Diagnosing Breast Cancer

The outlook for women diagnosed with breast cancer has been gradually improving, with significant progress made in recent decades. Nonetheless, despite medical advances, breast cancer causes the greatest number of cancer-related deaths among women. In 2024, it is estimated that 694,000 women died from breast cancer. 

Diagnosing the disease early and getting state-of-the-art treatment are the most important strategies to save the lives of patients. More than 90 percent of women diagnosed at the earliest stage survive the disease for at least five years, according to Cancer Research UK.

Prevention and Detection

Risk increases with age, with most breast cancers being found in women aged 55 and older. About 5 to 10 percent of breast cancer cases are thought to be hereditary, meaning they result directly from gene changes (mutations) passed on from a parent.

Another risk factor is breast density. Dense breasts have relatively high amounts of glandular tissue and fibrous connective tissue and relatively low amounts of fatty breast tissue. Dense breasts are common. Nearly half of all women who are 40 and older who get mammograms are found to have dense breast tissue.

Women with dense breasts have a higher risk of breast cancer, and the risk rises with increasing density. Also, mammograms can be harder to read in women with dense breasts, which means cancer is more likely to be missed or detected only later, at an advanced stage. Therefore, breast density is an important risk factor for doctors to consider when deciding whether a patient should have additional screening examinations.

Diagnosis and breast cancer screening options

The most common symptom of breast cancer is a new lump or mass, but other symptoms are also possible. Any change in breast tissue should be checked by a health care provider. However, many women with breast cancer have no symptoms. This is why regular breast cancer screening is important, especially for women at high risk.

Different tests can be used to look for and diagnose breast cancer. If a doctor detects an area of concern on a screening test (a mammogram), or if there are symptoms that could indicate breast cancer, more tests will be needed to get an accurate diagnosis.

For example, contrast-enhanced X-ray mammography and breast MRI (magnetic resonance imaging) may reveal additional breast cancers which could be missed by standard mammography, especially in women with high breast density.