Dutch researchers have found no link between in vitro fertilization (IVF) and increased risk of developing breast cancer, according to a study published Tuesday in the Journal of the American Medical Association (JAMA).
Researchers have analyzed data from more than 25,000 women, collected between 1980 and 1995. They observed no difference in breast cancer rates among women who underwent IVF and those who did not receive treatment.
Breast cancer is one of the major health problems affecting women worldwide. The World Cancer Research Fund said it was the most common cancer diagnosed among females in 2012. Rates of breast cancer in North America have been increasing over the last decade.
Researchers previously thought that procedures involving IVF might increase chances of developing breast cancer. Physicians have agreed that high exposure to exogenous and endogenous estrogens and progestogens could be linked with disease.
IVF can temporarily decrease levels of progesterone. However, it apparently doesn’t increase the incidence of breast cancer, according to researchers at the Netherlands Cancer Institute in Amsterdam.
IVF is a surgical process to remove eggs from the ovaries of a woman, which are later combined with sperm in a laboratory and returned to the body of the woman. 67,996 children were born in the United States in 2013 from mothers who received IVF treatment.
Study details: Risk of developing breast cancer is not different among IVF-treated women
A team led by Alexandra W. van Den Belt-Dusebout, a researcher at the Netherlands Cancer Institute, has evaluated the impact of ovarian stimulation for IVF in the development of breast cancer in the long-term.
Researchers obtained data from 19,158 women who received IVF treatment between 1983 and 1995. They also evaluated data from 5,950 women who underwent different fertility treatments between 1980 and 1995 (non-IVF group).
The average age of women participating in the study was 54 for the first group and 55 for the non-IVF group Study details: risk of developing breast cancer is not different among IVF-treated women when the study was coming to an end. 839 women developed breast cancer after a follow-up of 21 years, said researchers in a press release.
Other 109 women developed non-invasive breast cancer during the same period. The risk of developing the disease was not different among women in the non-IVF group. Researchers evaluated details such as the age of participants at the time they gave birth and number of IVF attempts, said the New York Times.
The first manifestations of breast cancer among participants were observed 20 years after they had received IVF treatment, the authors said. They also found that women who obtained modest results of IVF treatment had fewer chances of developing breast cancer.
The epidemiologist Belt-Dusebout said that patients who usually receive IVF treatment are older than women who don’t need assistance to give birth. More than five million children worldwide have been born from mothers who received assisted reproductive treatment.
“Analysis indicated that breast cancer risk in IVF-treated women was not significantly different from that in the general population and from the risk in the non-IVF group. The cumulative incidences of breast cancer at age 55 were 3 percent for the IVF group and 2.9 percent for the non-IVF group,” concluded the team.
Breast cancer in the United States: There will be 246,660 new cases in 2016
Breast cancer is the second most common type of cancer among American women, as reported by the Centers for Disease Control and Prevention (CDC). There would be an estimated 246,660 new cases of breast cancer in the nation by the end of 2016.
Approximately 12 percent of females in the U.S. will develop breast cancer during their lifetime. The Breast Cancer Organization said that an estimated 40,505 would die from the disease in 2016. Various studies may differ from the Netherlands Cancer Institute and its new findings.
A study that involved 21,000 Australian participants has suggested that women who begin IVF at 24 years old or younger could have an increased risk of developing breast cancer, as reported by the New York Times. The same relationship was not found among older women.
“These findings are consistent with the absence of a significant increase in the long-term risk of breast cancer among women treated with these IVF regimens,” The Dutch team said in a press release.
Mia Gaudet, the strategic director of breast and gynecologic cancer research at the American Cancer Society, told the NY Times that new findings from the Netherlands Cancer Institute are not conclusive but are still positive for women interested in IVF.
Researchers will continue to investigate the risk of developing breast cancer among women who undergo IVF. Gaudet said that most participants in the study were under 60 years old. It would be interesting to evaluate the incidence of breast cancer among postmenopausal women.