By the end of World War I, the use of chemical weapons had resulted in over 1,000,000 casualties on both sides, including many disabled and wounded. Through a series of unintended events, these chemical weapons set in motion discoveries that led to the development of chemotherapy.

Following the war, medical researchers noticed that mustard gas destroyed lymphatic tissue and bone marrow, leading them to experiment with applying nitrogen mustard, a derivative of mustard gas, to shrink tumors in mice. By the beginning of World War II in the early 1940s, the first therapeutic experiments with the intravenous use of mustard agents were conducted in patients with cancer, providing temporary benefit. Several drugs derived from mustard agents are still used today to treat certain forms of cancer.

Matthew Naylor, PhD, president and CEO of the National WWI Museum and Memorial in Kansas City, MO, described these discoveries and their impact on modern cancer treatment during the opening keynote at the 2022 AACI/CCAF Annual Meeting.