People may also assume that finding a lump in their breast would be harder if you wear a triple-D cup compared to someone who wears, say, an A cup.
This article reviews the risk factors of breast cancer including gender, age, weight, family history, genetics, alcohol consumption, and dense breast tissue.
Breast Size and Breast Cancer Risk
There have been no large, peer-reviewed studies that support breast size as a factor in the development of breast cancer.
Obesity plays a significant role in the development of breast cancer, especially for post-menopausal women. Often, obese women have larger breasts than the average woman, which may suggest that those with larger breasts are at higher risk. However, it is more likely that weight or body mass index (BMI) is the risk factor rather than actual breast size.
Factors in Assessing Breast Cancer Risk
Beyond weight, there are key factors you should consider when assessing your breast cancer risk. Gender, age, family history, genetic predisposition, and alcohol consumption are a few known risk factors.
Gender and Age
Being a woman and growing older are the greatest risk factors for breast cancer. While it can occur at a younger age, most breast cancer is found in women 50 years and older.
Family History of Breast Cancer
Up to 10% of breast cancer cases are associated with family history. Research shows that having a first-degree relative (parent, sibling, or child) with breast cancer doubles your risk.
The risk increases more if your family member was young or male. There is also an increase in risk if second-degree relatives (aunts, uncles, nieces, nephews, grandparents, or grandchildren) from either side of your family have had breast cancer.
If you have any of these familial risk factors, talk to your healthcare provider. They may suggest more intensive breast screening (such as at an earlier age) or genetic testing.
Family members with multiple types of cancer First or second-degree family member with high-grade prostate cancer Multiple first or second-degree relatives with breast cancer Male family member with breast cancer More than one family member with the same type of cancer Family member with cancer in both breasts or ovaries Relative with both breast cancer and ovarian cancer
Alcohol Consumption
Research shows that women who drink a moderate amount of alcohol increase their breast cancer risk by approximately 10%. Because alcohol can increase estrogen levels, this is especially true for estrogen receptor (ER) positive breast cancer.
Heavy alcohol use can also directly damage deoxyribonucleic acid (DNA) in the cells of breast tissue. Damage like this can cause cells to multiply abnormally and at a heightened rate, giving rise to precancerous and cancerous tumors.
Genetic Predisposition
When a mutated gene has been passed down from a parent, including the father, it increases a woman’s chance of breast cancer. The most common genetic mutations associated with breast and ovarian cancer occur in the BRCA1 or BRCA2 genes. Typically, these genes help fight cancer by suppressing tumors. However, when they are mutated, it allows tumors to develop.
If genetic testing shows you have a mutation in one of the BRCA genes, your healthcare provider may recommend more frequent monitoring. They may also talk with you about preventative surgeries and medications.
Some groups are at a higher risk of BRCA mutations. One in 40 women of Ashkenazi-Jewish heritage has a BRCA gene mutation.
Breast Density
Breasts are made of glandular, connective, and fatty tissue. Glandular tissue is the part of the breasts that makes milk, while connective tissue holds the breasts in place. Those with dense breasts have less fatty tissue.
About 43% of women aged 40 to 74 have dense breast tissue, and women with dense breasts are at higher risk of developing breast cancer. Further research is needed to determine the exact cause.
Lastly, mammograms of dense breasts are harder to read and interpret than those of fatty breasts. Dense breast tissue and lumps both show up white on a mammogram, making it difficult to tell the difference.
Summary
While obesity and dense breasts increase the risk of breast cancer, there is no scientific evidence that breast size does.
Being a woman and getting older are two significant risk factors. Family history, genetic mutations, dense breasts, and alcohol intake can also increase risk. Those with a mutation in the BRCA1 or BRCA2 have a 50% chance of developing breast cancer than those who do not have the mutation.
A Word From Verywell
Having an increased risk for breast cancer can be overwhelming and scary. If you have any of these risk factors, talk with your healthcare provider. They may discuss the possibility of earlier mammograms or other imaging studies. Depending on the risk factor, they may also talk to you about genetic testing, preventative surgeries, or medications.
Many of these factors are beyond your control. However, you decrease the risks within your control by eating well, exercising, and avoiding smoking or excessive alcohol.
