beta(2)-microglobulin in Hodgkin's lymphoma: prognostic significance in patients treated with ABVD or equivalent...

Serum beta-2 microglobulin (sbeta(2)m) is an established prognostic factor for several lymphoproliferative disorders. Because its significance in Hodgkin's lymphoma (HL) is controversial, we determined sbeta(2)m levels in pretreatment serum samples of patients with HL in order to elucidate its prognostic value in this condition.

Pretreatment sbeta(2)m levels were determined in 379 HL patients who were treated with ABVD or equivalent regimens with or without radiotherapy (RT), using a radioimmunoassay (upper normal limit 2.4 mg/l). Sbeta(2)m levels were correlated with several clinical and laboratory parameters.

Elevated sbeta(2)m levels were detected in 138/379 (36%) patients and correlated with all clinical and laboratory baseline features except gender, lung involvement and mediastinal bulk. They also correlated with serum soluble CD30 and interleukin-10 levels. The 8-year failure-free survival (FFS) was 78 -/+ 4% for patients with normal versus 65 -/+ 7% for patients with elevated sbeta(2)m levels (p=0.003). The corresponding rates among early-stage patients were 83 -/+ 53% versus 71 -/+ 9% (p=0.003), while for advanced stages they were 70 -/+ 6% versus 64 -/+ 8% (p=0.54). In multivariate analysis of the whole patient population elevation of sbeta(2)m levels was not predictive of FFS, but it was strongly predictive among early-stage patients. The 8-year overall survival (OS) rates were 91 -/+ 3% for patients with normal versus 59 -/+ 11% (p <0,0001) for patients with elevated sbeta(2)m levels, while unrelated mortality at 8 years was 1 -/+ 1% versus 27 -/+ 12% (p<0.0001).

Our data suggest that sbeta(2)m levels may be a potent prognostic factor for FFS in patients with early stage HL treated with ABVD and equivalent regimens. Their effect on OS is confounded by the higher unrelated mortality in patients with elevated baseline sbeta(2)m levels, probably due to the strong association between sbeta(2)m and older age.