In a study of 16,331 patients in the California Cancer Registry, 5.7% developed a second primary malignancy more than 1 year after diagnosis. The 10-year cumulative incidence of developing any second primary malignancy was similar among patients who did and did not receive autologous stem cell transplant. The 10-year cumulative incidence of hematologic second primary malignancies was higher among autologous stem cell transplant recipients; however, mortality was driven by multiple myeloma and non-cancer causes.

Rosenberg AS, Brunson A, Tuscano J, et al. Effect of autologous hematopoietic stem cell transplant on the development of second primary malignancies in multiple myeloma patients. Blood Cancer J. 2021;11(1):5.