The impact of prior malignancies on second malignancies and survival in MM patients: a population-based study

Abstract

Abstract: In the present study, we aimed to evaluate 2 hypotheses. First, we hypothesize that prior malignancy is a proxy for genetic susceptibility that could be a risk factor for subsequent malignancy development in multiple myeloma (MM) patients. Second, we hypothesize that survival after MM is influenced by a prior malignancy. All patients diagnosed with MM from 1 January 1973 to 31 December 2010 were identified from the Swedish Cancer Register. Cox regression model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) where prior malignancy was compared in MM patients who developed a subsequent malignancy and MM patients who did not. In another Cox regression model, survival was compared in MM patients with and without a prior malignancy diagnosis. A total of 19 791 patients were diagnosed with MM. Patients with a prior malignancy diagnosis had a significantly increased risk of developing a subsequent malignancy compared with MM patients without (HR 1.42, 95% CI 1.23-1.65, P 1 prior malignancy reduces survival even further.