P-248 - Evaluation of the use and effectiveness of adjuvant chemotherapy in patients with stage II colon cancer: data from the Hospital of Lithuanian Univer...

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Anti-Cancer Agents & Biologic Therapy
Colon Cancer
Presenter D. Vaitiekus
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors D. Vaitiekus1, L. Simaskaite2, S. Liutkauskiene1, D. Janciauskas3, E. Juozaityte1, R. Janciauskiene1
  • 1Dept. of Oncology and Hematology, Kaunas/LT
  • 2Lithuanian University of Health Sciences, Kaunas/LT
  • 3Dept. of Pathology, Kaunas/LT

Abstract

Introduction

The use of adjuvant chemotherapy in stage II colon cancer is still controversial. Benefit from this treatment modality is not well established yet. In this study we have analyzed the prevalence and effectiveness of adjuvant chemotherapy in retrospective cohort of stage II colon cancer patients.

Methods

Retrospective data of the patients who underwent surgical treatment at 2004 -2009 due to stage II colon were collected from hospital database. We have identified 305 patients. Patients were divided in two groups: group 1 – patients who underwent surgical treatment and observation, group 2 - patients who underwent surgery and received adjuvant chemotherapy with fluorouracil based regimen. Survival was evaluated using Kaplan Maier curves. Difference was considered statistically significant when p value was <0.05.

Results

We found 259 patients (84.9, 3%) in group 1 and 46 patients (15.1%) in group 2. Average number of adjuvant treatment cycles was 4.91 (ranges between 2-8). Group 1 and 2 were homogeneous regarding the sex, number of dissected lymph nodes, histology type (adenocarcinoma or mucinous carcinoma), and differentiation grade. Statistically significant difference was found regarding the median age (median age in groups – 70 vs 62 years) – patients in group 2 were younger. Also there was a statistically significant difference in tumor size T4 in a group 1 was 12.0% vs 34.8% in group 2 (p <0.05). Overall 5 year survival (OS) of all stage II patients was 84.1%. Cancer specific 5 year survival was 86.8%. There was seen trend for better survival for those with dissected more than 12 lymph nodes (p 0.136). 5 year OS survival of patients in a group 1 was 84.1% comparing with 83.8% in a group 2 (p = 0.304). Adjuvant treatment did not help to improve survival of patients with a different tumor grade (G1 vs G2 vs G3), lymph/blood vessel invasion, and age (<65 and ≥ 65 years old). We have found tendency for the better survival for patients with greater T who received adjuvant treatment (p = 0.192). Cox regression analysis did not reveal adjuvant chemotherapy as independent factor for overall survival.

Conclusion

Only 15.1% of stage II colon cancer patients diagnosed at the period 2004-2009 were treated with adjuvant chemotherapy. Young age and tumor size were the most significant factors for physicians deciding to prescribe adjuvant treatment. We have not found statistically significant difference in survival in adjuvant chemotherapy group comparing with surgery alone, but tendencies were seen for chemotherapy benefit in greater (T4) tumors. In multivariate analysis the only one independent factor for better survival was higher number of removed lymph nodes.