It is a wonderful organ capable of transforming metabolized food into a liquid that contains everything that a newborn needs. Not only nutrients, but also other substances that provide protection against the adversities of starting to live in a more hostile environment than the comfortable float in the placenta.
In the breasts, protected by fat and supportive tissue, there are like bunches of grapes: they are the glands. The cells lining the alveoli make milk when the baby stimulates them after delivery. The fluid flows through the ducts to the nipple. In each period, when the uterus prepares to receive the fertilized ovum in the tubes, the cells of the mammary glands reproduce to be ready in case of pregnancy. The most are more taut and voluminous. In each cycle, due to the very nature of mitosis, there is a risk that some cells will mutate with carcinogenic potential. More when the breasts are young. Hence, one of the main cancer risks is early menarche. Another late menopause. However, if that breast, eager to breastfeed, does so within the first cycles, a phenomenon such as calming anxiety occurs and that woman is somewhat protected against cancer. Early menarche, late menopause, nulliparity, or older first child are risk factors for breast cancer. A hormone dependent cancer. And that is why harboring a lot of fat after menopause, the place where female hormones are produced, increases the risk of cancer; However, before menopause, when women have a different hormonal profile, they are elevated by thinness. Alcohol consumption and, marginally, sedentary lifestyle also increases the risk. There is no evidence that diet or tobacco affects them. As for hormonal treatments, estrogens with progestogens, the pill, increase the risk.
Breast cancer, today the most common in women, has helped us understand many things. In the early 1960s, a radiologist convinced a New York health plan to investigate the usefulness of mammography in the early detection of cancer. The statistician who examined the data, Levine, realized two things that are now laws: 1.-) That to know if the intervention is effective it is not worth counting survival, the variable most loved in the clinic. It is because it will always be increased because cancer is discovered earlier, but it does not ensure that early treatment has served: Mortality must be compared. 2.-) Fast-growing cancers, the most deadly, can appear between screenings while this will discover some slow cancers that would never reach the clinic. In breast cancer not less than 20%. Cancers that are treated as if they were fatal, with consequent deformation. It was precisely there that a lot of quality was gained. It was in Turin, in the 1970s, where they dared to treat small cancers with conservative surgery and showed that it was just as effective with radical surgery. Today it is done without income. Then the entire string of ganglia was still removed and the arm would swell and hurt. Being a chain, the first one is supposed to be affected if the others were. A method was designed to look at it with isotopes: it is the sentinel node that prevents lymphangitis. As it is a hormone-dependent cancer, it must have receptors for them to work. It was shown that when they appear in the surgical piece, a treatment with a drug that cancels them, called tamoxifen, improves survival. It is the first treatment against a target and not the only one. We have several biologic drugs that are highly effective.
All these advances, and some more that I do not review, have made many breast cancers cure. A cancer, almost the only one, of the upper classes. Good nutrition advances menarche and the social environment delays the age of the first childbirth. But if 50 years ago this cancer was rare in poor countries, changes in diet and culture accelerated its incidence. And they have no means of prevention and treatment: their mortality grows almost at the rate of incidence.