[Impact of immunochemotherapy on survival of patients with metastatic renal cell carcinoma. A retrospective study comparing interferon-alpha-2a/vinblastine versus interferon-alpha-2a/interleukin-2/5-fluorouracil].

The prognosis for patients with metastatic renal cell carcinoma (RCC) remains unsatisfactory to date. Combined immunochemotherapy (ICT) strives for a synergistic effect avoiding a substantial increase of therapy-related adverse events. The combination therapy regimes consisting of either interferon-alpha-2a/vinblastine (IFN-alpha2a/VBL) or interferon-alpha-2a/interleukin-2/5-fluorouracil (IFN-alpha2a/IL-2/5-FU) demonstrated objective remission rates, surpassing the results obtained with the administration of single immunotherapeutic agents. Despite the data from a recently published study, the role of these two therapy combinations did not seem clearly defined. Therefore, we compared the impact of IFN-alpha2a/VBL and IFN-alpha2a/IL-2/5-FU on remission and survival as well as the safety profile in a retrospective study in patients with metastatic RCC. In a retrospective single-center study, 105 patients with metastatic RCC having received treatment between 1992 and 2002 with either s.c. IFN-alpha2a/ i.v. VBL ( n=70, group 1) or s.c. IFN-alpha2a/ s.c. IL-2/ i.v. 5-FU ( n=35, group 2) were evaluated. At a median follow-up of 17 months, remission and survival rates as well as the toxicity profiles of the respective groups were documented and compared. The median age throughout the entire patient population was 61 years. Patients in the IFN-alpha2a/VBL group reached a median overall survival of 20 months compared to 17 months for the patients in the IFN-alpha2a/IL-2/5-FU population ( p=0.850). The objective response rate in the first patient group reached 25.7%, whereas the tumor remission rate of group 2 amounted to 22.9% ( p=0.680). Patients showing an objective response reached a significantly higher survival rate than patients without response reaction (median survival was 36 vs 10 months, p=0.0001). The incidence of each therapy-induced adverse event was higher throughout the second treatment group. These differences were significant with respect to flu-like symptoms (85.7 vs 57.1%, p=0.003), grade 3/4 elevations of liver enzymes (14.3 vs 1.4%, p=0.007), nausea/vomiting (74.3 vs 50%, p=0.017), the severity of erythemas (74.3 vs 10%, p<0.001), and patients with lung edema (17.1 vs 2.9%, p=0.009). Eight patients discontinued the ICT, two of whom died of a myocardial infarction.Despite an overall limited prognosis, patients showing a tumor remission seem to benefit from ICT in terms of overall survival. While both treatment options offer comparable remission and survival rates, the IFN-alpha2a/VBL regimen induces fewer adverse events than the treatment with IFN-alpha2a/IL-2/5-FU.