The ypT may better predict the efficacy of neoadjuvant chemoradiotherapy than tumor regression grade in locally advanced rectal cancer patients diagnosed ypT1-4N0.

PURPOSE: This study aimed to assess the impact of ypT stage and tumor regression grade (TRG) on the long-term prognosis of patients with locally advanced rectal cancer (LARC) stage ypT1-4N0 after neoadjuvant chemoradiotherapy (NCRT). METHODS: We retrospectively analyzed 585 patients with histologically diagnosed middle-low LARC (cT3-4 or cN + by pelvic MRI) from 2014 to 2019. All patients underwent NCRT, followed by total mesorectal excision. Disease-free survival (DFS) rates were compared among patients with different ypT stages and TRGs by Kaplan-Meier survival analysis. The chi-square test was used to analyze the relationship between clinicopathological or therapeutic factors and ypT stage. RESULTS: The median follow-up was 35.8 months (range 2.8-71.8 months). The 3-year DFS was 79.5%. A better 3-year DFS was achieved in patients with a pathologic complete response (94.0% vs. 74.3%, p < 0.001) and those in the ypT0-2 (86.5% vs. 66.6%, p < 0.001), ypN0 (85.0% vs. 60.2%, p < 0.001), and TRG0 + 1 (83.1% vs. 73.0%, p = 0.004) subgroups. A total of 309 patients (52.8%) achieved stage ypT1-4N0 after surgery. Among these patients, the ypT1-2N0 subgroup achieved a significantly higher 3-year DFS than the ypT3-4N0 subgroup (85.4% vs. 72.8%, p = 0.018); in contrast, the 3-year DFS did not significantly differ between the TRG1 and TRG2 + 3 subgroups (79.9% vs. 81.1%, p = 0.833). In the ypT1-2N0 or ypT3-4N0 subgroup, different TRG had no significant effect on failure patterns. CONCLUSIONS: For LARC patients with a ypT1-4N0 status after NCRT, ypT stage may be a more effective predictor of long-term prognosis than TRG.

Lymph node regression after neoadjuvant chemotherapy: A predictor of survival in gastric cancer.

BACKGROUND AND OBJECTIVE: Neoadjuvant chemotherapy (nCMT) has been increasingly used in advanced gastric cancer (GC). However, the prognostic impact of tumor response remains unclear. This study aimed to evaluate if tumor response at the primary site and lymph nodes (LN) correlate with survival in GC patients after nCMT. METHODS: Patients with gastric adenocarcinoma treated with nCMT followed by gastrectomy were evaluated. Residual tumor was graded from 0% to 100%, defining two groups: poor (PR) and major response (MR). LN regression rate (LNRR) was determined based on tumor/fibrosis examination at each LN and a cutoff value established by receiver operating characteristic curve. RESULTS: Among 62 cases, 20 (32.2%) had MR and 42 (67.7%) PR. Smaller size, diffuse histology, lower ypT status and less advanced stage were associated with the MR group. Based on cutoff value of 57, 45.6% and 54.4% patients were classified as low-LNRR and high-LNRR. High-LNRR correlated with absence of venous, lymphatic and perineural invasion, and less advanced stage. Survival was equivalent between MR and PR (P = .956). High-LNRR had better disease-free survival (DFS) than low-LNRR (P < .001). In multivariate analysis, only LNRR associated with DFS. CONCLUSION: High-LNRR associates with DFS in GC treated with nCMT. Response at the primary site does not correlate with survival.

Can tumor regression grade influence survival outcome in ypT3 rectal cancer?

PURPOSE: Locally advanced rectal cancer (LARC) patients achieving ypT3 status following neoadjuvant chemoradiation are considered to have poor response with minimal downstaging. However, residual cancer cell amounts vary in the subserosa/perirectal fat. Tumor regression grading (TRG) is an evaluation method based on the proportion of fibrosis and residual cancer cells. The aim of this study is to assess the influence of TRG in ypT3 rectal cancer patients who received neoadjuvant chemoradiation. METHODS: We retrospectively reviewed 325 LARC patients who received neoadjuvant chemoradiation and surgery. TRG scores were recorded by two independent pathologists. Among these patients, 143 were staged as ypT3. We analyzed TRG and other clinicopathological factors and their relationship with survival outcome including overall survival (OS) and disease-free survival (DFS). RESULTS: Among 143 ypT3 patients, 44 (30.8 %) were TRG1, 84 (58.7 %) were TRG2 and 15 (10.5 %) were TRG3. Seventy-nine (55.3 %) of these patients had metastatic lymph nodes. In univariate analysis, TRG was not associated with DFS (TRG2 vs TRG1, P = 0.852; TRG3 vs TRG1, P = 0.593) or OS (TRG2 vs TRG1, P = 0.977; TRG3 vs TRG1, P = 0.665). Palliative surgery (HR 3.845; 95 % CI 1.670-8.857; P = 0.002) and metastatic lymph nodes after surgery (HR 5.894; 95 % CI 1.142-3.48; P = 0.015) were significantly associated with decreased DFS, while palliative surgery was the only factor associated with worse OS (HR 6.011; 95 % CI 2.150-16.810; P = 0.001). Palliative surgery (HR 3.923; 95 % CI 1.696-9.073; P = 0.001) and metastatic lymph nodes (HR 2.011; 95 % CI 1.152-3.512; P = 0.014) also showed prognostic significance for DFS in multivariate analysis. CONCLUSIONS: Residual cancer cells evaluated by TRG score after neoadjuvant chemoradiation do not influence survival outcome in ypT3 rectal cancer patients. However, lymph node status is a significant prognostic factor in ypT3 patients.