Second Primary Malignancy Risk in Multiple Myeloma from 1975 to 2018

Area of Science:

• Oncology
• Epidemiology
• Hematology

Background:

• Improving survival for multiple myeloma (MM) patients has raised concerns about the risk of developing a second primary malignancy (SPM).
• Understanding the epidemiology and outcomes of SPMs in MM survivors is crucial for patient management and long-term care.

Purpose of the Study:

• To evaluate the risk and survival associated with second primary malignancies (SPMs) in multiple myeloma (MM) survivors.
• To identify factors influencing SPM occurrence and survival in the MM survivor population.

Main Methods:

• Utilized the Surveillance, Epidemiology, and End Results (SEER) 9 Registry Database (1975-2018).
• Calculated standardized incidence ratios (SIR), absolute excess risk (AER), and cumulative incidence (CMI) for SPM.
• Employed hazard ratios (HRs) for survival analysis and conducted subgroup analyses by race, sex, age, diagnosis time, and SPM site.

Main Results:

• Among 43,825 MM patients, 7.1% developed 3407 SPMs.
• MM patients had a decreased risk of solid tumors (SIR = 0.93) but an increased risk of hematological malignancies (SIR = 1.90).
• Ten-year CMI for SPM was 7.38% (6.11% solid, 1.27% hematologic). Age, sex, race, and diagnosis time were associated with SPM risk. SPM patients had longer survival post-MM diagnosis (HR = 0.67).

Conclusions:

• Multiple myeloma survivors exhibit differential risks for SPMs, with a notable increase in hematological malignancies.
• Age, race, and sex are significant predictors of SPM risk in MM survivors.
• Site- and time-specific surveillance strategies are recommended for monitoring SPMs in high-risk MM patient populations.