Pathfinders in oncology from the beginning of modern surgery of intracranial tumors to the introduction of the Pap smear

During the period from 1922 to 1942, several carcinogens were identified in coal tar, industrial oils, and petroleum, and radium was added to x‐ray as a potential carcinogen. It was proven that some viruses are capable of causing cancer, and the dependency of prostatic and mammary hyperplasia and carcinoma on naturally occurring hormones was established. Colon cancer was linked to hereditary and nonhereditary polyposis. A permanent place for...