And take note: Some people don’t have any noticeable signs in the early stages of breast cancer, Monique Gary, DO, a breast surgical oncologist at St. Luke’s Cancer Care Associates Surgical Oncology, in Pennsylvania, tells SELF. “Lumps from breast cancer can happen in any part of the breast or in the armpit but most commonly occur in the outer quadrants of either the right or left breast,” Carmen Calfa, MD, a breast medical oncologist at Sylvester Comprehensive Cancer Center in the University of Miami Health System, tells SELF. Take note: In young people, especially, breast cancer lumps can look similar to fibrocystic breast changes, or noncancerous lumpy or ropelike breast texture caused by hormonal changes around your period.