# Pathologic complete response (pCR)

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

## TL;DR

No invasive cancer left in the breast and lymph nodes when the surgeon removes the tissue after pre-surgery treatment.

## Summary

Pathologic complete response (pCR) means that no invasive cancer remains in the breast and lymph nodes when the surgeon removes tissue after pre-surgery treatment, recorded as ypT0/is ypN0. It is strongly prognostic in Triple-negative breast cancer (TNBC) and HER2-positive breast cancer and is accepted for accelerated approval of neoadjuvant regimens, as in KEYNOTE-522. Trials now use it as a decision point: OptimICE-pCR (A012103) tests de-escalating therapy after pCR, while other studies escalate treatment for residual disease. The term is cited by the Oesophageal and Bladder & urothelial cancer entries, by CheckMate 816, KATHERINE, PHERGain, NICHE-2 and MATTERHORN, and by the related terms Major pathological response (MPR) and Clinical complete response (cCR).

## Fields

- Kind: Term
- Last checked: 2026-09-04
- Also known as: pathological complete response; ypT0; ypN0; non-pCR; residual invasive disease; residual disease after neoadjuvant

## Notes

- Triple-negative disease is where pathological complete response means most: in the CTNeoBC pooled analysis of 11,955 patients, eradication of tumour from breast and nodes (ypT0/is ypN0) was associated with event-free survival hazard ratio 0.24 and overall survival 0.16 in triple-negative disease, the strongest association of any subtype, yet trial-level increases in the rate did not predict survival gains (Cortazar 2014).
- Triple-negative patients reach a complete response more often than others (22 against 11 percent in the MD Anderson series, 1985 to 2004) and then have similar survival, while those with residual disease do worse, particularly in the first three years (Liedtke 2008). Adding pembrolizumab to platinum chemotherapy raised the rate from 51.2 to 64.8 percent in KEYNOTE-522 (Schmid 2020).

## Sources

- ClinicalTrials.gov NCT03036488: KEYNOTE-522: https://clinicaltrials.gov/study/NCT03036488
- ClinicalTrials.gov NCT05812807: OptimICE-pCR (A012103): https://clinicaltrials.gov/study/NCT05812807
- Cortazar, Lancet 2014: pathological complete response and long-term benefit, the CTNeoBC pooled analysis: https://doi.org/10.1016/s0140-6736(13)62422-8
- Liedtke, J Clin Oncol 2008: response to neoadjuvant therapy and long-term survival in triple-negative breast cancer: https://doi.org/10.1200/jco.2007.14.4147
- Schmid, N Engl J Med 2020: KEYNOTE-522, pembrolizumab for early triple-negative breast cancer: https://doi.org/10.1056/nejmoa1910549

## Connected records

- terms: [AJCC 8th edition prognostic stage for breast cancer](https://onco.cc/terms/ajcc-prognostic-stage-breast/), [Androgen receptor-positive triple-negative breast cancer](https://onco.cc/terms/androgen-receptor-positive-tnbc/), [Clinical complete response (cCR)](https://onco.cc/terms/clinical-complete-response/), [Complete response](https://onco.cc/terms/complete-response/), [Complete response (CR) and partial response (PR)](https://onco.cc/terms/complete-response-term/), [Drugs before or after the operation](https://onco.cc/terms/neoadjuvant-versus-adjuvant-breast/), [Endpoint](https://onco.cc/terms/endpoint/), [ER and PR negative under 1 percent (the triple-negative threshold, and ER-low)](https://onco.cc/terms/er-pr-negative-threshold/), [Event-free / disease-free survival (EFS, DFS, iDFS, RFS)](https://onco.cc/terms/efs/), [Histological response to induction chemotherapy (osteosarcoma and Ewing sarcoma)](https://onco.cc/terms/histological-response-induction/), [Homologous recombination deficiency (HRD) in breast cancer](https://onco.cc/terms/hrd-in-breast-cancer/), [Invasive disease-free survival (iDFS)](https://onco.cc/terms/idfs/), [Ki-67 in triple-negative breast cancer](https://onco.cc/terms/ki-67-in-tnbc/), [Luminal androgen receptor (LAR) subtype](https://onco.cc/terms/luminal-androgen-receptor/), [Major pathological response (MPR)](https://onco.cc/terms/major-pathological-response/), [Necrosis](https://onco.cc/terms/necrosis/), [Neoadjuvant / adjuvant / perioperative](https://onco.cc/terms/neoadjuvant-adjuvant/), [Residual disease after neoadjuvant therapy in triple-negative breast cancer: the decision point](https://onco.cc/terms/tnbc-residual-disease-decision/), [Response-adaptive randomisation](https://onco.cc/terms/response-adaptive-randomisation/), [Surrogate endpoint](https://onco.cc/terms/surrogate-endpoint/), [Surrogate endpoint validation: which stand-ins have earned trust](https://onco.cc/terms/surrogate-validation/), [Triple-negative breast cancer trials open today (registry snapshot and UK sites)](https://onco.cc/terms/tnbc-trials-open-today/), [Which staging edition a breast report uses: UICC TNM 8, TNM 9 and the AJCC prognostic stage](https://onco.cc/terms/tnm-breast-cancer-editions/), [Window-of-opportunity trial](https://onco.cc/terms/window-of-opportunity-trial/)
- cancers: [Advanced cutaneous squamous cell carcinoma](https://onco.cc/cancers/advanced-cutaneous-scc/), [Basal-like 1 triple-negative breast cancer (BL1)](https://onco.cc/cancers/tnbc-basal-like-1/), [Basal-like 2 triple-negative breast cancer (BL2)](https://onco.cc/cancers/tnbc-basal-like-2/), [Bladder & urothelial cancer](https://onco.cc/cancers/urothelial/), [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Cutaneous squamous cell carcinoma](https://onco.cc/cancers/cutaneous-scc/), [Early HER2-positive breast cancer](https://onco.cc/cancers/her2-positive-early-breast-cancer/), [Early triple-negative breast cancer](https://onco.cc/cancers/tnbc-early/), [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/), [Luminal androgen receptor triple-negative breast cancer (LAR)](https://onco.cc/cancers/tnbc-luminal-androgen-receptor/), [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Oesophageal cancer](https://onco.cc/cancers/esophageal/), [Resectable stage I to III non-small-cell lung cancer](https://onco.cc/cancers/resectable-nsclc/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- trials: [ACOSOG Z1071 (Alliance)](https://onco.cc/trials/acosog-z1071/), [ASCENT-05 / OptimICE-RD (AFT-65, GBG 119, NSABP B-63)](https://onco.cc/trials/ascent-05/), [BARBICAN](https://onco.cc/trials/barbican/), [CALGB 40603 (Alliance)](https://onco.cc/trials/calgb-40603/), [CAO/ARO/AIO-12](https://onco.cc/trials/cao-aro-aio-12/), [CheckMate 816](https://onco.cc/trials/checkmate-816/), [CROSS](https://onco.cc/trials/cross/), [DESTINY-Breast11](https://onco.cc/trials/destiny-breast11/), [EV-303 / KEYNOTE-905](https://onco.cc/trials/ev-303/), [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/), [IMpassion031](https://onco.cc/trials/impassion031/), [International Watch & Wait Database](https://onco.cc/trials/iwwd/), [KATHERINE](https://onco.cc/trials/katherine/), [KEYNOTE-522](https://onco.cc/trials/keynote-522/), [KRISTINE](https://onco.cc/trials/kristine/), [MATTERHORN](https://onco.cc/trials/matterhorn/), [Neoadjuvant cemiplimab for resectable stage II to IV skin squamous cell carcinoma](https://onco.cc/trials/neoadjuvant-cemiplimab-cscc/), [NeoPACT](https://onco.cc/trials/neopact/), [Neotorch](https://onco.cc/trials/neotorch/), [NeoTRIP (NeoTRIPaPDL1)](https://onco.cc/trials/neotrip/), [NICHE-2](https://onco.cc/trials/niche-2/), [NSABP B-51 / RTOG 1304](https://onco.cc/trials/nsabp-b51/), [OptimICE-pCR (A012103)](https://onco.cc/trials/optimice-pcr/), [PARTNER](https://onco.cc/trials/partner/), [PHERGain](https://onco.cc/trials/phergain/), [TRAIN-2](https://onco.cc/trials/train-2/)
- ideas: [ADC for residual disease after KEYNOTE-522](https://onco.cc/ideas/idea-post-neoadjuvant-adc/), [An independent programme that validates surrogate endpoints, setting by setting](https://onco.cc/ideas/idea-tr1-surrogate-validation-programme/), [Can T-DXd alone cure early HER2-positive disease?](https://onco.cc/ideas/idea-tdxd-first-then-nothing/), [Give exceptional responders less: pembrolizumab omission after complete response, anthracycline-free regimens and chemotherapy omission in lymphocyte-rich stage I disease](https://onco.cc/ideas/idea-tnbc-de-escalation-for-exceptional-responders/), [Let the trial learn: response-adaptive allocation across many combination arms](https://onco.cc/ideas/idea-tr2-bandit-allocation/), [Pre-surgery platform trials that test combinations on pathological response in months](https://onco.cc/ideas/idea-tr2-neoadjuvant-combo-platform/), [Use pre-surgery immunotherapy windows as the field's biomarker engine](https://onco.cc/ideas/idea-bio2-neoadjuvant-biomarker-engine/)
- key papers: [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/), [Circulating tumor DNA in neoadjuvant-treated breast cancer reflects response and survival](https://onco.cc/key-papers/paper-magbanua-ispy2-ctdna-neoadjuvant-ann-oncol-2021/), [Clinical and molecular characteristics of HER2-low-positive breast cancer: pooled analysis of individual patient data from four prospective, neoadjuvant clinical trials](https://onco.cc/key-papers/paper-denkert-her2-low-pooled-neoadjuvant-lancet-oncol-2021/), [Germline mutation status, pathological complete response, and disease-free survival in triple-negative breast cancer: secondary analysis of the GeparSixto randomized clinical trial](https://onco.cc/key-papers/paper-hahnen-geparsixto-germline-brca-jama-oncol-2017/), [Homologous recombination deficiency (HRD) score predicts response to platinum-containing neoadjuvant chemotherapy in patients with triple-negative breast cancer](https://onco.cc/key-papers/paper-telli-hrd-score-platinum-tnbc-ccr-2016/), [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/), [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/), [Long-term efficacy and safety of addition of carboplatin with or without veliparib to standard neoadjuvant chemotherapy in triple-negative breast cancer: 4-year follow-up data from BrighTNess, a randomized phase III trial](https://onco.cc/key-papers/paper-geyer-brightness-4-year-follow-up-ann-oncol-2022/), [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/), [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/), [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/), [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/), [Pathological complete response and long-term clinical benefit in breast cancer: the CTNeoBC pooled analysis](https://onco.cc/key-papers/paper-cortazar-ctneobc-pcr-pooled-analysis-lancet-2014/), [Prognostic and predictive value of circulating tumor DNA during neoadjuvant chemotherapy for triple negative breast cancer](https://onco.cc/key-papers/paper-cavallone-tnbc-ctdna-neoadjuvant-sci-rep-2020/), [Refinement of Triple-Negative Breast Cancer Molecular Subtypes: Implications for Neoadjuvant Chemotherapy Selection](https://onco.cc/key-papers/paper-lehmann-tnbctype-4-refinement-plos-one-2016/), [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/), [Survival analysis of carboplatin added to an anthracycline/taxane-based neoadjuvant chemotherapy and HRD score as predictor of response-final results from GeparSixto](https://onco.cc/key-papers/paper-loibl-geparsixto-survival-hrd-ann-oncol-2018/), [Tumour-infiltrating lymphocytes and prognosis in different subtypes of breast cancer: a pooled analysis of 3771 patients treated with neoadjuvant therapy](https://onco.cc/key-papers/paper-denkert-tils-neoadjuvant-pooled-lancet-oncol-2018/)
- roadmaps: [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/)
- people: [Laura J. Esserman](https://onco.cc/people/laura-esserman/), [Sibylle Loibl](https://onco.cc/people/sibylle-loibl/), [Takayuki Ueno](https://onco.cc/people/ueno-takayuki/)
- bottlenecks: [Trial design, endpoints and cost](https://onco.cc/bottlenecks/b-trial-design/)
- companies: [German Breast Group (GBG)](https://onco.cc/companies/gbg/)

---
JSON: https://onco.cc/api/v1/entities/pcr.json