Neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy alone for patients with locally advanced rectal cancer: a propensity-score-matched analysis combined with SEER validation.

BACKGROUND: Neoadjuvant therapy followed by radical surgery is recommended for locally advanced rectal cancer (LARC). But radiotherapy can cause potential adverse effects. The therapeutic outcomes, postoperative survival and relapse rates between neoadjuvant chemotherapy (N-CT) and neoadjuvant chemoradiotherapy (N-CRT) patients have rarely been studied. METHODS: From February 2012 to April 2015, patients with LARC who underwent N-CT or N-CRT followed by radical surgery at our center were included. Pathologic response, surgical outcomes, postoperative complications and survival outcomes (including overall survival [OS], disease-free survival [DFS], cancer-specific survival [CSS] and locoregional recurrence-free survival [LRFS]) were analyzed and compared. Concurrently, the Surveillance, Epidemiology, and End Results Program (SEER) database was used to compare OS in an external source. RESULTS: A total of 256 patients were input into the propensity score-matching (PSM) analysis, and 104 pairs remained after PSM. After PSM, the baseline data were well matched and there was a significantly lower tumor regression grade (TRG) (P < 0.001), more postoperative complications (P = 0.009) (especially anastomotic fistula, P = 0.003) and a longer median hospital stay (P = 0.049) in the N-CRT group than in the N-CT group. No significant difference was observed in OS (P = 0.737), DFS (P = 0.580), CSS (P = 0.920) or LRFS (P = 0.086) between the N-CRT group and the N-CT group. In the SEER database, patients who received N-CT had similar OS in both TNM II (P = 0.315) and TNM III stages (P = 0.090) as those who received N-CRT. CONCLUSION: N-CT conferred similar survival benefits but caused fewer complications than N-CRT. Thus, it could be an alternative treatment of LARC.

Current treatment and surveillance modalities are not sufficient for advanced stage III colon cancer: Result from a multicenter cohort analysis.

OBJECTIVE: We conducted this multicenter cohort study to evaluate the current tumor-node-metastasis staging system and treatment modality by analyzing the survival outcomes of patient groups with stage III and IV colon cancer. PATIENTS AND METHODS: Stage III and IV colon cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database (SEER cohort) and prospectively maintained Sun Yat-sen University (SYSU) cohort were included in this study. Kaplan-Meier method was used to estimate the cumulative rate of overall survival (OS) between patient groups, and the inverse probability weighting method was used to calculated age and sex-adjusted survival curves. The Cox regression model was used to identify the risk factors for OS. RESULTS: A total of 17,911 and 1135 stage III-IV cases were included in the SEER and SYSU cohorts, respectively. Among them, 1448 and 124 resectable stage IV cases underwent curative-intent treatment in the SEER and SYSU cohorts, respectively. The T4N2b group showed a significantly worse survival outcome compared with the M1a subset receiving curative-intent treatment (HR, 1.46; p < 0.001). This finding was validated in the SYSU cohort, in which the T4N2 group had a worse outcome than that of the M1 group receiving curative-intent treatment (HR, 2.44; p < 0.001). These findings were confirmed in the adjusted survival analysis. In the multivariate analysis, the right-side tumor, poor-undifferentiated tumor, and age over 60 years were identified as independent risk factors for T4N2b patients. Based on this multivariate model, the high-risk T4N2b subgroup had a worse survival outcome compared with resectable M1b patients (HR, 1.24; p = 0.03). CONCLUSION: By comparing stage III with stage IV colon cancer patients, we identified a subgroup of stage III patients at a higher risk of death than more advanced stages, implying that current cancer care modalities are not sufficient for these high-risk substages.