Sentinel Node Biopsy Alone After Chemotherapy: Evidence Still Too Weak to Rule Out Harm

For women with breast cancer whose tumours shrink after neoadjuvant chemotherapy, one of the most contested questions in surgical oncology is whether the armpit can be managed with sentinel lymph node biopsy alone, sparing patients the long-term complications of a full axillary lymph node dissection. A new systematic review and meta-analysis published in BMC Cancer set out to answer that question by comparing survival and recurrence outcomes between the two approaches, and its conclusion is deliberately cautious: the available evidence is too uncertain to support de-escalation.

The researchers searched PubMed/MEDLINE, Embase, Scopus, the Cochrane Library, ClinicalTrials.gov and the WHO ICTRP from inception to 30 March 2026, with the protocol registered on PROSPERO (CRD420261490493). They included randomised and non-randomised comparative studies of sentinel lymph node biopsy alone versus axillary lymph node dissection with or without sentinel biopsy in patients who had received neoadjuvant chemotherapy. Despite screening 906 records, the team identified no randomised trial; the analysis ultimately rested on five non-randomised comparative studies covering 2,647 patients. Outcomes examined included axillary recurrence, disease-free survival, local and locoregional recurrence, distant recurrence, breast cancer-specific mortality and overall survival. Risk of bias was assessed with ROBINS-I, certainty of evidence with GRADE, and pooled risk ratios were computed with Mantel-Haenszel random-effects models, stratified by baseline clinical nodal status.

The pooled estimates were strikingly imprecise. Axillary recurrence appeared higher with sentinel biopsy alone, but the confidence interval spanned both harm and benefit (RR 1.45, 95% CI 0.75 to 2.79; I²=0%; five studies), meaning the data do not exclude a clinically important increase in axillary recurrence. Estimates for locoregional recurrence (RR 0.86, 95% CI 0.60 to 1.22; I²=0%) and local recurrence (RR 0.73, 95% CI 0.38 to 1.40; I²=43%) were similarly compatible with fewer or more events in either group. Results were reported separately for studies enrolling only clinically node-positive patients and for those including node-negative or mixed populations.

More troubling were the crude survival findings. Patients treated with sentinel node biopsy alone showed lower estimates of overall survival (RR 0.48, 95% CI 0.32 to 0.72; I²=60%), disease-free survival (RR 0.53, 95% CI 0.31 to 0.90; I²=78%), breast cancer-specific mortality (RR 0.39, 95% CI 0.25 to 0.59) and distant recurrence (RR 0.40, 95% CI 0.20 to 0.79). But the authors attribute these apparent advantages not to the surgery itself but to patient selection: the included studies were judged to be at serious or critical risk of bias from confounding, and the comparison groups differed in baseline prognostic factors. The certainty of evidence was rated very low for every outcome, leaving the true effect of sentinel biopsy alone on survival and recurrence deeply uncertain.

The authors’ conclusion is unambiguous: the pooled estimates do not establish equivalence between the two strategies, and the lower crude mortality and distant recurrence figures most likely reflect how patients were selected rather than a genuine treatment effect. They call for randomised or well-adjusted prospective comparative studies, analysed by baseline nodal status, before axillary de-escalation can be supported in the neoadjuvant setting. Until such trials exist, the question of whether a negative sentinel biopsy after chemotherapy is enough to safely omit a full axillary dissection remains open, and the morbidity-sparing promise of the less invasive approach cannot yet be weighed against reliable oncologic safety data.

Subject of Research: Comparing sentinel lymph node biopsy alone with axillary lymph node dissection after neoadjuvant chemotherapy in breast cancer

Article Title: Sentinel lymph node biopsy versus axillary lymph node dissection after neoadjuvant chemotherapy in breast cancer: a systematic review and meta-analysis

Article References: Farooq, A. K., Butt, T. S., Farooqui, A., Khalid, E., Khalil, M. H., Makandar, A. I., Ishfaq, A., Uzair, S. M., Ehtisham, A., Munir, T., Suhail, A., Khan, A., Lal, P. K., Farooqi, N., Saed, K., Kwakye, B., & Simon, J. (2026). Sentinel lymph node biopsy versus axillary lymph node dissection after neoadjuvant chemotherapy in breast cancer: a systematic review and meta-analysis. BMC Cancer. https://doi.org/10.1186/s12885-026-17249-8

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17249-8

Keywords: breast cancer, sentinel lymph node biopsy, axillary lymph node dissection, neoadjuvant chemotherapy, meta-analysis, axillary recurrence, disease-free survival, overall survival, risk of bias, surgical oncology, de-escalation, systematic review