Loading
Rectal cancer is bowel cancer in the last part of the large intestine, where surgery can mean a permanent stoma. Treatment now usually gives all the chemotherapy and radiotherapy first, and about half of people whose tumour disappears completely can keep their rectum and avoid surgery altogether.
Rectal cancer is staged by pelvic MRI, which shows the depth of invasion, the distance to the mesorectal fascia, extramural venous invasion and nodal disease and so decides who needs treatment before surgery. Total mesorectal excision, described by Heald in 1982, cut local recurrence from a quarter of patients to well under a tenth, and the German CAO/ARO/AIO-94 trial (2004) moved chemoradiation to before surgery, halving local recurrence again. Early tumours (cT1-2, node-negative) go straight to surgery, and small T1 tumours can be removed through the anus.
For locally advanced disease the sequence has been rebuilt as total neoadjuvant therapy: RAPIDO (2020) gave one week of radiotherapy then all the chemotherapy before surgery and cut distant failure and doubled complete responses; PRODIGE 23 (2021) gave induction mFOLFIRINOX before chemoradiation and improved disease-free and, later, overall survival. OPRA (2022) showed that with chemoradiation followed by consolidation chemotherapy about half of patients could avoid surgery through watch and wait without losing disease control, building on the Habr-Gama series from Sao Paulo. PROSPECT (2023) then showed that intermediate-risk tumours suitable for sphincter-sparing surgery can be treated with FOLFOX alone, with radiotherapy reserved for the 9 percent who do not respond.
The 5 to 10 percent of rectal cancers that are mismatch-repair deficient respond so completely to PD-1 blockade that surgery and radiotherapy can be omitted: in the Memorial Sloan Kettering study every patient treated with six months of dostarlimab had a clinical complete response (NEJM 2022, expanded 2025), and AZUR-1 is the registration study. Metastatic rectal cancer is treated as metastatic colorectal cancer, by genotype and sidedness. Open questions are how to select watch and wait safely, whether circulating tumour DNA can guide surveillance, and how to reduce the bowel, sexual and urinary harm that survivors carry.
About a third of colorectal cancers start in the rectum, the last 15 cm of the bowel; because the rectum sits in the narrow pelvis next to the bladder, sexual organs and sphincter, local recurrence, stomas and function matter more than for colon cancer.
Right-sided tumours behave differently from left-sided and rectal ones; the colon drains along its mesenteric vessels, the rectum into the mesorectum and pelvic side wall.
Same organ: Colon cancer (adenocarcinoma of the colon), Micropapillary adenocarcinoma of the colon and rectum, Adenoma-like adenocarcinoma of the colon and rectum, Lynch syndrome-associated colorectal cancer, Familial adenomatous polyposis-associated colorectal cancer, Mucinous adenocarcinoma of the colon and rectum, Signet ring cell carcinoma of the colon and rectum, Medullary carcinoma of the colon, Serrated adenocarcinoma of the colon and rectum, Peritoneal mesothelioma, Colorectal cancer, Mismatch-repair deficient (MSI-high) colorectal cancer, BRAF V600E-mutant colorectal cancer, HER2-amplified colorectal cancer, KRAS G12C-mutant colorectal cancer, Early-onset colorectal cancer (under 50), Anal cancer (squamous cell carcinoma), Appendiceal cancer and pseudomyxoma peritonei, Small intestine cancer (small bowel adenocarcinoma), Small intestinal neuroendocrine tumours, Anal high-grade squamous intraepithelial lesions (precursor), Localised anal squamous cell carcinoma (stage I to III), Metastatic and recurrent anal squamous cell carcinoma, Low-grade appendiceal mucinous neoplasm and pseudomyxoma peritonei, Appendiceal adenocarcinoma (mucinous and non-mucinous, including signet ring cell), Goblet cell adenocarcinoma of the appendix, Localised small bowel adenocarcinoma (stage I to III, resected), Advanced and metastatic small bowel adenocarcinoma
Nothing recorded yet.
Also on OnCo: Symptoms and red flags · Early detection roadmap.
Total mesorectal excision, increasingly robotic or laparoscopic; transanal local excision for small, well-differentiated T1 tumours; no radiotherapy.
Total neoadjuvant therapy: short-course radiotherapy then CAPOX or FOLFOX (RAPIDO), or induction mFOLFIRINOX then chemoradiation (PRODIGE 23); chemoradiation then consolidation chemotherapy when organ preservation is the goal (OPRA); surgery or watch and wait for complete responders.
Six cycles of FOLFOX with chemoradiation only if the tumour shrinks by less than 20 percent (PROSPECT), then total mesorectal excision.
Six months of dostarlimab or another PD-1 antibody with non-operative management for complete responders; surgery reserved for the rare non-responder.
As metastatic colorectal cancer: doublet chemotherapy with bevacizumab or, for RAS and BRAF wild-type left-sided tumours, an anti-EGFR antibody; primary tumour managed by symptoms; liver-limited disease resected.
Trials recruiting now, the landmark trials, the trials held by this cancer's subtypes, the key papers and what they mean, the latest literature, and the milestones year by year.
The targets of this cancer's medicines and the ones linked to it directly.
Cases by country, the UK and NHS pathway and other country lenses, the expert centres with trials on record, and the centres named on this cancer's subtypes.
One section per setting: the options named, what each is for, the trials behind them, the recorded trade-offs and the questions to ask.
Answer a few questions from a report and read the guideline statement that applies, quoted word for word with its source. Educational aids to prepare for an appointment, not advice.
Bleeding that does not stop by itself, bleeding from more than one site, or new bruising in several places or one large area.
Sudden severe abdominal pain, a hard or very tender abdomen, or abdominal pain with vomiting and fever. Boxed warning for gastrointestinal perforation on bevacizumab.
Persistent headache with extreme tiredness, nausea, dizziness on standing or low blood pressure. Vomiting, severe weakness or collapse is adrenal crisis.
The bowel cancer regimens share low blood counts, tiredness, sickness and a sore mouth. Oxaliplatin adds cold-triggered tingling, irinotecan adds early and late diarrhoea, capecitabine adds hand-foot syndrome and needs a DPD test first, and cetuximab or panitumumab add an acne-like rash and low magnesium. The rule for all of them: ring the 24-hour number rather than wait.
The shared side effects of drugs that block blood vessel growth (bevacizumab, ramucirumab and VEGFR kinase inhibitors): high blood pressure, protein leaking into the urine, nosebleeds and more serious bleeding, slow wound healing, and rarely holes in the bowel.
Reactions around the moment a drug is given: chills, fever or breathlessness from antibodies (infusion reactions), true allergy (hypersensitivity, rarely anaphylaxis), and leakage of a damaging drug into tissue around the vein (extravasation).
See all on the product pages:BevacizumabCAPOX (capecitabine, oxaliplatin)CetuximabDostarlimabFOLFIRI (5-FU, leucovorin, irinotecan)FOLFOX (5-FU, leucovorin, oxaliplatin)Panitumumab·Printable cards in the navigator
Newly diagnosed? Read the first 60 days with Rectal cancer, then print the one-page appointment sheet with room for the answers.
Print this page for your appointment (your browser's print command). These prompts are for discussion; your clinical team knows your case.
Everything in development, the medicines held by this cancer's subtypes, the open problems and what is being done about them, the roadmaps, and what changed on this record.
Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked.