Cypy Healthy

Guardian Unlimited - A common medical condition caused by the lining of the womb growing elsewhere in the body raises the risk of women developing a range of different cancers, doctors reported on Monday.

Endometriosis affects up to 15% of women of reproductive age, and in severe cases, it can leave them infertile. The cells of the womb lining often grow on the outside of the uterus and form painful scar tissue, which can only be removed by surgery.

The condition has been associated with a raised risk of cancer before, but doctors believed this was due to fewer women with endometriosis having children. Hormonal changes triggered by childbirth are known to be protective against some cancers.

A team of doctors from Sweden have now found strong evidence to suggest endometriosis increases cancer risk regardless of whether women have given birth before.

The doctors studied medical records for 63,630 women who had been diagnosed with endometriosis between 1969 and 2002. A total of 3,822 went on to develop cancer. Whilst the scientists found no overall increase in the risk of cancer, they found the women faced a substantially higher risk of certain forms of the disease.

The risk of ovarian cancer was 37% greater than in the general population, with endocrine, kidney, thyroid and brain tumours more common by 38%, 36%, 33% and 27% respectively. Malignant melanoma, the most dangerous form of skin cancer, was increased by 23% and breast cancer risk rose by 8%. Surprisingly, endometriosis also reduced the risk of cervical cancer by 29%.

There was no difference between the level of risk for women who had become mothers and those who had remained childless, the scientists announced at the annual meeting of the European Society of Human Reproduction and Embryology in Lyon.

Anna-Sofia Melin, from Karolinska University hospital in Stockholm, said the study "increases the possibility that it is the endometriosis disease in itself that causes the cancer and not the infertility issue. Various theories have been suggested. For ovarian cancer it might be the exposure of the ovaries to the hostile endometrium cells that 'invade' the ovary during the course of endometriosis disease. Or it could be defects in the immune system that allow the endometriosis to grow and also might allow cancer cells to grow in different parts of the body. "Maybe the treatment of endometriosis, hormonal or surgical, can influence cancer development. We do not know yet."

Dr Melin added that it was too early to use the results to offer guidance to doctors treating women for endometriosis. "Our hope is that doctors in general start to view the endometriosis disease as a serious disease that causes a lot of suffering to the patient and also may lead to cancer," she said.