Adverse radiologic and pathologic features appear to predict worse survival outcomes in patients with small renal masses following nephrectomy, according to research presented at the International Kidney Cancer Symposium (IKCS) 2021.
Preoperative imaging for adverse features of cT3 disease in small renal masses (≤4 cm) has poor sensitivity. Thus, the investigators retrospectively reviewed small renal masses of patients who had partial or radical nephrectomy at Memorial Sloan Kettering Cancer Center between 2010 and 2020. They hypothesized that adverse radiologic and pathologic T3 features are predictive of worse outcomes in small renal masses.
To test this hypothesis, the researchers compared small renal masses with and without adverse preoperative radiologic and/or pathologic features (cT3/pT3, cT1a/pT3) to lower-stage small renal masses (cT1a/non-pT3). Cases with known advanced (pT4, M1) preoperative disease were excluded. Multivariate Cox proportional-hazards regression modeling was used to evaluate potential predictors of survival outcomes.
The investigators identified 2146 patients, with a median age of 60.8 years (interquartile range [IQR], 51.8-67.7), who underwent partial (94%) or radical nephrectomy of small renal masses. The median follow-up duration was 3.3 years (IQR, 1.5-6.1).
Upon postoperative review, 181 of the 2146 cases (8.4%) were found to be pT3 (3.8% cT3/pT3; 4.6% cT1a/pT3). Of these pT3-small renal masses, 45.9% had adverse preoperative cT3 radiologic features and 54.1% had been unexpectedly upstaged to pT3.
The pT3-small renal masses compared with non-pT3 small renal masses had higher rates of positive margins (cT1a/pT3, 9.2%; cT3/pT3, 12.05%; cT1a/non-pT3, 4.8%; P =.003) and metastasis (4.1%; 1.2%; 0.76%, respectively; P =.04). The pT3-small renal masses compared with non-pT3 small renal masses were also associated with higher rates of overall mortality (cT1a/pT3, 6.1%; cT3/pT3, 9.6%; cT1a/non-pT3, 3.9%; P =.03) and cancer-specific mortality (2.0%; 2.4%; 0.25%, respectively; P =.0005).
In the multivariate model adjusted for covariate (age, body-mass index, mass size, histology, and Charlson comorbidity index), cT3/pT3 was a significant predictor of worse overall and cancer-specific survival (hazard ratio [HR], 2.3 and 5.7, respectively; P <.05) but not of incidence of metastases. Neither cT3 or pT3 alone were significant predictors. Unexpected upstaging (cT1a/pT3) was associated with worse metastasis-free survival (HR, 4.7; P =.0083) but not overall survival or cancer-specific survival.
“While rare, adverse pathologic upstaging portends worse outcomes for [small renal masses], particularly in the presence of concurrent adverse radiologic features. [Small renal mass] substratification by these features may aid in surgical and potentially multimodal treatment planning,” concluded the investigators.
Khaleel S, Hong T, Jiang S, Davelman B, Coleman J, Hakimi A, Russo P. Adverse radiologic and pathologic features impact survival outcomes for small renal masses following nephrectomy. Presented at IKCS 2021; November 5-6, 2021. Abstract N36.