A physician’s job is to do no harm. That is the oath we took upon graduation from medical school right before we got to put “Dr.” before our name. So when patients ask me if their medication for IVF can cause ovarian cancer, I respond very carefully.
Ovarian cancer is one of the most deadly cancers. This is partially because it is caught at a very late stage when it has already spread throughout the abdomen. Doctors have not yet figured out a way to detect ovarian cancer in its early stages. It is estimated there will be 22,000 new diagnoses of ovarian cancer and 14,000 deaths from this disease in 2013.
The most common type of ovarian cancer is called serous epithelial cancer. It used to be that we believed this type of cancer originated from the surface of the ovary and became cancerous through repeated episodes of ovulation. For this reason women who had infertility or who took medication to induce multiple eggs to ovulate were at greater risk. We now believe that this type of cancer is no longer caused from excessive ovulation.
New studies done using molecular markers for mutations such as TP53 have implicated the fallopian tube in the beginnings of serous ovarian cancer. If this is true, it would dispel the belief that ovarian cancer could be caused by fertility drugs. This makes medical sense and agrees with many current studies and common observations within our field.
There has never been a study that proves gonadotropin exposure (fertility medication) causes malignant transformation of cells. Furthermore, studies on ovulation counter the belief that “incessant ovulation” causes ovarian cancer.
Women with PCOS who ovulate infrequently are at a slightly increased risk of ovarian cancer, rather than decreased. Both types of birth control pills (those that prevent ovulation and those that do not) decrease the risk of ovarian cancer by 50%. And pathology studies have found early ovarian cancer-type cells in the fallopian tubes of women with BRCA mutations (who we know are at increased risk for ovarian cancer.)
So when I give an answer to the patients who ask whether fertility drugs can cause ovarian cancer, I state that ovarian cancer is very complex and we are just now gaining greater understanding. However, some evidence supports the fact that “incessant ovulation” with or without fertility drugs does not appear to cause epithelial ovarian cancer.
Because of the association between infertility and ovarian cancer, patients should see their gynecologist yearly and stay up to date on current research. Hopefully the next time I blog about this, we will even have a greater understanding of this deadly disease.