P-326 - Usefulness of Carcinoembryonic Antigen (CEA) as Prognosis Factor in Patients with Stage III Rectal Cancer Treated with Neo- adjuvant Chemoradiotherapy

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Anti-Cancer Agents & Biologic Therapy
Biomarkers
Rectal Cancer
Surgery and/or Radiotherapy of Cancer
Presenter P. Luna-Perez
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors P. Luna-Perez, M.D.L. Ramirez-Ramirez, R. Silva-Martinez, M. Gutierrez de la Barrera
  • Instituto Mexicano del Seguro Social, Mexico City/MX

Abstract

Introduction

Approximately 10–40% of rectal cancer patients undergoing CRT had lymph node metastasis. Most of them developed recurrence. There is little information about the usefulness of prognostic indicators in such patients. Objective. To analyze the usefulness of CEA as prognostic identifier of recurrence.

Methods

Between 1996 and 2010, 131 patients with rectal adenocarcinoma treated with CRT + surgery were classified as stage III. CEA levels were classified into 3 groups: I (pre and post treatment <5 ng), II (pre treatment >5 ng and post <5 ng) and III (pre and post treatment >5 ng). Factors associated with recurrence were analyzed by Cox regression analysis. Five- year disease-free survival with the Kaplan-Meier method and comparison with log-rank test.

Results

There were 72 males and 59 females, mean age was 55.9 years. Mean tumor size, 6 cm; mean pretreatment value of CEA was 15.4 ng. Surgeries were: low anterior resection (63), abdominoperineal resection (35) and pelvic exenteration (33). Mean of harvested lymph nodes and metastatic lymph nodes was 19.5 and 8.8, respectively. Post-radiated surgical stages were: IIIA (18), IIIB (66) and IIIC (47). At median follow-up of 72 months, 59 (45%) patients developed recurrences as follows: locoregional (15.2%), local + distant (2.2%) and systemic (27.4%). Recurrences according to tumor stage were: IIIA, 11%, IIIB, 51.5% and IIIC, 48.9% (p= 0.03). Recurrences according to CEA level <5 ng was: local 15%, distant 17%, conversely with >5 ng was: local 17.8% and distant 37% (p = 0.009). Disease-free 5-year survival according the 3 groups of CEA level was: was 59%, 37% and 25%, respectively (p = 0.001). Associated factors with recurrence were: group I CEA level, ypN2 stage and tumor size >5 cm. Factors associated with survival were: pre and post-treatment CEA <5 ng and ypN1.

Conclusion

Pre- and post treatment CEA level is a powerful tool to identify patients with high risk of recurrences and probably support the administration of induction chemotherapy before CRT in those patients with pretreatment CEA levels >5 ng.