Non-Hodgkin's lymphoma in Manitoba, 1968-77: the impact of chemotherapy.

Manitoba tumour registry data for patients with non-Hodgkin's lymphoma diagnosed between 1968 and 1977 inclusive who were given chemotherapy were reviewed. The Rappaport classification of these tumours enabled general pathologists in the province to distinguish three main prognostic groups. Combination chemotherapy improved survival significantly more than single-agent chemotherapy only for the patients with diffuse histiocytic lymphoma, not for those with diffuse poorly differentiated lymphocytic lymphoma or the more favourable histologic types of non-Hodgkin's lymphoma--diffuse well differentiated lymphocytic and nodular poorly differentiated lymphocytic. For the last two types, therefore, the more intensive chemotherapy is not justified.