J Korean Soc Ther Radiol Oncol.  2001 Dec;19(4):327-334.

Surgery Alone or Postoperative Adjuvant Radiotherapy in Rectal Cancer: With Respect to Survival, Pelvic Control, Prognostic Factor

• Nam TK
• Ahn SJ
• Nah BS

Abstract

PURPOSE: To find out the role of postoperative adjuvant radiotherapy in the treatment of rectal cancer by comparing survival, pelvic control, complication rate, and any prognostic factor between surgery alone and postoperative radiotherapy group.
MATERIALS AND METHODS
From Feb. 1982 to Dec. 1996 total 212 patients were treated by radical surgery with or without postoperative radiotherapy due to rectal carcinoma of modified Astler-Coller stage B2-C3. Of them, 18 patients had incomplete radiotherapy and so the remaining 194 patients were the database analyzed in this study. One hundred four patients received postoperative radiotherapy and the other 90 patients had surgery only. Radiotherapy was performed in the range of 39.6-55.8 Gy (mean: 49.9 Gy) to the whole pelvis and if necessary, tumor bed was boosted by 5.4-10 Gy. Both survival and pelvic control rates were calculated by Kaplan-Meier method and their statistical significance was tested by Log-rank test. Multivariate analysis was performed by Cox proportional hazards model.
RESULTS
5-year actuarial survival rate (5YSR) and 5-year disease-free survival rate (5YDFSR) of entire patients were 53% and 49%, respectively. 5YSRs of surgery alone group and adjuvant radiotherapy group were 63% vs 45%, respectively ( p=0.03). This difference is thought to reflect uneven distribution of stages between two treatment groups ( p<0.05 by x2-test) with more advanced disease patients in adjuvant radiotherapy group. 5YSRs of surgery alone vs adjuvant radiotherapy group in MAC B2+3, C1, C2+3 were 68% vs 55% ( p=0.09), 100% vs 100%, 40% vs 33% ( p=0.71), respectively. 5YDFSRs of surgery alone vs adjuvant radiotherapy group in above three stages were 65% vs 49% ( p=0.14), 100% vs 100%, 33% vs 31% ( p=0.46), respectively. 5-year pelvic control rate (5YPCR) of entire patients was 72.5%. 5YPCRs of surgery alone and adjuvant radiotherapy group were 71% vs 74%, respectively (p=0.41). 5YPCRs of surgery alone vs adjuvant radiotherapy group in B2+3, C1, C2+3 were 79% vs 75% ( p= 0.88), 100% vs 100%, 44% vs 68% ( p=0.01), respectively. Multivariate analysis showed that only stage was significant factor affecting overall and disease-free survival in entire patients and also in both treatment groups. In view of pelvic control, stage and operation type were significant in entire patients and only stage in surgery alone group but in adjuvant radiotherapy group, operation type instead of stage was the only significant factor in multivariate analysis as a negative prognostic factor in abdominoperineal resection cases.
CONCLUSION
Our retrospective study showed that postoperative adjuvant radiotherapy could improve the pelvic control in MAC C2+3 group. To improve both pelvic control and survival in all patients with MAC B2 or more, other treatment modality such as concurrent continuous infusion of 5-FU, which is the most standard agent, along with radiotherapy should be considered.

MeSH Terms

Disease-Free Survival
Fluorouracil
Humans
Multivariate Analysis
Pelvis
Proportional Hazards Models
Radiotherapy
Radiotherapy, Adjuvant*
Rectal Neoplasms*
Retrospective Studies
Survival Rate
Fluorouracil