Carcinoma in situ, or stage 0 cancer, refers to precancerous cells in a limited area. It is not cancer and may not become malignant. Learn more.

But if they are not treated, in situ cancers can develop into invasive cancer. What is melanoma in situ? Melanoma skin cancer starts in cells called melanocytes. Melanoma in situ means the cancer ...

Researchers found that between 1975 and 2018, the adjusted lifetime risk of being diagnosed with melanoma in situ increased from 0.17% to 2.7% in White men and 0.08% to 2% in White women.