[Criteria for the effectiveness of interleukin-2 immunotherapy in a spontaneous murine mammary tumor model].

A novel approach is suggested to identify more homogenous subgroups involved in the follow-up of growth of spontaneous mammary tumors in mice (116, history-based analysis). That depends on subclinical period (preneoplastic and non-invasive stages of tumor growth) as well as rate of growth after clinical manifestation. An analysis of tumor growth rate versus survival of experimental and control animals after primary diagnosis and clinical manifestation of tumor showed that following a single peritumoral 2.5 x 10(6) IU IL-2 treatment tumor growth slowed down (n = 29; p < or = 0.05) while survival tended to improve. Originally fast-growing tumors without significant subclinical stage continued to grow but slowly. Females with such tumors survived longer than untreated controls without showing, however, any improvement on that parameter.