rintasyöpätyyppien

Rintasyöpätyypit refers to the classification of breast cancer based on its cellular origin and characteristics. Understanding these types is crucial for diagnosis, treatment, and prognosis. The primary distinction is between non-invasive and invasive breast cancers.

Non-invasive breast cancers, also known as in situ carcinomas, are confined to the milk ducts or lobules where they originated and have not spread into surrounding breast tissue. The two main types are ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). DCIS is considered a pre-cancerous condition where abnormal cells are found within the milk ducts. LCIS is a marker of increased risk for developing invasive breast cancer in either breast.

Invasive breast cancers have spread beyond the milk ducts or lobules into the surrounding breast tissue. The most common type is invasive ductal carcinoma (IDC), which begins in the milk ducts and then breaks through the ductal wall, invading nearby tissue. Invasive lobular carcinoma (ILC) originates in the lobules and then invades the surrounding tissue. Other less common types include inflammatory breast cancer, Paget's disease of the nipple, and rare subtypes like medullary, tubular, mucinous, and papillary carcinomas.

Further classification involves molecular subtypes based on the presence of hormone receptors (estrogen receptor, ER, and progesterone receptor, PR) and the human epidermal growth factor receptor 2 (HER2) protein. Luminal A cancers are ER-positive, HER2-negative, and typically slow-growing. Luminal B cancers are ER-positive and can be HER2-positive or negative, and tend to grow faster. HER2-enriched cancers are HER2-positive, and can be ER-positive or negative. Triple-negative breast cancers are ER-negative, PR-negative, and HER2-negative, and often more aggressive. This subtyping guides treatment decisions, particularly regarding hormone therapy and targeted therapies.