Preoperative CCRT in Colorectal Cancer: Advantages and Disadvantages

1. Preoperative CCRT in Colorectal Cancer 嘉義長庚醫院 大腸直腸外科 葉重宏

2. The Goal of Pre-OP CCRT • Radical resection is the principal treatment of rectal carcinoma • Unfortunately, the local recurrence rate is 30 ~ 50 % • The carcinoma of rectum is relative sensitive to irradiation • 5-FU is a chemo-sensitizer • Adjuvant therapy with chemo-radiation has been employed

3. The Advantage of Pre-OP CCRT • Increase the resectability • Increase the possibility of curative resection • Down-staging of the resected cancer • Reduce the local and distal relapses • Increase the chance of sphincter-preserving operation

4. The Disadvantage of Pre-OP CCRT • Under-estimate the surgical staging • Over treatment for early rectal cancer -- 20 % ~ 30 % of CCRT is T1 or T2 • Potential increase the operative morbidity and mortality • Delay the operation

5. Review of literature (1) • EORTC ( European Organization for Research and Treatment of Cancer ) -1988 3450cGy pre-OP irradiation Local recurrence rate decrease Increase post-OP perineal wound infection and hospital stay No difference in long term survival

6. Review of literature (2) • Stockholm Rectal Cancer study group–1990 2500 cGy over 5 ~ 7 days Reduce pelvic recurrence No difference in distal metastasis and over-all survival. Prolong the time of local recurrence and distal metastasis Increase in post –OP morbidity

7. Review of literature (3) • Pahlman and Glimelius – 1990 2550 cGy in 5 to 7 days No radiation-related complication nor increase mortality Lower local recurrence Equal survival • Mendenhall -1992 Local recurrence 8 % vs. 33 % 5-year survival rate 66 % vs. 40 %

8. Review of literature (4) • Swedish multicenter study (1)– 1993 2500 cGy in 5 days No increase in post –OP mortality Increase in perineal wound infection No increase in anastomotic dehiscence or other post-OP complication • Swedish multicenter study (2)– 1995 No increase in post –OP mortality Decrease in local recurrence

9. Review of literature (5) • Swedish multicenter study (3) – 1996 4-field box technique Reduce treatment volume Reduce local recurrence Improve survival length No significant increase mortality

10. Review of literature (6) • Holm et al. – 1995 2500 cGy in 5 ~ 7 days Increase in perineal wound infection –APR No increase in anastomotic leakage –AR No increase in post-OP mortality –APR and AR Reduce in local recurrence – APR and AR No difference in survival –APR and AR

11. Review of literature (7) • Kerman et al. – 1992 4500 ~ 5000 cGy No treatment related mortality Low post-Op complication rate -- 5.2 % Low local recurrence rate – 4.2 % Low distal failure rate – 10.5 % 5 year survival 66 % Disease-free survival rate 64 % 10 year survival 52 %

12. Review of literature (8) • Bannon et al. – 1995 4500 ~ 7000 cGy AAR vs full thickness local excision Local recurrence 9 % and 14 % 5 year survival rate 85 % and 90 % • Minsky et al. – 1995 4680 cGy + 360 cGy LAR and coloanal anastomosis Local recurrence 12 % 4 year survival 75 %

13. Review of literature (9) • Myerson et al. – 1995 Izar et al. – 1992 3600 cGy ~ 5000 cGy Local control 88 %~ 90 % 5 year disease-free survival 70 %~73 % 10 year-survival 50 %

14. Summary (1) • Improvement in radiation Prone position Multi-field technique Computerized dosimetry High energy linear accelerator Bladder distension Standard fraction size ( 180~200 cGy ) • Frequent protocol 4000 ~ 4500 cGy in 4 ~ 6 weeks 6 weeks interval before operation • Protective colostomy Not necessary if dose < 4500 cGy

15. Summary (2) • Improve the resectability • Destroy the Malignant cells in regional LN – down-staging • Increase local control • Alter the viability of the shed malignant cell – May decrease distant dissemination

16. Thank you