I had just read the article John Rock's Error by Malcolm Gladwell.
It piqued my interest as as a friend of mine has recently lost her battle to cancer.
It gives a layman's understanding of what is cancer:
"Cancer, after all, occurs because as cells divide and reproduce they sometimes make mistakes that cripple the cells’ defenses against runaway growth."
It talks about the female reproduction system and how John Rock, the inventor of the birth control pill thought that women would find it strange not to have monthly menstruation. How presumptuous! A man could never understand a woman.
I find the alternative argument based on evolution instead of theology more convincing. In the evolutionary case, a medical researcher Straussman went to South African to study the woman's reproduction system in pre-industrial era. Read this in the past, a woman only had about 100 menstruation cycle compared to the current 350 to 400 in her lifetime. It is due to demographic shift whereby women today do not have so much children (8 to 9 in the past) and also shorter period of nursing.
It also fills the information gap on women on the pill having a higher chance of having breast cancer. The reason is the the pill works by releasing the hormone progestin which leads the body to think that it is slightly pregnant. This helps to reduce the number of times the egg breaks into the ovarian walls and the sloughing off of the thickened uterus lining. On the whole, the risk of ovarian and endometrium cancer will be greatly lowered. However, whatever good the progestin does is undone as the same hormone is responsible for preparing the breast for child-birth. Again, the division and reproduction of cells heighten the risk of breast cancer.
I like the last segment which is an argument in logics on why Henderson and Pike do not believe that it is the environment that causes breast cancer:
"Henderson and Pike, however, became fascinated by a number of statistical pecularities. For one thing, the rate
of increase in breast-cancer risk rises sharply throughout women’s thirties and forties and then, at menopause, it starts
to slow down.
If a cancer is caused by some toxic outside agent, you’d expect that rate to rise steadily with each advancing year, as the number of mutations and genetic mistakes steadily accumulates. Breast cancer, by contrast, looked as if it were being driven by something specific to a woman’s reproductive years. What was more, younger women who had had their ovaries removed had a markedly lower risk of breast cancer; when their bodies weren’t producing estrogen and progestin every month, they got far fewer tumors.
Pike and Henderson became convinced that breast cancer was linked to a process of cell division similar to that of ovarian and endometrial cancer. The female breast, after all, is just as sensitive to the level of hormones in a woman’s body as the reproductive system. When the breast is exposed to estrogen, the cells of the terminal-duct lobular unit—where most breast cancer arises—undergo a flurry of division. And during the mid-to-late stage of the menstrual cycle, when the ovaries start producing large amounts of progestin, the pace of cell division in that region doubles."