A 71-year-old with a threatened mesorectal margin, a 0.9 L FEV1 and an absolute refusal of a stoma
A 71-year-old woman presents with 3 months of rectal bleeding and tenesmus. Rigid sigmoidoscopy shows a circumferential, ulcerated tumour 5 cm from the anal verge; biopsy confirms moderately differentiated adenocarcinoma. MRI shows a T3 tumour with extramural venous invasion, two suspicious mesorectal nodes, and a mesorectal fascia margin of 1 mm on the right; the tumour abuts but does not invade the internal sphincter. CT shows no distant metastases; CEA is 12 ng/mL. She lives alone, walks 100 m before stopping because of COPD, has an FEV1 of 0.9 L, and takes prednisolone for emphysema. She is independent in all activities of daily living but is frightened of anaesthesia. Her daughter, a nurse, has told her that "surgeons always give you a bag", and she states firmly that she would rather take her chances than have a permanent stoma.
1. What staging information do you need before any treatment, and why does MRI change management more than CT does?
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Staging before treatment:
- Tissue diagnosis with grade and molecular markers (mismatch repair/MSI status; RAS and BRAF if metastatic disease is contemplated).
- High-resolution MRI of the pelvis: depth of invasion and extramural spread (T3), nodal status, distance from the anal verge, relationship to the internal sphincter and puborectalis, extramural venous invasion, and above all the circumferential resection margin - hers is 1 mm, which is threatened.
- Distant staging with CT of chest, abdomen and pelvis; baseline CEA; rigid sigmoidoscopy with a measured height.
- PET-CT is not routine.
Why MRI matters more: CT cannot resolve the mesorectal fascia or sphincter complex. The circumferential margin is the strongest predictor of local recurrence after total mesorectal excision, and a threatened margin of 1 mm or less is the principal indication for preoperative radiotherapy. MRI also defines whether sphincter-preserving surgery is anatomically achievable, because a tumour invading the sphincter commits the patient to abdominoperineal excision. Extramural venous invasion and nodal positivity independently raise recurrence risk and support neoadjuvant treatment. In this patient, MRI converts an apparently straightforward operable cancer into a borderline-margin case and therefore sets the sequence of treatment - something CT alone could not have done.
2. Justify neoadjuvant treatment for this tumour and set out the operative options, including the limitations of "watch and wait".
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The case for neoadjuvant long-course chemoradiotherapy (45–50.4 Gy in 25–28 fractions with concurrent capecitabine or 5-fluorouracil): a T3 tumour with a 1 mm circumferential margin, extramural venous invasion and suspicious nodes carries a high local recurrence risk. Preoperative radiotherapy shrinks the tumour, sterilises the threatened margin and reduces local recurrence even when the margin is ultimately clear at surgery. It is not given to improve survival - that remains unproven - so consent must be honest about a modest absolute reduction in local recurrence, temporary bowel and bladder symptoms, and a risk of pelvic insufficiency fracture. Restaging MRI is repeated 6–8 weeks after completion, with surgery at about 8–12 weeks.
Operative options:
- Total mesorectal excision is the standard. Low anterior resection with coloanal anastomosis and a defunctioning ileostomy is feasible if a clear margin of at least 1 mm from the sphincter can be achieved after downsizing.
- Abdominoperineal excision with an end colostomy if the sphincter is involved.
- Watch and wait is appropriate only for a complete clinical response confirmed by MRI, endoscopy and examination, ideally within a protocol of intense surveillance. It is not an alternative to surgery with residual tumour, and 25–30% of complete responders still regrow locally. She is also a poor candidate for later salvage surgery because of her lungs.
- Her FEV1 of 0.9 L mandates cardiopulmonary exercise testing, smoking cessation and chest physiotherapy. Laparoscopy reduces wound complications, but pneumoperitoneum and steep positioning must be weighed against her respiratory reserve. Prednisolone increases anastomotic and infective risk and should be tapered if possible.
3. She refuses any operation that will leave a permanent stoma. How do you handle this, and what are your professional obligations if she continues to refuse?
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First, understand the fear rather than argue with it. "A bag" often means a permanent, life-limiting disability in the patient's imagination, and the daughter's remark has reinforced that. I would explain that most low rectal cancers are treated without a permanent stoma, that a temporary ileostomy is usually reversed, that neoadjuvant treatment may shrink the tumour and make sphincter preservation possible, and that no decision about a permanent stoma needs to be made today. I would involve the stoma nurse specialist early, with photographs and patient accounts, and offer a second surgical opinion plus a clinical nurse specialist as a continuing contact. I would ask the daughter to step back so the patient's own wishes are heard.
Capacity is the key. If she understands the information, retains it, weighs it and communicates a choice, she has capacity and her refusal must be respected even if it risks her life. I cannot operate against a capacitous refusal, and I must not make surgery conditional on accepting a stoma. I would document the discussion, what was offered, and that she understood the consequences of declining.
I would offer the alternatives she is entitled to consider - a period of chemoradiotherapy with reassessment, or best supportive care - and keep the door open. If her wishes appear driven by coercion or by depression, or if conflict with the family is irreconcilable, I would seek a psychiatry or ethics committee opinion. The obligation is to inform and support, not to persuade by fear.