Clinical Epidemiological Study on Multiple Myeloma in China: A 18-Year Retrospective Study in a Representative Center

Aims To make up the absence of the intact epidemiological data by investigating the clinical epidemiological features of Chinese patients with multiple myeloma in a representative center.

Methods: Medical records of patients with MM from January 1990 to December 2007 in our hospital were retrospectively studied, and divided into 2 groups (1990s and 2000s) to make a comparison.

Results:

1. Patients A total of 944 cases, who came from 26 Provinces, were enrolled during the past 18 years. 416 of the cases were diagnosed in 1990s, and 528 cases were enrolled after 2000.

2. Presenting and clinical features The median onset age was 58 years with a spike of 55–65 years.

   There were no significant differences in the median onset age and spike period between the 2 groups, while the percentage of younger (< 40 years) was lower and elder (≥70 years) was higher in 2000s than those in 1990s (10.2% vs 5.3%, 11.3% vs 15.1%). The ratio of male to female was 2.35:1 in 2000s and 1.72:1 in 1990s.The median onset course was 5 months in 1990s and 4 months in 2000s. The main presenting symptoms were bone pain (60%) and fatigue (50%), followed by infection (20%) and bleeding (6%).534 of 688 (77.6%) previously untreated patients were in D-S stage III. The staging distribution between the two groups were no obvious difference, but patients in 2000s had lower renal insufficiency than those in 1990s (16.32% vs 33.22%). The paraprotein typed was defined in 744 cases. 47.1% were IgG type followed by IgA type (23.9%), light chain type(20.6%). IgD type was identified in 3.2%, biclonal type in 0.97%, IgM type in 0.55% and nonsecretory type in 3.87% of patients. Among the 251 patients who had convention karyotype analysis, 61.4% were normal karyotype, followed by hypodiploidy (11.95%), hyperdiploid (8.8%). Complex karyotypes were seen in 15.9% of patients, □¢13 in 8.8%, abnormality of chromosome 14 in 10.4%. 19.0% of the 100 patients with the FISH detection of 13q⁻ (RB1 probe) was positive.

3. Treatment and response The main treatment regimens in 1990s were MP, M2 and VAD. The response rate (≥PR) were 48.6%, with 14.9% reached ≥VGPR. There were 438 cases accepted successive treatment mainly with MPT, VAD-T/DVD-T and VD(velcade + HD-DXM)-like regimens in 2000s. The total RR were 82.0%, with 31.0% of patients reached ≥VGPR. The total response rate especially ≥VGPR was significantly improved after 2000(P<0.01).

4. Follow-up and survival The median OS of patients in 1990s and 2000s was 30.5 and 42 months, respectively. The median OS of patients in 2000s was significant longer than those of 1990s (P<0.01)

5. Prognostic factors The multivariate analysis of the 438 patients after 2000 indicated that β2-macroglobin, lactic dehydrogenase, 13q⁻ had independent prognostic value for survival. The International Staging System and Durie-Salmon Staging System were effective for Chinese myeloma patients.

Conclusions

1. The number of patients admitted to hospital and the percentage of patients received successive treatment are increasing after 2000.

2. Compared with patients in western countries, Chinese MM patients had some specific features: younger onset age, longer course before diagnosis, more invasive performance, advanced clinical stage, more unfavorable prognostic factors.

3. The OS of patients in China was relative shorter than those reported in the western countries during the same period. The OS duration was significantly prolonged after the year 2000 with the application of thalidomide, bortezomib, and autologous haemopoietic stem cell transplantation.

4. The main unfavorable prognostic factors of Chinese patients were similar to that of the western patients.