Top Line: Data is mounting in favor of a modest radiation boost for locally advanced rectal cancer.
The Study: This Chinese phase 2 trial randomized 106 patients receiving standard neoadjuvant pelvic radiation via IMRT 50 Gy in 25 fractions with concurrent capecitabine to +/- a simultaneous integrated boost (SIB) to 56 Gy for the primary tumor/mesorectal region and 60 Gy for involved lateral pelvic nodes (clinically apparent in 18%). Ultimately, 22% of the SIB group and 26% without SIB did not undergo surgery. At a median follow-up of nearly 10 years, an SIB did not improve pathologic complete response rate (15% with SIB vs 18% without). But outcomes diverged when it came to long-term disease control and survival: at 9 years local control was 87% with SIB v 70% (HR 0.40), disease-free survival was 71% vs 47% (HR 0.46), and overall survival 74% vs 49% (HR 0.43). The benefit appeared particularly pronounced among patients who did not receive perioperative dedicated chemotherapy.
TBL: In this phase 2 trial a 6-Gy boost to the primary tumor and 10-Gy boost to involved lateral nodes was associated with striking survival gains without increasing toxicity. | Gastrointestinal
The Study: This Chinese phase 2 trial randomized 106 patients receiving standard neoadjuvant pelvic radiation via IMRT 50 Gy in 25 fractions with concurrent capecitabine to +/- a simultaneous integrated boost (SIB) to 56 Gy for the primary tumor/mesorectal region and 60 Gy for involved lateral pelvic nodes (clinically apparent in 18%). Ultimately, 22% of the SIB group and 26% without SIB did not undergo surgery. At a median follow-up of nearly 10 years, an SIB did not improve pathologic complete response rate (15% with SIB vs 18% without). But outcomes diverged when it came to long-term disease control and survival: at 9 years local control was 87% with SIB v 70% (HR 0.40), disease-free survival was 71% vs 47% (HR 0.46), and overall survival 74% vs 49% (HR 0.43). The benefit appeared particularly pronounced among patients who did not receive perioperative dedicated chemotherapy.
TBL: In this phase 2 trial a 6-Gy boost to the primary tumor and 10-Gy boost to involved lateral nodes was associated with striking survival gains without increasing toxicity. | Gastrointestinal