BRISBANE, Australia -- Australian researchers said on Wednesday that they had for the first time established a link between smoking and ovarian cancer.

"It's not a very strong link -- not nearly as strong as the type of risk that you'll find for lung cancer -- but women who smoke definitely are about twice as likely to get ovarian cancer as women who don't smoke," said David Purdie of the Queensland Institute of Medical Research.

"Many other cancers are linked to smoking -- pancreas, bladder, kidney and cervical cancer," AFP quoted Purdie as saying.

"In our study we did not start by hypothesizing a link between smoking and ovarian cancer and were pretty surprised by the results ourselves," he said.

Purdie said the Australian research was the first extensive study to identify the link between smoking and ovarian cancer, the sixth most common cancer occurring in women.

He said a survey of 1,679 women in Australia had also shown that women who had several children and those taking contraceptive pills were less likely to get ovarian cancer.

Since pregnancy, breastfeeding and the use of oral contraceptives prevent women from ovulating, the researchers concluded that the risk of ovarian cancer "increased proportionately to the total number of lifetime ovulatory cycles".