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Source created 2026-08-24 · updated 2026-08-24
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ASCRS Ch28 - Rectal Cancer Nonoperative Management

Citation

Garcia-Aguilar J, Perez RO. Rectal Cancer: Nonoperative Management. In: Steele SR, et al., eds. The ASCRS Textbook of Colon and Rectal Surgery, 4th ed. Springer; 2022. pp. 491–508 (book pagination; References end p. 508).

Scope

Twenty-eighth chapter of the ASCRS 4th-edition textbook (sixth of Part III, Colorectal Cancer) — the textbook's dedicated chapter on the Watch and Wait (WW) organ-preservation strategy for rectal cancer patients achieving a complete or near-complete clinical response to neoadjuvant therapy. Covers terminology and definitions, the rationale for organ preservation, patient/tumor selection criteria, assessment of tumor response (clinical, endoscopic, radiological), surveillance/follow-up strategy, local regrowth and its management, systemic recurrence risk, oncologic and functional outcomes, and emerging tools for predicting tumor response.

Key content and reconciliation approach

This is genuinely new ground for the wiki — no dedicated page previously existed for Watch and Wait/ non-operative management. The topic was previously touched only briefly: Rectal Cancer's "Evolution of treatment" section has a short paragraph (from the Sabiston chapter, citing Habr-Gama) noting WW's origin and that it's "not currently standard of care," and Total Neoadjuvant Therapy (TNT)'s "Surgery and non-operative management (NOM)" section has primary-literature-sourced content on NOM eligibility, locoregional/distant relapse rates, and the OPRA trial's TME-free survival data.

  • New concept page created: concepts/Watch and Wait (Nonoperative Management).md — a full treatment of terminology (pCR/cCR/ypT0N0, local regrowth vs. local recurrence, accidental vs. intentional WW), primary tumor assessment/selection criteria (including the mrCRM/EMVI/N-stage/ LPNM indications for nCRT that determine WW candidacy), tumor location considerations, response assessment methodology (the three-tier clinical-response classification and its DRE/endoscopy/MRI components, mrTRG), surveillance/follow-up protocol, local regrowth and systemic recurrence rates, oncologic outcomes (including the DFS-vs-OS distinction seen in pooled analyses), functional outcomes/quality of life, and emerging tumor-response-prediction research (genomic markers, DNA repair gene scores, patient-derived organoids).
  • Total Neoadjuvant Therapy (TNT)'s existing NOM section is cross-linked to, not duplicated: that section's primary-literature-sourced content (locoregional relapse 20–40%, distant metastatic risk 5–15%, the OPRA trial's TME-free survival data) remains authoritative for those specific figures; this chapter's textbook-level pooled-analysis figures (e.g. 2-year regrowth rate 15.7% per one pooled analysis) are reported on the new page as a related but distinct data point, not merged.
  • Rectal Cancer's brief watch-and-wait paragraph is extended with a pointer to the new page rather than expanded in place, resolving that page's own previously-flagged "watch-and-wait protocol specifics ... not detailed" open item.

Limitations

  • Textbook chapter, not primary literature. The chapter itself is explicit about the limitations of the WW evidence base: current evidence is based on retrospective institutional case series with strong potential for selection bias, heterogeneous patient populations/staging/regimens, and inconsistent response-assessment criteria and follow-up length — it explicitly states a randomized trial of WW vs. proctectomy is unlikely to be feasible.
  • Individual studies cited within (Maas et al. on DRE/endoscopy/MRI accuracy, the pooled analysis reporting 15.7% 2-year regrowth, the OPRA trial referenced by name here as well as more thoroughly documented via TNT.md, prediction-of-response studies) are not independently ingested from primary publications on this wiki.

Relevance

Establishes a new, substantial concept page on Watch and Wait/NOM — the wiki's first dedicated treatment of this topic — cross-linked into both Total Neoadjuvant Therapy (TNT) and Rectal Cancer rather than duplicating either page's existing content.