- MRI criteria effectively select “good-prognosis” patients with rectal cancer who could have primary surgery and forgo preoperative chemoradiotherapy.
- The authors say that preoperative chemoradiotherapy might not be needed for all stage II/III rectal cancer.
Why this matters
- Current recommendation is chemoradiotherapy before surgery for stage II/III rectal cancer, which decreases risk for local recurrence but offers no survival or functional outcome improvement.
- Prospective, nonrandomized, multicenter phase 2 Quicksilver study ; 82 patients with new diagnosis, Canada, September 30, 2014 to October 21, 2016.
- MRI criteria for “good prognosis” lesions:
- distance to mesorectal fascia >1 mm;
- definite T2, T2/early T3, definite T3
- absent or equivocal extramural venous invasion.
- Patients identified as having “good-prognosis” tumors had only primary surgery.
- Outcome: proportion in study with positive circumferential margin rate.
- Funding: Mount Sinai Hospital-University Health Network Academic Medical Organization Innovation Fund.
- The final pathology for tumors identified using MRI criteria:
- 91% T2 or greater;
- 29% node-positive;
- 59% stage II/III.
- Positive circumferential margin rate: 4 of 82 (4.9%; 95% CI, 0.2%-9.6%).
- 88% with stage II/III received no form of chemotherapy.
- High-volume centers, highly experienced clinicians, generalizability unclear.