Different age limits for elderly patients with indolent and aggressive non-hodgkin lymphoma and the role of relative survival with increasing age.

BACKGROUND

There is no consistent definition at what age patients with non-Hodgkin lymphoma (NHL) are considered "elderly." This might hamper well balanced decisions with respect to treatment.

METHODS

From a population-based NHL registry the age groups younger than 60 years, 60-64 years, 65-69 years, 70-74 years, and 75 years and older were analyzed in relation to the revised European-American lymphoma classification and to the age-adjusted International Prognostic Index (IPI). The prognostic value of the variables from the age-adjusted IPI was determined. The relative survival probabilities were calculated.

RESULTS

The incidence of diffuse large B-cell lymphoma (DLBL) increased with advancing age, as was the case for small lymphocytic lymphomas. Follicular lymphomas were less frequently encountered with advancing age. With respect to the so-called indolent lymphomas, a decreasing complete remission rate and overall survival rate (5-year) was observed for patients older than 70 years, whereas patients with DLBL fared worse when older than 65 years and 60 years, respectively. The age-adjusted IPI score was discriminative for prognosis. However, even with an IPI score nil, the age group older than 75 years fared significantly worse (P < 0.009), but less so with the relative survival model. The relative survival at 5 years was 60%, 53%, 48%, 35%, and 32% for the 5 respective age groups.

CONCLUSIONS

Patients with indolent lymphomas become elderly when they are older than 70 years, but when aggressive lymphoma is concerned this occurs when patients are older than 65 years. For patients with an IPI score nil, age older than 75 years is the dominant prognostic factor. The negative influence of concomitant disease on overall survival, although continuously increasing in older age groups, seems to diminish for patients older than 75 years when compared with the general Dutch population.