Rectal Cancer Watch-and-Wait Management of Patients With Tumors Within Versus Beyond the Reach of Digital Rectal...

Watch-and-wait management (WW) of rectal cancer is accepted for select patients with a complete clinical response (cCR) to neoadjuvant therapy (NAT). The appropriateness of WW for cancers beyond the reach of digital rectal examination (DRE) and/or with a delayed cCR is unclear.

In this retrospective multicenter study, tumor palpability and clinical response were determined after NAT. Local regrowth-free survival (LRFS), disease-free survival (DFS), rectal organ preservation (OP), and salvage surgery outcomes were assessed.

Among 477 patients, 427 (90%) had palpable tumers, with initial cCR in 389 (91%) and delayed cCR in 38 (9%) patients, respectively, whereas 50 (10%) had nonpalpable tumors, with initial pCR in 38 (76%) and delayed pCR in 12 (24%) patients, respectively (p < 0.01). The 3-year LRFS rate was 81.4% (95% confidence interval [CI], 76.6-86.2%) for palpable tumors and 74.3% (95% CI, 61.0-88.6%) for nonpalpable tumors. The DFS rates were 80.8 % (95 % CI, 75.9-85.7%) and 74.3% (95% CI, 61.0-88.6%), respectively. The 3-year rectal OP rate was 82.7% (95% CI, 77.9-87.5%) and 76.0% (95%, CI, 62.9-89.1%), respectively, with no difference in the survival curves for these three outcomes. (all p > 0.05). The patients with initial cCR or delayed cCR also had no differences in LRFS, DFS, or OP, but the interval to each of these outcomes were decreased with delayed cCR (all p < 0.01).

Watch-and-wait management of rectal tumors beyond the reach of DRE is appropriate, with oncologic and rectal organ preservation rates that do not differ from patients with palpable tumors. In comparison to cancers with initial cCR, cancers with delayed cCR have accelerated intervals to local regrowth, disease recurrence, and rectal organ loss.