Regional lymph nodes were examined in 4 groups of oncologic patients (with cancer of oral cavity, breast, stomach and lung). Histological types of the lymph node reaction were correlated to patients' survival. Favourable prognosis in all four groups was related to lymphocytic predominance, especially when combined with sinus histiocytosis. The predominance of germinal centres (combined with sinus histiocytosis) was a favourable sign but in stomach cancer. A marker of unfavourable prognosis was lymphocytic depletion, especially when sinus histiocytosis was absent.