Abandonment of Routine Radiotherapy for Nonlocally Advanced Rectal Cancer and Oncological Outcomes.

Importance: Neoadjuvant short-course radiotherapy was routinely applied for nonlocally advanced rectal cancer (cT1-3N0-1M0 with >1 mm distance to the mesorectal fascia) in the Netherlands following the Dutch total mesorectal excision trial. This policy has shifted toward selective application after guideline revision in 2014. Objective: To determine the association of decreased use of neoadjuvant radiotherapy with cancer-related outcomes and overall survival at a national level. Design, Setting, and Participants: This multicenter, population-based, nationwide cross-sectional cohort study analyzed Dutch patients with rectal cancer who were treated in 2011 with a 4-year follow-up. A similar study was performed in 2021, analyzing all patients that were surgically treated in 2016. From these cohorts, all patients with cT1-3N0-1M0 rectal cancer and radiologically unthreatened mesorectal fascia were included in the current study. The data of the 2011 cohort were collected between May and October 2015, and the data of the 2016 cohort were collected between October 2020 and November 2021. The data were analyzed between May and October 2022. Main Outcomes and Measures: The main outcomes were 4-year local recurrence and overall survival rates. Results: Among the 2011 and 2016 cohorts, 1199 (mean [SD] age, 68 [11] years; 430 women [36%]) of 2095 patients (57.2%) and 1576 (mean [SD] age, 68 [10] years; 547 women [35%]) of 3057 patients (51.6%) had cT1-3N0-1M0 rectal cancer and were included, with proportions of neoadjuvant radiotherapy of 87% (2011) and 37% (2016). Four-year local recurrence rates were 5.8% and 5.5%, respectively (P = .99). Compared with the 2011 cohort, 4-year overall survival was significantly higher in the 2016 cohort (79.6% vs 86.4%; P < .001), with lower non-cancer-related mortality (13.8% vs 6.3%; P < .001). Conclusions and Relevance: The results of this cross-sectional study suggest that an absolute 50% reduction in radiotherapy use for nonlocally advanced rectal cancer did not compromise cancer-related outcomes at a national level. Optimizing clinical staging and surgery following the Dutch total mesorectal excision trial has potentially enabled safe deintensification of treatment.

Distribution of lymph node metastases in esophageal adenocarcinoma after neoadjuvant chemoradiation therapy: a prospective study.

BACKGROUND: The distribution of lymph node metastases in esophageal adenocarcinoma following neoadjuvant chemoradiation (nCRTx) is unclear, but may have consequences for radiotherapy and surgery. The aim of this study was to define the distribution of lymph node metastases and relation to the radiation field in patients following nCRTx and esophagectomy. METHODS: Between April 2014 and August 2015 esophageal adenocarcinoma patients undergoing transthoracic esophagectomy with 2-field lymphadenectomy following nCRTx were included in this prospective observational study. Lymph node stations according to AJCC 7 were separately investigated. The location of lymph node metastases in relation to the radiation field was determined. The primary endpoint was the distribution of lymph node metastases and relation to the radiation field, the secondary endpoints were high-risk stations and risk factors for lymph node metastases and relation to survival. RESULTS: Fifty consecutive patients were included. Lymph node metastases were found in 60% of patients and most frequently observed in paraesophageal (28%), left gastric artery (24%), and celiac trunk (18%) stations. Fifty-two percent had lymph node metastases within the radiation field. The incidence of lymph node metastases correlated significantly with ypT-stage (p = 0.002), cT-stage (p = 0.005), lymph angioinvasion (p = 0.004), and Mandard (p = 0.002). The number of lymph node metastases was associated with survival in univariable analysis (HR 1.12, 95% CI 1.068-1.173, p < 0.001). CONCLUSIONS: Esophageal adenocarcinoma frequently metastasizes to both the mediastinal and abdominal lymph node stations. In this study, more than half of the patients had lymph node metastases within the radiation field. nCRTx is therefore not a reason to minimize lymphadenectomy in patients with esophageal adenocarcinoma.