Thermal ablation for small renal masses: Identifying the most appropriate tumor size cut-off for predicting perioperative and oncological outcomes.

OBJECTIVES: To test TRIFECTA achievement [1) absence of CLAVIEN-DINDO ≥3 complications; 2) complete ablation; 3) absence of ≥30% decrease in eGFR] and local recurrence rates, according to tumor size, in patients treated with thermal ablation (TA: radiofrequency [RFA] and microwave ablation [MWA]) for small renal masses. METHODS: Retrospective analysis (2008-2020) of 432 patients treated with TA (RFA: 162 vs. MWA: 270). Tumor size was evaluated as: 1) continuously coded variable (cm); 2) tumor size strata (0.1-2 vs. 2.1-3 vs. 3.1-4 vs. >4 cm). Multivariable logistic regression models and a minimum P-value approach were used for testing TRIFECTA achievement. Kaplan-Meier plots depicted local recurrence rates over time. RESULTS: Overall, 162 (37.5%) vs. 140 (32.4%) vs. 82 (19.0%) vs. 48 (11.1%) patients harboured, respectively, 0.1 to 2 vs. 2.1 to 3 vs. 3.1 to 4 vs. >4 cm tumors. In multivariable logistic regression models, increasing tumor size was associated with higher rates of no TRIFECTA achievement (OR:1.11; P< 0.001). Using a minimum P-value approach, an optimal tumor size cut-off of 3.2 cm was identified (P< 0.001). In multivariable logistic regression models, 3.1 to 4 cm tumors (OR:1.27; P< 0.001) and >4 cm tumors (OR:1.49; P< 0.001), but not 2.1 to 3 cm tumors (OR:1.05; P= 0.3) were associated with higher rates of no TRIFECTA achievement, relative to 0.1 to 2 cm tumors. The same results were observed in separate analyses of RFA vs. MWA patients. After a median (IQR) follow-up time of 22 (12-44) months, 8 (4.9%), 8 (5.7%), 11 (13.4%), and 5 (10.4%) local recurrences were observed in tumors sized 0.1 to 2 vs. 2.1 to 3 vs. 3.1 to 4 vs. >4 cm, respectively (P= 0.01). CONCLUSION: A tumor size cut-off value of ≤3 cm is associated with higher rates of TRIFECTA achievement and lower rates of local recurrence over time in patients treated with TA for small renal masses.

Comparison of Mexican-American vs Caucasian prostate cancer active surveillance candidates.

BACKGROUND: We compared upgrading and upstaging rates in low risk and favorable intermediate risk prostate cancer (CaP) patients according to racial and/or ethnic group: Mexican-Americans and Caucasians. METHODS: Within Surveillance, Epidemiology and End Results database (2010-2015), we identified low risk and favorable intermediate risk CaP patients according to National Comprehensive Cancer Network guidelines. Descriptives and logistic regression models were used. Furthermore, a subgroup analysis was performed to test the association between Mexican-American vs. Caucasian racial and/or ethnic groups and upgrading either to Gleason-Grade Group (GGG II) or to GGG III, IV or V, in low risk or favorable intermediate risk CaP patients, respectively. RESULTS: We identified 673 (2.6%) Mexican-American and 24,959 (97.4%) Caucasian CaP patients. Of those, 14,789 were low risk (434 [2.9%] Mexican-Americans vs. 14,355 [97.1%] Caucasians) and 10,834 were favorable intermediate risk (239 [2.2%] Mexican-Americans vs. 10,604 [97.8%] Caucasians). In low risk CaP patients, Mexican-American vs. Caucasian racial and/or ethnic group did not result in either upgrading or upstaging differences. However, in favorable intermediate risk CaP patients, upgrading rate was higher in Mexican-Americans than in Caucasians (31.4 vs. 25.5%, OR 1.33, P = 0.044), but no difference was recorded for upstaging. When comparisons focused on upgrading to GGG III, IV or V, higher rate was recorded in Mexican-American relative to Caucasian favorable intermediate risk CaP patients (20.4 vs. 15.4%, OR 1.41, P = 0.034). CONCLUSION: Low risk Mexican-American CaP patients do not differ from low risk Caucasian CaP patients. However, favorable intermediate risk Mexican-American CaP patients exhibit higher rates of upgrading than their Caucasian counterparts. This information should be considered at treatment decision making.