# Operative versus nonoperative treatment for stage 0 distal rectal cancer following chemoradiation therapy: long-term results

Source: https://onco.cc/key-papers/paper-habr-gama-nonoperative-stage-0-rectal-ann-surg-2004/  
OnCo record `paper-habr-gama-nonoperative-stage-0-rectal-ann-surg-2004` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

In São Paulo, Angelita Habr-Gama simply watched the patients whose rectal cancers had disappeared after chemoradiotherapy instead of operating. Ten-year survival was 98 percent, and she had invented watch and wait.

## Summary

Habr-Gama, Perez, Nadalin and colleagues treated 265 patients with resectable distal rectal adenocarcinoma with neoadjuvant chemoradiation using fluorouracil, leucovorin and 5,040 cGy. Patients with an incomplete clinical response were referred for radical surgical resection. Those with a complete clinical response treated without operation (the observation group) were compared with those whose incomplete clinical response was treated surgically and whose specimens proved to be stage p0 (the resection group).

In the resection group nine definitive colostomies and seven diverting temporary ileostomies were performed, which is the morbidity the observation strategy avoids.

## Fields

- Kind: Key paper
- Last checked: 2026-09-24
- Tags: colorectal-evidence
- Journal: Annals of Surgery
- Year: 2004
- DOI: 10.1097/01.sla.0000141194.27992.32
- Authors: Habr-Gama A, Perez RO, Nadalin W, et al.
- Findings: Overall and disease-free ten-year survival across the series 97.7 percent and 84 percent.; Complete clinical response after chemoradiation in 71 of 265 patients (26.8 percent), managed without operation.; Twenty-two patients (8.3 percent) had an incomplete clinical response and pT0N0M0 resected specimens.; Five-year overall and disease-free survival 100 percent and 92 percent in the observation group against 88 percent and 83 percent in the resection group.; Three systemic recurrences in each group and two endorectal recurrences in the observation group.
- What it means: The origin of organ preservation in rectal cancer. Twenty years later OPRA made it a planned strategy and the dostarlimab series made it the expected outcome in mismatch repair-deficient disease.
- Caveats: A single-centre non-randomised comparison of two groups defined by their response, so the comparison is confounded by prognosis.; Clinical complete response was assessed without modern MRI restaging, and local regrowth rates in later series are higher than reported here.; Long follow-up but no central review.

## Sources

- Ann Surg 2004: https://doi.org/10.1097/01.sla.0000141194.27992.32
- PubMed: https://pubmed.ncbi.nlm.nih.gov/15383798/

## Connected records

- key papers: [Dostarlimab alone cures mismatch-repair-deficient rectal cancer without surgery or radiotherapy](https://onco.cc/key-papers/paper-cercek-dmmr-rectal-nejm-2022/), [Organ preservation in patients with rectal adenocarcinoma treated with total neoadjuvant therapy (OPRA)](https://onco.cc/key-papers/paper-garcia-aguilar-opra-organ-preservation-jco-2022/)
- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Rectal cancer](https://onco.cc/cancers/rectal-cancer/)
- fronts: [Radiation Therapy](https://onco.cc/fronts/radiation/), [Surgery & Interventional](https://onco.cc/fronts/surgery/)
- terms: [Chemoradiation (chemoradiotherapy, CRT)](https://onco.cc/terms/chemoradiation/), [Clinical complete response (cCR)](https://onco.cc/terms/clinical-complete-response/), [Complete response](https://onco.cc/terms/complete-response/), [Organ preservation (watch-and-wait, bladder-sparing, larynx preservation)](https://onco.cc/terms/organ-preservation/), [Radiotherapy](https://onco.cc/terms/radiotherapy/)
- people: [Angelita Habr-Gama](https://onco.cc/people/angelita-habr-gama/)
- bottlenecks: [Surgery and radiotherapy cure most, get least](https://onco.cc/bottlenecks/b-surgery-radiation-innovation/), [Toxicity and quality of life are undervalued](https://onco.cc/bottlenecks/b-toxicity-qol/)
- roadmaps: [Colorectal cancer roadmap: from the adenoma-carcinoma sequence and the first screening trials to total mesorectal excision, oxaliplatin, RAS testing, immunotherapy for mismatch repair-deficient disease, ctDNA-guided treatment and organ preservation](https://onco.cc/roadmaps/colorectal-roadmap/)
- ideas: [Randomise organ preservation against surgery in mismatch repair-proficient rectal cancer, with bowel function as a co-primary endpoint](https://onco.cc/ideas/idea-crc-organ-preservation-randomised-in-pmmr-rectal/)

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