Prognostic value of sarcomatoid histology and volume‐weighted mean nuclear volume in renal cell carcinoma

Objective To determine the prognostic value of two histopathological factors, sarcomatoid histology and volume-weighted mean nuclear volume (MNV) in renal cell carcinoma (RCC). Patients and methods The study included 106 patients (72 men and 34 women, mean age 63 years, range 32–83) with RCC, all of whom were surgically treated between 1985 and 1995. The presence of any sarcomatoid component was determined and MNV estimated using a stereological method in histological slides of tumour specimens from these patients. The prognostic significance of the two variables was evaluated by univariate and multivariate analyses in comparison with other histopathological variables (T, N and M categories, nuclear grade, tumour size, tumour type), using the cause-specific and progression-free survival of the patients as the endpoints. Results Among the 106 RCC cases examined, a sarcomatoid component was detected in 34 (32%); the MNV was 90–627 μm3 (mean 225). By univariate and multivariate analysis, both variables were significant prognostic factors for cause-specific survival in all patients. In addition, multivariate analysis of the 74 patients with localized RCCs (T1–3, N0 M0) showed that sarcomatoid histology was a significant prognostic factor for disease progression. Conclusion The presence of sarcomatoid histology and the MNV, both of which can be examined with no specialized laboratory procedures, seem to be useful tumour-related prognostic factors in RCC.