P-060 - Intestinal versus Diffuse Gastric Cancer – Chemoradiation for all or do we need different therapeutic approaches?

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Anti-Cancer Agents & Biologic Therapy
Gastric Cancer
Surgery and/or Radiotherapy of Cancer
Presenter A. Garcia
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors A. Garcia1, N. Saraiva1, A. Nogueira1, P. Jacinto2, M. Marques3, N. Bonito1, J. Ribeiro1, H. Gervasio1
  • 1Portuguese Oncology Institute of Coimbra, Coimbra/PT
  • 2Instituto Português de Oncologia Francisco Gentil, Coimbra/PT
  • 3Portuguese Institute of Oncology Coimbra, Coimbra/PT

Abstract

Introduction

Despite its incidence in Europe has declined over the last decades, gastric cancer (GC) is still the second cause of cancer-related deaths worldwide. Although different histological subtypes are known for many years, in daily clinical practice GC is usually considered as a single disease. Our aim was to compare intestinal and diffuse GC subtypes regarding the clinical outcome, disease-free survival (DFS) and overall survival (OS) of patients submitted to adjuvant chemoradiation.

Methods

A total of 76 patients with gastric adenocarcinoma who underwent curative resection between 2006 and 2012 were included. Early or recurrent GC, palliative resection and patients submitted to perioperative chemotherapy were excluded. All patients underwent chemotherapy with 5-fluorouracil (5-FU) (200 mg/m2/day) and radiation therapy (45 Gy/25 fr/5 weeks). LV5FU2 or LV5FU2-P was administered before and after chemoradiation. Histological subtype according to Lauren's classification was documented. Mixed-type tumours (N= 10) were listed as diffuse type. A total of 15 patients were excluded due to lost follow-up. Demographic and clinical characteristics of the population were recorded. Standard statistical tests were used.

Results

Our study group had 61 patients, with an average follow–up of 51 months (62,3% male) and median age of 62 years (40-78). Total gastrectomy was performed in 26,2% (16/61) of patients, while the remaining underwent subtotal gastrectomy.

Diffuse tumors were the majority (50,8%), followed by intestinal tumours (36,1%). Mucinous aspects were found in 8 patients. Sex, age, location of the tumor and type of surgery were similar between diffuse and intestinal subtypes. According to TNM classification, diffuse tumours were more advanced (15 patients in stage II and 12 in stage III vs. 18 patients in stage II and only 1 patient with stage III in intestinal subtype; p = 0,015). Metastasized resected nodes were in larger number in diffuse subtype (p = 0,034), but there was no difference in lymphadenectomy. Chemoradiation scheme was completed in 15 patients with diffuse subtype and 10 patients with intestinal subtype (p= 0,83). Recurrence rates were similar between these groups (intestinal vs diffuse: 27,2% vs 32,3%; p = 0,768).

Mean DFS for intestinal subtype was 70 months and 74,1 for diffuse, with no significant difference (p = 0,61). Mean OS for intestinal subtype was 80,6 months and 75,7 months for diffuse (p = 0,18).

Conclusion

Our analysis suggests that diffuse subtype is diagnosed in more advanced stage than intestinal subtype and has more metastasized nodes at diagnosis, but it does not influence recurrence or survival rates. Future clinical trials should take in account these differences and surgical teams should perform extended surgery and lymphadenectomy in diffuse GC patients.