Breast cancer is the most common cancer among women in India and much of the world. In India, it has overtaken cervical cancer, which was, for many years, the most common cancer among Indian women. Therefore, it is natural to wonder why healthy women fall victim to breast cancer.
To understand this, it is important to understand what causes a cell to become cancerous. Every cell in the body contains DNA that carries genes that regulate all of its functions, including its growth. Damage to a gene is called a mutation and can result in uncontrolled growth and other changes that allow the damaged cell to move out of its normal location and develop the ability to grow in other parts of the body. Factors that increase the risk of a mutation, thus increasing the risk of cancer.
What are the causes of breast cancer?
Breast cancer occurs mainly due to mutations caused by the female hormone, estrogen. A large number of mutations are detected by the body and can never turn a normal cell into a cancer cell. However, some can escape this surveillance by the body’s immune system and turn into cancer cells.
It is natural, then, that situations that result in more or less exposure to estrogen result in a greater or lesser risk of cancer-causing mutations. Estrogen is produced in large amounts at the beginning of each menstrual cycle. Estrogen exposure is therefore increased in women in whom menstrual periods start early or menopause occurs late. This, in turn, increases the risk of breast cancer.
Factors that can increase the risk of breast cancer
1. Age and pregnancy
Since the menstrual cycle is interrupted in pregnant or lactating women, these reduce estrogen exposure and are protective. Therefore, a healthy woman who has not been pregnant has a higher risk of breast cancer compared to a woman who has given birth. This is also true for the woman’s age at first full-term pregnancy; younger age results in earlier termination of estrogen exposure and has a protective effect. Having multiple children and breastfeeding them also has a protective effect, reducing the risk of breast cancer.
Interestingly, in addition to the ovaries, fat cells also produce estrogen. This becomes relevant in women who have gone through menopause and the ovaries are not producing estrogen. Overweight and obese women therefore have higher estrogen levels after menopause compared to women of normal body weight. This increases your risk of developing breast cancer.
3. Alcohol consumption
Alcohol increases estrogen levels in the body and regular alcohol consumption leads to an increased risk of developing cancer in a healthy person. This is partially related to the estrogen pathway and can also occur unrelated to estrogen.
In addition to the above, some women may be inherently susceptible to cancer due to an abnormality in their genetic makeup. The most common of these are abnormalities in the BRCA 1 and 2 genes. The normal function of these genes is to repair damaged DNA. An apparently healthy person can carry mutations in any of the genes, usually inherited, which increases susceptibility to certain types of cancer, mainly breast and ovarian. In addition, mutations in other genes, such as TP53, PTEN, CDH1, ATM, CHEK2, or PALB2, also increase the risk of breast cancer. Such hereditary cancers account for about 5 to 10 percent of all breast cancers in India.
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How to avoid the risk of breast cancer
In conclusion, some causes of breast cancer are modifiable. Lifestyle habits can sometimes reduce the risk of breast cancer. Postmenopausal women who maintain a normal body weight and exercise regimen are at the top of this list. Restricting or avoiding regular alcohol intake is another. Some risk factors are subject to social norms, personal choice, and constraints, such as timing of first birth, number of children, and breastfeeding. However, some are not modifiable, such as an inherited risk.
Breast cancer treatment outcomes have improved significantly in recent years thanks to advances in detection, research, and treatment. Therefore, regular breast cancer screening based on age and risk profile should necessarily be part of a woman’s self-care regimen.