Pregnant women are not at higher risk of developing melanoma than women who are not pregnant, and the prognosis for melanoma is not worse if it develops during pregnancy, researchers report online ahead of print in Journal of the American College of Surgeons (Apr. 27, 2017).
For decades there has been some belief in the medical community that pregnancy has an adverse effect on the course of melanoma. Some think pregnancy can increase the risk of melanoma development, its ability to spread throughout the body, and likelihood of recurrence, said study coauthor Dr. Mark Faries, a press release. Dr. Faries was director of therapeutic immunology at the John Wayne Cancer Institute in Santa Monica, Calif. at the time the study was conducted.
To try to determine the real risk of melanoma in these women, investigators identified female patients of reproductive age with stage 0 to IV cutaneous melanoma in the John Wayne Cancer Institute’s prospectively maintained database.
Data from the 2,025 women identified who were treated at the Institute between 1971 and 2016, including clinical and histopathologic factors, was statistically analyzed. Univariable and multivariable analysis were used on matched data to compare disease-free survival (DFS), overall survival (OS), and melanoma-specific survival (MSS) for stage 0–III pregnancy-associated melanomas (PAMs) vs. non-PAMs.
“In general what is important to note about melanoma is that its incidence continues to increase fairly rapidly, particularly among young women in their 20s and 30s, the same group that would be affected by a pregnancy-associated melanoma,” Dr. Faries said. “So it’s crucial to make sure that these women are getting appropriate screening and treatment.”
A total of 156 women were identified who had developed melanoma during their pregnancies.
Investigators found that patient factors were similar for pregnancy-associated melanomas and non-pregnancy associated melanomas, with no significant differences in Breslow thickness, histologic type, or where the tumor first appeared on the skin. There was also no difference in stage at diagnosis, on average.
Recurrence rates were also similar between the two groups, with approximately 38% of pregnant women having a melanoma recurrence compared to 36% of their non-pregnant counterparts.
Analyses of OS rates and MSS rates for pregnancy-associated melanomas versus non-pregnancy-associated melanomas in stages 0 to III melanoma showed no differences. There were not enough patients with stage IV melanoma to include them in the analyses. At 10 years, disease-free survival was 65.7% and 62.3% for the non-pregnant women and pregnant women, respectively.
Dr. Faries said that this study upends the long held belief that pregnancy and melanoma are an adverse combination. “Pregnant patients should be screened for melanoma in a similar manner to non-pregnant patients and should be counselled that their prognosis is not adversely affected by pregnancy. This finding should be very reassuring to both the patients and physicians who are involved in their care.”