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 diagnostic radiology was defined and radiation therapy advanced to preoperative and postoperative modalities using x-ray and radium. The trend toward the use of radical surgery for primary and metastatic cancers continued. Although several new radical surgical procedures were developed and advanced as far as the technical skills of surgeons and the anatomic setting permitted, several innovative, less radical procedures were introduced. In chemotherapy, the basic principle of the treatment of advanced cancers with hormones was inaugurated. Pathologists synthesized what was known in tumor pathology, named new microscopic entities, recognized carcinoma in situ, developed histologic grading and pathologic staging of cancers, and introduced aspiration cytology and exfoliative cytology as new fields in oncology. It is interesting that despite profound global economic, social, and political upheaval and wars and preparation for wars, writers and producers of musicals and movies presented more memorable works than ever before. In the fields of science and technology, particularly nuclear physics and chemistry, profound discoveries were made that became a permanent part of human life. The progress made in oncology between 1922 and 1942 came about through the dedicated work of many individuals. However, there were 7 pathfinders (3 surgeons, 2 pathologists, 1 physician-chemist, and 1 physician-cytologist) who, despite their widely diverse backgrounds, personalities, and interest, made outstanding contributions to oncology to the magnitude that they deserve a permanent place in the history of medicine and oncology.