Follicular low-grade non-Hodgkin's lymphoma: long-term outcome with or without tumor progression.

Long-term outcome for 127 patients with follicular low-grade lymphoma was investigated. Therapy included radiotherapy (n = 23), low toxicity chemotherapy with or without radiotherapy (n = 76), or more intensive chemotherapy (n = 22). 6 patients had no initial therapy. Complete remission was obtained in 67% of patients. For patients under 60 years of age median survival was 8.7 yr compared with 3.8 yr for older patients, but survival from lymphoma was identical for the two age-groups: 75% at 5 yr, and 58% at 10 yr. The relatively low tumor mortality contrasted with a relapse-free survival of 30% at 10 yr, and relapse 8-9 yr after first remission. Examining the disease topography and the stability of histologic subtype in 78 patients with recurrent lymphoma, two types of relapse with different prognoses were identified: 1) with tumor progression (lymphoma dissemination to atypical extranodal sites and/or histologic conversion to an intermediate/high-grade lymphoma) seen in 56% of patients with a survival from lymphoma of 13% at 10 yr; and 2) without tumor progression (involvement of nodal sites, and unchanged histology) seen in 44% with a survival from lymphoma of 77% at 10 yr. Actuarial risk of tumor progression was 44% at 5 yr, and 67% at 10 yr. Except from the negative impact of a large tumor burden, it was not possible to identify patients with high risk for tumor progression. More important than all pretreatment factors was poor response to initial therapy (p = 0.0001). Due to lack of reliable risk factors, it is recommended that all younger patients be treated with the intention of achieving complete remission; a significant fraction might be curable.