Time Trend of Multiple Myeloma and Associated Secondary Primary Malignancies in Asian Patients: A Taiwan Population–Based Study

Huey-En Tzeng,Chi-Jung Chung,Ya-Wen Cheng,Wen-Li Hwang,Cheng-Li Lin,Chih-Hsin Tang,Fung-Chang Sung,Chun-Hao Tsai,Robert K Hills

doi:10.1371/journal.pone.0068041

Huey-En Tzeng, Chi-Jung Chung + Show 7 more

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https://doi.org/10.1371/journal.pone.0068041

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Abstract

Studies involving second malignancies in patients with multiple myeloma are limited for the Asian population. Using data from population-based insurance claims, we assessed the risk of developing secondary malignancies after multiple myeloma, in particular hematologic malignancies. A retrospective cohort study was conducted in 3970 patients with newly diagnosed multiple myeloma from the registry of catastrophic illnesses between 1997 and 2009. A total of 15880 subjects without multiple myeloma were randomly selected as comparisons from the insured population, frequency-matched based on gender, age, and the date of diagnosis. The incidence of secondary malignancies was ascertained through cross-referencing with the National Cancer Registry System. The Cox proportional hazards model was used for analyses. The incidence of multiple myeloma in the insured population increased annually. The overall incidence of secondary malignancy was lower in the multiple myeloma cohort than in the comparison cohort (93.6 vs. 104.5 per 10,000 person-years, IRR = 0.90, 95% CI = 0.78–1.04). The incidence of hematologic malignancies was 11-fold greater for multiple myeloma patients (47.2 vs. 4.09 per 10,000 person-years) with an adjusted HR of 13.0 (95% CI = 7.79–21.6) compared with the comparison cohort. The relative risk of secondary malignancy was also strong for myeloid leukemia (21.2 vs. 1.36 per 10,000 person-years). Gender- and age-specific analysis for secondary hematologic malignancies showed that males and patients with multiple myeloma <60 years of age had a higher risk of secondary malignancy than females and patients with multiple myeloma >60 years of age. In conclusion, patients with multiple myeloma, especially younger patients, are at a high risk of hematologic malignancies.

Highlights

Multiple myeloma (MM), a malignant disorder of plasma cells, accounts for approximately 1% of all reported neoplasms and is the second most common haematologic cancer, accounting for 10%–15% of these malignancies [1,2]
The over all incidence of secondary malignancies in MM patients was slightly lower than the incidence of new malignancies in the comparison cohort, and not statistically significant (93.56 vs. 104.48 per 10,000 person-years, incidence rate ratio (IRR) = 0.90, 95% confidence interval (CI) = 0.78–1.04; Table 2)
The risk of myeloid leukemia was greatest for MM patients with an adjusted hazard ratio (HR) of 23.9

Summary

Introduction

Multiple myeloma (MM), a malignant disorder of plasma cells, accounts for approximately 1% of all reported neoplasms and is the second most common haematologic cancer, accounting for 10%–15% of these malignancies [1,2]. MM is a disease of the elderly, with an increase in the median age at diagnosis from 70 to 74 years over the last 50 years; only 15% of patients are ,40 years of age at the time of diagnosis [4,5]. The incidence of MM has increased over time. The reasons for the increase in the incidence of MM include a complete cancer registry report system, improved survival with new medical treatments, and the increasing elderly population with an longer life expectancy [4,5]. The objectives of the current study were to determine the time trends in the incidence of MM between 1997 and 2009, and to investigate the association between MM and secondary tumours in Taiwan

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