Clinical Presentation, Prognostic Factors and Treatment Outcome of Multiple Myeloma (MM) in African American (AA) Patients.

AAs have the highest incidence of MM among all racial groups. The impact of race on disease presentation and outcome is the focus of this retrospective study. We analyzed 118 patients of 200 AA patients evaluated at our center from 1998 to 2006. The median age was 54 yrs (range: 28–75); 12 (10%) were younger than 40 yrs. Main presenting symptoms included pain (n= 60, 51%), spinal cord compression (n=9, 8%) and fatigue (n=26, 22%). Eleven patients (9%) were diagnosed following routine blood work and 8 (7%) progressed from prior MGUS. Four patients, all < 41 yrs, had plasma cell leukemia plus MM. MM subtype included IgG (n=77, 66%), IgA (n=19, 16%), light chain only (n=16, 14%) and non–secretory (n=4, 3%). Lytic bone disease was present in 67% of the patients; 19% had hypercalcemia. Patients presented with hemoglobin < 8 g/dl (n=33, 28%), creatinine > 2 mg/dl (n=32, 28%), albumin < 3.4 g/dL (n=71, 63%) and B2M > 5.5 g/mL (n=32, 28%) and > 3.5–5.5 (n=19, 17%). Ten patients required Hemodialysis, including 3 at initial presentation. Eighty-eight percent had Durie/Salmon stage III. Cytogenetics samples were available for 100 patients; the median number of samples was 4 per patient (range: 1–15). Abnormal karyotype was detected in 29% of the first sample and in 27% of the patients on follow samples. Hyperdiploid karyotype was seen in 16% of the patients and hypodiploid in 6%. Complex abnormalities of chromosomes 1, 3, 8, 9, 11, 13, 14 and 17 were detected in 17, 10, 5, 6, 6, 14, 6, 7 of the patients, respectively. Induction therapy included dexamethasone (n=21, 18%), dexa/thalidomide (n=29, 25%) and various chemotherapy regimens including MP, VAD, DT-PACE, bortezomib (n=65, 55%). Eight-eight patients (75%) received high dose chemotherapy (transplant) at a median of 0.7 yrs (range: 0.1, 9.2 yrs) after diagnosis; however, only 45% were transplanted within 12 months of diagnosis. After transplant 22% of the patients received consolidation chemotherapy and 40% received thalidomide maintenance; 10% had tandem transplants. A complete, near complete or partial response was achieved by 9 %, 1% and 66% of the patients before transplant and by 26%, 22% and 45% after transplant, respectively. Median event free survival after transplant was 1.9 yrs (CI: 1.5–2.7). Median survival from transplant was 4.6 yrs (CI: 3.9–7.6) and 6.7 yrs (CI: 5–8.6) from diagnosis. Median survival after relapse was 2 yrs (CI: 1.1–3) for transplanted patients. The median follow up for entire group (n=118) was 4 yrs and the median survival from diagnosis was 7.4 yrs (95% CI: 5–8.6 yrs); median survival has not been reached yet for non-transplanted nor MGUS patients. A Cox regression model revealed that B2M and abnormalities of chromosome 13 were predictive of survival (p=0.0001, 0.0017, respectively). These data were compared to the landmark analysis of newly diagnosed MM patients by Kyle et al. (2003). AA patients presented at a younger median age 54 yrs with 10 % < 40 yrs compared with 67 yrs and 2% for Caucasians. AA patients had more severe anemia and renal failure compared to Caucasians (28 vs 7% and 28 vs 18%, respectively). In conclusion, MM present at a younger age in AA. There is delay in diagnosis as reflected by the advanced stage at diagnosis. The median survival was > 7 yrs., a significant improvement in the last 5 years compared to the 3 yr survival reported for MM (AA and Caucasians) patients in the last 3 decades.