Could fertility drugs raise risk of cancer?
Q - Is there any evidence that fertility drug use increases the risk of ovarian cancer?
A - Two theories in particular have prompted researchers to examine fertility drugs as a risk factor for ovarian cancer.
First, an increased number of uninterrupted ovulations in a woman's lifetime increases her risk of ovarian cancer.
This may explain why pregnancy, breast-feeding, and use of oral contraceptives are associated with a decreased risk of ovarian cancer.
Second, increased levels of certain hormones associated with ovulation (such as human chorionic gonadotropin) increase the risk of ovarian cancer.
Fertility drugs can increase both the number of ovulations and the levels of hormones associated with ovulation. But evidence from recent studies and meta-analysis suggests fertility drugs do not put women at a higher-than-average risk of ovarian cancer.
Ovarian cancer was not associated with infertility resulting from anovulation, tubal, cervical or uterine causes. But endometriosis and unknown causes of infertility increased cancer risk.
The women studied were relatively young (mostly in their 40s) and the incidence of ovarian cancer peaks in the fifth and sixth decade.
We need to wait for longer follow-up studies for conclusive evidence, but the results to date are encouraging.
Mr Narendra Pisal and
Dr Michael Sindos,
department of women's health, Whittington Hospital,