Malignant melanoma in different ethnic groups in Israel. Incidence and biologic behavior

The Jewish population of Israel is divided into two ethnic groups: Ashkenazic Jews (AJ) who immigrated from Europe and are fair-skinned, and Sephardic Jews (SJ) who immigrated from the Orient and Africa and who are dark-skinned. The biologic behavior of malignant melanoma (MM) in these two groups has not been investigated.

Three hundred forty-eight of 380 patients with MM, who could be accurately grouped ethnically, constitute this study group. The gender, site and depth of primary tumor, metastatic involvement and survival analysis, including univariate analysis for level of invasion, were examined.

Of 348 patients with MM, 285 were AJ and 63 were SJ. The female:male ratio was 2:1 and 0.9:1, for AJ and SJ, respectively (P < 0.05). Lesion site distribution was similar. The lesions were more invasive in SJ, 53% Clark level 4-5 versus 41% in AJ (P < 0.05). The 5-year survival was worse in SJ relative to AJ--50% versus 71% for female patients and 30% versus 62% for male patients--but did not reach statistical significance (NS). The actuarial 10-year survival showed poorer survival for female SJ: 27% versus 67% in female AJ (P < 0.05) and male SJ; 32% versus 65% in male AJ (P < 0.01). For all stage I MM, the actuarial 10-year survival was in male patients 32% versus 79% (P < 0.05), and in female patients, 27% versus 72% (P < 0.05) in SJ and AJ, respectively. For the more invasive lesions (Clark levels 4 and 5), the actuarial 10-year survival was for male patients 19% versus 75% (P < 0.05) and for female patients, 65% versus 67% (NS) in SJ and AJ, respectively.

The dark-skinned SJ tend to have MM less than the fair-skinned AJ, but once MM occurs in SJ, it appears to have a more virulent nature.