EssentialFRCS
Sign inStart free

Colorectal surgery

Major Clinical Specialty Areas · 41 questions · 1 free to try

Colorectal cancer staging, neoadjuvant and adjuvant therapy and surveillance, hereditary bowel cancer, polyp surveillance, inflammatory bowel disease including acute severe colitis, diverticular disease, anal cancer, and the benign proctology of fissures, haemorrhoids, fistulas and prolapse.

Every question in this topic is a single best answer item in the style of the exam, followed by an explanation that gives the reasoning for the correct option, why each distractor is wrong, a key point to carry into the exam and, where one applies, the guideline or trial it rests on. Practice mode lets you work through the topic on its own or mixed with others; exam mode draws it into timed papers.

Sample question from this topic

A 61-year-old man is diagnosed with adenocarcinoma of the mid rectum at 8 cm on colonoscopy performed for rectal bleeding. Staging CT of the chest, abdomen and pelvis shows no metastases. Pelvic MRI reports a T3c tumour with three suspicious mesorectal nodes and tumour extending to within 0.5 mm of the mesorectal fascia anteriorly; there is extramural venous invasion. He is fit, with performance status 0. What is the most appropriate initial management?

  1. AImmediate anterior resection with total mesorectal excision, giving adjuvant chemotherapy guided by histology
  2. BShort-course radiotherapy (25 Gy in five fractions) with surgery within one week
  3. CLocal excision by transanal endoscopic microsurgery
  4. DNeoadjuvant long-course chemoradiotherapy (or total neoadjuvant therapy) followed by restaging and planned resection
  5. EPalliative chemotherapy
Show answer and explanation

Correct answer: D

MRI is the cornerstone of rectal cancer staging precisely because it defines the relationship of tumour to the mesorectal fascia — the intended circumferential resection margin of total mesorectal excision. Tumour within 1 mm of the fascia means the margin is threatened: operating first risks an involved margin, which is the strongest predictor of local recurrence. Such patients receive neoadjuvant long-course chemoradiotherapy (increasingly delivered as total neoadjuvant therapy with systemic chemotherapy incorporated before surgery), aiming to downstage the tumour and sterilise the threatened margin, followed by restaging MRI and total mesorectal excision after an appropriate interval. The nodal burden and extramural venous invasion reinforce the case for neoadjuvant treatment.

Why the others are wrong: A — surgery first with a threatened margin invites an R1 resection and pelvic recurrence, which is usually incurable. B — short-course radiotherapy with immediate surgery suits resectable tumours with clear margins needing modest risk reduction; it does not provide the downstaging a threatened margin requires (though short-course with delayed surgery features within some total neoadjuvant protocols). C — local excision is for selected early T1 tumours; a T3c node-positive cancer would be grossly undertreated. E — there is no metastatic disease; intent is curative.

Key point: Rectal cancer within 1 mm of the mesorectal fascia on MRI has a threatened circumferential margin and requires neoadjuvant (chemo)radiotherapy to downstage before total mesorectal excision, never immediate surgery.

Guidelines: NICE colorectal cancer guidance (NG151): preoperative chemoradiotherapy (or total neoadjuvant therapy, per RAPIDO and PRODIGE-23 evidence) for MRI-defined locally advanced rectal cancer with threatened margins.

Practise colorectal surgery questions

A free account includes questions from every part of the syllabus, including 1 from this topic. Subscribe for all 41 in this topic and the rest of the bank.

Create your free account

Other topics in Major Clinical Specialty Areas