Having at least two kids might half ovarian cancer risk   by Eveline Gan     Here is a reason why you should do your part to raise Singapore's flagging birth rate. Childbearing might just help to reduce your risk of ovarian cancer, said medical experts at the Ovarian Cancer Expert Meeting which took place here last week.   According to gynaecological oncologist Dr Tay Eng Hseon, medical director of Thomson Women's Cancer Centre, there is a link between the disease and childbearing. Genetic predisposition aside, women who have never given birth are at a higher risk of ovarian cancer than those who have.   Dr Tay cited the theory of "incessant ovulations". During ovulation, the ovary releases an egg, which breaks through a wall of tissue for fertilisation.   "Afterwards, the ovary will have to repair the rupture. This repeats with every menstrual cycle," he said   "For women at risk - for instance, those with a genetic predisposition - there is a constant opportunity for cancer to form when the cells do not repair themselves properly."   It is believed that pregnancy and breastfeeding - during which ovulation stops - "put the ovaries to sleep", and hence reducing the risk of cancer transformation, said Dr Tay.   The fifth most common cancer here, ovarian cancer affects 1,405 women in Singapore - a figure which has doubled in the last 30 years, according to figures from the Singapore Cancer Registry.   "In the same span of time, fertility rates in Singapore have dipped. It's obvious there is a close association between reduced child-bearing and the severe surge of this highly fatal cancer," said Dr Tay.   He added that a similar trend can be seen in countries such as Hong Kong, Japan, Korea and Taiwan where birth rates have declined.       A tough fight   Incidence of other women cancers such as breast and uterine cancers has similarly increased in Singapore. Unlike those cancers, however, ovarian cancer is notoriously hard to detect in the early stages. The doctors said it is the deadliest of all gynaecological cancers.   Presently there is no effective screening test to detect ovarian cancer early.   As a result, majority of sufferers usually discover the cancer only in the advanced stages when "survival rates are dismal and relapse rate is high", explained Dr Tay.   Despite medical improvements, 75 per cent of survivors relapse within two years, noted Associate Professor Marcela del Carmen from the division of gynaecologic oncology at Massachusetts General Hospital, Harvard Medical School.   "It's a very clever cancer, because it gets ahead of you very quickly by spreading directly to other nearby organs," she said. Assoc Prof del Carmen was in town to present findings of a new clinical trial, dubbed CALYPSO, on recurrent ovarian cancer.       Halting the cancer in its tracks   While there isn't a magic number, Dr Tay added that having at least two children would half a woman's risk of ovarian cancer.   "The idea is that the more kids you have, the longer time your ovaries have to rest. Many women are unaware of the protective effects childbearing has on this cancer. Patients often express surprise on learning this fact," he said.   What about women who do not wish to have children?   Associate Prof del Carmen said oral contraceptives could work as a "chemical way" of allowing the ovaries to rest. She advised women who are not planning for babies to be on the birth control pill for at least five years to reduce their risk of the cancer.           This article was featured in Today August 2, 2011. http://www.todayonline.com/Health/EDC110802-0000011/Ovarian-cancer-on-the-rise