Identification of prognostic factors of the efficiency of bevacizumab therapy in patients with metastatic renal-cell cancer

Background. The design and introduction of novel medicaments into clinical practice has confirmed that it is necessary to search for new prognostic factors to re-evaluate the clinical and biological properties of a tumor and to identify a subgroup of patients who will benefit from drug treatment. An individual approach and personalization of performed therapy will be able to substantially enhance its efficiency. Subjects and methods. Thirty-four oncology and urology research and health care institutions from 8 federal districts of the Russian Federation took part in the investigation. It enrolled 145 metastatic renal-cell cancer patients who had received targeted therapy with a combination of bevacizumab and interferon-α (IFN-α), in whom an objective response (complete or partial regression) or stabilization of tumor foci was recorded during at least 3-month treatment. The main task of the investigation was to estimate the clinical importance of chosen criteria (an interval from the diagnosis to start of treatment; physical activity according to the Karnofsky scale; a history of nephrectomy; the site and number of metastatic foci; the levels of hemoglobin, neutrophils, platelets, calcium, and alkaline phosphatase) as predictors for the efficiency of bevacizumab therapy. Results. The median follow-up was 9 months (interquartile range (IQR) 6–13 months). The duration of treatment varied between 3 to 22 months; the median was 9 months (IQR 6–13 months). Patients with 3-month progression were excluded from the investigation. A complete and partial responses were recorded in 5 (3.4 %) and 19 (13.1 %) patients, respectively; the tumor process was stabilized in 118 (81.4 %) patients. The median duration of response to therapy with a combination of bevacizumab and IFN-α was 7 months (IQR 5–10 months). The progression-free survival was significantly influenced by prognostic factors, such as hemoglobin and neutrophil levels, age, and time from the diagnosis to starting therapy (p < 0.05). A history of nephrectomy had a significant impact on overall survival (p < 0.05). Conclusion. Our findings suggest that a history of nephrectomy and elevated neutrophil and alkaline phosphatase levels affect the efficiency of performed treatment in terms of an objective response to therapy. The factors influencing progression-free survival included the levels of hemoglobin and neutrophils, age, and time to diagnosis to start therapy.