Link between cancer, pill ‘inconslusive’

Press, 11 September 1989, Page 2

Link between cancer, pill ‘inconslusive’

By

DEBORAH MCPHERSON

Overseas studies linking breast cancer to oral contraceptives are inconclusive, says an Australian radiologist, Dr Mary Rickard.

Dr Rickard helped set up a State-funded breast cancer X-ray screening programme in New South Wales. She was in Christchurch recently for a mammography screening seminar. She said British and American studies linking the pill to breast cancer sampled only small numbers of women and were inconclusive.

While breast cancer was common, with one in every 10 Australian and New Zealand women likely to develop cancer after the age of 40, no-one knew what caused it, she said.

A British study of 47,000 women found that women between the ages of 30 and 34 who had used the pill were three times more likely to develop breast cancers than nonusers in the same group. An American study

comparing 407 breast cancer patients with 427 women hospitalised for other conditions found that pill use doubled the risk of the disease by the age of 45, but pill use of 10 years or longer quadrupled the risk.

Dr Rickard said she would expect national cancer registers to bear out the studies, but the incidence of breast cancer had not changed.

"It would be easier to link a rare disease with something that was commonly used like the pill, but since breast cancer and pill usage are both so common, it is difficult,” she said.

The pill’s content had also changed dramatically since it was first introduced 30 years ago. Now lower doses and different combinations of the hormones estrogen and progesterone were available.

Factors other than oral contraceptives have been linked to breast cancer including age, delayed childbirth, remaining childless, immediate family history, high fat

diet, early menstruation and late menopause, and were “negligible risk factors,” said Dr Rickard. “They do not occur in every case.”

Dr Rickard said a mobile screening programme had been popular with women since it started 18 months ago.

So far about 7500 women had come forward to be screened. A van with ’ a mammography machine stopped regularly at shopping malls and main thoroughfares asking women if they wanted the test.

Dr Rickard said it was important national screening programmes were not underfunded if they were to be successful.

Radiologists and radiographers had to be properly trained for what was an exacting procedure.

“Women do not want to be falsely assured everything is all right, but they do not want to be called back unnecessarily,” she said.