Malignant melanoma in pregnancy. A population-based evaluation.

BACKGROUND: For many years, there has been controversy in the medical community regarding the correlation of female hormonal factors with the outcome of women with malignant melanoma. There have been multiple reports that women with high hormone states, such as pregnancy, had thicker tumors and/or a worse prognosis compared with a group of control women.

METHODS: The authors used a database that contained maternal and neonatal discharge records from the entire state of California from 1991 to 1999 and linked those records to the California Cancer Registry, which maintains legally mandated records of all cancers reported in California during the same time period. Four hundred twelve women with malignant melanoma diagnosed during or within 1 year after pregnancy were identified (145 antepartum, 4 at delivery, and 263 postpartum) and were compared with a group of age-matched, nonpregnant women with melanoma (controls). The database captured only pregnancies at > or = 20 weeks of gestation.

RESULTS: When comparing women who had pregnancy-associated melanoma with the control group, the authors found no difference in the distribution of disease stage (82.0% of pregnant and postpartum women had localized melanoma vs. 81.9% of control women) or the tumor thickness (mean: 0.77 mm for pregnant women, 0.90 mm for postpartum women, and 0.81 mm for the control group). In a multiple regression model that controlled for age, race, stage, and tumor thickness, pregnancy had no impact on survival in women with melanoma. Lymph node assessment and positivity of lymph nodes also were equivalent between the two groups. Maternal and neonatal outcomes did not differ between pregnant women with melanoma and control women who were pregnant and had no history of malignancy. Small numbers of women with advanced melanoma and the inability to capture melanoma that occurred in pregnancies that were lost or were terminated prior to 20 weeks limited the conclusions primarily to women with localized melanoma.

CONCLUSIONS: In this large, population-based study of pregnant women in California from 1991 to 1999 with malignant melanoma, there were no data found to support a more advanced stage, thicker tumors, increased metastases to lymph nodes, or a worsened survival. The outcome for women with localized melanoma associated with pregnancy was excellent. Maternal and neonatal outcomes also were equivalent to those of pregnant women without melanoma.