Outcomes of neoadjuvant chemoradiotherapy followed by radical resection for T4 colorectal cancer

BACKGROUND Patients with clinical T4 colorectal cancer(CRC)have a poor prognosis because of compromised surgical margins.Neoadjuvant therapy may be effective in downstaging tumors,thereby rendering possible radical resection with clear margins.AIM To evaluate tumor downsizing and resection with clear margins in T4 CRC patients undergoing neoadjuvant concurrent chemoradiotherapy followed by surgery.METHODS This study retrospectively included 86 eligible patients with clinical T4 CRC who underwent neoadjuvant concurrent chemoradiotherapy followed by radical resection.Neoadjuvant therapy consisted of radiation therapy at a dose of 45-50.4 Gy and chemotherapy agents,either FOLFOX or capecitabine.A circumferential resection margin(CRM)of<1 mm was considered to be a positive margin.We defined pathological complete response(p CR)as the absence of any malignant cells in a specimen,including the primary tumor and lymph nodes.A multivariate logistic regression model was used to identify independent predictive factors for p CR.RESULTS For 86 patients who underwent neoadjuvant chemoradiotherapy and surgery,the rate of p CR was 14%,and the R0 resection rate was 91.9%.Of the 61 patients with rectal cancer,7(11.5%)achieved p CR and 5(8.2%)had positive CRMs.Of the 25 patients with colon cancer,5(20%)achieved p CR and 2(8%)had positive CRMs.We observed that the FOLFOX regimen was an independent predictor of p CR(P=0.046).After a median follow-up of 47 mo,the estimated 5-year overall survival(OS)and disease-free survival(DFS)rates were 70.8%and 61.4%,respectively.Multivariate analysis revealed that a tumor with a negative resection margin was associated with improved DFS(P=0.014)and OS(P=0.001).Patients who achieved p CR exhibited longer DFS(P=0.042)and OS(P=0.003)than those who did not.CONCLUSION Neoadjuvant concurrent chemoradiotherapy engenders favorable p CR and R0 resection rates among patients with T4 CRC.The R0 resection rate and p CR are independent prognostic factors for patients with T4 CRC.

Effects of the number of neoadjuvant therapy cycles on clinical outcomes, safety, and survival in patients with metastatic colorectal cancer undergoing metastasectomy

The controversial outcomes in patients with metastatic colorectal cancer(mCRC)highlight the need for developing effective systemic neoadjuvant treatment strategies to improve clinical results.The optimal treatment cycles in patients with mCRC for metastasectomy remain undefined.This retrospective study compared the efficacy,safety,and survival of cycles of neoadjuvant chemotherapy/targeted therapy for such patients.Sixty-four patients with mCRC who received neoadjuvant chemotherapy/targeted therapy following metastasectomy were enrolled between January 2018 and April 2022.Twenty-eight patients received 6 cycles of chemotherapy/targeted therapy,whereas 36 patients received≥7 cycles(median,13;range,7–20).Clinical outcomes,including response,progression-free survival(PFS),overall survival(OS),and adverse events,were compared between these two groups.Of the 64 patients,47(73.4%)were included in the response group,and 17(26.6%)were included in the nonresponse group.The analysis revealed chemotherapy/targeted therapy cycle and pretreatment serum carcinoembryonic antigen(CEA)level as independent predictors of the response as well as overall survival and chemotherapy/targeted therapy cycle as an independent predictor of progression(all p<0.05).Furthermore,our results revealed shorter operation time,lower estimated operative blood loss,higher response rate,lower progression rate,and higher survival rate in≥7 cycles of chemotherapy/targeted therapy group(all p<0.05),but no statistical differences in adverse events were observed between the two groups(all p>0.05).The median OS and PFS were 48 months(95%CI,40.855–55.145)and 28 months(95%CI,18.952–37.48)in the≥7-cycle group and 24 months(95%CI,22.038–25.962)and 13 months(95%CI,11.674–14.326)in the 6-cycle group,respectively(both p<0.001).The oncological outcomes in the≥7-cycle group were significantly better than those in the 6-cycle group,without significant increases in adverse events.However,prospective randomized trials are mandatory to confirm the potential advantages of cycle numbers of neoadjuvant chemotherapy/targeted therapy.