450 FACTORS AFFECTING CIRCUMFERENTIAL RESECTION MARGIN AFTER ESOPHAGECTOMY AND ITS PROGNOSTIC SIGNIFICANCE-LARGE SINGLE CENTRE EXPERIENCE

The evidence regarding the importance of circumferential resection margin (CRM) as a prognostic factor after esophagectomy is inconclusive in the era of neoadjuvant therapy. We retrospectively analysed our prospectively maintained database for factors that affect CRM positivity, and whether a positive CRM affects event free and overall survival. 2843 patients underwent esophagectomy with curative intent from October 2004 to 2019 at our centre. CRM was analysed as negative, close but technically free (<1 mm) and involved. Methods Data on the following variables was retrospectively extracted from prospective database. CRM status was noted for clinic-radiological T and N stage, level of growth, histology, differentiation grade and neoadjuvant treatment. Intra-operative details such as surgical procedure, approach, surgeon grade, lymphadenectomy and resection status were analysed. On final histopathology; proximal and distal margins, lymph node positivity, lymphovascular invasion(LVI), tumour regression grade(TRG) were analysed. The effect of CRM on development of recurrence and overall survival was evaluated. CRM data was available for 2439 (85.78%) patients. 71.2% of the patients received neoadjuvant chemotherapy. Factors were analysed separately for both close and positive margins. Results 75.8% had negative, 15.6% close and 8.6% positive CRM. Univariately, T stage, adenocarcinoma, poor differentiation, transhiatal approach, R+ resection, positive margins, TRG > 3, LVI and upfront surgery predicted positive CRM. On multivariate, negative CRM was seen in T1/T2 stage [OR 0.325, 95% CI-0.144-0.732, p = 0.007], squamous carcinoma [OR 0.574, 95% CI-0.351-0.958, p = 0.027], R0 resection [OR 0.228, 95% CI-0.086-0.599, p = 0.003] while positive CRM was seen in upfront surgery [OR 2.32, 95% CI-1.55-3.46, p < 0.001], positive nodes [OR 1.748, 95% CI-1.19-2.56, p = 0.004] and LVI [OR 2.73, 95% CI-1.87-3.98, p < 0.001]. Median event-free survival in CRM negative was 64 months compared to 14 months in CRM positive (p < 0.001). Conclusion Positive CRM involvement is a prognostic indicator in patients undergoing esophagectomy and associated with worse event-free and overall survival. CRM-positive disease in esophageal cancer may represent residual tumor, advanced disease, aggressive biology, or poor response to neoadjuvant treatment. All attempts should be made to achieve a clear circumferential resection margin. More evidence is needed to evaluate if adjuvant therapy is justified in these patients and the type of therapy also needs to be determined.

So sánh kết quả đánh giá giai đoạn ung thư biểu mô trực tràng giữa cộng hưởng từ và giải phẫu bệnh

Mục tiêu: So sánh kết quả đánh giá giai đoạn ung thư biểu mô (UTBM) trực tràng giữa cộng hưởng từ (CHT) so với giải phẫu bệnh (GPB). Đối tượng và phương pháp: Nghiên cứu được tiến hành dưới dạng mô tả cắt ngang, chọn mẫu thuận tiện trên 109 bệnh nhân được chẩn đoán UTBM trực tràng được phẫu thuật cắt trực tràng triệt căn tại Trung tâm Phẫu thuật Đại trực tràng - Tầng sinh môn, Bệnh viện Hữu nghị Việt Đức từ tháng 10/2016 đến tháng 05/2019. Kết quả: CHT có mối tương quan với GPB về giai đoạn T (p<0,001). Hạn chế đánh giá giai đoạn sớm (T1), độ chính xác trong đánh giá mức độ xâm lấn thành trực tràng của khối u (giai đoạn T) là 71,56%. Không ghi nhận có tương quan trong chẩn đoán hạch di căn giữa kết quả CHT và GPB. Kết quả tốt trong đánh giá xâm lấn diện cắt chu vi (CRM- Circumferential resection margin), xâm lấn mạch máu, bạch huyết, thần kinh (EMVI). Kết luận: CHT có khả năng đánh giá tốt mức độ xâm lấn của u, diện cắt chu vi (CRM) và xâm lấn mạch máu, bạch huyết, thần kinh (EMVI- extramural vascular invasion). Nên ứng dụng CHT rộng rãi trong đánh giá giai đoạn trước mổ của ung thư trực tràng để quyết định lựa chọn phương pháp điều trị phù hợp.

Multimodal Treatment of cT3 Rectal Cancer in a Prospective Multi-Center Observational Study: Can Neoadjuvant Chemoradiation Be Omitted in Patients with an MRI-Assessed, Negative Circumferential Resection Margin?

<b><i>Background/Aim:</i></b> Neoadjuvant chemoradiation (nCRT) in rectal cancer is associated with significant long-term morbidity. It is unclear whether nCRT in resectable mesorectal fascia circumferential resection margin (mrCRM)-negative rectal cancer treated by adequate total mesorectal excision (TME) is beneficial. The aim was to determine if nCRT can be omitted in patients with MRI-assessed cT3 rectal cancer and a negative mrCRM undergoing good-quality TME. <b><i>Methods:</i></b> By means of a prospective nationwide registry (<i>n</i> = 43.147; prospective multi-center observational study), patients with cT3 rectal cancer &#x3c;12 cm from the anal verge with a negative (&#x3e;1 mm) MRI-assessed CRM undergoing radical resection from 2006 to 2008 were selected. Overall, 87 patients were available for the final analysis (TME-alone, <i>n</i> = 25; nCRT+TME, <i>n</i> = 62). Groups were balanced for age, sex, and ASA score, with a nonsignificant predominance of males in the nCRT+TME group. As main outcome measures, local and distant recurrence rates were compared between patients undergoing primary surgery (TME-alone) vs. neoadjuvant chemoradiation + surgery (nCRT+TME). <b><i>Results:</i></b> In the TME-alone group, tumors were located closer to the anal verge (<i>p</i> = 0.018) and demonstrated a smaller minimal circumferential distance from the resection margin (<i>p</i> = 0.036). TME quality was comparable, as was median follow-up (48.9 vs. 44.9 months; <i>p</i> = 0.268). Local recurrences occurred at a similar rate in the TME-alone (<i>n</i> = 1; 5.3%) and nCRT+TME groups (<i>n</i> = 3; 5.5%) (<i>p</i> = 0.994) and were diagnosed at 10 months (TME-alone) and at 8, 13, and 18 months (nCRT+TME). Distant recurrences occurred in 28.9 and 17.4% of the cases, respectively (<i>p</i> = 0.626). The analysis was limited to cT3 cancers with a negative mrCRM. In addition, caution is required when appraising these results because of the limited number of evaluable subjects (especially in the TME-alone group), which adds some uncertainty to the statistical analysis. <b><i>Conclusions:</i></b> In this cohort of patients with rectal cancer located &#x3c;12 cm from the anal verge and a negative mrCRM undergoing adequate TME, omission of nCRT had no impact onto the local recurrence rate.