P-327 - Biologic Therapy in the management of locally advanced rectal cancer, experience of the National Medical Center November 20, Mexico City

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Anti-Cancer Agents & Biologic Therapy
Rectal Cancer
Presenter L. Torres
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors L. Torres, G. Sanchez, M. Garcia
  • ISSSTE CMN 20 de Noviembre, Mexico City/MX

Abstract

Introduction

Introduction: In Mexico, cancer of the colon and rectum, is within the top 5 causes of death, with an incidence of 6356 cases for both sexes, being more common in men, with a ratio 1.2: 1, cancer Straight occurs most often in people over 50 years, the treatment of rectal cancer involves the administration of QT / RT and surgery in locally advanced stages, the use of white therapy based on KRAS during neoadjuvant and / or and subsequently concomitant surgery, has not been associated with relapse-free survival and pathological complete response rate.

The KRAS mutation is associated with resistance to radiotherapy. However, at present there is a preclinical study that meets this answer.

Objectives: Describer the disease-free survival as primary end point in 2 populations with rectal cancer in locally advanced stages who received neoadjuvant chemotherapy and concomitant radiotherapy and then surgery, population 1 was treated with Biologic Therapy and population 2 no, considering this as a case control during the period March 2008-June 2014.

Methods

It is a study in the department of medical oncology at the Centro Medico Nacional 20 de Noviembre, cases and controls, 20 cases patients receiving biologic therapy during neoadjuvant therapy (bevacizumab or cetuximab) with chemotherapy (XELOX, FOLFOX) chemotherapy (capecitabine) + RT, if KRAS WT concomitant plus (Cetuximab), compared with 25 control patients with locally advanced rectal cancer who were treated with neoadjuvant (XELOX or FOLFOX), QT / RT, patients underwent surgery resection abdominal perineal or mesorectal, during the period from March 9, 2008 to June 12, 2014 with a follow up of 27 months for both groups, recurrence-free time as a primary objective, secondary objective was complete responses and overall Survival was obtained, all patients had colonoscopy, abdominal CT scan biopsy. RT received 50.4 Gy / 25 fractions, underwent surgery for the patient decided to be subjected to this procedure, in case of not accepting was kept in close surveillance.

Results

The average age of patients was 59 years, EC II 19 patients, 23 patients EC III, IVa EC 3 patients, the numbers of cycles of neoadjuvant average for both groups were 2 XELOX or FOLFOX, the experimental group 19 patients received bevacizumab during neoadjuvant and only one of them received cetuximab, the experimental group the progression-free survival was 22 months vs 10.8 months, p = 0.002, the rate of complete responses were 8 in the experimental group vs 5 in the control group with an OR of 2.6, the overall survival was 27.4 months vs 16.4 months, both groups were receiving neoadjuvant and subsequently conjunction with RT, and were undergoing surgery should accept the procedure.

Conclusion

The use of Biologic therapy based on the status of Kras may be considered as a predictive marker of response to impact on SLE and complete responses, prospective studies are needed to evaluate this hypothesis