BETHESDA, MD — For 70 years, physicians and researchers have been aware of secondary primary malignancies (SPM) in patients with multiple myeloma. In the last decade, advances in treatment for MM have resulted in an increased incidence of SPMs in this population, but the impact on survival remains unclear.
Researchers at the Walter Reed Military Medical Center (WRMMC) in Bethesda, MD, and the David Grant USAF Medical Center in Fairfield, CA, tapped into the CancerLinQ registry created by the American Society of Clinical Oncology to identify patterns in SPMs in patients with MM and associated mortality. The team retrospectively analyzed records of patients diagnosed with MM between 2009 and 2021 in more than 100 U.S. oncology clinics and hospitals.
Of the 34,234 patients who met the inclusion criteria, 3,634 (10.62%) developed any SPM.
In a presentation at the 64th American Society of Hematology Annual Meeting in New Orleans on Dec. 12, John Cooper, MD, of WRMMC, noted the seemingly counterintuitive finding that MM patients subsequently diagnosed with an SPM had a 26% survival advantage. The data showed longer median overall survival, 130 months, for patients with SPMs than MM patients who did not develop a second malignancy, 103 months, (HR: 0.741, 95% CI 0.690-0.796, p<0.001).1
The apparent survival benefit was extended in patients subsequently diagnosed with nonmelanoma cutaneous cancers by 53%, breast cancer by 42%, prostate cancer 40%, non-Hodgkin lymphoma 30%, diffuse large B-cell lymphoma 29% and melanoma at 26% compared to those without SPMs. Other SPMs did not affect overall survival, including colorectal cancer, acute lymphoblastic leukemia and chronic lymphocytic leukemia.
Patients diagnosed with acute myeloid leukemia (AML), conversely, had a 52% increase in mortality risk and those who developed lung cancer following their MM diagnosis had a 37% increased in risk of mortality.
While the finding that some types of secondary primary malignancies were associated with increased overall survival, the research team noted that many factors likely affect that outcome. It “could reflect patients with more indolent disease biology or those who received better treatments, resulting in higher longevity and immortal time bias.”
In addition, “the finding that patients diagnosed with AML lived shorter, likely is indicative of dramatically worse outcomes of secondary AML in the MM population. The shorter survival of patients diagnosed with lung cancer may also represent a causal signal,” they observed. “The finding that both AML and lung cancer as SPMs resulted in shorter survival is consistent with what would be expected in the general population, and serves as a good internal control.”
- Cooper JD, Thornton JA, Gibson SJ, Pham K, Sunderland K, DeStefano CB. Survival of Patients with Multiple Myeloma Diagnosed with Second Primary Malignancies: An ASCO Cancerlinq Analysis. Abstract 4510. 2022 ASH Annual Meeting. Dec. 12, 2022.
