The magnetic resonance imaging-based approach for identification of high-risk patients with upper rectal cancer.
OBJECTIVE
To assess the efficacy of preoperative magnetic resonance imaging (MRI) in identifying upper rectal cancer patients who are at high risk for local recurrence.


METHODS
110 upper rectal cancer patients with locally advanced (pT3-4N0 or pTanyN+) tumors treated with tumor-specific mesorectal excision and no adjuvant radiotherapy were identified from an institutional database at a large academic medical center in Korea. Information on the extent of mesorectal invasion, sacral-side involvement was collected from preoperative MRI.


RESULTS
At a median follow-up of 47 months, 5 patients (4.5%) experienced local recurrence (LR). LR rates for patients with intermediate risk (T1-2/N1, T3N0), moderately high risk (T1-2/N2, T3N1, T4N0), and high risk (T3N2, T4/N1-2) were 3%, 4.8%, and 8.7%, respectively. Patients who did not have sacral-side involvement or mesorectal invasion of 5 mm or less did not experience LR. The patients with sacral-side involvement and intermediate risk, moderately high risk, and high risk had an LR rate of 4.2%, 5.6%, and 10%, respectively, or 11.1%, 33.3%, and 18.2%, respectively, when combined with those with mesorectal invasion of greater than 5 mm. Multivariate analyses demonstrated the presence of both sacral-side location and mesorectal invasion of greater than 5 mm was significantly associated with adverse disease-free and overall survival (P < 0.05).


CONCLUSIONS
Patients with mesorectal invasion of greater than 5 mm and sacral-side involvement identified on MRI were at an increased risk of local recurrence. The detection of these features on MRI provides prognostic information that is not available in conventional risk classification systems. Improved identification of a high-risk subset of upper rectal cancer patients may guide indications for preoperative chemoradiotherapy in this subset.
Departments of *Radiation Oncology †Radiology ‡Surgery §Yonsei Cancer Research Institute, Yonsei University College of Medicine, Seoul, Korea.
Jee Suk
JS
Chang
Youngin
Y
Lee
Joon Seok
JS
Lim
Nam Kyu
NK
Kim
Seung Hyuk
SH
Baik
Byung So
BS
Min
Hyuk
H
Huh
Woong Sub
WS
Koom
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery; D056910:Republic of Korea; D012189:Retrospective Studies; D018570:Risk Assessment
D003287:Contrast Media; D019786:Gadolinium DTPA