Breast cancer has become the most common cancer, worldwide, surpassing lung cancer for the first time sine 2020! Other than skin cancer, breast cancer is the most common cancer among American women. It is the leading cause of cancer death in developing countries and the second leading cause of cancer death in American women.
While breast cancer predominantly affects women, men also have a risk of developing breast cancer. Because breast cancer is primarily seen as a “woman’s disease”, men will typically ignore symptoms which can lead to potentially worse outcomes. With more than 3.8 million breast cancer survivors in the US, it is estimated that there will be an estimated 290,500 new diagnoses in 2022, with 2,710 of these diagnoses being in the male populations.
Risk factors - A risk factor is anything that can increase your chances of getting a disease such as cancer. It does not mean you will be diagnoses with the disease, but it helps to identify things which can be changed or avoided.
Lifestyle-related breast cancer risk factors include:
Drinking alcohol - those who drink 1 alcoholic drink per day have a 7-10% increase in risk, those who have 2-3 alcoholic drinks daily have a 20% higher risk.
Being overweight or obese - after menopause a woman’s ovaries no longer make estrogen and most estrogen will come from fatty tissue. Those with more fat tissue can raise estrogen levels, thereby increasing the chance of breast cancer. For women who are obese before menopause, the risk is a bit lower than those who put on weight after menopause.
Not being physically active - it is not clear how regular physical activity reduces breast cancer risk, but the evidence is there that it does. It is thought to be due to the effects on body weight, inflammation and hormone levels, especially in women past menopause.
Not having children - women who have not had children, or who have had children after the age of 30 are at higher risk for breast cancer. Having many pregnancies, or children at a young age reduces breast cancer risk.
Not breastfeeding - most studies suggest that breastfeeding will lower breast cancer risk, especially if one breastfeeds for a year or more.
Use of birth control and menopausal hormone therapy (PHT) - some birth control methods use hormones, and which may increase breast cancer risk.
Breast implants have not been linked with an increased risk of breast cancer, but have been linked with other types of cancer, including breast implant-associated anaplastic large cell lymphoma (BIA-ALCL).
Breast cancer risk factors you cannot change include:
Being born female - this is the main risk factor.
Getting older - as you get older your risk factor increases; most breast cancers are found in women 55 and older.
Inherited genes - about 5% of 10% of breast cancers are thought to be hereditary; the most common cause of hereditary breast cancer is a genetic mutation in the BRCA1 or BRCA2 genes. Other gene mutations which can lead to breast cancer can be found within the ATM, PALB2, TP53, CHEK2, PTEN, CDH1, and STK11 genes, but are far less common.
Having a family or personal history of breast cancer - most women who get breast cancer do not have a family history, but women who have a close blood relative with breast cancer has almost double the risk. A woman with two close blood relatives has three times the risk.
Race/ethnicity - Caucasian women are more likely to develop breast cancer than African American women, with the exception in women under the age 40 and African American women have a higher likelihood to develop breast cancer over Caucasian women. African American women are more likely to die from breast cancer at any age. Asian, Hispanic and Native American women have a lower risk of developing and dying from breast cancer.
Height - taller women have a higher risk of developing breast cancer. It is not clear why, but it is thought to do with factors that affect early growth, nutrition early in love and hormonal or genetic factors.
Having dense breast tissue - breasts are made of fatty tissue, fibrous tissue and glandular tissue. Dense tissue usually results from more fibrous and glandular tissue than fatty tissue, and it can make breast cancers more difficult to identify on mammograms.
Having certain breast conditions - those who are diagnosed with non-cancerous breast conditions are at a higher risk for developing breast cancer.
Starting menstrual cycles early and going through menopause later - these are thought to be due to a longer lifetime exposure to estrogen and progesterone.
History of radiation therapy to the chest, usually when the breasts are still developing.
Exposure to diethylstilbestrol (DES) - this was given to pregnant women from the 1940’s-1970’s to support a pregnancy; women whose mothers took took this while pregnant are also at increased risk.
Breast cancer early detection and diagnosis:
Many women with breast cancer have no symptoms which is why regular breast screening is so important. When found early, when the cancer is small and has not spread to other tissues, treatment is more successful. Having regular screenings, yearly mammograms, is the most reliable way to detect breast cancer early. New technology, digital breast tomosynthesis (three-dimensional mammography), appears to find more breast cancers and provides a more thorough exam in women with dense breasts, but it is not yet available in all breast imaging centers. Studies are being conducted to compare outcomes between the standard two-dimensional mammogram and the newer three-dimensional mammograms. Currently, both types of mammograms are in line with the current screening recommendations.
As always, it remains an important part of everyone’s habits to become familiar with their own body and tissues by self-examination. When you know what you look and feel like, you can be aware of changes and report them to your healthcare provider right away.
Resources:
Breast Cancer Research Foundation
American Cancer Society - Breast Cancer
Centers for Disease Control and Prevention
American Cancer Society - Recommendations for the Early Detection of Breast Cancer