The potentially life-threatening effects of total body ionizing radiation exposure have been known for more than a century. Despite considerable advances in our understanding of the effects of radiation over the past six decades, efforts to identify effective radiation countermeasures for use in case of a radiological/nuclear emergency have been largely unsuccessful. Vitamin E is known to have antioxidant properties capable of scavenging free radicals, which have critical roles in radiation injuries. Tocopherols and tocotrienols, vitamin E analogs together known as tocols, have shown promise as radioprotectors. Although the pivotal mechanisms of action of tocols have long been thought to be their antioxidant properties and free radical scavenging activities, other alternative mechanisms have been proposed to drive their activity as radioprotectors. Here we provide a brief overview of the effects of ionizing radiation, the mechanistic mediators of radiation-induced damage, and the need for radiation countermeasures. We further outline the role for, efficacy of, and mechanisms of action of tocols as radioprotectors, and we compare and contrast their efficacy and mode of action with that of another well-studied chemical radioprotector, amifostine.
We report potent radiosensitization of prostate cancers in vitro and in vivo using goserelin-conjugated gold nanorods. Progressive receptor-mediated internalization of conjugated nanorods over time increases the radiation interaction cross-section of cells and contributes to the effects observed in vitro. The low concentrations of gold required, the long interval between injection of nanoparticles and radiation, and the use of megavoltage radiation to generate radiosensitization in vivo foretell the possibility of eventual clinical translation of this approach.
megavoltage radiation therapy; gold nanoparticles; tumor targeted delivery; conjugated; prostate cancer; goserelin acetate
Biliary cancers are highly aggressive tumors that are often diagnosed an advanced disease stage and have a poor outcome with systemic therapy. Recent efforts towards molecular characterization have identified a subset of biliary patients that have HER2/neu amplification or mutation. HER2/neu amplification is associated with response to HER2/neu-directed therapy in breast and gastric cancers. However, the efficacy of HER2/neu-targeted therapy in biliary cancers is unknown.
Patients and methods
We retrospectively reviewed cases of advanced gallbladder cancer and cholangiocarcinoma with HER2/neu genetic aberrations or protein overexpression who received HER2/neu-directed therapy between 2007 and 2014. Clinical data were retrieved from medical records, and imaging studies were independently reviewed.
Nine patients with gallbladder cancer and five patients with cholangiocarcinoma had received HER2/neu-directed therapy (trastuzumab, lapatinib, or pertuzumab) during the study period. In the gallbladder cancer group, HER2/neu gene amplification or overexpression was detected in eight cases. These patients experienced disease stability (n = 3), partial response (n = 4), or complete response (n = 1) with HER2/neu-directed therapy. One patient had HER2/neu mutation and experienced a mixed response after lapatinib therapy. The duration of response varied from 8+ to 168 weeks (median 40 weeks), and three patients are still on therapy. One patient developed HER2/neu amplification as a secondary event after FGFR-directed therapy for FGF3-TACC3 gene fusion. The cholangiocarcinoma cases treated in this series had a higher proportion of HER2/neu mutations, and no radiological responses were seen in these patients despite HER2/neu-directed therapy.
HER2/neu blockade is a promising treatment strategy for gallbladder cancer patients with gene amplification and deserves further exploration in a multi-center study.
Receptor; ErbB-2; Gallbladder neoplasms; Cancer of the biliary tract
Locally advanced rectal cancers are treated with neoadjuvant chemoradiation therapy followed by surgery. In a minority (∽20%) of patients, no tumor is present at the time of surgery; these patients with a complete pathologic response (pathCR) to neoadjuvant therapy have better treatment outcomes. Unfortunately, the inherent radioresistance of colorectal cancer (CRC) cells dictates that the majority of patients do not achieve a pathCR. Efforts to improve these odds have fueled the search for novel, relatively less-toxic radiosensitizers with distinct molecular mechanism(s) and broad-spectrum anticancer activities. Here, we use zerumbone, a sesquiterpene from the edible ginger (Zingiber zerumbet Smith), to enhance radiosensitivity of CRC cells. Short exposure to zerumbone (7 h) profoundly sensitized CRC cells, independent of their p53 or k-RAS status. Zerumbone enhanced radiation-induced cell cycle arrest (G2/M), increased radiation-induced apoptosis, but induced little apoptosis by itself. Zerumbone significantly enhanced radiation-induced DNA damage, as evident by delayed resolution of post-irradiation nuclear γH2AX foci, whereas zerumbone treatment alone did not induce γH2AX foci formation. Zerumbone pretreatment inhibited radiation-induced nuclear expression of DNA repair proteins ataxia-telangiectasia mutated (ATM) and DNA-PKcs. Interestingly, zerumbone-mediated radiosensitization did not involve reactive oxygen species (ROS), but was mediated through depletion of cellular glutathione (GSH). Ability of only thiol-based antioxidants to abrogate zerumbone-mediated radiosensitization further corroborated this hypothesis. The α,β-unsaturated carbonyl group in zerumbone was found to be essential for its bioactivity as zerumbone analog α-Humulene that lacks this functional group, could neither radiosensitize CRC cells, nor deplete cellular GSH. Our studies elucidate novel mechanism(s) of zerumbone's ability to enhance CRC radiosensitivity.
Colorectal cancer; DNA repair; glutathione; radiation; sesquiterpene
Defining hepatocellular carcinoma (HCC) gross tumor volume (GTV) requires multimodal imaging, acquired in different perfusion phases. The purposes of this study were to evaluate the variability in contouring and to establish guidelines and educational recommendations for reproducible HCC contouring for treatment planning.
Methods and Materials
Anonymous, multiphasic planning computed tomography scans obtained from 3 patients with HCC were identified and distributed to a panel of 11 gastrointestinal radiation oncologists. Panelists were asked the number of HCC cases they treated in the past year. Case 1 had no vascular involvement, case 2 had extensive portal vein involvement, and case 3 had minor branched portal vein involvement. The agreement between the contoured total GTVs (primary + vascular GTV) was assessed using the generalized kappa statistic. Agreement interpretation was evaluated using Landis and Koch’s interpretation of strength of agreement. The S95 contour, defined using the simultaneous truth and performance level estimation (STAPLE) algorithm consensus at the 95% confidence level, was created for each case.
Of the 11 panelists, 3 had treated >25 cases in the past year, 2 had treated 10 to 25 cases, 2 had treated 5 to 10 cases, 2 had treated 1 to 5 cases, 1 had treated 0 cases, and 1 did not respond. Near perfect agreement was seen for case 1, and substantial agreement was seen for cases 2 and 3. For case 2, there was significant heterogeneity in the volume identified as tumor thrombus (range 0.58–40.45 cc). For case 3, 2 panelists did not include the branched portal vein thrombus, and 7 panelists contoured thrombus separately from the primary tumor, also showing significant heterogeneity in volume of tumor thrombus (range 4.52–34.27 cc).
In a group of experts, excellent agreement was seen in contouring total GTV. Heterogeneity exists in the definition of portal vein thrombus that may impact treatment planning, especially if differential dosing is contemplated. Guidelines for HCC GTV contouring are recommended.
We report a magneto-fluorescent theranostic nanocomplex targeted to neutrophil gelatinase associated lipocalin (NGAL) for imaging and therapy of pancreatic cancer.
Materials and Methods
Gold nanoshells resonant at 810 nm were encapsulated in silica epilayers doped with iron oxide and the NIR dye ICG, resulting in theranostic gold nanoshells (TGNS), which were subsequently conjugated with antibodies targeting NGAL in AsPC-1-derived xenografts in nude mice.
AntiNGAL-conjugated TGNS specifically targeted pancreatic cancer cells in vitro and in vivo providing contrast for both NIR fluorescence and T2 weighted MR imaging with higher tumor contrast than can be obtained using long-circulating but non-targeted PEGylated nanoparticles. The nanocomplexes also enabled highly specific cancer cell death via NIR photothermal therapy in vitro.
Theranostic gold nanoshells with embedded NIR and MR contrasts can be specifically targeted to pancreatic cancer cells with expression of early disease marker NGAL, and enable molecularly targeted imaging and photothermal therapy.
nanoshells; optical imaging; photothermal; pancreatic cancer; noninvasive imaging; MRI
Improvements in accuracy and efficacy in treating tumors with radiation therapy (RT) over the years have been fueled by parallel technological and conceptual advances in imaging and image-guidance techniques, radiation treatment machines, computational methods, and the understanding of the biology of tumor response to RT. Recent advances in our understanding of the hallmarks of cancer and the emergence of strategies to combat these traits of cancer have resulted in an expanding repertoire of targeted therapeutics, many of which can be exploited for enhancing the efficacy of RT. Complementing this advent of new treatment options is the evolution of our knowledge of the interaction between nanoscale materials and human tissues (nanomedicine). As with the changes in RT paradigms when the field has encountered newer and maturing disciplines, the incorporation of nanotechnology innovations into radiation oncology has the potential to refine or redefine its principles and revolutionize its practice. This review provides a summary of the principles, applications, challenges and outlook for the use of metallic nanoparticles in RT.
Cancer; nanoparticles; nanotechnology; radiation therapy (RT); review
Despite remarkable achievements in the treatment of breast cancer, some obstacles still remain. Gold nanoparticles may prove valuable in addressing these problems owing to their unique characteristics, including their enhanced permeability and retention in tumor tissue, their light absorbance and surface plasmon resonance in near-infrared light, their interaction with radiation to generate secondary electrons, and their ability to be conjugated with drugs or other agents. Herein, we discuss some basic concepts of gold nanoparticles, and early results from studies regarding their use in breast cancer, including toxicity and side effects. We also discuss these particles’ potential clinical applications.
Gold nanoparticle; Breast neoplasms; Theranostics; Nanotechnology
The Rare Cancer Network (RCN) was formed in the early 1990’s to create a global network that could pool knowledge and resources in the studies of rare malignancies whose infrequency prevented both their study with prospective clinical trials. To date, the RCN has initiated 74 studies resulting in 46 peer reviewed publications. The First International Symposium of the Rare Cancer Network took place in Nice in March of 2014. Status updates and proposals for new studies were heard for fifteen topics. Ongoing studies continue for cardiac sarcomas, thyroid cancers, glomus tumors, and adult medulloblastomas. New proposals were presented at the symposium for primary hepatic lymphoma, solitary fibrous tumors, Rosai-Dorfman disease, tumors of the ampulla of Vater, salivary gland tumors, anorectal melanoma, midline nuclear protein in testes carcinoma, pulmonary lymphoepithelioma-like carcinoma, adenoid cystic carcinoma of the trachea, osteosarcomas of the mandible, and extra-cranial hemangiopericytoma. This manuscript presents the abstracts of those proposals and updates on ongoing studies, as well a brief summary of the vision and future of the RCN.
rare; diseases; cancer; carcinoma; Rare Cancer Network
Breast cancer metastasis and disease recurrence are hypothesized to result from residual cancer stem cells, also referred to as tumor-initiating cells, which evade initial treatment. Using both syngeneic mouse and human xenograft models of triple-negative breast cancer, we have demonstrated that a subpopulation enriched in cancer stem cells was more resistant to treatment with 6 gray of ionizing radiation than the bulk of the tumor cells, and accordingly their relative proportion increased 48 to 72 hours after ionizing radiation treatment. In contrast, we achieved a larger reduction in tumor size without a concomitant increase in the percentage of cancer stem cells by treating with local hyperthermia for 20 minutes at 42°C after ionizing radiation using intravenously administered, optically activated gold nanoshells. Forty-eight hours after treatment, cells derived from the tumors treated with ionizing radiation plus hyperthermia exhibited both a marked decrease in tumorigenicity and a more differentiated phenotype than mock- and ionizing radiation–treated tumors. Thus, we have confirmed that these cancer stem cells are responsible for accelerated repopulation in vivo and demonstrated that hyperthermia sensitizes this cell population to radiation treatment. These findings suggest that local hyperthermia delivered by gold nanoshells plus radiation can eliminate radio-resistant breast cancer stem cells.
The first annual workshop for preclinical and clinical development of radiosensitizers took place at the National Cancer Institute on August 8–9, 2012. Radiotherapy is one of the most commonly applied and effective oncologic treatments for solid tumors. It is well recognized that improved clinical efficacy of radiotherapy would make a substantive impact in clinical practice and patient outcomes. Advances in genomic technologies and high-throughput drug discovery platforms have brought a revolution in cancer treatment by providing molecularly targeted agents for various cancers. Development of predictive biomarkers directed toward specific subsets of cancers has ushered in a new era of personalized therapeutics. The field of radiation oncology stands to gain substantial benefit from these advances given the concerted effort to integrate this progress into radiation therapy. This workshop brought together expert clinicians and scientists working in various disease sites to identify the exciting opportunities and expected challenges in the development of molecularly targeted agents in combination with radiation therapy.
Child-Turcotte-Pugh (CTP) score is the standard tool to assess hepatic reserve in hepatocellular carcinoma (HCC), and CTP-A is the classic group for active therapy. However, CTP stratification accuracy has been questioned. We hypothesized that plasma insulin-like growth factor 1 (IGF-1) is a valid surrogate for hepatic reserve to replace the subjective parameters in CTP score to improve its prognostic accuracy.
We retrospectively tested plasma IGF-1 levels in the training set (n = 310) from MD Anderson Cancer Center. Recursive partitioning identified three optimal IGF-1 ranges that correlated with overall survival (OS): greater than 50ng/mL = 1 point; 26 to 50ng/mL = 2 points; and less than 26ng/mL = 3 points. We modified the CTP score by replacing ascites and encephalopathy grading with plasma IGF-1 value (IGF-CTP) and subjected both scores to log-rank analysis. Harrell’s C-index and U-statistics were used to compare the prognostic performance of both scores in both the training and validation cohorts (n = 155). All statistical tests were two-sided.
Patients’ stratification was statistically significantly stronger for IGF-CTP than CTP score for the training (P = .003) and the validation cohort (P = .005). Patients reclassified by IGF-CTP relative to their original CTP score were better stratified by their new risk groups. Most important, patients classified as A by CTP but B by IGF-CTP had statistically significantly worse OS than those who remained under class A by IGF-CTP in both cohorts (P = .03 and P < .001, respectively, from Cox regression models). AB patients had a worse OS than AA patients in both the training and validation set (hazard ratio [HR] = 1.45, 95% confidence interval [CI] = 1.03 to 2.04, P = .03; HR = 2.83, 95% CI = 1.65 to 4.85, P < .001, respectively).
The IGF-CTP score is simple, blood-based, and cost-effective, stratified HCC better than CTP score, and validated well on two independent cohorts. International validation studies are warranted.
We report noninvasive modulation of in vivo tumor radiation response using gold nanoshells. Mild-temperature hyperthermia generated by near-infrared illumination of gold nanoshell-laden tumors, noninvasively quantified by magnetic resonance temperature imaging, causes an early increase in tumor perfusion that reduces the hypoxic fraction of tumors. A subsequent radiation dose induces vascular disruption with extensive tumor necrosis. Gold nanoshells sequestered in the perivascular space mediate these two tumor vasculature-focused effects to improve radiation response of tumors. This novel integrated antihypoxic and localized vascular disrupting therapy can potentially be combined with other conventional antitumor therapies.
Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the United States after cancers of the lung and the breast/prostate. While the incidence of CRC in the United States is among the highest in the world (approximately 52/100,000), its incidence in countries in India is among the lowest (approximately 7/100,000), suggesting that lifestyle factors may play a role in development of the disease. Whereas obesity, excessive alcohol consumption, a high-calorie diet, and a lack of physical activity promote this cancer, evidence indicates that foods containing folates, selenium, Vitamin D, dietary fiber, garlic, milk, calcium, spices, vegetables, and fruits are protective against CRC in humans. Numerous agents from “mother nature” (also called “nutraceuticals,”) that have potential to both prevent and treat CRC have been identified. The most significant discoveries relate to compounds such as cardamonin, celastrol, curcumin, deguelin, diosgenin, thymoquinone, tocotrienol, ursolic acid, and zerumbone. Unlike pharmaceutical drugs, these agents modulate multiple targets, including transcription factors, growth factors, tumor cell survival factors, inflammatory pathways, and invasion and angiogenesis linked closely to CRC. We describe the potential of these dietary agents to suppress the growth of human CRC cells in culture and to inhibit tumor growth in animal models. We also describe clinical trials in which these agents have been tested for efficacy in humans. Because of their safety and affordability, these nutraceuticals provide a novel opportunity for treatment of CRC, an “old age” disease with an “age old” solution.
nutraceuticals; CRC; curcumin; gingerol; piperine
γ-Tocotrienol has attracted great attention due to its multiple health benefits. This study developed and validated a simple, specific, sensitive and reliable LC/MS/MS method to analyze γ-tocotrienol in rat plasma. Plasma samples (50 µL) were extracted with internal standard solution (25 ng/mL of itraconazole) in acetonitrile (200 µL) with an average recovery of 44.7% and an average matrix effect of −2.9%. The separation of γ-tocotrienol and internal standard from the plasma components was achieved with a Waters XTerra® MS C18 column with acetonitrile/water as mobile phases. Analysis was performed under positive ionization electrospray mass spectrometer via the multiple reaction monitoring. The standard curve was linear over a concentration range of 10 – 1000 ng/mL with correlation coefficient values > 0.997. The method was validated with intra- and inter-day accuracy (relative error) ranged from 1.79 to 9.17% and 2.16 to 9.66%, respectively, and precision (coefficient of variation) ranged from 1.94 to 9.25% and 2.37 to 10.08%, respectively. The short-term disability, freeze-thaw stability and the processed sample stability tests were performed. This method was further applied to analyze γ-tocotrienol plasma concentrations in rats at various time points after administration of a 2 mg/kg single intravenous dose, and a pharmacokinetic profile was successfully obtained.
γ-tocotrienol; vitamin E; LC/MS/MS; pharmacokinetics; rat plasma
Development of chemoresistance, poor prognosis, and metastasis often renders the current treatments for colorectal cancer (CRC) ineffective. Whether ursolic acid (UA), a component of numerous medicinal plants, either alone or in combination with capecitabine, can inhibit the growth and metastasis of human CRC was investigated.
The effect of UA on proliferation of colorectal cancer cell lines was examined by mitochondrial dye-uptake assay, apoptosis by esterase staining, NF-κB activation by DNA binding assay and protein expression by western blot. The effect of UA on the growth and chemosensitization was also examined in orthotopically-implanted CRC in nude mice.
We found that UA inhibited the proliferation of different colon cancer cell lines. This is correlated with inhibition of constitutive NF-κB activation and downregulation of cell survival (Bcl-xL, Bcl-2, cFLIP, survivin), proliferative (Cyclin D1), and metastatic (MMP-9, VEGF, ICAM-1) proteins. When examined in an orthotopic nude-mice model, UA significantly inhibited tumor volume, ascites formation and distant organ metastasis, and this effect was enhanced with capecitabine. Immunohistochemistry of tumor tissue indicated that UA downregulated biomarkers of proliferation (Ki-67) and microvessel density (CD31). This effect was accompanied by suppression of NF-κB, STAT3, and β-catenin. In addition, UA suppressed EGFR, and induced p53, and p21 expression. We also observed bioavailability of UA in the serum and tissue of animals.
Overall our results demonstrate that UA can inhibit the growth and metastasis of CRC and further enhance the therapeutic effects of capecitabine through suppression of multiple biomarkers linked to inflammation, proliferation, invasion, angiogenesis, and metastasis.
Agents that can potentiate the efficacy of standard chemotherapy against pancreatic cancer are of great interest. Because of their low cost and safety, patients commonly use a variety of dietary supplements, although evidence of their efficacy is often lacking. One such commonly used food supplement, Zyflamend, is a polyherbal preparation with potent anti-inflammatory activities, and preclinical efficacy against prostate and oral cancer. Whether Zyflamend has any efficacy against human pancreatic cancer alone or in combination with gemcitibine, a commonly used agent, was examined in cell cultures and in an orthotopic mouse model. In vitro, Zyflamend inhibited the proliferation of pancreatic cancer cell lines regardless of p53 status and also enhanced gemcitabine-induced apoptosis. This finding correlated with inhibition of NF-κB activation by Zyflamend and suppression of cyclin D1, c-myc, COX-2, Bcl-2, IAP, survivin, VEGF, ICAM-1, and CXCR4. In nude mice, oral administration of Zyflamend alone significantly inhibited the growth of orthotopically transplanted human pancreatic tumors, and when combined with gemcitabine, further enhanced the antitumor effects. Immunohistochemical and Western blot analyses of tumor tissue showed that the suppression of pancreatic cancer growth correlated with inhibition of proliferation index marker (Ki-67), COX-2, MMP-9, NF-κB, and VEGF. Overall, these results suggest that the concentrated multiherb product Zyflamend alone can inhibit the growth of human pancreatic tumors and, in addition, can sensitize pancreatic cancers to gemcitabine through the suppression of multiple targets linked to tumorigenesis.
Zyflamend; pancreatic cancer; inflammation
Although evidence of inflammation and fatigue has been noted in cancer survivors, whether inflammation is linked to the expression of fatigue and other symptoms arising from concurrent chemoradiation therapy (CXRT) has not been well studied. Patients undergoing CXRT for locally advanced colorectal or esophageal cancer (n = 103) reported multiple symptoms weekly via the M. D. Anderson Symptom Inventory (MDASI) from start of therapy. Serum samples were collected weekly to examine changes in inflammatory markers (interleukin [IL]-6, IL-8, IL-10, IL-1 receptor antagonist [IL-1RA], vascular endothelial growth factor [VEGF], and soluble receptor 1 for tumor necrosis factor [sTNF-R1]) via enzyme-linked immunosorbent assay. Relationships between symptom severity and inflammatory-marker concentration levels were estimated using mixed-effect regression analysis, controlled for week of therapy, age, sex, body mass index, pre-CXRT tumor stage, pre-CXRT chemotherapy, pre-CXRT statin use, and type of cancer. Fatigue was the most severe symptom over time, its development profile shared with pain, distress, drowsiness, poor appetite, and disturbed sleep. sTNF-R1 and IL-6 shared a similar pattern of symptom development, with significant increase during CXRT and decrease after completion of CXRT. Serum concentrations of sTNF-R1 were positively associated over time with the severity of fatigue (p = .00097), while sTNF-R1 and IL-6 were positively related to the severity of a component score of the six most severe symptoms (both p < .0001). This longitudinal study suggests a role for over-expressed sTNF-R1 and IL-6 in the development of fatigue and other severe sickness symptoms during CXRT in patients with colorectal or esophageal cancer.
fatigue; symptoms; sickness behavior; cytokines; cancer; inflammation; MDASI; chemoradiation
Neoadjuvant chemoradiotherapy for rectal cancer is associated with improved local control and may result in complete tumor response. Associations between tumor response and disease control following radical resection should be established before tumor response is used to evaluate treatment strategies. The purpose of this study was to assess and compare oncologic outcomes associated with the degree of pathologic response after chemoradiotherapy.
Patients and Methods
All patients with locally advanced (cT3-4 or cN+ by endorectal ultrasonography, computed tomography, or magnetic resonance imaging) rectal carcinoma diagnosed from 1993 to 2008 at our institution and treated with preoperative chemoradiotherapy and radical resection were identified, and their records were retrospectively reviewed. The median radiation dose was 50.4 Gy with concurrent chemotherapy. Recurrence-free survival (RFS), distant metastasis (DM), and local recurrence (LR) rates were compared among patients with complete (ypT0N0), intermediate (ypT1-2N0), or poor (ypT3-4 or N+) response by using Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression.
In all, 725 patients were classified by tumor response: complete (131; 18.1%), intermediate (210; 29.0%), and poor (384; 53.0%). Age, sex, cN stage, and tumor location were not related to tumor response. Tumor response (complete v intermediate v poor) was associated with 5-year RFS (90.5% v 78.7% v 58.5%; P < .001), 5-year DM rates (7.0% v 10.1% v 26.5%; P < .001), and 5-year LR only rates (0% v 1.4% v 4.4%; P = .002).
Treatment response to neoadjuvant chemoradiotherapy among patients with locally advanced rectal cancer undergoing radical resection is an early surrogate marker and correlate to oncologic outcomes. These data provide guidance with response-stratified oncologic benchmarks for comparisons of novel treatment strategies.
Numerous cancer therapeutics were originally identified from natural products used in traditional medicine. One such agent is acetyl-11-keto-beta-boswellic acid (AKBA), derived from the gum resin of the Boswellia serrata known as Salai guggal or Indian frankincense. Traditionally it has been used in Ayurvedic medicine to treat proinflammatory conditions. In the present report, we hypothesized that AKBA can affect the growth and metastasis of colorectal cancer (CRC) in orthotopically-implanted tumors in nude mice. We found that the oral administration of AKBA (50-200 mg/kg) dose-dependently inhibited the growth of CRC tumors in mice, resulting in decrease in tumor volumes than those seen in vehicle-treated mice without significant decreases in body weight. In addition, we observed that AKBA was highly effective in suppressing ascites and distant metastasis to the liver, lungs, and spleen in orthotopically-implanted tumors in nude mice. When examined for the mechanism, we found that markers of tumor proliferation index Ki-67 and the microvessel density CD31; were significantly downregulated by AKBA treatment. We also found that AKBA significantly suppressed NF-κB activation in the tumor tissue and expression of pro-inflammatory (COX2), tumor survival (bcl-2, bcl-xL, IAP-1, survivin), proliferative (cyclin D1), invasive (ICAM-1, MMP-9) and angiogenic (CXCR4 and VEGF) biomarkers. When examined for serum and tissue levels of AKBA, a dose-dependent increase in the levels of the drug was detected, indicating its bioavailability. Thus, our findings suggest that this boswellic acid analogue can inhibit the growth and metastasis of human CRC in vivo through downregulation of cancer-associated biomarkers.
AKBA; colorectal cancer; NF-κB; growth; metastasis
Locally advanced rectal cancer is commonly treated with chemoradiation prior to total mesorectal excision (TME). Studies suggest that metformin may be an effective chemopreventive agent in this disease as well as a possible adjunct to current therapy. In this study, we examined the effect of metformin use on pathologic complete response (pCR) rates and outcomes in rectal cancer. The charts of 482 patients with locally advanced rectal adenocarcinoma treated from 1996 to 2009 with chemoradiation and TME were reviewed. Median radiation dose was 50.4 Gy (range 19.8–63). Nearly, all patients were treated with concurrent 5-fluorouracil-based chemotherapy (98%) followed by adjuvant chemotherapy (81.3%). Patients were categorized as nondiabetic (422), diabetic not taking metformin (40), or diabetic taking metformin (20). No significant differences between groups were found in clinical tumor classification, nodal classification, tumor distance from the anal verge or circumferential extent, pretreatment carcinoembryonic antigen level, or pathologic differentiation. pCR rates were 16.6% for nondiabetics, 7.5% for diabetics not using metformin, and 35% for diabetics taking metformin, with metformin users having significantly higher pCR rates than either nondiabetics (P = 0.03) or diabetics not using metformin (P = 0.007). Metformin use was significantly associated with pCR rate on univariate (P = 0.05) and multivariate (P = 0.01) analyses. Furthermore, patients taking metformin had significantly increased disease-free (P = 0.013) and overall survival (P = 0.008) compared with other diabetic patients. Metformin use is associated with significantly higher pCR rates as well as improved survival. These promising data warrant further prospective study.
Chemotherapy; metformin; radiation; rectal cancer
Cirrhosis and hepatocellular carcinoma (HCC) together form a two-disease state that affects survival of patients with HCC and dictates treatment decisions and prognostic stratification of patients in clinical trials. The study objective was to improve prognostic stratification of patients with HCC.
Patients and Methods
We prospectively collected plasma samples and baseline clinicopathologic features from 288 new patients with HCC, and plasma insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF) levels were tested. We applied Cox regression and log-rank tests to assess association of IGF-1 and VEGF with overall survival (OS), Kaplan-Meier curves to estimate OS, and recursive partitioning to determine optimal cutoff points for IGF-1 and VEGF. Prognostic ability of conventional and molecular Barcelona Clinic Liver Cancer classifications was compared using the c-index.
Lower plasma IGF-1 and higher plasma VEGF levels significantly correlated with advanced clinicopathologic parameters and poor OS, with optimal cut points of 26 ng/mL and 450 pg/mL, respectively. The combination of low IGF-1 and high VEGF predicted median OS of 2.7 months compared with 19 months for patients with high IGF-1 and low VEGF (P < .001), further refining the prognostic ability of conventional HCC staging (P < .001).
Baseline levels of plasma IGF-1 and VEGF correlated significantly with survival in patients with HCC. Integrating IGF-1 and VEGF into HCC staging significantly enhanced prognostic stratification of patients. If validated, these results may prove to be useful in designing strategies to personalize management approaches among these patients.
Historically, the use of external beam radiotherapy for hepatocellular carcinoma (HCC) has been limited by toxicity to the uninvolved liver and surrounding structures. Advances in photon radiotherapy have improved dose conformality to the tumor and facilitated dose escalation, a key contributor to improved HCC radiation treatment outcomes. However, despite these advances in photon radiotherapy, significant volumes of liver still receive low doses of radiation that can preclude dose escalation, particularly in patients with limited functional liver reserves. By capitalizing on the lack of exit dose along the beam path beyond the tumor and higher biological effectiveness, charged particle therapy offers the promise of maximizing tumor control via dose escalation without excessive liver toxicity. In this review we discuss the distinctive biophysical attributes of both proton and carbon ion radiotherapy, particularly as they pertain to treatment of HCC. We also review the available literature regarding clinical outcomes and toxicity of using charged particles for the treatment of HCC.
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.