Table 1. Main characteristics of all studies included in the review.
| First author; publication year; country of origin | Study period | No. patients Low/high NLR | Treatment received | Follow-up | Age (median – ys) | No of distal metastasis | No of deaths | Type of study | Cut-off | Survival analysis | Significant variables |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Azab et al., 2012; USA | 2004–2006 |
NLR < 1.8 – n = 77 1.80 ≤ NLR < 2.45 – n = 80 2.45 ≤ NLR < 3.33 – n = 78 NLR ≥ 3.3 – n = 81 |
Surgery | 1–7 ys | 59, 3/60, 8/60, 8/67 | NR |
NLR < 1.8 1 y – 0 ; 2y – 4% 5 y – 13% NLR ≥ 3.3 1 y – 16% 2 y – 25% 5 y – 44% |
Retrospective |
Multiple cut-off NLR < 1.8 1.80 ≤ NLR < 2.45 2.45 ≤ NLR < 3.33 NLR ≥ 3.3 |
Long-term mortality | Older age Tumour size Nodal status Clinical staging |
| Forget et al., 2013; Belgium | 2010 | 172 – centre 1 162 – centre 2 - (Ketorolac or diclofenac use – 20-30 mg/75 mg) |
Surgery | 24 mo | NR |
Centre 1 NLR < 4 – 6.3% NLR ≥ 4 – 16.5% Centre 2 NLR ≥ 3 11.6% NLR < 3 – 2, 2% |
Centre 1 NLR < 4 – 2.4% NLR ≥ 4 – 8.2% Centre 2 NLR ≥ 3 – 7.9% NLR < 3 – 3.4% |
Retrospective | 5 < NLR ≥ 5 4 < NLR ≥ 4 |
DFS; OS | Age Lymph node invasion |
| Azab et al., 2013; USA | 2004–2006 |
NLR < 1.8 – n = 104 1.8 ≤ NLR < 2.4 – n = 106 2.4 ≤ NLR < 3.3 – n = 108 NLR ≥ 3.3 – n = 119 |
Surgery | 48 mo | 63,6 |
NLR < 1.8 – 2 NLR ≥ 3.3 – 24 |
NLR <
1.8 – 1 (1.9%) NLR ≥ 3.3 – 37 (44%) |
Retrospective |
Multiple cut-off NLR < 1.8 1.8 ≤ NLR < 2.4 2.4 ≤ NLR < 3.3 NLR ≥ 3.3 |
OS | Age Clinical staging (I-III) Radiotherapy |
| Noh et al., 2013; Korea | 2000–2010 |
NLR < 2.5
(n ≤ 327); NLR ≥ 2.5 (n = 115) |
NR | 5,9 ys | 50 |
NLR < 2.5 – 43 NLR ≥ 2.5 – 16 |
NLR <
2.5 – 17 NLR ≥ 2.5 – 15 |
Retrospective |
Multiple cut-off NLR < 2.5 (n = 327); NLR ≥ 2.5 (n = 115) |
DFS | Nodal status Age ER Luminal A subtype |
| Forget et al., 2014; Belgium | 2003–2008 | 720 | Surgery | 69,8 mo | 56/60 | 36 | 37 | Retrospective | 3.3 ≤ NLR > 3.3 | DFS; OS | Tumour size NSAIDs |
| Dirican et al., 2014; Turkey | 2006–2011 | NLR < 1 – n = 60 1.0 ≤ NLR < 2.0 – n = 698 2.0 ≤ NLR < 3.0 – n = 458 3.0 ≤ NLR < 4.0 – n = 170 4.0 ≤ NLR < 5.0 – n = 65 |
Surgery and multiple-therapy | 30 mo | NR | 90 | – | Retrospective | Multiple cut-off 1.0 ≤ NLR < 2.0 2.0 ≤ NLR< 3.0 3.0 ≤ NLR < 4.0 4.0 ≤ NLR < 5.0 |
OS; DFS | Tumour depth (pT) Nodal status Clinical staging Metastasis |
| Cihan et al., 2014; Turkey | 2005–2010 |
NLR <
3 – n = 228 NLR ≥ 3.3 – n = 122 |
Surgery and multiple-therapy | 5 ys | 55,3 | 45 | – | Retrospective | 3.0 ≤ NLR ≥ 3.3 | DFS; OS; PFS | Histopathological diagnosis Perinodal invasion Tumour stage HER2 subtype Age |
| Nakano et al., 2014; Japan | 2001–2011 |
NLR <
2.5 – n = 120 NLR ≥ 2.5 – n = 47 |
Surgery | 85,8 mo | 58,9/55,1 |
NLR < 2.5 – 15 NLR ≥ 2.5 – 14 |
NLR < 2.5 – 9 NLR ≥ 2.5 – 10 |
Retrospective | 2,5 < NLR ≥ 3.3 | DFS; OS | Histological grade Perinodal invasion BMI |
| Koh et al., 2014; Korea | 2002–2010 |
NLR ≤ 2.25 – n = 91 NLR > 2.25 – n = 66 |
Surgery and multiple-therapy | 21 mo | 44 | 25 | – | Retrospective |
Multiple cut-off NLR ≤ 2.25 NLR > 2.25 |
DFS; OS | Clinical staging (I–III) |
| Yao et al., 2014; China | 2009–2011 |
NLR ≤ 2.57 – n = 496 NLR > 2.57 – n = |
Surgery | 5,9 ys | 50 | NR | NR | Retrospective | 2.57 ≤ NLR > 2.57 | DFS | Nodal status HER2 subtype Diabetes |
| Pistelli et al., 2015; Italy |
2006–2012 |
NLR ≤
3 – n = 73 NLR > 3 – n = 17 |
Surgery and multiple-therapy | 53,8 mo | 53 |
NLR ≤ 3 – 8 NLR > 3 – 5 |
NLR ≤ 3 – 4 NLR > 3 – 4 |
Retrospective | NLR ≤ 3 NLR > 3 |
DFS; OS | Age, menopausal status, tumour size, lymph nodes status, Ki-67, necrosis and lymphovascular invasion |
| Koh et al., 2015; Asia |
2000–2008 |
NLR ≤
1.39 – n = 226 1.39 < NLR ≤ 2 – n = 379 2 < NLR ≤ 2.58 – n = 305 2.58 < NLR ≤ 4 – n = 331 NLR ≥ 4 – n = 194 |
Surgery and multiple-therapy | Patients were followed up in the breast clinic (1 February 2014) |
56/53/50/49/50 |
NLR ≤
1.39 – 15 1.39 < NLR ≤ 2 – 30 2 < NLR ≤ 2.58 – 37 2.58 < NLR ≤ 4 – 54 NLR ≥ 4 – 61 |
NLR ≤
1.39 – 75 1.39 < NLR ≤ 2 – 135 2 < NLR ≤ 2.58 – 113 2.58 < NLR ≤ 4 – 158 NLR ≥ 4 – 118 |
Retrospective |
Multiple cut-off NLR ≤ 1.39 1.39 < NLR ≤ 2 2 < NLR ≤ 2.58 2.58 < NLR ≤ 4 NLR ≥ 4 |
OS | Age; no. of positive lymph nodes; metastasis; HER2 status |
| Ulas et al., 2015; Turkey | 2009–2014 |
NLR <
2.38 – n = 119 NLR > 2.38 – n = 68 |
Adjuvant transtuzumab | 26 mo | 51,4 |
NLR <
2.38 –15 NLR > 2.38 – 11 |
– | Retrospective | 2.38 < NLR > 2.38 |
DFS; OS | No significant correlations between NLR and clinico-pathological factors. |
| Asano et al., 2015; Japan | 2007–2013 |
NLR <
3 – n = 58 NLR > 3 – n = 119 |
Preoperative chemotherapy | 3.4 y | 56 | – | – | Retrospective | NLR < 3 NLR > 3 |
DFS; OS | Younger age; premenopausal status; pCR result; TNBC phenotype |
| Hong et al., 2015; China | 2009–2010 |
NLR <
1.93 – n = 298 NLR > 1.93 – n = 189 |
Surgery | 55 mo | 55 | 48 | 5 | Retrospective | 1.93 < NLR > 1.93 | DFS; OS | TNBC phenotype |
| Jia et al., 2015; China | 2000–2010 |
NLR >
2 – n = 804 NLR ≤ 2 – n = 766 |
Surgery and multiple-therapy | 79 mo | 47 | 242 | 108 | Retrospective | NLR > 2 NLR ≤ 2 |
DFS; OS | Age, node status; TNBC phenotype |
| Suppan et al., 2015; Austria |
2001–2012 |
NLR= 4.97 NLR = 2.63 247 |
Surgery and multiple-therapy | 123 mo | 52 | – | – | Retrospective | NLR = 4.97 NLR = 2.63 |
DFS | TNM (pN1; pN2 + pN3) |
| Bozkurt et al., 2015; Turkey |
2002–2013 |
NLR ≤ 2 = 33 NLR > 2 = 52 |
Surgery and multiple-therapy | 60 mo | 50 | – | – | Retrospective | NLR > 2 NLR ≤ 2 |
DFS; OS | Age, menopausal status, tumour size, lymph node status, grade, Ki-67. |
Abbreviations: BMI: body-mass index; DFS: disease-free survival; ER: oestrogen receptor; Mo: months; OS: overall survival; PFS: progression-free survival; NLR: neutrophil-to-lymphocyte ratio; NR: not recorded; NSAIDs: non-steroidal anti-inflammatory drugs; Ys: years; pCR: pathological complete response; TNBC: triple-negative breast cancer.