Although modern medicine has not yet been able to conclude the cause of breast cancer, there is evidence that estrogen hormone (Estrogen) which is the female sex hormone in women’s bodies, stimulates breast tissue cells to divide and increase in number Normally, the body relies on the hormone Estrogen for various changes during reproductive stages such as puberty, menstruation, pregnancy, and menopause. It can be said that nature has designated the hormone Estrogen as the female sex hormone, playing an important role in the body’s functions to sustain reproduction.
Therefore, it can be said that factors associated with high levels of estrogen hormone in the body are considered important risk factors for breast cancer.
This section will present risk factors for breast cancer, which can be divided into 2 groups:
1. Risk factors that can be avoided or controlled
- Obesity : Obesity in postmenopausal women, even though the ovaries have stopped producing estrogen, there is still a low level of hormone produced by the fat tissue in the body. Therefore, obesity increases estrogen levels in the body, increasing the risk. Obesity in women who are still menstruating is not considered a risk factor; on the contrary, obesity may reduce the risk of breast cancer in menstruating women.
- Diet : Consuming plant-based foods, vegetables, and fruits while avoiding fatty foods and meat can help reduce the risk of breast cancer.
- Exercise : It is recommended to exercise regularly for 45-60 minutes, 4-5 days per week.
- Alcohol consumption
- Smoking
- Taking oral contraceptives
- Hormone supplementation in menopausal women
- Stress
2. Risk factors beyond control
- Age : Increasing age is a basic risk factor for cancer in general, not specific only to breast cancer.
- Genetics: All types of cancer are considered genetic diseases caused by mutations in genes located in the DNA strands inside cells. These gene mutations may occur from
1. Inherited from parents (hereditary)
2. Occurring spontaneously later (sporadic) such as exposure to various carcinogens in the environment
The term “gene” refers to the genetic code of living organisms (whether plants or animals). Genes are responsible for producing proteins in the body. If there is an abnormality or mutation in a gene, the body will produce abnormal proteins from the defective gene. These abnormal proteins will then perform abnormal functions. In cancer cases, abnormal proteins are often those involved in controlling cell division, such as enzymes that stimulate cell division processes including Growth factors, Growth factor receptors Ligands or enzymes that inhibit (inhibit) cell division processes. In breast cancer, genes related to breast cancer have been identified, notably BRCA1 and BRCA2 which are tumor suppressor genes controlling cell division. People with mutations in these genes have a 70-80% lifetime risk of developing breast cancer and can pass these genes to their offspring.
For breast cancer, only a small portion of patients have hereditary causes. Most patients develop cancer spontaneously without any family history of breast cancer, as explained below.
1. About 10% are clearly hereditary breast cancer (Hereditary breast cancer) with BRCA genes inherited from the family
- It is definitely hereditary if there are direct relatives with the disease, which is considered high risk. Such individuals should see a doctor for risk management because every cell in their body carries this defective gene, increasing the chance of cancer in any organ related to this gene, commonly the breast, ovary, uterus, colon, pancreas, and prostate in men.
- There is no data on how common this gene is among Thai people, but it is prevalent among Ashkenazi Jews (Ashkenazi Jews)
- Among Thai people, it is believed to be not very common, estimated at about 5-10 percent of the population
- In practice, patients suspected of having this type are frequently encountered.
- Treatment for patients suspected to be in this group is more specialized than for general patients because many considerations must be made, including treatment options such as surgery type, medication, monitoring for cancers in other organs, and also treatment for family members.
2. About 20% are familial breast cancer, related to having family members with any type of cancer (Familial breast cancer)
- Often involves abnormalities in genes related to various cancers inherited from the family.
- Several known genes cause instability in the DNA strands, leading to mutations in other genes more easily, making the person more susceptible to cancer.
3. About 70% are sporadic breast cancer with no hereditary history (Sporadic breast cancer)
- Gene mutations related to breast cancer occur later and are not inherited from the family.
- Often related to exposure to carcinogens or lifestyle risks.
- Depends on various risk factors for breast cancer, including
- Early menarche before age 12 years
- Late menopause after age 55 years
- Late first childbirth after age 30
Pol. Lt. Col. Dr. Hasan Muhammad
Specialist in Surgical Oncology
Raktaen Breast Center, Phyathai 1 Hospital
