Melanoma's implications for pregnancy

October 21, 2005

Various papers published in the 1950s described cases of melanoma patients who died from metastatic disease that became rampant after the patients became pregnant.

Chicago - One-third of women with melanoma are of childbearing age at the time of diagnosis, so dermatologists need to be prepared to answer a variety of questions regarding the impact of pregnancy on melanoma prognosis, evaluation and management, Jean L. Bolognia, M.D., says.

Speaking at the American Academy of Dermatology's Academy '05, Dr. Bolognia, professor of dermatology, Yale University, New Haven, Conn., reviews a number of issues that may be raised by women with melanoma.

Does pregnancy affect melanoma prognosis?

"Based on those reports, the literature at the time contained recommendations that women with melanoma should consider never getting pregnant or even (should undergo) surgical sterilization," Dr. Bolognia tells Dermatology Times.

However, the patients described in those reports often had thick tumors and unrecognized metastatic disease that blossomed during pregnancy. That situation is in marked contrast to the current era when most melanomas are diagnosed early (≤1mm in depth). More recent case-control studies performed with analyses adjusting for prognostic factors such as tumor thickness indicate that current or future pregnancy has no adverse effect on melanoma prognosis.

"Several studies published in the 1980s and 1990s demonstrated no difference in five-year survival rates or disease-free intervals among women with melanoma who then became pregnant compared with controls who did not, and there are at least half a dozen additional studies comparing women who were pregnant at the time of melanoma diagnosis and those who were not that found no difference in survival between the two groups after controlling for Breslow depth," Dr. Bolognia says.

Future pregnancy considerations

A 2-year waiting period between the diagnosis of melanoma and attempting pregnancy has been recommended as a general guideline based on the observation that the majority of metastatic disease becomes apparent within two years of the initial diagnosis. Therefore, a woman who has not developed metastatic disease during that period has an excellent chance of being a long-term survivor and living to be a parent for her offspring.

"The two-year wait takes into account the welfare of the future child more so than concern that a pregnancy will worsen the mother's prognosis," Dr. Bolognia explains.

However, she also points out that the two-year wait should be viewed as a middle ground rather than a hard and fast rule. The situation of each patient should be considered individually, taking into account the woman's age and Breslow depth.

"Physicians need to be flexible and willing to practice at both ends of the spectrum. For example, I might suggest to a 40-year-old woman with melanoma in situ that there is no need to delay pregnancy at all, whereas I would recommend to a 16-year-old with a 4-mm thick lesion and lymph node involvement to wait at least 3 years," Dr. Bolognia explains.

Changing moles during pregnancy

In three fairly large case-control studies evaluating the effect of pregnancy on melanoma outcome, lesions in women who were pregnant at the time of diagnosis had a greater Breslow depth than in non-pregnant controls.

Those differences may be explained by several factors, including the potential tumor-stimulating effects of hormones and placenta-derived growth factors or the relatively immunosuppressed state of the pregnant woman. However, delay in diagnosis secondary to a misconception that benign moles normally change during pregnancy may also play a role, Dr. Bolognia notes.

"We don't know the relative roles of these various factors, but among the possible explanations for why pregnant women may be diagnosed with more advanced melanoma, the latter is the only one that we can potentially modulate," she says.

Considering that information and the results from a 1997 study from researchers at the University of Connecticut who found that melanocytic nevi do not significantly change in size during pregnancy (except on the lower anterior trunk), clinicians should be more aggressive in their surveillance efforts and lower their threshold for obtaining a biopsy of a suspicious lesion in pregnant women.