Association of a high versus low number of negative lymph nodes removed with survival and recurrence-free survival after lymph node dissection in breast cancer: a systematic review and meta-analysis of observational studies

Q: How did the study define “high” versus “low” numbers of negative lymph nodes removed?

Sensitivity analysis defined removal of ≥ 10 NLNs as the high NLN group and removal of < 10 NLNs as the low NLN group.

Q: Which survival outcomes were assessed in the meta-analysis?

The analysis assessed overall survival (OS) and recurrence-free survival (RFS) after axillary lymph node dissection.

Q: What databases and time range were used to search for eligible studies?

Searches covered PubMed, Embase, Scopus, Google Scholar, and Web of Science, along with study references, for publications from the beginning of 2000 to October 2024.

Sep 29, 2026

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Although higher numbers of negative lymph nodes (NLNs) removed at breast cancer surgery have been linked to improved overall survival in many studies, reported effect sizes vary, likely reflecting limited sample sizes in primary research. This systematic review and meta-analysis evaluates whether removing a high number of NLNs during surgery is associated with overall survival (OS) and recurrence-free survival (RFS) in patients considered for axillary lymph node dissection.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Abstract

Introduction

Methods

Literature search

Results

Clinical and Experimental Medicine (2026) 26:88 [https://doi.org/10.1007/s10238-025-01967-7](https://doi.org/10.1007/s10238-025-01967-7) REVIEW Association of a high versus low number of negative lymph nodes removed with survival and recurrence-free survival after lymph node dissection in breast cancer: a systematic review and meta-analysis of observational studies Mansour Bahardoust1,2 · Danyal Yarahmadi3 · Fatemeh Naseri Rad3 · Mohammad Mehdikakoienejad3 · Benyamin Kazemi3 · Babak Goodarzy3 · Adnan Tizmaghz4 Received: 3 July 2025 / Accepted: 1 November 2025 © The Author(s) 2025 Abstract Although most studies have reported that a high number of negative lymph nodes (NLNs) at surgery can be associated with improved overall survival (OS) in patients with breast cancer (BC), the effect size was reported differently in several studies, which may be due to the small sample size of the primary studies. This systematic review and meta-analysis aimed to investigate the association of a high number of NLNs removed during surgery with OS and recurrence-free survival (RFS) in BC patients who are candidates for axillary lymph node dissection. We searched the PubMed, Embase, Scopus, Google Scholar, and Web of Science databases, as well as study references, to identify related articles published from the beginning of 2000 to October 2024. Based on sensitivity analysis, the removal of ≥ 10 NLNs was defined as the high number of NLNs removed group, and the removal of < 10 NLNs was defined as the low number of NLNs removed group. The heterogeneity between studies was assessed using Cochran’s Q and I2 tests. Publication bias was assessed using Egger’s test. Ultimately, 14 studies encompassing 36,576 BC patients were included. A pooled estimate of 14 studies showed that a high number of NLN removed compared to a low number of NLN removed was significantly associated with improved 5-year OS (HR: 0.82, 95% CI: 0.74, 0.90), I2 = 93.8) and RFS rate (HR:0.76, CI: 0.765, 0.86), I2 = 86.3) . A higher number of NLNs removed during surgery in BC patients who are candidates for axillary lymph node dissection appears to be associated with improved OS and RFS. Keywords Five-year survival rate · Surgery · Breast cancer · Recurrence-free survival Mansour Bahardoust and Benyamin Kazemi are equal first authors. 􀀍 Adnan Tizmaghz [adnan_ti@yahoo.com](adnan_ti@yahoo.com) 1 Department of Epidemiology, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2 Breast Cancer Research Center, Iran University of Medical Sciences, Tehran, Iran 3 School of Medicine, Iran University of Medical Sciences, Tehran, Iran 4 Firoozabadi Clinical Research Development Unit (FACRDU), University of Medical Sciences(IUMS) , Tehran, Iran Introduction Breast cancer accounts for 36% of all cancer cases and is the most commonly diagnosed malignant tumor and the leading cause of cancer-related death in women worldwide [1] . According to recent studies, in 2018, more than 2 million patients were diagnosed with breast cancer, and its incidence and prevalence are increasing worldwide [2, 3] . The incidence of BC is higher in developed countries, and more than half of the cases occur in industrialized countries [4] . Although the improvement and progress of diagnostic and therapeutic methods have improved the survival of patients, BC is still one of the main causes of death from cancer [5, 6] . Studies have estimated that in 2020, more than 685,000 deaths from BC in women were recorded, and BC was the cause of 1 out of every 6 (16%) cancer deaths [6–8] . 1 3 The 5-year survival of breast cancer patients is estimated between 80 and 90% based on various studies [9] . The overall survival (OS) and recurrence-free survival (RFS) rates have improved with the improvement of BC management in recent years [10] . Treatment depends on various factors, including local treatment approaches (such as surgery and radiation therapy) and system

FAQs

How did the study define “high” versus “low” numbers of negative lymph nodes removed?

Sensitivity analysis defined removal of ≥ 10 NLNs as the high NLN group and removal of < 10 NLNs as the low NLN group.

Which survival outcomes were assessed in the meta-analysis?

The analysis assessed overall survival (OS) and recurrence-free survival (RFS) after axillary lymph node dissection.

What databases and time range were used to search for eligible studies?

Searches covered PubMed, Embase, Scopus, Google Scholar, and Web of Science, along with study references, for publications from the beginning of 2000 to October 2024.

Sep 29, 2026

Upload by Hazel