Melanoma and Pregnancy

Abstract

Pregnancy and its dramatic increase in endogenous hormones may affect malignant melanoma (MM), either through initiation or promotion of a lesion or by affecting prognosis. There is physiological evidence that endogenous and exogenous hormones can affect pigmentation, and animal experiments have shown estrogens to promote tumor growth. This evidence originates from several areas:

• Pregnancy is normally associated with pigment deposition in areas already pigmented and occasionally results in hyperpigmentation of the face.

• Melanocyte-stimulating hormone rises progessively throughout pregnancy with its highest concentration at term (Ances and Pomerantz 1974).

• Steroid hormone receptors have been found in human melanomas (Neifeld and Lippman 1980; Grill et al. 1982).

• Exogenous hormones, primarily oral contraceptives, have been shown to be associated with melasma and the magnitude of this effect increases with duration of use of these agents (Carruthers 1966).

• Experiments with mice have shown an increase in melanoma tumor size upon administration of estrogens in both male and female animals (Lopez et al. 1978).

• Some studies have reported an association between the long-term use of oral contraceptives prior to being diagnosed as having MM (Bain et al. 1982; Holly et al. 1983; Beral et al. 1984), indicating that exogenous hormones may play a role.

The work reported in this paper was supported in part by NCI grants CA 34382 and CA 19408 to the Northern California Cancer Program