HLA-ANTIGEN AS PREDICTIVE INDEX FOR THE OUTCOME OF BREAST-CANCER PATIENTS WITH ADJUVANT IMMUNOCHEMOTHERAPY WITH PSK

We demonstrated that the prognosis of breast cancer patients who recei ved adjuvant immunochemotherapy with Krestin (PSK) showed a tendency t o be better than that of breast cancer patients receiving chemotherapy only. We retrospectively investigated the usefulness of HLA typing fo r selecting patients to receive adjuvant immuno-chemotherapy with PSK. One hundred and thirty-four patients with operable breast cancer were typed as HLA-A, -B, -C by a lymphocytotoxicity test. Patients without vascular invasion had no adjuvant therapy (NA group). Patients with v ascular invasion in the tumor and/or in the metastatic lymph node were randomized into two groups. In group 1 (FEMP only), a combination che motherapy of 100 mg of 5-fluorouracil (F), 50 mg of cyclophosphamide ( E), 2 mg of mitomycin C (M), and 5 mg of predonisolone (P) was orally administered daily for 28 days (one course). In group 2 (FEMP+PSK), FE MP and 3.0 g of PSK were orally administered for 28 days (one course). Two courses a year of these agents were given for five years in both groups. Each group (NA, FEMP, FEMP+PSK) was stratified by the presence of HLA B40 type (B40(+))or not (B40(-)). Five- and 10-year disease-fr ee survival (DFS) rates (93%, 80%, respectively) of patients with B40( +) seemed to be better than those (83% and 51%) of patients with B40(- ). In the NA group, 5- and 10-year DFS were 100% and 71% in patients w ith B40(+), 92% and 76% in those with B40(-), respectively. In the FEM P group (chemotherapy only), 5- and 10-year DFS of patients with B40() were both 84%. These were not statistically significant compared wit h those (82% and 33%) of patients with B40(-). On the other hand, in t he FEMP+PSK group, 5- and 10-year DFS of patients with B40(+) were bot h 100%, and those of patients with B40(-) were 76% and 55%, respective ly. DFS of patients with B40(+) was significantly better than that of patients with B40(-). It is concluded that HLA typing may be a predict ive index in determining the use of immunochemotherapy combined with P SK for patients with operable breast cancer.