The impact on early diagnosis and survival outcome of M-protein screening-driven diagnostic approach to multiple myeloma in China: a cohort study

Background: Most multiple myeloma (MM) patients in China were diagnosed only until severe complications occurred. The incidence of MM in China is 7.3 times lower than that of the United States, which could have been underestimated due to high rate of miss diagnosis and diagnostic delay in China. In Zhongshan Hospital Fudan University, serum protein electrophoresis (SPEP) is routinely incorporated into liver function test panel, and therefore providing us unique opportunities to carry out a hospital-population-based M-protein screening by SPEP and establish a screening-driven diagnostic approach. Methods: A retrospective cohort study analyzing data of patients screened by SPEP and diagnosed with MM from 2014 to 2017 was performed. We compared the baseline features and outcome of patients diagnosed via screen-driven approach and symptom-driven approach. We also analyzed the efficacy of M-protein screening. Results: A total of 690,000 people were screened and 335 eligible MM patients were identified, among which 151 of them were diagnosed via screening-driven approach. Compared to symptom-driven group, patients in screening-driven group had earlier ISS stage disease (P = 0.025), lower frequency of anemia (P = 0.000) and bone lesion (P = 0.012), and lesser number of end-stage symptoms (P = 0.000). M-protein screening approach demonstrated significantly (P = 0.029, HR: 0.415) better outcome (3-yr OS, 76.9%) than those in symptom-driven subgroup (3-yr OS, 46.6%) after being adjusted for age, gender, CRAB symptoms and ECOG score with a Cox proportional hazards model. Furthermore, the annual incidence of MM in Zhongshan Hospital screening population is 20.82/100,000, much higher than that in the whole China despite of selection bias. Conclusion: We concluded that the actual MM incidence in China may have been underestimated and M-protein screening in hospital population by SPEP is an effective approach to improve early diagnosis rate and outcome.