RAPID COMMUNICATION P rognostic Significance of the Ki-67 -Associated Proliferative Antigen in Aggressive Non-Hodgkin’s Lymphomas: A Prospective Southwest Oncology Group Trial

The growth fraction of tumors from patients with non-Hodgkin’s lymphomas (NHL) has been shown to correlate with survival in retrospective studies. The growth fraction can be evaluated using immunohistochemical techniques employing the Ki-67 monoclonal antibody (MoAb) that marks a nuclear protein present in cycling cells. The purpose of this study was to evaluate the clinical utility of the Ki-67 MoAb for predicting survival. Using a prospective trial design in a multi-institutional cooperative trials group, the proliferative index, clinical outcome, and statistical correlations were independently assessed for previously untreated patients with advanced stages of intermediateand high-grade histologies of NHL treated on Southwest Oncology Group study (SWOG 8516, Intergroup 0067). The proportion of Ki-67-positive cells was determined on