Warning over contraceptive pill

An international health authority has sounded a warning about the combination contraceptive pill, used by about 10 per cent of Kiwi women of child-bearing age.

The World Health Organisation's cancer agency had previously concluded that the oestrogen-progestogen pill could cause liver cancer. After a review of existing research, the International Agency for Research on Cancer has declared the pill also slightly increases the risk of breast and cervical cancer.

However, the agency also confirmed the pill protects against endometrial and ovarian cancer.

The group published its conclusions in a policy statement in the Lancet Oncology magazine, but has yet to publish its analysis of the data it considered when making its recommendations.

Health experts in New Zealand are cautious about acting on the agency's advice.

Medsafe spokesman Stewart Jessamine said the Medicines Adverse Reactions Committee would look at the data once it was available to see whether any changes to prescriber and patient information was needed.

"Prescriber information for the majority of commonly prescribed oral contraceptives already notes the small possibility of increased risk of some cancers," he said.

Auckland reproductive endocrinologist Megan Ogilvy, who sees about 10 to 12 women each week who are on the pill, said she doubted there would be any major changes to how the combination pill was prescribed in New Zealand.

"The pill is an effective, very convenient form of contraception that protects against endometrial and ovarian cancer."

However, she said doctors prescribing the pill would likely be even more vigilant about discussing the risks of cancer with women with a personal or family history of breast or cervical cancer.

Cancer Society policy adviser Betsy Marshall said the society would be seeking advice from clinical experts.

- HERALD ON SUNDAY