NEW DELHI — A new study of women in India reveals that having used birth-control pills elevates the risk of developing breast cancer nearly tenfold, and having had an abortion increases their risk of breast cancer more than sixfold.
The study, published in the most recent issue of the Indian Journal of Cancer, matched 320 women with newly diagnosed breast cancer with 320 healthy women of similar age, economic and social status and medical background, and it found that “the risk of breast cancer was 9.50 times higher in women having a history of consumption of oral contraceptive pills.”
Doctors at the Department of Gastroenterology and Human Nutrition Unit at the All India Institute of Medical Sciences (AIIMS) in New Delhi conducted the study to investigate the association of various reproductive factors with breast cancer.
“We found long-term use of oral contraceptive pills (OCP) higher among those suffering from breast cancer, 11.9%, compared to healthy individuals, 1.2%,” Dr. Umesh Kapil, a lead author of the study told the Times of India. Breast cancer is caused by repeated exposure of cells to circulating ovarian hormones, he explained, and long-term use of birth-control pills, which contain estrogen and progesterone, may contribute to the elevated risk.
“The relationship between contraceptive use and occurrence of breast cancer is not known,” Dr. G. K. Rath, the head of Bhim Rao Ambedkar Institute Rotary Cancer Hospital, told the Times of India in the wake of the study. “But there is enough evidence to show the hormonal imbalance caused by them, increasing the risk. Early menarche, late marriage and childbirth and abortions are important factors.”
The risk associated with oral-contraceptive use in the study was higher than all the other known risk factors examined, except a lack of breastfeeding. Women who breastfed fewer than 12 months had a 14.9 times higher risk of getting breast cancer than women who breastfed longer than 12 months.
The U.S. Centers for Disease Control (CDC) estimates that about 80% of American women born since 1945 have used oral contraceptives. It is the leading contraceptive choice for teenagers and women under 30, never-married women and women with no children.
A history of abortion was also found to be “significantly higher in breast cancer cases as compared to controls, with the Relative Risk (RR) = 6.26 in women having a history of abortion,” the scientists reported, though they did not distinguish between spontaneous miscarriage and induced abortions.
Other Contraceptives Even More Dangerous?
Dr Ajeet Singh Bhadoria, a public-health specialist and co-author of the study, told the Times that other forms of hormonal contraceptives may be more dangerous. Use of the birth-control pill is declining, but the uptake of morning-after pills has spiked.
“Morning-after pills contain a higher dose of hormones and are meant for emergency. However, many young women use them regularly to prevent pregnancy in case of unprotected sex,” he said. “Awareness about the side effects of long-term use is a must.”
While Indian doctors are sounding the alarm, American medical agencies have dismissed oral-contraceptive cancer risks. The Food and Drug Administration made Plan B emergency contraception available over the counter last May, meaning it could be purchased by children as young as 15 without medical oversight.
In 2002, the CDC issued a press release declaring there is “no such association” between breast cancer and birth-control pills, after it published study findings of the National Institute of Child Health and Human Development.
But a number of subsequent studies found a positive connection and forced advisory organizations to admit a possible elevated risk.
“Does taking birth-control pills increase my risk of developing breast cancer?” asks WebMD online. “Maybe.”
The Susan G. Kormen Foundation mentions a “slightly” elevated risk of breast cancer for women taking oral contraceptives, but suggests it is offset by the reduced risk of much rarer ovarian and endometrial cancers, although it mentions, too, that oral contraceptives are associated with higher incidences of cervical cancer and liver tumors.
The Abortion Link
The abortion-breast cancer connection is flatly denied by Western cancer-advocacy groups. Although the Breast Cancer Prevention Institute (BCPI) in Somerville, N.J., provides an exhaustive list of abortion-breast cancer studies since 1957, recording 57 reporting a positive correlation between abortion and breast cancer compared to 16 that don’t, the National Cancer Institute concluded in 2003 that no such correlation exists.
“At this time, the scientific evidence does not support the notion that abortion of any kind raises the risk of breast cancer or any other type of cancer,” the American Cancer Society website states, echoing the NCI. A fact sheet about breast cancer and abortion implies that the highest risk is for post-partum women who have recently carried a baby to term and delivered. It does not mention breastfeeding.
However, the study from India comes on the heels of another major study, published in November in the academic journal Cancer Causes Control, which found startling evidence of a link between abortion and breast cancer in China.
Twelve researchers from organizations including the Tianjin Medical University Cancer Hospital and China’s National Clinical Research Center for Cancer in Tianjin pooled results of 36 studies in 14 provinces and found that a single induced abortion is linked to a 44% rise in breast-cancer risk; a second abortion was linked to a 76% rise, and three or more abortions linked to a rise of 89%.
“The most important implication of this study is that IA [Induced Abortion] was significantly associated with an increased risk of breast cancer among Chinese females,” lead researcher Dr. Yubei Huang concluded, “and the risk of breast cancer increased as the number of IA increases.”
Dr. Joel Brind, a professor of endocrinology at Baruch College, City University of New York, was one of the first scientists to publicize the link between abortion and breast cancer. In a recent report for the Breast Cancer Prevention Institute, he pointed to two other studies from India showing abortion increasing breast cancer risks sixfold and twentyfold, respectively.
“These strong links are of the sort of magnitude that has typified the link between cigarettes and lung cancer, and much higher than the ABC [Abortion-Breast Cancer] link has typically shown in the West, where it has averaged only about 1.3,” said Brind.
The difference, he explained, is due to relative risk. “Since most of the known risk factors are related to reproductive patterns, in countries where almost all women are married at a young age, do not take contraceptive steroids (‘the pill’) and start having children young and breastfeed them all, breast cancer is typically quite rare.”
What is “truly alarming,” Brind added, is when conservative risk estimates are applied to the vast populations of India and China, which together include more than 1 billion women. “A lifetime risk of 2% translates to 20 million women. At a 50% mortality rate (much higher than in the West, at this point), we are talking about 10 million women dying of breast cancer during the coming decades, as a consequence of abortion, in India and China alone.”
The American Cancer Society estimates that one in eight American women will get breast cancer in her lifetime. In 2013, 232,340 new cases of invasive breast cancer were diagnosed in the U.S., and about 39,620 women died from the disease.
Celeste McGovern writes from Scotland.