How Melanoma Risks Pregnancy
Researchers estimate that nearly one-third of cases of melanoma, the most serious form of skin cancer, are diagnosed in women during their childbearing years. Since many women now are delaying pregnancy until their 30s or 40s, coupled with the fact that melanoma is the most common form of cancer for young adults 25-29 years old, more women could be faced with developing melanoma before or during pregnancy.
At the recent 67th Annual Meeting of the American Academy of Dermatology, dermatologist Marcia S. Driscoll, MD, FAAD, clinical associate professor of dermatology at the University of Maryland School of Medicine in Baltimore, presented evidence concerning the prognosis for women who become pregnant after surviving melanoma and for those who develop melanoma during pregnancy.
“Over the years, there has been ongoing controversy concerning the effect of hormones on melanoma,” said Dr. Driscoll. “Some researchers speculated that melanomas may grow rapidly and spread due to the hormones associated with pregnancy. While we know that hormones may impact other types of cancer, such as breast and ovarian cancer, a review of the research on pregnancy and melanoma shows there is no evidence that pregnancy has an adverse influence either on the prognosis of melanoma or the risk of developing melanoma.”
Prognosis Important when Considering Pregnancy after Melanoma
Dr. Driscoll explained that the best direct evidence of the prognosis for the woman who becomes pregnant after being diagnosed with melanoma is based on three small case-controlled studies. Reviewed collectively, these studies compared the prognosis of 530 women who became pregnant after being diagnosed with melanoma to 2,340 control subjects who completed their pregnancies prior to their diagnosis of melanoma.
“These studies found no significant difference between the prognoses of these two groups of women, indicating that hormones did not have a negative effect on melanoma,” said Dr. Driscoll. “Having researched this topic for 15 years, I personally have not found a solid link between hormones and melanoma.”
In counseling women who survived melanoma about future pregnancies, Dr. Driscoll said the most important factor to consider is a woman’s prognosis, which is based upon her stage of the disease. Stage of disease for melanoma is based on three variables – tumor thickness, presence or absence of ulceration, and whether the melanoma has spread to the lymph nodes or other organs. For example, if a tumor is less than 1 mm in depth (which is considered a “thin” melanoma, or in an early stage of the disease), no ulceration is present in the tumor (meaning the top layer of the skin when examined under the microscope is intact), and the melanoma is contained and has not spread, then the patient has what dermatologists consider a very good prognosis for surviving melanoma.
“When counseling women who survived melanoma about future pregnancies, I advise those with an excellent prognosis that there is no reason for them to delay pregnancy,” said Dr. Driscoll. “For the woman with a melanoma more than 1 mm in depth, her prognosis is a little unclear and her recurrence rate is higher than those diagnosed with thinner melanomas. In these instances, I would advise women to delay pregnancy for two to three years – as that is the most common time for a melanoma to recur. Women with advanced melanoma that has spread have a much poorer prognosis, making their situation more complex. Counseling is necessary to address very serious issues about their survivability.”
Melanoma Can Be Treated Safely during Pregnancy
Another concern for some women is what happens if a melanoma is diagnosed during pregnancy. Dr. Driscoll explained that there are additional data demonstrating that pregnancy does not affect the prognosis for women diagnosed with melanoma before, during or after pregnancy. Specifically, six case-control studies and two large population-based studies have found no effect on prognosis when melanoma is diagnosed during pregnancy.
“While being diagnosed with melanoma at any time can be scary, it can cause great anxiety if it develops while a woman is pregnant,” said Dr. Driscoll. “However, when you look at the whole body of evidence available on this subject, there is nothing to suggest that pregnancy adversely affects the patient’s outcome. Likewise, it is extremely rare for the baby to be affected - this is only seen in cases of women with advanced melanoma where spreading has occurred throughout the body.”
If a pregnant woman is diagnosed with a melanoma that has not spread (localized), then she typically would receive the same treatment as any other person – mainly a wide local excision to remove the tumor. Dr. Driscoll explained that this procedure should not be delayed and can be safely performed under local anesthesia during pregnancy. In cases where a wide local excision must be performed in a later stage of pregnancy, the patient’s obstetrician may be involved and collaborate with the dermatologist to monitor the fetus during the procedure.
However, if a melanoma is deeper than 1 mm, Dr. Driscoll advised that a procedure known as sentinel lymph node mapping and biopsy should be considered. This procedure has not been studied in a large number of pregnant women, and both when and how the procedure should be performed during pregnancy is controversial. In other melanoma patients, this has become a routine procedure.
“For a woman who has had a more advanced stage of melanoma, her treatment options may be more limited if melanoma returns during pregnancy,” said Dr. Driscoll. “Fortunately, most dermatologists do not frequently see these types of advanced cases. But when we do, multiple experts are consulted and involved in treatment.”
In addition, other studies which have observed the effect of hormones received from external sources – such as hormone replacement therapy (HRT) or oral contraceptive pills (OCPs) – have found no increased risk of developing melanoma. “One prospective study reported in 2004 in the British Journal of Cancer followed 206 women diagnosed with localized melanoma who received hormone replacement therapy within five years of being diagnosed with melanoma. When compared to 123 control patients who did not have melanoma, researchers found no adverse effect on survival in the HRT group and even improved survival rates compared to the control group,” said Dr. Driscoll.