Breast cancer is the most common cancer in women by a wide margin. An estimated 316,950 new cases will be diagnosed in American women in 2025 alone, nearly three times more than the second most common type. About 13 percent of women will be diagnosed with breast cancer at some point in their lives, with a median age of diagnosis around 64.
The Five Most Common Cancers in Women
Based on 2025 estimates from the American Cancer Society, the cancers diagnosed most frequently in women are:
- Breast cancer: 316,950 new cases
- Lung and bronchus cancer: 115,970 new cases
- Colorectal cancer: 71,810 new cases
- Uterine cancer: 69,120 new cases
- Melanoma (skin cancer): 44,410 new cases
Breast cancer accounts for roughly one in three new cancer diagnoses in women each year. Lung cancer, while less commonly diagnosed, is far more lethal. This distinction between the most common cancer and the most deadly one is important to understand.
Most Common Is Not Most Deadly
Lung cancer kills more women than any other cancer, despite being diagnosed less than half as often as breast cancer. The death rate for lung cancer is 30.2 per 100,000 women, compared to 10.4 per 100,000 for breast cancer. Colorectal cancer falls in between at 12.7 per 100,000.
The reason for this gap comes down to detection. Breast cancer is often caught early through routine screening, when treatment is most effective. Lung cancer, by contrast, tends to produce symptoms only after it has spread, which makes it harder to treat successfully. So while breast cancer is diagnosed far more often, it is also survived far more often.
Why Breast Cancer Is So Common
Breast tissue is highly sensitive to hormones, especially estrogen. The longer your body is exposed to estrogen over a lifetime, the higher the risk. This means factors like starting periods early, reaching menopause later, never having children or having a first child after 30, and using certain hormone replacement therapies all contribute. Obesity after menopause also raises risk because fat tissue produces estrogen.
Family history plays a role, but less than most people assume. Only about 5 to 10 percent of breast cancers are linked to inherited gene mutations like BRCA1 and BRCA2. The vast majority of women diagnosed have no family history at all. Age is the single biggest risk factor: most breast cancers develop in women over 50, and the risk continues to climb with each decade of life.
Screening Starts at 40
The U.S. Preventive Services Task Force updated its guidelines in 2024, now recommending that all women begin screening mammograms at age 40 and continue every two years through age 74. This was a notable change from previous guidance, which had left the decision to start screening in your 40s up to individual preference. The updated recommendation applies to all women at average risk, regardless of family history.
For women with a strong family history, known genetic mutations, or a history of chest radiation, screening often begins earlier and may include breast MRI in addition to mammography. If you’re unsure which category you fall into, a risk assessment tool can help you and your doctor determine the right approach.
Colorectal Cancer Is Rising in Younger Women
While breast cancer holds the top spot overall, one trend worth watching is the rise of colorectal cancer in younger adults. Diagnoses in people under 50 are increasing by about 1.4 percent per year, even as rates in older adults continue to decline by roughly 3.1 percent annually. This shift prompted screening guidelines to lower the recommended starting age for colonoscopies from 50 to 45.
The reasons behind this increase aren’t fully understood, but researchers point to rising obesity rates, more sedentary lifestyles, and changes in diet as likely contributors. Symptoms like persistent changes in bowel habits, rectal bleeding, or unexplained weight loss in younger women should not be dismissed as too unlikely to be cancer.
Cervical Cancer: A Success Story in Prevention
Cervical cancer was once one of the leading causes of cancer death in women. Today it ranks much lower, with about 7.6 new cases per 100,000 women each year. Two tools drove that decline: the Pap smear, which catches precancerous changes before they become cancer, and the HPV vaccine.
HPV vaccination has proven remarkably effective. Early vaccination reduces cervical precancers by 40 percent and cuts the overall risk of developing cervical cancer by more than 80 percent. The vaccine works best when given before any exposure to the virus, which is why it’s recommended for preteens, though it can be given through age 26 and in some cases up to 45. Cervical cancer is one of the most preventable cancers that exist, yet cases still occur primarily in women who were never screened or vaccinated.
What You Can Do to Lower Your Risk
No single action eliminates cancer risk, but several habits meaningfully reduce it across multiple cancer types. Maintaining a healthy weight is one of the most impactful, particularly after menopause, when excess body fat drives estrogen production and raises breast cancer risk. Regular physical activity, even moderate walking for 30 minutes a day, is independently associated with lower risk of breast and colorectal cancer.
Limiting alcohol matters more than many women realize. Even one drink per day modestly increases breast cancer risk, and the risk rises with each additional drink. Not smoking dramatically reduces the chances of lung cancer, which remains the deadliest cancer in women despite being largely preventable. And staying current with recommended screenings for breast, cervical, and colorectal cancer remains the most reliable way to catch problems early, when treatment works best and survival rates are highest.