kartsinoomid

Kartsinoomid, commonly translated as carcinomas, are cancers that originate in epithelial cells, the tissues that line the surfaces and cavities of organs and form the skin. These cells create a protective barrier and participate in absorption, secretion, and sensation. Carcinomas are by far the most common type of cancer, accounting for a large majority of malignant tumors worldwide, with prevalence varying by organ site and population.

Subtypes include squamous cell carcinoma, which arises from squamous epithelium; adenocarcinoma, from glandular epithelium; basal cell carcinoma, from the basal layer of the epidermis; and transitional cell carcinoma, from transitional epithelium such as in the urinary tract. Carcinomas can develop in many organs, most notably the skin, lungs, breast, colon, prostate, and pancreas, as well as the esophagus and stomach.

Causes and pathogenesis are driven by genetic and epigenetic alterations accumulated in epithelial cells, often influenced by environmental factors. Common risk factors include tobacco use, ultraviolet radiation, chronic infections (such as HPV, hepatitis B and C, or H. pylori), dietary factors, and certain occupational exposures. The exact driver mutations vary by carcinoma type and site and can affect pathways controlling proliferation, apoptosis, and cellular differentiation.

Diagnosis relies on imaging and clinical assessment, with confirmation by biopsy and histopathological examination. Immunohistochemistry and molecular testing help classify subtypes and guide treatment. Staging uses the TNM system to assess tumor size, nodal involvement, and distant metastasis, guiding prognosis and therapy.

Treatment depends on type and stage and may include surgery, radiation therapy, chemotherapy, targeted therapies, and immunotherapy. Prognosis varies widely; early-stage carcinomas amenable to local treatment have favorable outcomes, while advanced or high-grade tumors carry higher risks.