Breast Cancer and Age: What’s the Connection?

Age is the strongest risk factor for breast cancer in women in the United States. The older a person is, the higher their risk of developing breast cancer. Most breast cancers are found in women aged 50 and older. 

Age is the main risk factor because the older we are, the more likely it is that our cells have gone under abnormal changes that led to mutations. This article will discuss the age connection to breast cancer risk, as well as other risk factors that you can change to lower your risk. 

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How Common Is Breast Cancer by Age?

Being diagnosed with breast cancer before age 40 is rare, and the chance increases with each decade of life. 

Breast Cancer Statistics

The National Cancer Institute estimates that 12.9% of women born in the United States will be diagnosed with breast cancer at some point in their lives. This gives the average American woman a 1 in 8 chance of experiencing breast cancer. It’s important to remember that each woman’s chance of not experiencing breast cancer is 7 in 8. Men born in the United States have a 0.13% chance of developing breast cancer. This translates to a chance of 1 out of 800.

The median age of diagnosis of breast cancer in the United States is 63 years. This median age varies by race and ethnicity. Black women tend to be diagnosed younger than white women, and the median age for Black women is 60 years old. While at much lower risk, the median age of diagnosis of breast cancer for men is 68 years. 

Risk of Breast Cancer by Age

A woman’s risk of developing breast cancer based on her age is as follows:

  • 30 years old: 0.49% or 1 in 204
  • 40 years old: 1.55% or 1 in 65
  • 50 years old: 2.4% or 1 in 42
  • 60 years old: 3.54% or 1 in 28
  • 70 years old: 4.09% or 1 in 24

About 5% of breast cancer cases occur in women under 40 years old. It may be more difficult to diagnose breast cancer in young women because their breast tissue is denser than that of older women. Young women and their doctors may also be more likely to ignore a breast lump because of their low risk. 

Breast cancer that occurs in young women tends to be more aggressive and less likely to respond to treatment. Women who are diagnosed with breast cancer before age 40 are more likely to have a genetic mutation that puts them at higher risk. Screening for the BRCA gene mutation may begin at age 25. 

Other signs for young women to be aware of include:

  • A lump (or lumps) in the breast
  • Nipple discharge
  • Focal pain
  • Skin changes on the breast

Mammogram screening is recommended to begin between ages 40 and 50 based on your individual risk factors. 

Breast Cancer Risk Factors

Your personal risk of developing breast cancer is unique to you and made up of several factors.

Things You Can Change 

Fortunately, there are risk factors for breast cancer that are under your control. These factors include:

  • Sedentary lifestyle: Women who are not physically active are at an increased risk of developing breast cancer. 
  • Obesity: Older women who are overweight or obese have a higher risk of being diagnosed with breast cancer. 
  • Hormone replacement therapy: Women who take hormones such as estrogen or progesterone for over five years during menopause are at higher risk of developing breast cancer. Women who take oral contraceptives may also be at higher risk. 
  • Alcohol use: A woman’s risk of breast cancer may increase with the number of alcoholic drinks she consumes.

Why Is Weight a Factor?

Women who are overweight or obese have higher levels of estrogen in their bodies. Even though the ovaries stop making estrogen after menopause, the hormone is still stored and produced in fat tissue. Estrogen causes certain types of breast cancer to grow and spread. Work with your doctor to develop a weight loss plan that fits your life, if necessary. 

Things You Can’t Change (Other Than Age)

One of the main risk factors is age, and the older we get, the higher the risk. Other risk factors that you cannot control include:

  • Genetic mutations: Changes in the genes, either inherited or acquired, increase your risk of developing breast cancer. Two genes that affect one’s breast cancer risk are BRCA1 and BRCA2. Mutations in these genes also raise the risk of ovarian cancer. It’s possible that up to 10% of breast cancers are caused by an inherited gene mutation such as the BRCA1 or BRCA2 genes. If breast cancer runs in your family, ask your doctor about meeting with a genetic counselor.
  • Reproductive history: Being exposed to reproductive hormones for long periods of time raises your risk of breast cancer. That is why women who experience early menstrual periods before age 12 or late menopause after age 55 are at increased risk. 
  • Dense breast tissue: Dense breasts tend to have more connective tissue than fatty tissue. This dense tissue can make it harder to visualize tumors on a mammogram.
  • History of breast disease: Women who have a history of breast cancer or noncancerous breast diseases like atypical hyperplasia or lobular carcinoma in situ can raise their risk of breast cancer. 
  • Family history: Having a family history of breast or ovarian cancer is associated with an increased risk of breast cancer. 
  • History of radiation therapy: Women who have been exposed to radiation to their chest or breasts before age 30 are at higher risk of developing breast cancer. 
  • Exposure to diethylstilbestrol (DES): We now know that women who took DES during their pregnancy to prevent miscarriage are at a higher risk of breast cancer. Women whose mothers took the drug during pregnancy are also at risk. This medication was frequently used from 1940 to 1971. 

Summary 

Age is a strong risk factor for breast cancer in women. The average American woman has a 1 in 8 chance of developing breast cancer at some point in her lifetime. Other risk factors that you cannot control include genetic mutations, reproductive history, dense breast tissue, family history, exposure to radiation, and exposure to DES.

Fortunately, there are risk factors that you can change by increasing your activity levels, maintaining a healthy weight, avoiding hormone replacement therapy, and reducing alcohol use. 

A Word From Verywell

As we age, we are more at risk of experiencing health problems. This is overwhelming and is often beyond our control. While age does raise the risk of developing breast cancer, there are steps that you can take to lower your risk. Talk with your doctor about your risk factors and how to address them. 

Frequently Asked Questions

  • Can a 20-year-old get breast cancer?

    Yes, while uncommon, it is possible for a 20-year-old to be diagnosed with breast cancer. The chances of developing breast cancer in your 20s, however, are about 0.06% or 1 in 1,732.

  • How fast can cancer grow?

    The rate at which breast cancer grows and spreads depends on several factors, including your type of breast cancer, how advanced it already is, your age, your menopausal state, and your medical history. Compared with many other types of cancer, breast cancer has a relatively low growth fraction, which means that the cancer cells do not reproduce rapidly. 

  • Is it normal for a teenage girl to have a lump in her breast?

    Anytime you detect a new lump in your breast, regardless of your age, see your doctor to be evaluated. A lump in a teenage girl is not likely related to cancer but should always be checked out.

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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. What are the risk factors for breast cancer?. Updated September 20, 2021. 

  2. National Cancer Institute. Breast cancer risk in American women. Updated December 16, 2020. 

  3. Susan G. Komen. Age. Updated June 8, 2021. 

  4. Cleveland Clinic. Breast cancer in young women (under 40). Updated September 18, 2019. 

  5. Yale Medicine. Too young to screen: Breast cancer in younger women. Updated September 28, 2020. 

  6. Cancer Treatment Centers of America. Breast cancer causes & factors that put you at risk. Updated September 21, 2021. 

  7. Breastcancer.org. Risk of developing breast cancer. Updated December 20, 2018.