A.P. Bercz1, R. Rosen1, P.B. Paty1, A. Cercek2, E. Pappou1, P.B. Romesser3, J. Garcia-Aguilar1, J.J. Smith1 1Memorial Sloan-Kettering Cancer Center, Colorectal Surgery, New York, NY, USA 2Memorial Sloan-Kettering Cancer Center, Gastrointestinal Oncology, New York, NY, USA 3Memorial Sloan-Kettering Cancer Center, Radiation Oncology, New York, NY, USA
Introduction: Rectal strictures noted by endoscopy following total neoadjuvant therapy (TNT) in the context of an overall robust treatment response can occur; however their management is poorly described. The MSK Regression Schema, a widely utilized reference assessing candidacy for watch-and-wait (WW) management, does not factor the presence of strictures into the tiers of clinical response. Furthermore, endoscopic features of strictures which may confer favorable oncologic outcomes with WW have not been defined.
Methods: Medical records of rectal cancer patients treated from 2006-2020 were appraised with specific attention given to endoscopic findings at initial post-TNT reassessment. Cases documenting evidence of rectal stricture (key terms: “stricture,” “stenosis,” and “narrowing”) were included. Strictures were categorized as “smooth” if pale, white scar was the only additional endoscopic finding, or “irregular” if associated with the presence of mucosal irregularities, nodularities, ulcerations, erythema, or adenomatous tissue. Clinicopathologic data was collected including success of organ preservation (OP), incidences of local and distant recurrences, and pathologic complete response (pCR) versus incomplete response for those managed by surgery. Comparison of percentages were analyzed with Fisher’s test.
Results: 43 patients with rectal strictures following TNT were identified (Figure 1), constituting 23 (53%) smooth strictures and 20 (47%) irregular strictures. WW was pursued in 14/23 (61%) patients with smooth strictures and 5/20 (25%) with irregular strictures. OP was achieved in 11/14 (79%) patients with smooth strictures and 3/5 (60%) with irregular strictures with median follow-up of 3.5 years post-TNT completion, P=0.57. Three of the 14 (21%) patients who maintained OP developed distant failure, all occurring in cases with smooth strictures. Local regrowth occurred in 5/19 (26%) WW patients, of which one subsequently developed local recurrence and two developed distant recurrences. Of the 24 patients who underwent upfront surgery, pCR occurred in 50% of patients, including 7/9 (78%) of smooth strictures and 5/15 (33%) of irregular strictures, P=0.089. There were no (0/12) distant recurrences in patients achieving pCR, whereas 4/12 (33%) non-pCR patients developed distant failure, P=0.093.
Conclusions: The presence of smooth versus irregular stricture features is not associated with success of OP, microscopic residual disease, or distant disease progression. However, strictures which do not harbor residual carcinoma are associated with excellent control of pelvic and distant disease, regardless of smooth or irregular features at restaging.