Does a Bad Mood Cause Breast Cancer? What Factors Are Related to Breast Cancer?

I am often asked: can a bad mood, being easily angered or irritable, or tense interpersonal relationships, cause breast cancer? This is a question many women care about, and a great many TCM books also name a bad mood as the chief culprit behind breast cancer. Ancient TCM often held that a woman who "did not get along with her parents-in-law" would develop "ru yan" (breast rock/breast cancer); some TCM writers repeatedly mention that widows, nuns, and other women without a male partner are more prone to breast cancer. So are these claims correct?

The answer is no. To date, scientists have conducted several large-scale investigations of this question, and not a single one has produced strong evidence supporting these views. So women with a gloomy mood or heavy burden of pressure need not worry that this will cause them to develop breast cancer.

Women are indeed more emotional than men in handling many matters, and women develop breast cancer at a rate hundreds of times higher than men (it should be noted that men, too, can get breast cancer). This leads many people to wrongly conclude that women's emotionality is one of the chief causes of breast cancer. In fact, the reason women are more susceptible than men is that their breast tissue is more developed and, over a lifetime, is long exposed to estrogen, making them more prone to breast cancer.

That said, emotionality does affect a woman's relationships with those around her. After breast cancer is diagnosed, patients with poor social support receive less help than those with strong relationships, and this does affect quality of life and survival. So women should still try to overcome their character flaws and maintain good relationships.

What, then, actually raises a woman's risk of breast cancer?

First among them is age: the older a woman is, the more likely she is to develop breast cancer. The rising incidence of breast cancer in modern society has a great deal to do with increasing life expectancy. Young women rarely get breast cancer; women over 50 are more susceptible.

Next are estrogen and progesterone. A woman's whole life is influenced by these hormones. Imbalanced endocrine function causes many problems, and women with excessive expression of estrogen and progesterone are more prone to breast cancer. Women who have an early menarche (first menstrual period) and a late menopause (last menstrual period) have a higher risk than women with later menarche and earlier menopause.

The generally accepted normal age of menarche is 13–14, and of menopause 50–51. If menarche comes early and menopause late, the breast is exposed to estrogen stimulation for a longer portion of life, raising the risk of breast cancer.

Obesity is also a high-risk factor. Excess fat promotes estrogen secretion and stimulates the breast, and this stimulation raises the risk of breast cancer. So women should control their weight not just for beauty but, more importantly, for health.

In recent years, breast cancer has become more and more common among urban Chinese women, and patients are getting younger. This is closely related to over-nutrition and high body fat among urban women. The young breast-cancer patients I have seen were mostly overweight.

Women with a family history of breast or ovarian cancer are also more susceptible. Women with breast or ovarian cancer on either the paternal or maternal side should be on guard. Certain genetic mutations (such as BRCA1 and BRCA2) cause breast and ovarian cancer.

Women with a family history may, if finances allow, undergo genetic testing to see whether they carry BRCA1 or BRCA2 mutations. If a mutation is present, they should take preventive measures against breast and ovarian cancer. Of course, BRCA1 and BRCA2 mutations are not the whole hereditary story; half of breast-cancer patients with a family history still have no identifiable cause. There may be other breast-cancer-related genes that scientists have not yet discovered.

Smoking and drinking both raise the risk of breast cancer, so quitting smoking and limiting alcohol is a responsible approach to one's health. In addition, a sedentary lifestyle also raises the risk; increasing physical activity not only lowers the chance of breast cancer but also strengthens immunity.

Breast-cancer patients also have a higher risk of developing a second breast cancer (not a recurrence of the original), which may be related to their genes and long-term lifestyle.

Women with benign breast nodules also have a higher risk of breast cancer; some cystic nodules can undergo malignant transformation. Women whose breasts have abundant connective tissue and relatively little fat are more prone to breast cancer. So women with benign breast nodules should seek timely treatment, adjust their lifestyle, stop smoking, limit alcohol, control weight, and have regular check-ups to lower their risk.