In Vitro Fertilization (IVF) Not Linked To Increased Risk of Cancer: Study

New research suggests that women who received in vitro fertilization (IVF) treatments do not face any higher risk for breast cancer or other gynecological cancers than other women, contradicting the findings of prior studies that indicated there is a potential link between the fertility treatments and cancer. 

The study was published in the January 30, 2013 issue of Fertility and Sterility, finding a slightly elevated risk of endometrial cancer in women who received between one and three IVF cycles, but those receiving four or more cycles of IVF did not demonstrate an increase risk; with the risk actually appearing to decrease with the additional cycles.

“We found no significant relationships of IVF exposures to the risks of breast, endometrial, or ovarian cancers,” said Louise Brinton, lead author and chief of the Hormonal and Reproductive Epidemiology Branch at the National Cancer Institute in Rockville, Maryland.

Researchers reviewed the medical records of nearly 90,000 Israeli women treated at the Israeli Maccabi Healthcare Services from September 1994 through June 2011 to determine the likelihood of cancer development after IVF treatment.  The study revealed 1,500 women who were diagnosed with breast, endometrial, ovarian, in situ cervical or invasive cervical cancer. However, of the 1,500 women, there was no heightened risk for cancer solely based on receiving IVF treatment.

Fertility treatments often involve drugs which stimulate ovulation and procedures such as ovary puncture for egg collection. Researchers initially suspected these procedures would place women receiving IVF treatment at higher risk of developing cancer.

Conversely, a higher risk of ovarian cancer from IVF treatment was found in women who received four or more cycles. However, researchers also say the study was too small to conclusively link IVF to an increased risk of ovarian cancer, considering only 45 cases within the entire study were confirmed.

It is unclear if the cases of ovarian cancer are directly linked to the IVF treatments or to the dysfunction of the ovaries to begin with. Researchers also pointed to findings which indicated a decrease for in situ and invasive cervical cancers among women who received IVF or other fertility treatments.

Previous studies linked IVF treatment to a heightened risk of breast cancer and borderline ovarian tumors. A Dutch study published in 2011 found women who received IVF treatments were twice as likely to develop ovarian cancer and were also at greater risk of developing borderline ovarian tumors, cancerous cells which typically do not develop into cancer.

Researchers say a larger study group would be necessary to conclusively determine long-term risks of cancer. They also recommend women receiving IVF be monitored closely by their doctors to ensure against developing any forms of breast or gynecological cancers.

“Women receiving IVF should continue to be monitored given that the procedures involve potent ovulation stimulators and repeated ovarian punctures,” the researchers concluded.