The most common time to get breast cancer is in older women, with about 80% of cases occurring after age 50, and the risk increasing significantly with age, peaking around 70-74 years old. While the majority of diagnoses are in older adults, breast cancer is still the most commonly diagnosed cancer in younger women (under 40), though at lower rates, and is a leading cause of cancer death in that group. The average age for diagnosis is around 61-62 years old.
Risk factors you cannot change
The risk for breast cancer increases with age. Most breast cancers are diagnosed after age 50. Genetic mutations. Inherited changes (mutations) to certain genes, such as BRCA1 and BRCA2, increase risk of breast and ovarian cancer.
About 90% of cancers are caused by environmental and lifestyle factors, not genetics, including smoking, poor diet (red meat, fried foods), alcohol, sun exposure, pollutants, infections, obesity, and inactivity; only 5–10% are due to inherited genetic defects, with most cancers arising from lifestyle-induced genetic mutations. Tobacco alone accounts for about a third of cancer deaths, while diet, obesity, and inactivity contribute significantly, with controllable factors being key to prevention.
The older a woman is, the more likely she is to get breast cancer. Rates of breast cancer are low in women under 40. About 4% of women diagnosed with breast cancer in the U.S. are younger than 40 [6]. Rates begin to increase after age 40 and are highest in women over age 70 (see Figure 2.1 below).
The most common sign of breast cancer is a lump or mass. It is usually hard, painless, and has uneven edges. Some lumps, however, can be soft and rounded. If you find one we recommend you contact your physician — a primary care doctor or a gynecologist — to have the lump evaluated.
The "2-week rule" for breast cancer (and other cancers) is a UK-based initiative, now largely replaced or evolved, that aimed to get patients with suspected cancer seen by a specialist within two weeks of a GP referral to speed up diagnosis, reduce anxiety, and improve outcomes, although it led to increased urgent referrals and longer waits for non-urgent cases. It required urgent referral if certain suspicious symptoms (like persistent breast changes, nipple issues, or a lump) were present, ensuring quick specialist assessment and investigation, though it's important to remember most lumps are benign.
Signs and symptoms:
Rates of breast cancer in the U.S. vary by race and ethnicity. Non-Hispanic white women and non-Hispanic Black women have the highest incidence of breast cancer (rate of new breast cancer cases) overall [336]. Hispanic women have the lowest incidence (see Figure 2.3 below) [336].
The 5 key warning signs of breast cancer often involve changes like a new lump or thickening, a change in breast size or shape, skin changes such as dimpling or redness, nipple changes like inversion or discharge, and persistent pain or swelling in the breast or armpit, though many symptoms can overlap, and you should see a doctor for any new or unusual breast change.
10 tips for breast cancer prevention
Cervical cancer is one of the most preventable cancers thanks to the HPV vaccine. HPV, or the human papillomavirus, causes 99% of all cervical cancers. The HPV vaccine, which is given in 2 doses, targets 9 different types of the virus.
General risk factors
Age – the risk of developing cancer increases as you get older. Lifestyle factors – these include smoking, your weight, your diet, how active you are, sun exposure and sunbed use, and how much alcohol you drink. You can read more about how to reduce your risk below.
Lung and bronchial cancer causes more deaths in the U.S. than any other type of cancer in both men and women.
Overall, women who get regular exercise have a 10%-20% lower risk of breast cancer than women who aren't active [139-146]. This benefit is seen most clearly in postmenopausal women, but study findings also show a benefit in premenopausal women [139-146].
The earliest stage of breast cancer, Stage 0 is non-invasive, meaning it hasn't spread outside of its original location in the breast tissue, and is highly treatable when detected early. If left undetected or untreated, however, it can spread into surrounding breast tissue.
It's likely that breast cancer happens through a complex interaction of your genetic makeup and the world around you. Healthcare professionals know that breast cancer starts when something changes the DNA inside cells in the breast tissue. A cell's DNA holds the instructions that tell a cell what to do.
These lifestyle choices, including smoking, drinking alcohol, and eating poorly may all raise your risk. Regular physical activity and maintaining a healthy weight are effective methods to lower your risk. This disease may also arise as a result of certain birth control methods and hormone replacement therapy.
5 Symptoms of Cancer You Might Be Ignoring-But Shouldn't!
Signs and symptoms suggestive of breast cancer: Unexplained discrete breast or axillary lump, ulceration, skin dimpling, breast distortion. Bloody or serous unilateral nipple discharge. Persistent nipple eczema, nipple ulceration, new nipple retraction/distortion.
Here are some tips:
You can't change some factors, such as getting older or your family history, but you can help lower your risk of breast cancer by taking care of your health in the following ways: Keep a healthy weight. Be physically active. Choose not to drink alcohol, or drink alcohol in moderation.
A study published in Nature last fall suggests that breast cancer is slightly more common on the left side of the body than it is on the right. That same study also indicates that left-sided breast cancer is more aggressive and associated with poorer treatment outcomes.
Conclusions. Qualitative analysis of articles has revealed a possible association between stress and cancer, especially regarding stressful life events.
Symptoms (beyond lumps) to look for include:
Commonly developing from the mammary glands or ducts, such malignant lumps generally (about 50 percent) appear in the upper, outer quadrant of the breast, extending into the armpit, where tissue is thicker than elsewhere.