Cancer Causes Stress, but Stress Does Not Cause Cancer!

Stress, considered a modern-age illness, is known to cause some diseases. Cancer is likewise often viewed as modern, making the two seem similar. However, historical evidence shows both have existed as long as humans. A causal relationship between stress and cancer has also been proposed. Cancer clearly causes sadness, anxiety and stress, an observable and demonstrable fact. But what about the reverse? Does stress cause cancer?

Although stress is proposed as a cause, many scientific studies show otherwise. “Does stress cause cancer?” particularly worries women and is a question frequently put to oncologists.

Scientists are conducting serious research based on several mechanisms.

These mechanisms include;

1. Stress causing immune suppression through glucocorticoid and catecholamine hormone release via pathways such as HPA axis and sympathetic nervous system activation,
2. And the suggestion that stress hormones may trigger cancer by regulating DNA repair, cancer cell growth and angiogenesis.
3. Alongside these physiological mechanisms, indirect behavioral changes such as weight gain, inactivity, smoking and alcohol use also raise suspicions of increased cancer risk.

However, an opposing argument is that stress may reduce breast cancer risk by suppressing estrogen secretion as a possible effect.

The Study

A new study published in the respected Breast Cancer Research on 15 July followed women older than 16 with no breast cancer history, totaling 113.000, from 2003 to 2012. A scale of different stress situations was created while considering known breast cancer risk factors such as age, sex, obesity and smoking. General stress over the past five years (often, sometimes, occasionally, never), serious stressors (bereavement, divorce or separation, job loss, serious illness), and loss of a parent before age 20 were regularly recorded.

Results

Of 106.612 people completing the study, 1783 developed breast cancer (approximately %2). Examination of stress data found 4 under constant stress and 4 experiencing at least one adverse event, such as bereavement or divorce, in the past five years. Comparing those who developed breast cancer with those who did not, no relationship between stress and breast cancer was found.

Individual stress factors also showed no significant association except one: a very small relationship among those losing their mother before 20. Excluding people whose mothers had ovarian or breast cancer again removed significance, suggesting a genetic basis. A very weak association between divorce and estrogen-negative breast cancer was also seen, but because it arose from only 25 individuals, claiming a risk factor was considered unfounded.

In conclusion; as this years-long study of 106.612 people shows, there is no relationship between stress and breast cancer, providing sufficient grounds to dispel unnecessary fears.