Prospective Analysis of the Survival of Patients With a Reduction in the Number of Lymph Nodes in Rectal Cancer After Neoadjuvant Chemoradiotherapy

According to the International Union Against Cancer a minimum of 12 lymph nodes (LN) should be obtained in the surgical specimen for colorectal cancer staging. Recent studies have reported that the use of neoadjuvant chemoradiotherapy (QRN) may result in failure to obtain the minimum number of LN in the piece in 30-52% of patients. Objective: To analyze the survival of patients with a reduction in the number of resected LN in patients submitted to neoadjuvant and total excision of the mesorectum with rectal cancer. Patients and methods: From January 2013 to January 2015, patients with rectal cancer were submitted to QRN (5-FU and 5040 Gys) followed by total excision of mesorectum with ligation of the inferior mesenteric vessels in their roots. Patients with T3, T4 and / or N + staging that were up to 10 cm from the anal border were included. Patients whose treatment with neoadjuvant chemoradiotherapy was incomplete or who had significant delays in re- staging and / or performing the surgery were excluded. All were staged by rectal examination, colonoscopy, chest and abdominal CT, and pelvic MRI, and also re-staged 8 weeks after neoadjuvant termination, operated and submitted to total excision of the mesorectum. The patients were divided into 4 groups: a) Incomplete pathological response with less than 12 LN. b) Incomplete pathological response with 12 or more LN. c) Complete pathological response with less than 12 LN. d) Complete pathological response with 12 or more LN. The possible variables related to the number of LN obtained and related to general and disease free survival were studied.

Expected results:

To analyze the survival rate between patients Complete Pathologic Response with less than 12 LN and 12 or more LN. To determine the difference in survival between patients with less than 12 LN in complete versus incomplete response. Demonstrate that patients with complete pathologic response and less than 12 LN have a disease-free survival equal to or better than patients with 12 LN or more.