The CDKN2A tumour suppressor gene: no mutations detected in patients with melanoma and additional unrelated cancers.

Germ-line mutations of the CDKN2A tumour suppressor gene have been reported in association with familial melanoma, sporadic melanoma with multiple primary lesions and also pancreatic cancer. We studied the hypothesis that patients with melanoma and additional unrelated cancers may harbour mutations in the CDKN2A gene. Twenty seven patients with histologically confirmed melanoma who also had additional cancers such as breast, colorectal, lymphoma and other neoplasms were studied. We also examined 17 additional patients, 13 of whom had a first-degree relative with melanoma and four who had two or more primary melanomas. Some patients belonged to more than one of these categories. No mutations of the CDKN2A tumour suppressor gene were detected among patients with melanoma and additional cancers. The previously described Met53Ile CDKN2A mutation located in exon 2 was detected in a female patient with melanoma metastatic to the regional lymph nodes, multiple primary cutaneous lesions, atypical naevi and a first-degree relative with melanoma. The studied cohort is too small for firm conclusions. However, it would appear that melanoma and additional, apparently unrelated, cancers developing in the same individual are likely to be related to a combination of low-risk susceptibility genes and environmental factors.

Overexpression of HER-2 in thick melanoma.

In this study we evaluated the overexpression status of HER-2 and its prognostic significance on survival in patients with thick cutaneous malignant melanoma. The immuno-alkaline phosphatase antigen detection technique was applied to archival diagnostic material from 51 patients with primary lesions measuring >or= 10 mm in Breslow thickness. Eleven additional patients with primary lesions measuring

Prognostic factors of cutaneous melanoma and a new staging system proposed by the American Joint Committee on Cancer (AJCC): validation in a cohort of 1284 patients.

This study, involving a cohort of 1284 evaluable patients, validates the American Joint Committee on Cancer (AJCC) proposal for the introduction of ulceration of primary cutaneous melanoma as an independent prognostic factor of survival. In univariate analyses, ulceration (Hazard Ratio (HR) 1.983; P<0.0001; 95% Confidence Intervals (CI) 1.692-2.325) was a predictor of worse overall survival. In multivariate analyses, ulceration (HR 1.302; P=0.022; (95% CI: 1.039-1.633) retained its prognostic significance for survival independent of tumour thickness (HR 1.101; P<0.0001; 95% CI: 1.055-1.150); mitotic activity (HR 1.039; P=0.005; 95% CI: 1.012-1.067); and age (HR 1.009; P=0.006; 95% CI: 1.003-1.016). Ulceration lost its significance in a subgroup analysis of 256 patients with clinically apparent regional lymph node metastases to the number of lymph nodes involved (HR 1.15; P=0.004; 95% CI:1.047-1.263). Ulceration is prognostically significant in the tumour but not the nodal classification of melanoma, with mitotic activity the second most important prognostic factor after tumour thickness.

Serum S100beta protein as a marker of disease activity in patients with malignant melanoma.

The purpose of the study was to evaluate serum S100beta protein as a marker of disease activity in patients with malignant melanoma (MM) and compare it with serum alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). One hundred sixty-four patients with MM, stages I-IV according to the American Joint Committee on Cancer (AJCC), were studied. Recurrent disease was categorized as active (AD) if metastases were evident clinically or with imaging investigations and inactive (ID) if no metastases were apparent at the time of sample collection. The sensitivity and specificity of S100beta, LDH, and ALP for discrimination between AD and ID were calculated using receiver-operating characteristic curve (ROC) analysis. Serum S100beta, LDH, and ALP concentrations were significantly higher in AD compared to ID. Serum S100beta protein was the best discriminator between AD and ID, the areas under the ROC curve being 0.89, 0.71, and 0.70 for S100beta, LDH, and ALP, respectively. Serum S100beta and LDH levels (both p < 0.0001) and serum ALP levels (p = 0.0014) corresponded with the number of metastatic sites involved. Using a cutoff point of 0.20 microg/L for serum S100beta protein, a specificity of 93% with a sensitivity of 68% was obtained for AD in MM. In stage IV disease, S100 was an independent predictor of survival in univariate (p = 0.001; hazard ratio = 1.0156) and multivariate (p = 0.038; hazard ratio = 1.0108) analyses. Serum S100beta protein is a better indicator of disease activity in MM than LDH or ALP and is an independent predictor of survival in stage IV disease.

Oxaliplatin is active in vitro against human melanoma cell lines: comparison with cisplatin and carboplatin.

We have previously confirmed the in vitro activity of cisplatin and carboplatin against human melanoma cell lines. Both drugs are important components in the chemotherapy used in our service for advanced metastatic melanoma. In this communication we report the in vitro activity of oxaliplatin against human melanoma cell lines in comparison with cisplatin and carboplatin. Oxaliplatin was found to be active against C32 and G361 cell lines with IC50 values of 49.48 and 9.07 microM (1 h exposure), 9.47 and 1.30 microM (4 h exposure), and 0.98 and 0.14 microM (24 h exposure), respectively. The cytotoxic activity of oxaliplatin in this in vitro system appears to be significantly superior to that of carboplatin. Its activity becomes comparatively closer to that of cisplatin as exposure time increases. Indeed at a 24 h exposure oxaliplatin appears to be significantly more active than cisplatin against the G361 cell line (p=0.0343). Oxaliplatin merits evaluation in the clinic both as a single agent and in combination with other drugs active against melanoma.

Detection of tyrosinase mRNA by RT-PCR in the peripheral blood of patients with advanced metastatic melanoma.

Detection of melanoma cells in the peripheral blood has been facilitated by the reverse transcriptase-polymerase chain reaction (RT-PCR), but their presence is of uncertain importance in the evolution of the disease. We studied the detection of melanoma cells using RT-PCR in the peripheral blood of 21 patients, four with regional lymph node metastases (American Joint Committee on Cancer [AJCC] stage III) and 17 with disseminated disease (AJCC stage IV). RNA was extracted from 10 ml of heparinized blood following density gradient centrifugation and converted into cDNA for PCR analysis. Assay sensitivity of 10 cells in 10(7) mononuclear cells and granulocytes obtained from 10 ml of peripheral blood was achieved using the G361 and C32 melanoma cell lines. Tyrosinase mRNA was not detected in control samples from healthy volunteers or patients with non-malignant disease. Six patients (one stage III, five stage IV) tested positive for tyrosinase mRNA (28.6%); with one exception, all patients were receiving chemotherapy at the time of sampling. Of the six positive results, three were from patients who initially tested negative but were subsequently positive after a 3-4 week interval. The low detection rates of melanoma cells in the peripheral blood of patients with widely disseminated disease is consistent with recent reports and correlates poorly with the clinical stage of melanoma. This may be partly explained by the clinically observed intermittent and random evolution of melanoma metastases.

Activity of platinum drugs against melanoma cell lines: is it modulated in vitro in the presence of tamoxifen?

Cisplatin and carboplatin have been used against human malignant melanoma as single agents and in combination. Tamoxifen is used in the treatment of breast cancer, but has no significant activity against human malignant melanoma. Tamoxifen, however, has been promoted as a modulator in some drug regimens. The addition of tamoxifen to cisplatin or carboplatin has been reported to enhance their activity against the human melanoma cell line T-289. We investigated whether tamoxifen potentiates, in vitro, the activity of cisplatin and carboplatin against C32, G361 and StMl11a melanoma cell lines. Tamoxifen alone at clinically achievable concentrations of 0.1 and 1.0 microM (168 hrs exposure) had no significant effect on growth. No chemopotentiation of the activity of cisplatin or carboplatin was observed with the addition of tamoxifen (0.1 and 1.0 microM). The platinum drugs were added for 1 hr (serially diluted from 100.0 microM). Against the G361 line there was a trend towards chemopotentiation of cisplatin by 0.1 microM of tamoxifen. However, this did not reach statistical significance. Tamoxifen (5.0 and 10.0 microM) produced some inhibitory activity, and a trend towards synergy with cisplatin was observed. However, these concentrations are not clinically feasible. Previous reports detecting synergistic interaction between tamoxifen (0.1 and 1.0 microM), and the platinum compounds against the T-289 melanoma cell line cannot be supported in our in vitro system.