Our cancer precursor project is intended to better understand how cancer arises by compiling a regularly updated spreadsheet of all distinct human cancers (now 1,232) and their precursors (now 191).
In part 1, we noted that the percentage of identified precursors varies widely by pathology subspecialty and we discussed precursors for subspecialties with epithelial sites (breast, head & neck, gyn, GI / liver, GU / adrenal and thoracic).
Epithelial malignancies, whether carcinomas or melanomas, typically have known risk factors associated with chronic inflammation, DNA changes, constitutive hormone production or immune system dysfunction. These risk factors promote changes in molecular pathways that produce intraepithelial neoplasia or dysplasia, in situ carcinoma and ultimately invasive malignancies.
In part 2, we discussed neuropathology related malignancies and their lack of precursors and speculated that contrary to current thinking, most nonepithelial malignancies may lack precursors. These nonepithelial malignancies often have no known risk factors and may arise from random processes or bad luck.
In the skin, of the 79 distinctive malignancies identified to date, only 6 malignancies have known precursors (5 melanocytic, 1 nonmelanocytic).
More text, images and links can be found at https://www.pathologyoutlines.com/dw/Cancerprecursorproject-characteristicsofpremalignantprecursorspart3adermatopathology.pdf.
Email any thoughts you have about this project to Nat@PathologyOutlines.com.
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