[Role of an anti-estrogen, tamoxifen, in the treatment of metastatic malignant melanoma]

Abstract

The hormone-dependence of malignant melanoma is brought to mind by some epidemiological facts (rarely found in children, more frequently in females, higher frequency in case of prolonged use of oral contraceptives from an early age). On the other hand, estrogen receptors can be found in about 30 p. 100 of malignant melanomas. Starting from this hypothesis of a sub-population of hormone-dependent malignant melanomas, it seemed of interest to us to study the efficiency of an anti-estrogen, namely Tamoxifen (Nolvadex) in the management of metastatic malignant melanoma. It was used at a 40 mg daily dose-regimen on four patients (three post-menopausal females, one male) with multiple estrogen positive cutaneous metastases. In post-menopausal women, two cases of total regression were observed, associated with a distinct increase in progesterone receptors while under treatment and with a return to the initial stage when the treatment was stopped. This phenomenon can be explained by a double self-contradictory effect of the drug, already well known in other hormone-dependent cancers such as those of the breast or the endometrium, namely an anti-estrogen result on the tumoral growth and an estrogen result as attested by the synthesis of progesterone receptors. Certain malignant melanomas therefore behave as endocrine-dependent tumours and may so answer an anti-hormone treatment through a competitive fixation on estrogen-receptors. Our clinical results are in agreement with such a theory since Tamoxifen is at best effective on cutaneous metastases of post-menopausal women. The overall efficiency on all metastases is of the order of 10.6 p 100 (complete or partial regression).(ABSTRACT TRUNCATED AT 250 WORDS)