Breast cancer… There are many contributing factors that increase the risk of breast cancer. Associate Professor Dr. Kamonrat Piboon, a specialist in breast cancer surgery, breast-conserving surgery, and breast reconstruction at Phyathai 1 Hospital, will answer questions about risk factors that many people wonder about to clarify concerns for all women.
1. Which type of bra increases the risk of breast cancer?
Wearing a bra does not affect the occurrence of breast cancer but helps maintain the shape of the breasts to prevent sagging. Choosing a bra that fits well with your body shape will help preserve the breast shape effectively. “Bras with underwire do not cause breast cancer,” but if the underwire does not fit the breast properly, it may cause pressure, pain, or inflammation.
2. Does drinking soy milk cause breast cancer?
Soy milk contains substances similar to female hormones but with effects almost 100 times weaker than estrogen. “Currently, there is no evidence that drinking soy milk or other soy products in normal amounts causes breast cancer.” Countries that commonly consume tofu, such as China and Japan, actually have lower rates of breast cancer than Western countries.
Theoretically, consuming tofu in women whose ovaries still produce hormones may reduce the risk of breast cancer because the weaker hormonal effect of tofu results in an overall reduced stimulation. However, those who have breast cancer should avoid or be cautious about consuming large amounts of tofu, especially those with hormone-responsive types of cancer.
3. Do chemicals from underarm antiperspirants stimulate breast cancer?
Currently, there is no evidence that using antiperspirants is related to breast cancer! Generally, “the substances used in antiperspirants control sweating and do not contain female hormones that stimulate breast cells.” Moreover, applying antiperspirant under the arms, not on the breasts, means the effect is mainly localized under the arms. The chance of absorption into the bloodstream or lymphatic system and then back to the breasts is very low.
4. Are large breasts more at risk of breast cancer than small breasts?
Breast cancer arises from abnormalities in the milk ducts or milk glands, and the amount of milk ducts and glands in large or small breasts is not significantly different. Therefore, “whether breasts are large or small, the risk of breast cancer is similar.” However, large breasts may be harder to palpate, making self-examination more difficult. Small breasts are easier to examine, but if cancer develops, it can spread to the skin or chest muscles more easily due to less breast tissue, and breast-conserving surgery may be more challenging.
5. Does mammography increase the risk of breast cancer?
There has been widespread sharing on social networks claiming that breast compression during mammography causes breast cancer, which is not true! “Breast cancer results from abnormal cell growth that cannot be stopped and is not related to breast compression.” Compression or strong impact can cause bruising or internal bleeding in the breast, but if a lump already exists, the impact may cause pain, leading to the mistaken belief that the impact caused the tumor.
What causes more concern than breast compression during mammography is the radiation used, which can stimulate cancer development. Radiation doses above 50 mSv may increase cancer risk, but the radiation dose used in mammography is low, about 0.4 mSv, compared to other types of X-rays. The radiation from mammography is comparable to natural background radiation of about 3-4 mSv per year. Therefore, one mammogram equals about 7 weeks of natural radiation or the radiation received on a round-trip flight between Bangkok and Chiang Mai. “Having a mammogram once a year likely provides more benefits than harm.”
“Having an annual check-up and mammogram, even when no lumps or symptoms are detected, increases the chance of finding breast cancer at an early stage, which improves the likelihood of complete cure.”
Associate Professor Dr. Kamonrat Piboon
Specialist in Breast Cancer Surgery
Breast Care Center, Phyathai 1 Hospital
