Is Melanoma Hormonally Driven?

I developed melanoma during a pregnancy. I was 34 at the time. I have had a few friends develop it during pregnancies as well. I've read that studies say it is NOT a hormonally driven cancer. BUT, could it be pregnancy driven? When I asked my OB about that suspicious mole on my arm that was new/changing - he said it was normal to develop new moles during pg due to hormones. So if hormones during pg cause increase in moles, couldn't that increase risk of mel in those predisposed?

Doctor Answers 2

See A Dermatologist

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I URGE you to consult with a dermatologist, regarding the suspicious mole on your arm. The fact that you have a history of melanoma makes any advice to the contrary totally unjustified. 

Driscoll et al, in Clinics in Dermatology  Jan 2009 reviewed the rather copious literature on this subject. Their conclusion was a recommendation that pregnant women who have a changing pigmented lesion should undergo a biopsy promptly. Women who have atypical nevi or a past history of melanoma, should be closely monitored during their pregnancy. 

Melanoma is the most common malignancy encountered during pregnancy ( accounting for 31% of all malignancies in a very large Norwegian study). 

Three large studies, however, have shown that women who develop melanoma during pregnancy do not have a worse prognosis than those who are not pregnant.

I recall a woman in her 7th month whose husband was very concerned about a bleeding, black lesion on her upper chest. On examination, this proved to be a very innocent seborrheic keratosis which had been picked at. However, on examining her back, I detected an early melanoma. This stresses the importance of having a spouse periodically examine his wife's skin. Even a husband's mis-diagnoses might have saved this woman's life.

Virginia Beach Dermatologist

Relationship of melanoma and hormones is not quite worked out yet

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The evidence is confusing.  We know there is a relationship but different studies show different things.

Some studies imply that estrogens and estrogen receptors in the skin are beneficial in melanoma.  Estrogen receptors in the melanoma itself decrease in numbers when the melanoma is more invasive and more aggressive.  Which comes first the decrease in the receptors or the invasiveness of melanoma is unknown as of yet.  Also some studies show that women, particularly premenopausal women, have a better survival rate of melanoma than men or postmenopausal women.  There are also studies that show that blocking of hormones with medications like Tamoxifen, which is used for breast cancer treatment, is not effective.

Some studies show that women who start menarche late, have a shorter overall ovulatory lifespan and have hormonal abnormalities that decrease estrogens are less at risk for melanoma.

And also, some studies show that one of the reasons melanoma appears to be more aggressive during pregnancy is that there are more lymphatic vessels formed during pregnancy and that allows for easier access for metastatic cells.

So, it is still all very confusing.  One thing we do know for sure is that changing or new moles are not normal during pregnancy, just like they are not normal at any other time and need to be addressed promptly.

It used to be thought it's OK for a mole to grow or become more pigmented during pregnancy and that is how a lot of melanomas were missed.  A changing mole has to be shown to a dermatologist immediately.

Emily Altman, MD
Short Hills Dermatologic Surgeon

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