New study widens cancer risks and benefits of pill

Women who take the birth control pill could increase their risk of cervical and breast cancer, scientists said on Friday.

A review of research by the International Agency for Research on Cancer (IARC) in Lyon, France, part of the World Health Organization, concluded that oral contraceptives protected against some types of cancer but might trigger others.

Previously, liver cancer was indicated as a risk for women who take the pill, IARC said. But the latest research shows cervical and breast cancer are also possible risks.

The pill can protect against endometrial cancer and Ovarian cancer, IARC said, calling for more research to determine whether the total net benefits caused by the protective and carcinogenic effects were positive or negative.

"It is possible that the overall net public health outcome may be beneficial, but a rigorous analysis is required to demonstrate this," the agency said.

"This new information about cancer risks - and also protection against cancer in the case of oral contraceptives - makes it important that each woman who uses these hormonal products discuss the risks and benefits with her doctor," IARC said in a statement.

At the same time, the IARC, working group of 21 scientists, increased the warning on hormonal menopausal therapy to "carcinogenic" from "possibly carcinogenic."

The scientists concluded, based on an expanded study, that "combined menopausal therapy" increased the risk of breast cancer and in some cases endometrial cancer.

Worldwide, around 100 million women use oral contraceptives. In addition, around 20 million women in developed countries had used hormonal menopausal therapy.