Modification of American Joint Committee on cancer prognostic groups for renal cell carcinoma

BACKGROUND: To compare the predictive value of the current AJCC stage grouping for renal cell carcinoma (RCC) to our modifications. PATIENTS AND METHODS: A total of 2120 patients with RCC from Fudan University Shanghai Cancer Center (FUSCC) database and 74 506 counterparts from SEER database were included. Cox regression was used to calculate the relative impacts between prognostic groups. The predictive accuracy of overall survival (OS) was assessed using the concordance index (C‐index), which was compared by likelihood ratio test. RESULTS: In FUSCC cohort, the 5‐year‐OS rate for T3N0M0 patients was higher than T1‐3N1M0 (72.7% vs 38.1%). The 5‐year‐OS rate for T4N0M0 was 36.2%, which was close to T1‐3N1M0 but not to T4N1M0 (0%) and TanyNanyM1 (12.6%). The elements of AJCC groups were regrouped according to the ranks of hazard ratios. The modified stages II (T3N0M0), III (T1‐3N1M0, T4N0M0), and IV (T4N1M0, TanyNanyM1) exhibited greater survival stratification than AJCC groups. The modifications were validated in SEER cohort and yielded similar survival outcomes. The predictive accuracy of OS in modified prognostic groups was significantly higher than AJCC groups in stages II‐IV subgroups in both FUSCC (C‐index: 0.801 vs 0.779, P < 0.001) and SEER cohort (C‐index: 0.770 vs 0.764, P < 0.001). CONCLUSIONS: The modified AJCC prognostic groups for RCC provided significantly improved survival prediction compared with the 8th AJCC edition. A precise risk stratification of modified stages II‐IV disease provides an important basis for risk‐equivalent treatment recommendation.