Short-course preoperative radiation therapy followed by surgery and chemotherapy

The use of short-course radiation therapy was evaluated in a randomized study in the Swedish Rectal Cancer Trial (NCT00337545).[5][Level of evidence A1] In the trial, 1,168 patients younger than 80 years with stage I to stage III resectable rectal adenocarcinoma were randomly assigned to receive preoperative radiation therapy (25 Gy in five fractions) or to undergo immediate surgery. Patients did not receive adjuvant chemotherapy. Subsequently, the Polish Rectal Trial and the Trans-Tasman Radiation Oncology Group (TROG) compared short-course preoperative radiation therapy with the standard long-course preoperative chemoradiation therapy administered with 5-FU.

The use of short-course radiation therapy was evaluated in a randomized study in the Swedish Rectal Cancer Trial (NCT00337545).[5][Level of evidence A1] In the trial, 1,168 patients younger than 80 years with stage I to stage III resectable rectal adenocarcinoma were randomly assigned to receive preoperative radiation therapy (25 Gy in five fractions) or to undergo immediate surgery. Patients did not receive adjuvant chemotherapy. Subsequently, the Polish Rectal Trial and the Trans-Tasman Radiation Oncology Group (TROG) compared short-course preoperative radiation therapy with the standard long-course preoperative chemoradiation therapy administered with 5-FU.

The 5-year OS rate was 58% in the radiation therapy group and 48% in the surgery group (P = .005).

The use of short-course radiation therapy was evaluated in a randomized study in the Swedish Rectal Cancer Trial (NCT00337545).[5][Level of evidence A1] In the trial, 1,168 patients younger than 80 years with stage I to stage III resectable rectal adenocarcinoma were randomly assigned to receive preoperative radiation therapy (25 Gy in five fractions) or to undergo immediate surgery. Patients did not receive adjuvant chemotherapy. Subsequently, the Polish Rectal Trial and the Trans-Tasman Radiation Oncology Group (TROG) compared short-course preoperative radiation therapy with the standard long-course preoperative chemoradiation therapy administered with 5-FU.

The rate of local control was 11% in the radiation therapy group and 27% in the surgery group (P < .001).

In the Polish Rectal Trial, 312 patients with clinical stage T3 or T4 rectal cancer were randomly assigned to receive preoperative radiation therapy (25 Gy in five fractions) followed by total mesorectal excision within 7 days, 6 months of adjuvant 5-FU/LV or preoperative chemoradiation therapy (50.4 Gy in 28 fractions with concurrent bolus 5-FU/LV), total mesorectal excision in 4 to 6 weeks after completion of radiation therapy, and 4 months of adjuvant 5-FU/LV.[6] The primary end point of the study was to detect a difference of at least 15% in sphincter preservation with a power of 80%.

In the Polish Rectal Trial, 312 patients with clinical stage T3 or T4 rectal cancer were randomly assigned to receive preoperative radiation therapy (25 Gy in five fractions) followed by total mesorectal excision within 7 days, 6 months of adjuvant 5-FU/LV or preoperative chemoradiation therapy (50.4 Gy in 28 fractions with concurrent bolus 5-FU/LV), total mesorectal excision in 4 to 6 weeks after completion of radiation therapy, and 4 months of adjuvant 5-FU/LV.[6] The primary end point of the study was to detect a difference of at least 15% in sphincter preservation with a power of 80%.

The rates of sphincter preservation were 61.2% in the short-course group and 58% in the chemoradiation therapy group (P = .570).

In the Polish Rectal Trial, 312 patients with clinical stage T3 or T4 rectal cancer were randomly assigned to receive preoperative radiation therapy (25 Gy in five fractions) followed by total mesorectal excision within 7 days, 6 months of adjuvant 5-FU/LV or preoperative chemoradiation therapy (50.4 Gy in 28 fractions with concurrent bolus 5-FU/LV), total mesorectal excision in 4 to 6 weeks after completion of radiation therapy, and 4 months of adjuvant 5-FU/LV.[6] The primary end point of the study was to detect a difference of at least 15% in sphincter preservation with a power of 80%.

The actuarial 4-year survival rate was 67.2% in the short-course group and 66.2% in the chemoradiation therapy group (HR, 1.01; 95% CI, 0.69–1.48; P = .960).

In the Polish Rectal Trial, 312 patients with clinical stage T3 or T4 rectal cancer were randomly assigned to receive preoperative radiation therapy (25 Gy in five fractions) followed by total mesorectal excision within 7 days, 6 months of adjuvant 5-FU/LV or preoperative chemoradiation therapy (50.4 Gy in 28 fractions with concurrent bolus 5-FU/LV), total mesorectal excision in 4 to 6 weeks after completion of radiation therapy, and 4 months of adjuvant 5-FU/LV.[6] The primary end point of the study was to detect a difference of at least 15% in sphincter preservation with a power of 80%.

The HR for local recurrence in the short-course group compared with the chemoradiation therapy group was 0.65 (95% CI, 0.32–1.28; P = .210).

In the Polish Rectal Trial, 312 patients with clinical stage T3 or T4 rectal cancer were randomly assigned to receive preoperative radiation therapy (25 Gy in five fractions) followed by total mesorectal excision within 7 days, 6 months of adjuvant 5-FU/LV or preoperative chemoradiation therapy (50.4 Gy in 28 fractions with concurrent bolus 5-FU/LV), total mesorectal excision in 4 to 6 weeks after completion of radiation therapy, and 4 months of adjuvant 5-FU/LV.[6] The primary end point of the study was to detect a difference of at least 15% in sphincter preservation with a power of 80%.

There was no difference in late toxicity between the short-course group and the chemoradiation therapy group.

In the TROG trial (TROG 01.04 [NCT00145769]), 326 patients with ultrasound-staged or magnetic resonance imaging (MRI)–staged T3, N0 to N2, M0 rectal adenocarcinoma within 12 cm from the anal verge were randomly assigned to receive short-course radiation therapy (25 Gy in five fractions) followed by surgery 3 to 7 days later or long-course chemoradiation therapy (50.4 Gy in 28 fractions with concurrent continuous infusional 5-FU) followed by surgery in 4 to 6 weeks. All patients received adjuvant chemotherapy (5-FU/LV) after surgery. The trial was designed to have 80% power to detect a 10% difference in local recurrence at 3 years with a two-sided test at the 5% level of significance.[7]

In the TROG trial (TROG 01.04 [NCT00145769]), 326 patients with ultrasound-staged or magnetic resonance imaging (MRI)–staged T3, N0 to N2, M0 rectal adenocarcinoma within 12 cm from the anal verge were randomly assigned to receive short-course radiation therapy (25 Gy in five fractions) followed by surgery 3 to 7 days later or long-course chemoradiation therapy (50.4 Gy in 28 fractions with concurrent continuous infusional 5-FU) followed by surgery in 4 to 6 weeks. All patients received adjuvant chemotherapy (5-FU/LV) after surgery. The trial was designed to have 80% power to detect a 10% difference in local recurrence at 3 years with a two-sided test at the 5% level of significance.[7]

Cumulative incidence of local recurrence at 3 years was 7.5% for the short-course group and 4.4% for the long-course group (P = .24).

In the TROG trial (TROG 01.04 [NCT00145769]), 326 patients with ultrasound-staged or magnetic resonance imaging (MRI)–staged T3, N0 to N2, M0 rectal adenocarcinoma within 12 cm from the anal verge were randomly assigned to receive short-course radiation therapy (25 Gy in five fractions) followed by surgery 3 to 7 days later or long-course chemoradiation therapy (50.4 Gy in 28 fractions with concurrent continuous infusional 5-FU) followed by surgery in 4 to 6 weeks. All patients received adjuvant chemotherapy (5-FU/LV) after surgery. The trial was designed to have 80% power to detect a 10% difference in local recurrence at 3 years with a two-sided test at the 5% level of significance.[7]

The OS rate at 5 years was 74% for the short-course group and 70% for the long-course group (HR, 1.12; 95% CI, 0.76–1.67; P = .62).

The Medical Research Council of the United Kingdom and the National Cancer Institute of Canada built on the short-course experience and conducted a randomized study (MRC CR07 and NCIC-CTG C016 [NCT00003422]) that compared short-course preoperative radiation therapy with selective postoperative chemoradiation therapy.[8] In the trial, 1,350 patients from 80 centers who had resectable rectal adenocarcinomas that were less than 15 cm from the anal verge were randomly assigned. Of note, pelvic MRI or ultrasound was not mandated. Patients randomly assigned to short-course radiation therapy received 25 Gy in five fractions followed by total mesorectal excision and then adjuvant chemotherapy according to the local center policy about nodal and margin status. Patients randomly assigned to selective postoperative chemoradiation therapy received immediate surgery followed by postoperative chemoradiation (45 Gy in 25 fractions with concurrent 5-FU) if their circumferential resection margin was 1 mm or smaller. Adjuvant chemotherapy for the group that received selective chemoradiation therapy was again given based on local standards regarding nodal and margin status.[8]

The Medical Research Council of the United Kingdom and the National Cancer Institute of Canada built on the short-course experience and conducted a randomized study (MRC CR07 and NCIC-CTG C016 [NCT00003422]) that compared short-course preoperative radiation therapy with selective postoperative chemoradiation therapy.[8] In the trial, 1,350 patients from 80 centers who had resectable rectal adenocarcinomas that were less than 15 cm from the anal verge were randomly assigned. Of note, pelvic MRI or ultrasound was not mandated. Patients randomly assigned to short-course radiation therapy received 25 Gy in five fractions followed by total mesorectal excision and then adjuvant chemotherapy according to the local center policy about nodal and margin status. Patients randomly assigned to selective postoperative chemoradiation therapy received immediate surgery followed by postoperative chemoradiation (45 Gy in 25 fractions with concurrent 5-FU) if their circumferential resection margin was 1 mm or smaller. Adjuvant chemotherapy for the group that received selective chemoradiation therapy was again given based on local standards regarding nodal and margin status.[8]

The risk of local recurrence at 3 years was 4.4% in the preoperative short-course group and 10.6% in the selective chemoradiation therapy group (HR, 0.39; 95% CI, 0.27–0.58; P < .0001).

The Medical Research Council of the United Kingdom and the National Cancer Institute of Canada built on the short-course experience and conducted a randomized study (MRC CR07 and NCIC-CTG C016 [NCT00003422]) that compared short-course preoperative radiation therapy with selective postoperative chemoradiation therapy.[8] In the trial, 1,350 patients from 80 centers who had resectable rectal adenocarcinomas that were less than 15 cm from the anal verge were randomly assigned. Of note, pelvic MRI or ultrasound was not mandated. Patients randomly assigned to short-course radiation therapy received 25 Gy in five fractions followed by total mesorectal excision and then adjuvant chemotherapy according to the local center policy about nodal and margin status. Patients randomly assigned to selective postoperative chemoradiation therapy received immediate surgery followed by postoperative chemoradiation (45 Gy in 25 fractions with concurrent 5-FU) if their circumferential resection margin was 1 mm or smaller. Adjuvant chemotherapy for the group that received selective chemoradiation therapy was again given based on local standards regarding nodal and margin status.[8]

OS did not differ between the groups.