Newer birth control pills don't lower risk of breast cancer, study finds

Amanda Morris	
 
		Amanda Morris with her husband Christopher Bowen and daughters Jade and Hailey

Amanda Morris Amanda Morris with her husband Christopher Bowen and daughters Jade and Hailey

WEDNESDAY, Dec. 6, 2017 (HealthDay News) - Newer versions of the birth control pill carry a similar increased risk of breast cancer as earlier ones that were abandoned in the 1990s, a new study reveals.

The study of nearly 2 million women in Denmark looked at women using birth control methods such as the pill, NuvaRing, or implants.

While contraceptive drugs that contain oestrogen have always been suspected of increasing the likelihood of breast cancer, researchers had expected smaller doses of the hormone, often combined with the drug progestin, would be safer, said Lina Morch, an epidemiologist at Copenhagen University Hospital who led a study analysing the records of 1.8 million women in Denmark.

A hormone specialist at Brigham and Women's Hospital who deals with contraceptive issues says the study shouldn't alarm those taking oral contraceptives.

Use of oral contraceptives may increase risk of breast cancer, although the overall absolute increase for breast cancer cases was relatively small. However, he noted that the clinical implications of this study "must be placed in the context of the low incidence rates of breast cancer among younger women", pointing out that most of the new breast cancer cases occurring in the study were among women using oral contraceptives over the age of 40.

"There had been some changes to oral contraceptive formulations in the '90s, and there was the hope those formulations would result in a lower risk of breast cancer", said Gaudet, who was not part of the study. Therefore, it wasn't clear if this risk applied to newer formulations of birth control pills or to other birth control methods, including intrauterine devices (IUDs) and implants that contain only the hormone progestin.

Mørch said that "knowledge is needed on the potential beneficial influence of newer contraceptives on the risk of ovarian and colorectal cancer, since evidence now relates to older types of hormonal contraceptives".

The bottom line is that before starting or continuing to take hormonal contraceptives - or any medications - it's important to speak with your doctor about any potential risks and benefits, and make an informed decision from there. "But it does show an increased risk, so for people who don't have a great reason for taking oral contraceptives, or are amenable to alternatives, perhaps they should think about it". Condoms and diaphragms do not deliver hormones. Over the years, makers of birth control pills and hormone replacement therapy for women past menopause have reduced the amount of estrogen in their products. But these earlier studies looked mainly at older types of birth control pills, which had a higher dose of estrogen than today's pills.

"The relative risk increase in this study is only 1.2 on average". "The range of risks we're talking about here is much much smaller", she said. Don't forget there is relative risk of death in pregnancy, too.

The findings held even after the researchers took into account some factors that can affect the risk of breast cancer, such as becoming pregnant or having a family history of the disease.

The findings of alink between hormonal contraception and breast cancer is not new; studies going back decades have suggested that the hormones in birth control could raise the risk of breast cancer. Any woman's risk of breast cancer goes up as she gets older.

Beyond the fact that they provide an effective means of contraception and may benefit women with menstrual cramping or abnormal menstrual bleeding, "the use of oral contraceptives is associated with substantial reductions in the risks of ovarian, endometrial, and colorectal cancers later in life".