A randomized trial of polyadenylic-polyuridylic acid (Poly(A).Poly(U) given as an adjuvant in the treatment of operable breast cancer, has included 300 patients of the Institut Gustave-Roussy from September 1972 to December 1979; 145 patients were allocated to conventional treatment alone and 155 to conventional treatment plus Poly(A).Poly(U). Reviews after mean periods of follow-up of 50 and 87 months were previously published. The present review performed after a mean follow-up period of 111 months confirmed a significant increase in the overall survival of patients with invaded nodes treated with Poly(A).Poly(U). The best results were achieved in the subset of patients with up to three affected nodes who showed a significant increase of both overall and relapse-free survival. The benefit seemed to be greater in postmenopausal women (P = 0.07). Present status of other ongoing trials of adjuvant Poly(A).Poly(U) is presented.