# Neoadjuvant / adjuvant / perioperative

Source: https://onco.cc/terms/neoadjuvant-adjuvant/  
OnCo record `neoadjuvant-adjuvant` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Neoadjuvant therapy is treatment given before surgery, adjuvant therapy is treatment given after it, and perioperative therapy is both. Neoadjuvant treatment shrinks tumours and shows whether the drug works in the living patient; adjuvant treatment aims to kill microscopic disease left behind.

## Summary

Neoadjuvant, adjuvant and perioperative therapy mean treatment given before surgery, after surgery, or both; pre-operative and post-operative are the everyday equivalents. Neoadjuvant treatment shrinks tumours, tests drug sensitivity in the living patient through pathologic complete response and can allow surgery to be de-escalated, while adjuvant treatment aims to kill micrometastases. Immunotherapy appears to work better neoadjuvantly, as NADINA and CheckMate 816 suggested, because the primary tumour is still present to supply antigen. The term is anchored to KEYNOTE-522 and referenced by KEYNOTE-671 and SWOG S1801, by the Colorectal, Gastric, Oesophageal, Bladder & urothelial and Head and neck cancer entries, and by the related term Major pathological response (MPR).

## Fields

- Kind: Term
- Last checked: 2026-09-04
- Also known as: adjuvant vs neoadjuvant therapy; adjuvant versus neoadjuvant therapy; neoadjuvant vs adjuvant; pre-operative; preoperative; post-operative; postoperative; post-surgical

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Neoadjuvant_therapy
- Wikipedia: https://en.wikipedia.org/wiki/Neoadjuvant_therapy

## Connected records

- trials: [ACTICCA-1](https://onco.cc/trials/acticca-1/), [ALCHEMIST (Adjuvant Lung Cancer Enrichment Marker Identification and Sequencing Trials)](https://onco.cc/trials/alchemist/), [Alliance A021501](https://onco.cc/trials/alliance-a021501/), [Alliance A021806](https://onco.cc/trials/alliance-a021806/), [ARTISTIC meta-analysis](https://onco.cc/trials/artistic-meta-analysis/), [ATOMIC (Alliance A021502)](https://onco.cc/trials/atomic/), [CheckMate 238](https://onco.cc/trials/checkmate-238/), [CheckMate 577](https://onco.cc/trials/checkmate-577/), [CheckMate 816](https://onco.cc/trials/checkmate-816/), [CROSS](https://onco.cc/trials/cross/), [Dutch TME trial](https://onco.cc/trials/dutch-tme-trial/), [EORTC 22911](https://onco.cc/trials/eortc-22911/), [EORTC 40983](https://onco.cc/trials/eortc-40983/), [ESPAC-1](https://onco.cc/trials/espac-1/), [EV-303 / KEYNOTE-905](https://onco.cc/trials/ev-303/), [FOxTROT](https://onco.cc/trials/foxtrot/), [GAIN (AIO/CALGP/ACO)](https://onco.cc/trials/gain-igbc/), [I-SPY 1 (CALGB 150007/150012, ACRIN 6657)](https://onco.cc/trials/i-spy-1/), [I-SPY 2](https://onco.cc/trials/i-spy-2/), [I-SPY 2.2](https://onco.cc/trials/i-spy-2-2/), [IDEA collaboration](https://onco.cc/trials/idea-collaboration/), [JASPAC 01](https://onco.cc/trials/jaspac-01/), [KEYNOTE-091 (PEARLS)](https://onco.cc/trials/keynote-091/), [KEYNOTE-522](https://onco.cc/trials/keynote-522/), [KEYNOTE-564](https://onco.cc/trials/keynote-564/), [KEYNOTE-671](https://onco.cc/trials/keynote-671/), [KEYNOTE-689](https://onco.cc/trials/keynote-689/), [MATTERHORN](https://onco.cc/trials/matterhorn/), [MOSAIC](https://onco.cc/trials/mosaic/), [NADINA](https://onco.cc/trials/nadina/), [NEONAX](https://onco.cc/trials/neonax/), [Neotorch](https://onco.cc/trials/neotorch/), [NIAGARA](https://onco.cc/trials/niagara/), [NICHE-2](https://onco.cc/trials/niche-2/), [NIVOPOSTOP (GORTEC 2018-01)](https://onco.cc/trials/nivopostop/), [OPT-IN (EA2197)](https://onco.cc/trials/opt-in/), [PETACC-3](https://onco.cc/trials/petacc-3/), [POLCAGB](https://onco.cc/trials/polcagb/), [PREOPANC-1](https://onco.cc/trials/preopanc/), [PREOPANC-2](https://onco.cc/trials/preopanc-2/), [PREOPANC-3](https://onco.cc/trials/preopanc-3/), [QUASAR](https://onco.cc/trials/quasar/), [RADICALS-RT](https://onco.cc/trials/radicals-rt/), [RAVES (TROG 08.03/ANZUP)](https://onco.cc/trials/raves/), [SCOT](https://onco.cc/trials/scot/), [SWOG 8794](https://onco.cc/trials/swog-8794/), [SWOG S1505](https://onco.cc/trials/swog-s1505/), [SWOG S1801](https://onco.cc/trials/swog-s1801/), [TOSCA](https://onco.cc/trials/tosca/)
- cancers: [Adenosquamous carcinoma of the pancreas](https://onco.cc/cancers/pancreatic-adenosquamous-carcinoma/), [Advanced cutaneous squamous cell carcinoma](https://onco.cc/cancers/advanced-cutaneous-scc/), [ALK-positive non-small-cell lung cancer](https://onco.cc/cancers/alk-positive-nsclc/), [Bladder & urothelial cancer](https://onco.cc/cancers/urothelial/), [Borderline resectable pancreatic ductal adenocarcinoma](https://onco.cc/cancers/borderline-resectable-pdac/), [BRCA or PALB2-mutant pancreatic ductal adenocarcinoma](https://onco.cc/cancers/brca-palb2-pdac/), [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Colloid (mucinous non-cystic) carcinoma of the pancreas](https://onco.cc/cancers/pancreatic-colloid-carcinoma/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [EGFR-mutated non-small-cell lung cancer](https://onco.cc/cancers/egfr-mutant-nsclc/), [Gastric & gastro-oesophageal junction cancer](https://onco.cc/cancers/gastric/), [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/), [Invasive carcinoma arising in an intraductal papillary mucinous neoplasm (IPMN-associated carcinoma)](https://onco.cc/cancers/ipmn-associated-carcinoma/), [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Mucinous cystic neoplasm of the pancreas with associated invasive carcinoma (MCN-associated carcinoma)](https://onco.cc/cancers/mcn-associated-carcinoma/), [Oesophageal cancer](https://onco.cc/cancers/esophageal/), [Pancreatic acinar cell carcinoma](https://onco.cc/cancers/pancreatic-acinar-cell-carcinoma/), [Pancreatic ductal adenocarcinoma](https://onco.cc/cancers/pancreatic/), [Pancreatoblastoma](https://onco.cc/cancers/pancreatoblastoma/), [Renal cell carcinoma](https://onco.cc/cancers/rcc/), [Resectable pancreatic ductal adenocarcinoma](https://onco.cc/cancers/resectable-pdac/), [Resectable stage I to III non-small-cell lung cancer](https://onco.cc/cancers/resectable-nsclc/), [Stage IIB and IIC melanoma](https://onco.cc/cancers/stage-ii-melanoma/), [Stage III melanoma (after surgery)](https://onco.cc/cancers/stage-iii-melanoma/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- terms: [Conversion therapy in bowel cancer](https://onco.cc/terms/conversion-therapy-colorectal/), [Debulking (cytoreductive surgery)](https://onco.cc/terms/debulking/), [Downstaging and conversion therapy](https://onco.cc/terms/downstaging/), [Drugs before or after the operation](https://onco.cc/terms/neoadjuvant-versus-adjuvant-breast/), [FLOT regimen (perioperative chemotherapy for gastric cancer)](https://onco.cc/terms/flot-term/), [Locally advanced and locoregional disease](https://onco.cc/terms/locally-advanced/), [Lung cancer trials open today (registry snapshot)](https://onco.cc/terms/lung-trials-open-today/), [Maintenance therapy](https://onco.cc/terms/maintenance-therapy/), [Major pathological response (MPR)](https://onco.cc/terms/major-pathological-response/), [Neoadjuvant therapy versus surgery first for resectable and borderline resectable pancreatic cancer](https://onco.cc/terms/neoadjuvant-versus-upfront-surgery-pancreatic/), [Pancreatic cancer trials open today (registry snapshot and UK sites)](https://onco.cc/terms/pancreatic-trials-open-today/), [Pathologic complete response (pCR)](https://onco.cc/terms/pcr/), [Recurrence and relapse](https://onco.cc/terms/relapse-recurrence/), [Systemic versus local therapy](https://onco.cc/terms/systemic-vs-local-therapy/), [Window-of-opportunity trial](https://onco.cc/terms/window-of-opportunity-trial/)
- ideas: [A ctDNA residual disease-guided adjuvant trial after gallbladder cancer resection](https://onco.cc/ideas/idea-gbc-ctdna-residual-disease-guided-adjuvant-trial/), [A funded programme of organ-preservation trials to avoid radical surgery](https://onco.cc/ideas/idea-fund-organ-preservation-programme/), [A randomised trial of adjuvant chemoradiation after margin-positive or node-positive gallbladder cancer resection](https://onco.cc/ideas/idea-gbc-randomised-adjuvant-chemoradiation-r1-node-positive/), [A short pre-surgery drug window as the default early test of new agents](https://onco.cc/ideas/idea-tr1-window-of-opportunity-default/), [Add a cheap-drug factorial arm to every cooperative-group adjuvant cancer trial](https://onco.cc/ideas/idea-reg-factorial-addon-arms-cooperative-trials/), [Chemotherapy before surgery for every resectable pancreatic cancer, settled by the two perioperative trials rather than assumed](https://onco.cc/ideas/idea-pdac-neoadjuvant-chemotherapy-for-all-resectable-disease/), [Chemotherapy before the second operation for high-risk incidental gallbladder cancer](https://onco.cc/ideas/idea-gbc-neoadjuvant-for-high-risk-incidental-cancer/), [ctDNA-guided adjuvant decisions after residual disease: escalate the positive, spare the negative](https://onco.cc/ideas/idea-tnbc-ctdna-guided-adjuvant-decisions/), [Metastasis prevention as a formal indication with its own trials and regulatory pathway](https://onco.cc/ideas/idea-moon-metastasis-prevention-indication/), [Neoadjuvant immunotherapy with surgical window for glioblastoma](https://onco.cc/ideas/idea-neoadjuvant-io-glioblastoma/), [Take ctDNA-guided de-escalation beyond stage II, and stop escalating on a positive result until a trial says it helps](https://onco.cc/ideas/idea-crc-ctdna-de-escalation-beyond-stage-ii/), [Use pre-surgery immunotherapy windows as the field's biomarker engine](https://onco.cc/ideas/idea-bio2-neoadjuvant-biomarker-engine/)
- pairings: [CROSS chemoradiation → surgery → adjuvant nivolumab if residual disease](https://onco.cc/pairings/cross-then-nivolumab/), [Immunotherapy before surgery rather than with chemoradiation (HNSCC)](https://onco.cc/pairings/io-before-surgery-hnscc/), [Neoadjuvant checkpoint inhibitor → surgery (or no surgery) in dMMR colorectal cancer](https://onco.cc/pairings/neoadjuvant-io-dmmr/)
- key papers: [A phase III randomised clinical trial of perioperative therapy (neoadjuvant chemotherapy versus chemoradiotherapy) in locally advanced gallbladder cancers (POLCAGB): study protocol](https://onco.cc/key-papers/paper-polcagb-protocol-bmj-open-2019/), [A randomized trial of chemoradiotherapy and chemotherapy after resection of pancreatic cancer](https://onco.cc/key-papers/paper-espac-1-chemoradiotherapy-chemotherapy-resected-pancreatic-nejm-2004/), [ADAURA: exploratory eight-year overall survival update for adjuvant osimertinib in resected EGFR-mutated stage IB to IIIA lung cancer](https://onco.cc/key-papers/paper-adaura-8-year-os-jto-2026/), [ADAURA: three years of osimertinib after surgery for EGFR-mutated lung cancer](https://onco.cc/key-papers/paper-adaura-nejm-2020/), [Adjuvant atezolizumab after adjuvant chemotherapy in resected stage IB-IIIA non-small-cell lung cancer (IMpower010)](https://onco.cc/key-papers/paper-felip-impower010-adjuvant-atezolizumab-lancet-2021/), [Adjuvant Capecitabine for Breast Cancer after Preoperative Chemotherapy](https://onco.cc/key-papers/paper-create-x-adjuvant-capecitabine-nejm-2017/), [Adjuvant chemotherapy versus observation in patients with colorectal cancer: a randomised study (QUASAR)](https://onco.cc/key-papers/paper-quasar-adjuvant-chemotherapy-vs-observation-lancet-2007/), [Alectinib in resected ALK-positive non-small-cell lung cancer](https://onco.cc/key-papers/paper-wu-alina-adjuvant-alectinib-nejm-2024/), [Cercek 2022: six months of dostarlimab alone made rectal cancer disappear in every patient with mismatch-repair deficiency](https://onco.cc/key-papers/paper-cercek-dostarlimab-rectal-nejm-2022/), [CheckMate 816: three cycles of nivolumab plus chemotherapy before lung cancer surgery](https://onco.cc/key-papers/paper-checkmate-816-nejm-2022/), [Chemotherapy in non-small cell lung cancer: a meta-analysis using updated data on individual patients from 52 randomised clinical trials](https://onco.cc/key-papers/paper-nsclc-collaborative-group-chemotherapy-meta-analysis-bmj-1995/), [Comparisons between different polychemotherapy regimens for early breast cancer: meta-analyses of long-term outcome among 100,000 women in 123 randomised trials](https://onco.cc/key-papers/paper-ebctcg-polychemotherapy-regimens-meta-analysis-lancet-2012/), [Duration of adjuvant chemotherapy for stage III colon cancer (the IDEA collaboration)](https://onco.cc/key-papers/paper-idea-duration-adjuvant-stage-iii-colon-nejm-2018/), [DYNAMIC: a blood test safely halved chemotherapy use after surgery for stage II colon cancer](https://onco.cc/key-papers/paper-dynamic-nejm-2022/), [Five-Year Outcomes of FOLFIRINOX vs Gemcitabine as Adjuvant Therapy for Pancreatic Cancer: A Randomized Clinical Trial](https://onco.cc/key-papers/paper-prodige-24-five-year-outcomes-jama-oncol-2022/), [Impact of the addition of carboplatin and/or bevacizumab to neoadjuvant once-per-week paclitaxel followed by dose-dense doxorubicin and cyclophosphamide on pathologic complete response rates in stage II to III triple-negative breast cancer: CALGB 40603 (Alliance)](https://onco.cc/key-papers/paper-sikov-calgb-40603-carboplatin-bevacizumab-jco-2015/), [Improved survival with preoperative radiotherapy in resectable rectal cancer (Swedish Rectal Cancer Trial)](https://onco.cc/key-papers/paper-swedish-rectal-cancer-trial-preoperative-radiotherapy-nejm-1997/), [IMvigor011: using a blood test for leftover cancer to decide who gets immunotherapy after bladder surgery](https://onco.cc/key-papers/paper-imvigor011-nejm-2025/), [KATHERINE: switching to T-DM1 when HER2-positive breast cancer survives pre-surgery treatment](https://onco.cc/key-papers/paper-katherine-nejm-2019/), [KEYNOTE-522: adding pembrolizumab before and after surgery in early triple-negative breast cancer](https://onco.cc/key-papers/paper-keynote-522-nejm-2022/), [KEYNOTE-564: a year of pembrolizumab after kidney cancer surgery](https://onco.cc/key-papers/paper-keynote-564-nejm-2021/), [KEYNOTE-942: a personalised mRNA cancer vaccine plus pembrolizumab after melanoma surgery](https://onco.cc/key-papers/paper-keynote-942-lancet-2024/), [Levamisole and fluorouracil for adjuvant therapy of resected colon carcinoma](https://onco.cc/key-papers/paper-moertel-levamisole-fluorouracil-adjuvant-colon-nejm-1990/), [Localised colon cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up](https://onco.cc/key-papers/paper-esmo-localised-colon-cancer-guideline-ann-oncol-2020/), [Long-Term Prognostic Risk After Neoadjuvant Chemotherapy Associated With Residual Cancer Burden and Breast Cancer Subtype](https://onco.cc/key-papers/paper-symmans-rcb-long-term-prognosis-subtype-jco-2017/), [Lung adjuvant cisplatin evaluation: a pooled analysis by the LACE Collaborative Group](https://onco.cc/key-papers/paper-lace-adjuvant-cisplatin-pooled-analysis-jco-2008/), [monarchE: two years of abemaciclib after surgery in high-risk, hormone-receptor-positive early breast cancer](https://onco.cc/key-papers/paper-monarche-jco-2020/), [NADINA: two doses of ipilimumab plus nivolumab before surgery beat a year of nivolumab after surgery in stage III melanoma](https://onco.cc/key-papers/paper-nadina-nejm-2024/), [NATALEE: three years of ribociclib after surgery in a broad population of hormone-receptor-positive early breast cancer](https://onco.cc/key-papers/paper-natalee-nejm-2024/), [Neoadjuvant chemotherapy with gemcitabine plus cisplatin followed by radical liver resection versus immediate radical liver resection alone with or without adjuvant chemotherapy in incidentally detected gallbladder carcinoma after simple cholecystectomy or in front of radical resection of BTC (ICC/ECC) - a phase III study of the German registry of incidental gallbladder carcinoma platform (GR)- the AIO/ CALGP/ ACO- GAIN-trial](https://onco.cc/key-papers/paper-gain-trial-protocol-bmc-cancer-2020/), [Neoadjuvant Chemotherapy, Endocrine Therapy, and Targeted Therapy for Breast Cancer: ASCO Guideline](https://onco.cc/key-papers/paper-asco-neoadjuvant-therapy-breast-guideline-jco-2021/), [Neoadjuvant FOLFIRINOX versus neoadjuvant gemcitabine-based chemoradiotherapy in resectable and borderline resectable pancreatic cancer (PREOPANC-2): a multicentre, open-label, phase 3 randomised trial](https://onco.cc/key-papers/paper-preopanc-2-neoadjuvant-folfirinox-vs-chemoradiotherapy-lancet-oncol-2025/), [Neoadjuvant treatment for incidental gallbladder cancer: A systematic review](https://onco.cc/key-papers/paper-varshney-neoadjuvant-incidental-gallbladder-cancer-systematic-review-ahbps-2025/), [NIAGARA: durvalumab before and after cystectomy for muscle-invasive bladder cancer](https://onco.cc/key-papers/paper-niagara-nejm-2024/), [NICHE-2: a month of nivolumab and ipilimumab before surgery clears mismatch-repair-deficient colon cancer in most patients](https://onco.cc/key-papers/paper-niche-2-nejm-2024/), [Nomogram for predicting the benefit of adjuvant chemoradiotherapy for resected gallbladder cancer](https://onco.cc/key-papers/paper-wang-adjuvant-chemoradiotherapy-nomogram-gallbladder-cancer-jco-2011/), [OlympiA: a year of olaparib after surgery for BRCA-mutated, high-risk early breast cancer](https://onco.cc/key-papers/paper-olympia-nejm-2021/), [Oxaliplatin, fluorouracil, and leucovorin as adjuvant treatment for colon cancer (MOSAIC)](https://onco.cc/key-papers/paper-mosaic-oxaliplatin-adjuvant-colon-nejm-2004/), [Perioperative durvalumab for resectable non-small-cell lung cancer](https://onco.cc/key-papers/paper-heymach-aegean-perioperative-durvalumab-nejm-2023/), [Perioperative nivolumab and chemotherapy in stage III non-small-cell lung cancer](https://onco.cc/key-papers/paper-provencio-nadim-ii-perioperative-nivolumab-stage-iii-nejm-2023/), [Potentially Curable Pancreatic Adenocarcinoma: ASCO Clinical Practice Guideline Update](https://onco.cc/key-papers/paper-asco-potentially-curable-pancreatic-guideline-update-jco-2019/), [Preoperative Chemoradiotherapy Versus Immediate Surgery for Resectable and Borderline Resectable Pancreatic Cancer: Results of the Dutch Randomized Phase III PREOPANC Trial](https://onco.cc/key-papers/paper-preopanc-preoperative-chemoradiotherapy-jco-2020/), [Preoperative chemotherapy for operable colon cancer: mature results of an international randomized controlled trial (FOxTROT)](https://onco.cc/key-papers/paper-foxtrot-preoperative-chemotherapy-colon-jco-2023/), [Preoperative radiotherapy combined with total mesorectal excision for resectable rectal cancer (Dutch TME trial)](https://onco.cc/key-papers/paper-kapiteijn-dutch-tme-preoperative-radiotherapy-nejm-2001/), [Rectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up](https://onco.cc/key-papers/paper-esmo-rectal-cancer-guideline-ann-oncol-2017/), [Response to neoadjuvant therapy and long-term survival in patients with triple-negative breast cancer](https://onco.cc/key-papers/paper-liedtke-neoadjuvant-response-survival-tnbc-jco-2008/), [Sauer 2004: chemoradiotherapy before rather than after surgery for rectal cancer (CAO/ARO/AIO-94)](https://onco.cc/key-papers/paper-sauer-preoperative-chemoradiotherapy-rectal-nejm-2004/), [Surgical outcomes in gallbladder cancer: evidence from the UK nationwide CAPBIL study](https://onco.cc/key-papers/paper-mcclements-capbil-surgical-outcomes-gallbladder-cancer-hpb-2026/)
- roadmaps: [Gallbladder cancer roadmap: from a chance finding at gallstone surgery to a disease with its own trials](https://onco.cc/roadmaps/gallbladder-cancer-roadmap/), [Pancreatic cancer roadmap: from Whipple's operation to gemcitabine, FOLFIRINOX, adjuvant chemotherapy, PARP inhibition, KRAS inhibition, vaccines and the surveillance question](https://onco.cc/roadmaps/pancreatic-roadmap/), [Triple-negative breast cancer roadmap: from a remainder defined by three negative tests to immunotherapy, antibody-drug conjugates and the residual disease problem](https://onco.cc/roadmaps/tnbc-roadmap/)
- institutions: [Guangdong Provincial People's Hospital](https://onco.cc/institutions/guangdong-provincial-peoples-hospital/), [Leeds Cancer Centre, St James's University Hospital](https://onco.cc/institutions/leeds-cancer-centre/), [Netherlands Cancer Institute (NKI-AvL)](https://onco.cc/institutions/nki/), [University Hospitals Birmingham / University of Birmingham Cancer Research Centre](https://onco.cc/institutions/birmingham-cancer-centre/)
- people: [Bernard Fisher](https://onco.cc/people/bernard-fisher/), [Christian Blank](https://onco.cc/people/christian-blank/), [Emil "Tom" Frei III](https://onco.cc/people/emil-frei/), [Thomas U. Marron](https://onco.cc/people/thomas-marron/)
- bottlenecks: [Dormant cells and minimal residual disease](https://onco.cc/bottlenecks/b-dormancy-mrd/), [Fragmented care and guideline gaps](https://onco.cc/bottlenecks/b-care-fragmentation/)

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