Autologous haematopoietic stem cell transplantation in multiple myeloma patients from ethnic minority groups in an equal access healthcare system.
High-dose melphalan followed by autologous haematopoietic stem cell transplantation (ASCT) became part of the standard of care for most patients with multiple myeloma (MM) under the age of 65 years in the mid-to-late 1990s (Attal et al, 1996; Barlogie et al, 1997). While two smaller single-institution studies from the US reported better progression-free survival (PFS) but comparable overall survival (OS) in black compared with white MM patients following ASCT (Saraf et al, 2006; Verma et al, 2008), a recent large study by the Center for International Blood and Marrow Transplant Research (CIBMTR) did not observe any significant differences in PFS, OS, relapse rate, or non-relapse mortality (Hari et al, 2010). No systematic study has compared the outcome of Asians with blacks or whites. To address this gap in the literature, we evaluated the characteristics and outcomes of all MM patients who underwent a first ASCT at Hammersmith Hospital (HH), later Imperial College Healthcare NHS Trust (ICHNT), over a 16year period. This patient population came from a large multiethnic community of almost two million people in an equalaccess healthcare system. We identified all patients with MM who underwent a first ASCT at HH/ICHNT between 1994, when the ASCT programme for MM was initiated, and 2009. Over the study period, HH/ICHNT was the tertiary referral centre for haematopoietic stem cell transplantation for Northwest London. The 2001 UK Census recorded a Northwest London population of 1Æ73 million, consisting of 1Æ13 million whites (65%), 0Æ35 million Asians (20%), 0Æ15 million blacks (9%) and 0Æ1 million others (6%). Patients diagnosed with MM by primary and secondary healthcare providers who were considered eligible for ASCT were referred to HH/ICHNT upon completion of induction therapy. In accordance with the 2001 Census, we classified patient ethnicity as white (British, Irish, or other white ethnic background), black (Caribbean, African, or other black), or Asian (Indian, Pakistani, Bangladeshi, Middle Eastern, or other Southeast Asian). A reduced dose of melphalan was used at the transplant physicians’ discretion in patients over the age of 65 years, those with severe renal impairment, or those with other co-morbidities. Tandem ASCT was performed in patients considered to have chemorefractory disease. Responses were defined based on previously published criteria (Blade et al, 1998). Groups were compared using a Mann–Whitney test for continuous data and a Chi-squared test for categorical data. Probabilities for OS and PFS were calculated according to the Kaplan–Meier method and differences were tested with the log-rank test, and all analyses were carried out using the Statistical Package for the Social Sciences (spss) software (version 12.0.1, IBM, New York, NY, USA). P-values < 0Æ05 were deemed statistically significant. A total of 363 patients with a diagnosis of MM underwent a first ASCT at HH/ICHNT between 1994 and 2009. Of those, 270 (74Æ4%) were white, 56 (15Æ4%) were black, and 37 (10Æ2%) were Asian (Table I). There were no significant differences between the three ethnic groups in terms of gender, age, immunoglobulin