Second Primary Malignancies in Mantle Cell Lymphoma: A US Population-based Study

The risk of second primary malignancy (SPM) in mantle cell lymphoma (MCL) is not well-known. In this population-based study, we analyzed rates of SPM in adult patients with MCL.

We selected adult (≥18 years) patients with MCL as first primary malignancy diagnosed during January 1992 to December 2011 from National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) 13 database. We used multiple standardized incidence ratio (MP-SIR) session of SEER(*) stat software to calculate the risk of second primary malignancies.

Among 3,149 patients, 261 (8.29%) developed 287 second primary malignancies with observed/expected (O/E) ratio of 1.32 (95% confidence interval (CI=1.17-1.48, p<0.001). The median time to SPM from the time of diagnosis was 47 months (range=6 months to 17.91 years). The significant excess risks were observed for skin, excluding basal and squamous cancer, (N=22, O/E=2.24, CI=1.4-3.39, p<0.001), thyroid malignancy (O/E=3, CI=1.1-6.52, p<0.01), acute myeloid leukemia (O/E=7.74, CI=4.54-13.94, p<0.001), chronic lymphocytic leukemia (O/E=7.27, CI=4.44-11.23, p<0.001) and Non-Hodgkin's lymphoma (NHL) (O/E=3.79, CI=2.64-5.27, p<0.001). The risk of malignancies of brain, thyroid, rectum and anal canal were higher within the first two years of diagnosis of MCL. Risk of skin cancer, excluding basal and squamous cancer, was higher after two years of latency.

There is significantly higher risk of second primary malignancies in patients with mantle cell lymphoma compared to the general population. Patients may benefit from cancer-specific screening during follow-up.