We have previously reported that older patients with clinical Stage I and II primary cutaneous. melanoma had lower survival rates compared to younger patients We postulated that the incidence of nodal metastasis would therefore be higher among older melanoma patients.
Materials and Methods
The expanded AJCC Melanoma Staging Database contains a cohort of 7756 melanoma patients who presented without clinical evidence of regional lymph node or distant metastasis and who underwent a sentinel node biopsy procedure as a component of their staging workup
Although older patients had primary melanoma features associated with more aggressive biology, we observed paradoxically a significant decrease in the incidence of sentinel node metastasis as patient age increased. Overall, the highest incidence of sentinel node metastasis was 25.8% in patients under 20 years of age, compared to 15.5% in patients 80 years and older (p< 0.001). In contrast, five year mortality rates for Clinical Stage II patients ranged from a low of 20% for those 20–40 years of age up to 38% for those over 70 years of age. Patient age was an independent predictor of sentinel node metastasis in a multifactorial analysis (p<0.001)
Patients with clinical Stage I and II melanoma under 20 years of age had a higher incidence of sentinel lymph node metastasis but, paradoxically, a more favorable survival outcome compared to all other age groups. In contrast, patients >70 years had the most aggressive primary melanoma features and a higher mortality rate compared to all other age groups, but a lower incidence of sentinel lymph node metastasis.
We analyzed the importance of patient age as a component of melanoma staging and in the design and interpretation of clinical trials for patients with localized disease or with regional node metastases.
We postulated that the worse prognosis of melanoma with advancing age reflected more aggressive tumor biology and that in younger patients the prognosis would be more favorable.
Materials and Methods
The expanded AJCC melanoma staging database contained 11,088 patients with complete data for analysis, including mitotic rate.
With increasing age by decade, primary melanomas were thicker, exhibited higher mitotic rates, and were more likely to be ulcerated. In a multivariate analysis of patients with localized melanoma, thickness and ulceration were highly significant predictors of outcome at all decades of life (except for patients less than 20 years). Mitotic rate was significantly predictive in all age groups except patients < 20 years and >80 years. For patients with Stage III melanoma, there were four independent variables associated with patient survival: number of nodal metastases, patient age, ulceration, and mitotic rate.
Patients under 20 years of age had primary tumors with slightly more aggressive features, a higher incidence of sentinel lymph node metastasis, but, paradoxically, more favorable survival than all other age groups. In contrast, patients >70 years old had primary melanomas with the most aggressive prognostic features, were more likely to be head and neck primaries, and were associated with a higher mortality rate than the other age groups. Surprisingly, however, these patients had a lower rate of sentinel lymph node metastasis per T stage. Among patients between the two age extremes, clinicopathologic features and survival tended to be more homogeneous.
Melanomas in patients at the extremes of age have a distinct natural history.
Melanoma of unknown primary site (MUP) is not a completely understood entity with nodal metastases as the most common first clinical manifestation. The aim of this multicentric study was to assess frequency and type of oncogenic BRAF/NRAS/KIT mutations in MUP with clinically detected nodal metastases in relation to clinicopathologic features and outcome.
Materials and Methods
We analyzed series of 103 MUP patients (period: 1992–2010) after therapeutic lymphadenectomy (LND): 40 axillary, 47 groin, 16 cervical, none treated with BRAF inhibitors. We performed molecular characterization of BRAF/NRAS/KIT mutational status in nodal metastases using direct sequencing of respective coding sequences. Median follow-up time was 53 months.
BRAF mutations were detected in 55 cases (53 %) (51 V600E, 93 %; 4 others, 7 %), and mutually exclusive NRAS mutations were found in 14 cases (14 %) (7 p.Q61R, 4 p.Q61K, 2 p.Q61H, 1 p.Q13R). We have not detected any mutations in KIT. The 5-year overall survival (OS) was 34 %; median was 24 months. We have not found significant correlation between mutational status (BRAF/NRAS) and OS; however, for BRAF or NRAS mutated melanomas we observed significantly shorter disease-free survival (DFS) when compared with wild-type melanoma patients (p = .04; 5-year DFS, 18 vs 19 vs 31 %, respectively). The most important factor influencing OS was number of metastatic lymph nodes >1 (p = .03).
Our large study on molecular characterization of MUP with nodal metastases showed that MUPs had molecular features similar to sporadic non-chronic-sun-damaged melanomas. BRAF/NRAS mutational status had negative impact on DFS in this group of patients. These observations might have potential implication for molecular-targeted therapy in MUPs.
Phase 1 and 2 clinical trials of the BRAF kinase inhibitor vemurafenib (PLX4032) have shown response rates of more than 50% in patients with metastatic melanoma with the BRAF V600E mutation.
We conducted a phase 3 randomized clinical trial comparing vemurafenib with dacarbazine in 675 patients with previously untreated, metastatic melanoma with the BRAF V600E mutation. Patients were randomly assigned to receive either vemurafenib (960 mg orally twice daily) or dacarbazine (1000 mg per square meter of body-surface area intravenously every 3 weeks). Coprimary end points were rates of overall and progression-free survival. Secondary end points included the response rate, response duration, and safety. A final analysis was planned after 196 deaths and an interim analysis after 98 deaths.
At 6 months, overall survival was 84% (95% confidence interval [CI], 78 to 89) in the vemurafenib group and 64% (95% CI, 56 to 73) in the dacarbazine group. In the interim analysis for overall survival and final analysis for progression-free survival, vemurafenib was associated with a relative reduction of 63% in the risk of death and of 74% in the risk of either death or disease progression, as compared with dacarbazine (P<0.001 for both comparisons). After review of the interim analysis by an independent data and safety monitoring board, crossover from dacarbazine to vemurafenib was recommended. Response rates were 48% for vemurafenib and 5% for dacarbazine. Common adverse events associated with vemurafenib were arthralgia, rash, fatigue, alopecia, keratoacanthoma or squamous-cell carcinoma, photosensitivity, nausea, and diarrhea; 38% of patients required dose modification because of toxic effects.
Vemurafenib produced improved rates of overall and progression-free survival in patients with previously untreated melanoma with the BRAF V600E mutation. (Funded by Hoffmann–La Roche; BRIM-3 ClinicalTrials.gov number, NCT01006980.)
Data from patients with colorectal liver metastases (CRLM) who received neoadjuvant chemotherapy before resection were reviewed and evaluated to see whether neoadjuvant chemotherapy influences the predictive outcome of R1 resections (margin is 0 mm) in patients with CRLM.
Between January 2000 and December 2008, all consecutive patients undergoing liver resection for CRLM were analyzed. Patients were divided into those who did and did not receive neoadjuvant chemotherapy. The outcome after R0 (tumor-free margin >0 mm) and R1 (tumor-free margin 0 mm) resection was compared.
A total of 264 were eligible for analysis. Median follow-up was 34 months. Patients without chemotherapy showed a significant difference in median disease-free survival (DFS) after R0 or R1 resection: 17 [95% confidence interval (CI) 10–24] months versus 8 (95% CI 4–12) months (P < 0.001), whereas in patients with neoadjuvant chemotherapy the difference in DFS between R0 and R1 resection was not significant: 18 (95% CI 10–26) months versus 9 (95% CI 0–20) months (P = 0.303). Patients without chemotherapy showed a significant difference in median overall survival (OS) after R0 or R1 resection: 53 (95% CI 40–66) months versus 30 (95% CI 13–47) months (P < 0.001). In patients with neoadjuvant chemotherapy, the median OS showed no significant difference: 65 (95% CI 39–92) months for the R0 group versus the R1 group, in whom the median OS was not reached (P = 0.645).
In patients treated with neoadjuvant chemotherapy, R1 resection was of no predictive value for DFS and OS.
Medicine & Public Health; Oncology; Surgical Oncology; Surgery
Approximately 5–8% of melanoma patients will develop in-transit metastases (IT-mets). Tumor necrosis factor-α (TNF) and melphalan-based isolated limb perfusion (TM-ILP) is an attractive treatment modality in melanoma patients with multiple IT-mets. This study reports on a 20 years experience and outlines the evolution and major changes since the introduction of TNF in ILP.
A total of 167 TM-ILPs were performed in 148 patients, between 1991 and 2009. TM-ILPs were performed at high doses of TNF (3–4 mg) from 1991 to 2004 (n = 99) and at low doses of TNF (1–2 mg) from 2004 to 2009 (n = 68) under mild hyperthermic conditions (38°C–39.5°C.). Melphalan doses were unchanged at 10–13 mg/l (leg and arm, respectively). Characteristics for the 167 ILPs were: 81 stage IIIB, 65 stage IIIC, and 21 stage IV disease.
The overall response rate was 89% (n = 148). (Complete response [CR] = 61%; partial response [PR] = 28%). CR rates correlated with stage (P = .001) and with high-dose vs. low-dose TNF (70% vs. 49%; P < .006). High-dose TNF prolonged local control (median 16 months vs. 11 months; P = .076). Survival was not influenced by TNF dose. CR after ILP and number of lesions also correlated with local progression-free interval. Overall survival did correlate with stage of disease (P < .001), size of the lesions (P = .001), and a CR (P < .001).
This 2-decade single-center experience demonstrates that TM-ILP is a safe and effective treatment modality for melanoma patients with multiple IT-mets. Higher dose of TNF was associated with significantly higher CR rates and prolonged local control without an effect on overall survival.
Several clinical risk scores (CRSs) for the outcome of patients with colorectal liver metastases have been validated, but not in patients undergoing neoadjuvant chemotherapy. Therefore, this study evaluates the predictive value of these CRSs in this specific group.
Between January 2000 and December 2008, all patients undergoing a metastasectomy were analyzed and divided into two groups: 193 patients did not receive neoadjuvant chemotherapy (group A), and 159 patients received neoadjuvant chemotherapy (group B). In group B, the CRSs were calculated before and after administration of neoadjuvant chemotherapy. Results were evaluated by using the CRSs proposed by Nordlinger et al., Fong et al., Nagashima et al., and Konopke et al.
In groups A and B, the overall median survival was 43 and 47 months, respectively (P = 0.648). In group A, all CRSs used were of statistically significant predictive value. Before administration of neoadjuvant chemotherapy, only the Nordlinger score was of predictive value. After administration of neoadjuvant chemotherapy, all CRSs were of predictive value again, except for the Konopke score.
Traditional CRSs are not a reliable prognostic tool when used in patients before treatment with neoadjuvant chemotherapy. However, CRSs assessed after the administration of neoadjuvant chemotherapy are useful to predict prognosis.
The aim of this study was to evaluate the incidence and outcome of melanoma of unknown primary site (MUP) after therapeutic lymph node dissection (TLND) of palpable nodal melanoma metastases. Disease-free (DFS) and overall survival (OS) time of MUP patients were analyzed and compared to patients undergoing a TLND for known primary melanomas (MKP).
This single institution retrospective study analyzed 342 consecutive patients who were treated with 415 TLNDs for palpable nodal disease from 1982 to 2009. Univariate and multivariate analyses included: MUP versus MKP, gender, Breslow thickness, ulceration of primary tumor, site of primary tumor, site of dissection, extracapsular extension, number of collected nodes, number of positive nodes and the node positive ratio.
A total of 47 MUP were identified in 342 patients (13.7%). In univariate analysis, a trend was seen toward better survival for MUP patients compared to MKP patients having 5-year OS rates of 40% and 27%, respectively (P = 0.06). Multivariate analysis for OS showed two highly significant factors associated with worse prognosis: extracapsular extension and N3 status (both P < 0.001). Two factors were associated with a significant better prognosis: MUP (P = 0.03) and a neck dissection (P = 0.04).
Patients with MUP showed a statistically significant better OS compared to patients with melanoma metastases from known primary tumors. Presence of extracapsular extension and an increased number of positive nodes are statistically significantly negative prognostic factors for OS. The absence of a primary melanoma in stage III melanoma patients does not preclude surgery.
Standard treatment for localized soft tissue sarcoma (STS) is resection plus adjuvant radiotherapy (RTx). In approximately 10% of cases, resection would cause severe loss of function or even require amputation because of the extent of disease. Isolated limb perfusion (ILP) with tumor necrosis factor alpha (TNF-α) and melphalan can achieve regression of the tumor, facilitating limb-saving resection. RTx improves local control but may lead to increased morbidity.
In our database of over 500 ILPs, 122 patients with unifocal STS were treated by ILP followed by limb-sparing surgery. All included patients were candidates for amputation.
Surgery resulted in 69 R0 resections (57%), and in 53 specimens (43%) resection margins contained microscopic evidence of tumor (R1). Histopathological examination revealed >50% ILP-induced tumor necrosis in 59 cases (48%). RTx was administered in 73 patients (60%). Local recurrence rate was 21% after median follow-up of 31 months (2–182 months). Recurrence was significantly less in patients with >50% ILP-induced necrosis versus ≤50% necrosis (7% vs. 33%, P = 0.001). A similar significant correlation was observed for R0 versus R1 resections (15% vs. 28%, P = 0.04). In 36 patients with R0 resection and >50% necrosis, of whom 21 were spared RTx, no recurrences were observed during follow-up.
In patients with locally advanced primary STS, treated with ILP followed by R0 resection, and with >50% ILP-induced necrosis in the resected specimen, RTx is of no further benefit.
Unlike chemotherapy, which acts directly on the tumor, cancer immunotherapies exert their effects on the immune system and demonstrate new kinetics that involve building a cellular immune response, followed by changes in tumor burden or patient survival. Thus, adequate design and evaluation of some immunotherapy clinical trials require a new development paradigm that includes reconsideration of established endpoints. Between 2004 and 2009, several initiatives facilitated by the Cancer Immunotherapy Consortium of the Cancer Research Institute and partner organizations systematically evaluated an immunotherapy-focused clinical development paradigm and created the principles for redefining trial endpoints. On this basis, a body of clinical and laboratory data was generated that supports three novel endpoint recommendations. First, cellular immune response assays generate highly variable results. Assay harmonization in multicenter trials may minimize variability and help to establish cellular immune response as a reproducible biomarker, thus allowing investigation of its relationship with clinical outcomes. Second, immunotherapy may induce novel patterns of antitumor response not captured by Response Evaluation Criteria in Solid Tumors or World Health Organization criteria. New immune-related response criteria were defined to more comprehensively capture all response patterns. Third, delayed separation of Kaplan–Meier curves in randomized immunotherapy trials can affect results. Altered statistical models describing hazard ratios as a function of time and recognizing differences before and after separation of curves may allow improved planning of phase III trials. These recommendations may improve our tools for cancer immunotherapy trials and may offer a more realistic and useful model for clinical investigation.
We assessed molecular (presence of melanoma cells markers in lymph fluid [LY]) and pathological features (sentinel lymph node [SN] tumor burden according to Rotterdam criteria, metastases microanatomic location) and correlated them with survival and melanoma prognostic factors in a group of patients with positive SN biopsy.
We analyzed 368 consecutive SN-positive patients after completion lymph node dissection (CLND). In 321 patients we obtained data on SLN microanatomic location/tumor burden (only 7 cases had metastases <0.1 mm); in 137 we additionally analyzed 24-hour collected LY after CLND (multimarker reverse transcriptase-polymerase chain reaction [MM-RT-PCR] with primers for tyrosinase, MART1 (MelanA), and uMAGE mRNA (27.7% positive samples)]. Median follow-up time was 41 months.
According to univariate analysis, the following factors had a negative impact on overall survival (OS): higher Breslow thickness (P = .0001), ulceration (P < .0001), higher Clark level (P = .008), male gender (P = .0001), metastatic lymph nodes >1 (P < .0001), nodal metastases extracapsular extension (P < .0001), metastases to additional non-SNs (P = .0004), micrometastases size ≥0.1 mm (P = .0006), and positive LY MM-RT-PCR (P = .0007). SN tumor burden showed linear correlation with increasing Breslow thickness (P = .01). The 5-year OS rates for SLN tumor burden <0.1 mm, 1–1.0 mm, and >1.0 mm were 84%/66%/44%, respectively, and for positive and negative LY MM-RT-PCR 47%/0%, respectively. The independent factors for shorter OS (multivariate analysis): male gender, primary tumor ulceration, number of involved nodes ≥4, micrometastases size >1.0 mm, and, in additional model including molecular analysis—positive MM-RT-PCR results (hazard ratio [HR] 3.2), micrometastases size >1.0 mm (HR 1.13), and primary tumor ulceration (HR 2.17). Similar results were demonstrated for disease-free survival (DFS) data.
SN tumor burden categories according to Rotterdam criteria and the positive result of LY MM-RT-PCR assay demonstrated additional, independent prognostic value in SN-positive melanoma patients, showing significant correlation with shorter DFS and OS.
Lipid-based nanocarriers or liposomes have been proven successful in the delivery of chemotherapeutic agents and are currently applied clinically in the treatment of various types of cancer. Liposomes offer the advantage of a high drug payload, decreased drug toxicity and enhanced drug accumulation at tumor sites. Increased accumulation is due to the relatively leaky tumor vasculature that allows liposome extravasation. Between different types of tumors and even within one tumor, vascular permeability and thus liposome extravasation may differ greatly. Furthermore, upon accumulation of liposomes in the tumor area, drug bioavailability is not guaranteed. At present, these are the major issues for clinically used liposomal drugs.
Mild hyperthermia (HT), the heating of tumor tissue to temperatures of up to 43°C, has been developed in the past decades as an established and efficacious treatment modality in combination with chemo- and radiotherapy. HT can be used to further improve liposomal chemotherapy in two ways: HT is known to increase vascular permeability in solid tumors and may therefore increase levels of liposome accumulation, and thermosensitive liposomes have been developed that can be triggered to release their contents upon hyperthermia. By applying these two strategies, drug delivery to tumors can be strongly enhanced.
cancer; chemotherapy; hyperthermia; nanomedicine; thermosensitive liposomes; triggered release
Isolated limb perfusion (ILP) with chemotherapy alone has uniformly failed in the treatment of irresectable extremity soft tissue sarcomas. The addition of tumor necrosis factor-alpha (TNF-α) to this treatment approach contributed to a major step forward in the treatment of locally advanced extremity soft tissue sarcoma (STS). High response rates and limb salvage rates have been reported in multicenter trials, which combined ILP with TNF-α plus melphalan, which resulted in the approval of TNF-α for this indication in Europe in 1998. Subsequently a series of confirmatory single institution reports on the efficacy of the procedure have now been published. TNF-α has an early and a late effect; it enhances tumor-selective drug uptake during the perfusion and plays an essential role in the subsequent selective destruction of the tumor vasculature. These effects result in a high response rate in high-grade soft tissue sarcomas. This induction therapy thus allows for resection of tumor remnants some 3 months after ILP and thus avoidance of limb amputation. TNF-α-based ILP is a well-established treatment to avoid amputations. It represents an important example of tumor vasculatory-modulating combination therapy and should be offered in large volume tertiary referral centers.
The appearance of vitiligo and spontaneous regression of the primary lesion in melanoma patients illustrate a relationship between tumor immunity and autoimmunity. T lymphocytes play a major role both in tumor immunity and autoimmunity. CD28, Cytotoxic T lymphocyte antigen 4 (CTLA4) and inducible costimulator (ICOS) molecules are important secondary signal molecules in the T lymphocyte activation. Single nucleotide polymorphisms (SNPs) in the CD28/CTLA4/ICOS gene region were reported to be associated with several autoimmune diseases including, type-1 diabetes, SLE, autoimmune thyroid diseases and celiac disease. In this study, we investigated the association of SNPs in the CD28, CTLA4 and ICOS genes with the risk of melanoma. We also assessed the prognostic effect of the different polymorphisms in melanoma patients. Twenty-four tagging SNPs across the three genes and four additional SNPs were genotyped in a cohort of 763 German melanoma patients and 734 healthy German controls. Influence on prognosis was determined in 587 melanoma cases belonging to stage I or II of the disease. In general, no differences in genotype or allele frequencies were detected between melanoma patients and controls. However, the variant alleles for two polymorphisms in the CD28 gene were differentially distributed in cases and controls. Similarly no association of any polymorphism with prognosis, except for the rs3181098 polymorphism in the CD28 gene, was observed. In addition, individuals with AA genotype for rs11571323 polymorphism in the ICOS gene showed reduced overall survival. However, keeping in view the correction for multiple hypothesis testing our results suggest that the polymorphisms in the CD28, CTLA4 and ICOS genes at least do not modulate risk of melanoma and nor do those influence the disease prognosis in the investigated population.
Electronic supplementary material
The online version of this article (doi:10.1007/s00262-009-0751-2) contains supplementary material, which is available to authorized users.
Melanoma; Polymorphism; CD28/CTLA4/ICOS; Susceptibility; Prognosis
Both increased and decreased nitric oxide (NO) synthesis have been reported in patients treated with interferon-α (IFN-α). Animal studies showed that IFN-α administration results in increased levels of biogenic amines, subsequent activation of monoamine oxidases (MAOs), and finally in a change in NO production due to the H2O2 generated by MAOs. We examined the potential relationship between NO production in plasma and MAO-B activity in platelets of 43 cancer patients during 8 weeks of treatment with IFN-α. NO synthesis was quantitated by measuring both the ratio of citrulline and arginine (CIT/ARG-ratio) and total nitrite/nitrate (NOx) levels. Compared to baseline, MAO activity and NOx increased, while the CIT/ARG-ratio decreased. No associations were found between NOx, MAO and CIT/ARG-ratio. Only few associations were observed between changes in the biochemical parameters and changes in psychopathology induced by IFN-α, of which the association between changes in CIT and lassitude was the most consistent. The results suggest that peripheral NO production and MAO activity are unrelated to each other, and that peripheral changes in these biochemical parameters induced by IFN-α are unlikely to contribute to definite psychiatric disturbance.
Citrulline; Depression; Interferon-α; Nitric oxide; Monoamine oxidase; Cancer
Isolated hepatic perfusion with high-dose chemotherapy is a treatment option for patients with irresectable metastases confined to the liver. Prolonged local control and impact on survival have been claimed. Major drawbacks are magnitude and costs of the procedure. We developed an isolated hypoxic hepatic perfusion (IHHP) with retrograde outflow without the need for a heart-lung machine.
Patients and Methods
Twenty-four consecutive patients with irresectable metastases of various origins were treated. IHHP inflow was via the hepatic artery, outflow via the portal vein with occlusion of the retrohepatic caval vein. Radiolabeled albumine was used for leakage monitoring. Melphalan was used at 1–2 mg/kg. A 25-minute perfusion period was followed by a complete washout. Local and systemic melphalan concentrations were determined.
Compared with oxygenated classical IHP, the IHPP procedure reduced operation time from >8 h to 4 hours, blood loss from >4000 to 900 cc and saved material and personnel costs. Leakage was 0% with negligible systemic toxicity and 0% perioperative mortality. Tumor response: complete response (CR) in 4%, partial response (PR) in 58%, and stable disease (SD) in 13%. Median time to progression was 9 months (2–24 months); pharmacokinetics demonstrated intrahepatic melphalan concentrations more than 9 fold higher than postperfusion systemic concentrations.
IHPP is a relatively simple procedure with reduced costs, reduced blood loss, no mortality, limited toxicity, and response rates comparable to classic IHP. The median duration of 9 months of tumor control should be improved. Hereto, vasoactive drugs, will be explored in further studies.
Isolated hepatic perfusion; Retrograde outflow; Hypoxic; Metastasis; Melphalan
Purpose. The influence of initial inadequate excision (IIE) of soft tissue sarcoma (STS) on local control and overall survival
is not well established. It is generally believed that an IIE may have a negative impact on both, despite subsequent treatment
by radical surgery and radiotherapy. However, data on local recurrence-free survival/overall survival are conflicting and there
are no data on the effect of IIE on overall survival.
Patients and methods. A retrospective analysis was made of 86 patients with soft tissue sarcoma of the extremities and trunk
after an IIE had been performed due to inappropriate work-up. The minimal follow-up was 7 years. Specimens of the
subsequent radical resection were evaluated for residual tumor, grade of tumor and complications of IIE. Endpoints were
recurrence-free survival and overall survival.
Results. Specimens of the subsequent radical resection showed residual tumor in 66 patients (77%). The most common
complication after IIE was hematoma. In both univariate and multivariate analyses, grade II/III tumors and complications
after IIE are significant negative prognostic factors for local recurrence-free survival (P = 0.008 and P = 0.002, respectively,
in the Cox model). For this survival, three prognostic groups could be formed based on grade, or presence or absence of
complications. Adjuvant radiotherapy did not change the rate of local recurrence-free survival. For overall survival, only
tumor grade is a significant factor (log-rank test).
Conclusion. This retrospective study shows that complications associated with an IIE have a significant negative effect on
local control, but not on overall survival, because IIE is often the result of inappropriate work-up before surgery. For better
diagnosis and therapy STS should be treated in specialized centers.
MAGE-type genes are expressed by many tumors of different histological types and not by normal cells, except for male germline cells, which do not express major histocompatibility complex (MHC) molecules. Therefore, the antigens encoded by MAGE-type genes are strictly tumor specific and common to many tumors. We describe here the identification of the first MAGE-encoded epitopes presented by histocompatibility leukocyte antigen (HLA) class II molecules to CD4+ T lymphocytes. Monocyte-derived dendritic cells were loaded with a MAGE-3 recombinant protein and used to stimulate autologous CD4+ T cells. We isolated CD4+ T cell clones that recognized two different MAGE-3 epitopes, MAGE-3114–127 and MAGE-3121–134, both presented by the HLA-DR13 molecule, which is expressed in 20% of Caucasians. The second epitope is also encoded by MAGE-1, -2, and -6. Our procedure should be applicable to other proteins for the identification of new tumor-specific antigens presented by HLA class II molecules. The knowledge of such antigens will be useful for evaluation of the immune response of cancer patients immunized with proteins or with recombinant viruses carrying entire genes coding for tumor antigens. The use of antigenic peptides presented by class II in addition to peptides presented by class I may also improve the efficacy of therapeutic antitumor vaccination.
human; invariant chain; peptide; tumor; histocompatibility leukocyte antigen class II