Cancerous breast lumps tend to feel firm and irregularly shaped, while many benign breast lumps are smooth and firm, or rubbery to the touch
Medically reviewed by Harold J. Burstein, MD, PhD
Although breast cancer is the most common cancer found in women, most breast lumps are not cancer. In fact, more than 80 percent of them end up being benign. But can a woman tell if a breast lump is cancer?
While the majority of lumps are benign, experts at the Susan F. Smith Center for Women’s Cancers at Dana-Farber say it is important for women to speak with their doctor if they notice changes to their breasts.
In general, cancerous lumps tend to be more irregular in shape. They may also feel firm or solid, and might be fixed to the tissue in the breast. They are also often painless. However, in a small percentage of women, a painful breast lump turns out to be cancer.
Cancer tumors versus cysts and fibroadenomas
Cysts, which are fluid-filled lumps, are common in the breast and are benign. They form when fluid builds up inside breast glands, and tend to be smooth or round. Fibroadenomas, which are benign tumors made up of glandular and connective breast tissue, are usually smooth and firm or rubbery to the touch. Both of these conditions tend to affect younger women; fibroadenomas are most common in women in their 20s and 30s, and cysts are most common in women under 40.
Despite these common descriptions, it is impossible to tell by touch whether a lump is cancer.
Always seek medical attention
“The key point is that a woman should seek medical attention for any concerning lumps in her breasts,” says Harold Burstein, MD, PhD, a breast oncologist with the Susan F. Smith Center. “Simple imaging techniques such as a mammogram or breast ultrasound can usually provide reassurance that the breast lump is benign, and if necessary, a breast MRI or biopsy can be used to evaluate whether the lump is cancerous.”