[Show abstract][Hide abstract] ABSTRACT: Melanomas harbor aberrations in the c-Kit gene. We tested the efficiency of the tyrosine kinase inhibitor imatinib in selected patients with metastatic melanoma harboring c-Kit mutations or amplifications.
Forty-three patients with metastatic melanoma harboring c-Kit aberrations were enrolled on this phase II trial. Each patient received a continuous dose of imatinib 400 mg/d unless intolerable toxicities or disease progression occurred. Fifteen patients who experienced progression of disease were allowed to escalate the dose to 800 mg/d.
Forty-three patients were eligible for evaluation, and the median follow-up time was 12.0 months. The median progression-free survival (PFS) was 3.5 months, and the 6-month PFS rate was 36.6%. Rate of total disease control was 53.5%: 10 patients (23.3%; 95% CI, 10.2% to 36.4%) and 13 patients (30.2%; 95% CI, 16.0% to 44.4%) achieved partial response (PR) and stable disease (SD), respectively. Eighteen patients (41.9%) demonstrated regression of tumor mass. Notably, nine of the 10 PRs were observed in patients with mutations in exons 11 or 13. The 1-year overall survival (OS) rate was 51.0%. The median PFS and OS times for patients who had PR or SD versus disease progression were 9.0 months versus 1.5 months (P < .001) and 15.0 months versus 9.0 months (P = .036), respectively. Imatinib 400 mg/d was well tolerated, and only one of the 15 patients who received dose escalation to 800 mg/d achieved SD.
Imatinib demonstrated significant activity in patients with metastatic melanoma harboring genetic c-Kit aberrations, with an overall response rate of 23.3%. Escalation to 800 mg/d could not restore disease control.
Full-text · Article · Jun 2011 · Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Malignant melanoma is a rare disease in Asia, and knowledge on its characteristics and clinical outcome in Asian patients is limited. The purpose of this observational study was to determine the clinical presentation and outcome of patients with melanoma in China.
A database was prospectively established for the purpose of this analysis. The elements of the database included basic demographic data of patients and prognosticators previously reported in literature, as well as follow-up data including clinical outcome after treatment. Medical record of all patients with pathologically diagnosed malignant melanoma consulted in our center since 2006 were retrieved and reviewed. No patient was excluded in this study. Statistical analyses including survival and multivariate analyses of factors associated with survival were respectively performed by Kaplan-Meier method and Cox proportional hazard model.
A total of 522 consecutive and nonselected cases were evaluated. There were 218 cases (41.8%) of acral lentiginous melanoma (ALM), 118 (22.6%) of mucosal melanoma (MCM), 103 (19.7%) of nodular melanoma (NM), 33 (6.3%) of superficial spreading melanoma (SSM), and others were Lentigo maligna melanoma or unclassifiable disease. The proportion of patients with clinical stage I, II, III, and IV diseases were 6.1%, 55.9%, 25.1%, and 12.8%, respectively. Among the 357 cases of cutaneous melanoma, 234 patients (65.5%) had ulceration.The 5-year overall survival rate of all 522 patients was 41.6%, and the median survival time was 3.92 years (95% CI, 3.282 to 4.558). Five-year survival rates of patients with stage I, II, III, and IV diseases were 94.1%, 44.0%, 38.4% and 4.6% respectively (P < 0.001). Multivariate analysis revealed that clinical stage and the ulceration were two significant prognosticators for OS. In addition, extent of surgery and use of adjuvant therapy were significant prognosticators for DFS in patients with non-metastatic disease after definitive treatment. Pathological subtype was not a significant prognostic factor to predict wither OS or DFS.
Prognoses of patients with malignant melanoma diagnosed in China were suboptimal, and most patients were diagnosed with locally advanced disease (i.e., stage II or above). ALM and MCM are the two most commonly diagnosed pathological subtypes. Clinical staging and presence of ulceration was significantly associated with clinical outcome in terms of OS, while treatment strategy including extent of surgery and use of adjuvant therapy were significant predictors of DFS.
[Show abstract][Hide abstract] ABSTRACT: KIT aberrations were described in acral and mucosal melanomas in largely Caucasian populations. Asian populations are more prone to develop acral and mucosal than cutaneous melanomas, and may harbor a high frequency of KIT aberrations.
Melanoma subtypes (n = 502) were analyzed histologically to determine melanoma subtype. Tissue samples were analyzed for mutations in exons 9, 11, 13, 17, and 18 of KIT gene in genomic DNA by PCR amplification and Sanger sequencing. The copy numbers of the KIT gene were analyzed by quantitative PCR, and protein expression levels of KIT (CD117) were determined by immunohistochemistry.
The most common melanoma subtypes were acral (38.4%) and mucosal (33.3%) melanomas in this population. The overall incidence of somatic mutations within the KIT gene was 10.8% (54/502), and all subtypes of melanoma contained KIT mutations. Increases in KIT gene copy numbers were correlated to CD117 overexpression. The genetic mutations of KIT were unrelated to the age, gender, stage, thickness, and ulceration of primary melanomas. Importantly, the overall survival of melanoma patients with KIT mutations (P = 0.001) or with KIT aberrations (mutation plus amplification, P = 0.0002) was significantly shorter than that of patients without such alterations.
In China, the prevalent melanomas are acral and mucosal melanomas. KIT mutations are detected in all melanoma subtypes. Our study suggests that increases in KIT gene copy numbers, but not KIT mutations, may be correlated to CD117 overexpression. For the first time, our study suggests that genetic KIT aberration is an adverse prognostic factor for melanoma.
Preview · Article · Feb 2011 · Clinical Cancer Research