Long-term outcome from a study on the prevention of postoperative recurrence in patients with renal cell carcinoma: could PBL be a predictor of postoperative recurrence in patients postoperatively treated with IFN-gamma?

This study examined the outcome of postoperative recurrence therapy on renal cell carcinoma (RCC) prevention involving treatment with single doses of interferon-gamma (IFN-gamma). From 1990-2000, 37 patients with no distant metastasis at the time they underwent a nephrectomy were enrolled in this investigation. Subcutaneous IFN-gamma was administered once a week. Total and differential white blood cells were counted before the pre-administration of IFN-gamma and then monthly thereafter for all patients. Blood lymphocyte subsets were analyzed phenotypically by direct immunofluorescence. Disease-free survival rates (DFSR) at 5 and 10 years were 81.7% and 75.9%, respectively. To clarify the effects of preoperative peripheral blood lymphocyte (PBL) and NK activity on DFSR, we categorized the patients into two groups according to the median number of PBL before the administration of IFN-gamma. Except for CD11b, PBL level had no effect on DFSR. Multiple logistic regression analysis showed that CD11b levels greater than 16.5% were associated with 25.35 odds ratio increase in the risk of postoperative recurrence. A multivariate analysis found that CD11b may be an independent factor for postoperative recurrence. In terms of preventing postoperative recurrence, our results showed that an elevated CD11b level may indicate patients who can benefit from further combination therapy.