Preoperative radiation therapy as an adjuvant to surgery for carcinoma of the colon and rectum

The rationale to switch from postoperative hyperfractionated accelerated radiotherapy to preoperative hyperfractionated accelerated radiotherapy in rectal cancer

“…The dose increment between trial 89-02 and trial 91-9 1 was in accordance to the dose response data obtained by an extensive review of the literature (15,20,21,32,35,37,40,42). Low-dose radiotherapy has no significant effect on local control (20,32,37,40), whereas doses higher than 20 Gy seem to significantly affect local recurrence rate (15,42).…”

Importance of tumor regression assessment in predicting the outcome in patients with locally advanced rectal carcinoma who are treated with preoperative radiotherapy

“…30 To our knowledge, there have been no reports to date of complete tumor regression occurring when surgery is performed within 1 week after the end of radiotherapy, a finding that is consistent with our own data. 10,12,14,16,17,19 In contrast, in studies with a longer interval between the end of radiotherapy and surgery (Ͼ 10 days), complete histologic regression was reported in 2-11% of the patients. 7,30,38 -41 However, to diagnose complete tumor regression, the entire tumor region must be sampled and carefully screened for any small surviving foci of carcinoma by thorough histologic workup.…”

“…[5][6][7][8][9][10] Moderate-to high-dose neoadjuvant preoperative radiotherapy has been shown to induce tumor regression and downstaging, thus significantly improving local control. 7,10 -18 The role of preoperative radiotherapy in survival remains controversial, with some studies reporting a minimal effect, 17,19,20 whereas in other trials a significant impact has been shown. [7][8][9]13,14,16,[21][22][23] In a recent meta-analysis, it was suggested that preoperative radiotherapy significantly improves overall and cancer specific survival but much more in patients with Dukes Stage B and C tumors than in patients with Dukes Stage A tumors.…”

Preoperative Radiotherapy for Resectable Rectal Cancer

“…Among the 196 studies reviewed, 14 RCTs met the inclusion criteria. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] Studies were excluded if they combined preoperative and postoperative radiotherapy 23 ; if they did not have a surgery alone group as control 20,21 ; if they were nonrandomized [27][28][29][30] or if they enrolled randomized and nonrandomized patients 25,26 ; if they stopped after accruing only a few patients 31 ; or, if published as a preliminary report, 19,22,24,[32][33][34] a final article was published subsequently. Since all the trials reported as abstracts [36][37][38] were subsequently published as full articles, this meta-analysis included only peerreviewed reports.…”