Pathfinders in oncology from the first clinical use of single-agent chemotherapy to the introduction of mammography.

During the period from 1942 to 1962, treatment attempts with single-agent chemotherapy such as nitrogen mustard and urethan gained limited application. However, the groundbreaking success with aminopterin in the treatment of patients with pediatric acute leukemia and methotrexate in the treatment of gestational choriocarcinoma established single-agent chemotherapy as a pioneering contribution to oncology. The landmark discovery that early-stage Hodgkin disease is curable with radiation made radiotherapy into an essential specialty of oncology. Although radical surgical treatment dominated the field of surgery, the excision of localized cancers with or without adjuvant radiation emerged as new modality in therapy. Cytopathology and surgical pathology became new fields in medicine and pathologists became an integral part of the preoperative, intraoperative, and postoperative care of patients with cancer. The discovery of multiple new drugs demonstrated promising results and widened the field of oncology from the laboratory to the clinic. In the etiology of cancer, precancerous conditions were named and carcinoma of the lung was definitively linked to cigarette smoking. All things considered, the progress made between 1942 and 1962 came about through the dedicated work of many individuals. However, there were 7 distinguished pathfinders (2 pathologists, 1 pediatric pathologist-oncologist, 1 radiation therapist, 1 physician-actuary, 1 gynecologist-oncologist, and 1 chemist) who, despite their different backgrounds, interests, and sex, made groundbreaking contributions to oncology.