BREAST & OVARY CANCER

Because women who develop breast cancer tend to have begun their menstrual periods at an earlier age than the average it has long been suspected that the disease originates in childhood. Studies have shown that, as a group, women who have breast cancer had above average birthweight, suggesting that the disease begins in the womb. In Finland researchers examined the size and shape of the pelvic bones in mothers whose daughters developed breast or ovarian cancer. In the past the pelvic bones were routinely measured in antenatal clinics because a small or deformed pelvis, the result of rickets in childhood, caused problems during childbirth. The width of the pelvic bones is established at puberty, when girl’s hips become broader. This reshaping of the hips depends on adequate nutrition, and on the hormone estrogen, which begins to circulate in the girls blood at that time. Broad hips in a woman may be a sign of high levels of estrogen in the blood which continue through reproductive life.

daughters of women with broad hips are at increased risk of cancers of the breast and ovary.The Finnish studies showed that the daughters of women with broad hips are at increased risk of cancers of the breast and ovary. One explanation of this is that, in the weeks after conception, an embryo is in direct contact with the mother’s body fluids, including the estrogen circulating in her blood. The stem cells for the breast and ovary are laid down at that time. If a mother has high levels of estrogen this could make the stem cells genetically unstable and prone to cancer in later life. Studies of life in the womb are now yielding new clues to the causes of a number of cancers.