially resectable and borderline resectable pancreatic cancer.
This article is available for continuing medical education credit at CME.TheOncologist.com.
In this article, we review the rationale for and outcomes associated with the use of adjuvant and neoadjuvant therapy for resectable and borderline resectable cancer of the pancreatic head and uncinate process. Localized pancreatic cancer is a systemic disease that requires nonoperative therapies to minimize the local and systemic recurrences that almost invariably occur in the absence of such therapy, even following complete surgical resection. A well-defined role exists for the systemic administration of gemcitabine or 5-fluorouracil in the postoperative setting. Although the survival benefit associated with adjuvant chemoradiation has not been as rigorously defined, its use is supported by extensive historic experience; chemoradiation should be considered particularly for patients at high risk for local recurrence. Delivery of chemotherapy and/or chemoradiation prior to surgery has multiple potential advantages, although the superiority of neoadjuvant therapy over standard postoperative therapy has yet to be demonstrated. Neoadjuvant therapy may be particularly beneficial among patients with borderline resectable cancers. Although the existing literature is confusing, and indeed controversial, available evidence suggests that systemic chemotherapy and/or chemoradiation should be offered to all patients with pancreatic cancer who undergo potentially curative resection. Well-designed prospective trials are needed to define the optimal adjuvant or neoadjuvant therapy strategy for these patients.
Pancreatic cancer; Adjuvant therapy; Neoadjuvant therapy; Chemoradiation; Chemotherapy; Pancreaticoduodenectomy
Here, the techniques, tactics and strategies used to overcome a series of technical roadblocks in crystallization and phasing of the trimeric ebolavirus glycoprotein are described.
The trimeric membrane-anchored ebolavirus envelope glycoprotein (GP) is responsible for viral attachment, fusion and entry. Knowledge of its structure is important both for understanding ebolavirus entry and for the development of medical interventions. Crystal structures of viral glycoproteins, especially those in their metastable prefusion oligomeric states, can be difficult to achieve given the challenges in production, purification, crystallization and diffraction that are inherent in the heavily glycosylated flexible nature of these types of proteins. The crystal structure of ebolavirus GP in its trimeric prefusion conformation in complex with a human antibody derived from a survivor of the 1995 Kikwit outbreak has now been determined [Lee et al. (2008 ▶), Nature (London), 454, 177–182]. Here, the techniques, tactics and strategies used to overcome a series of technical roadblocks in crystallization and phasing are described. Glycoproteins were produced in human embryonic kidney 293T cells, which allowed rapid screening of constructs and expression of protein in milligram quantities. Complexes of GP with an antibody fragment (Fab) promoted crystallization and a series of deglycosylation strategies, including sugar mutants, enzymatic deglycosylation, insect-cell expression and glycan anabolic pathway inhibitors, were attempted to improve the weakly diffracting glycoprotein crystals. The signal-to-noise ratio of the search model for molecular replacement was improved by determining the structure of the uncomplexed Fab. Phase combination with Fab model phases and a selenium anomalous signal, followed by NCS-averaged density modification, resulted in a clear interpretable electron-density map. Model building was assisted by the use of B-value-sharpened electron-density maps and the proper sequence register was confirmed by building alternate sequences using N-linked glycan sites as anchors and secondary-structural predictions.
glycoproteins; structure determination; difficult structures; antibody complexes; viral proteins; human proteins; tactics to improve diffraction; techniques for phase determination; deglycosylation; model building
The ebolavirus (EBOV) envelope glycoprotein (GP) is solely responsible for viral attachment to, fusion with, and entry of new host cells, and consequently is a major target of vaccine design efforts. Recently determined crystal structures of key antibodies in complex with their EBOV epitopes have provided insights into the molecular architecture of GP and defined likely hotspots for viral neutralization. In this review, we discuss the structural basis for antibody-mediated neutralization of ebolavirus and its implications for novel therapeutic or vaccine strategies.
Glycoproteins mediate multiple, diverse and critical cellular functions, that are desirable to explore by structural analysis. However, structure determination of these molecules has been hindered by difficulties expressing milligram quantities of stable, homogeneous protein and in determining, which modifications will yield samples amenable to structural studies. We describe a platform proven effective for rapidly screening expression and crystallization of challenging glycoprotein targets produced in mammalian cells. Here, multiple glycoprotein constructs are produced in parallel by transient expression of adherent human embryonic kidney (HEK) 293T cells and subsequently screened in small quantities for crystallization by microfluidic free interface diffusion. As a result, recombinant proteins are produced and processed in a native, mammalian environment and crystallization screening can be accomplished with as little as 65 μg of protein. Moreover, large numbers of constructs can be screened for expression and crystallization and scaled up for structural studies in a matter of five weeks.