Prognostic role of pretreatment blood lymphocyte count in patients with solid tumors: a systematic review and meta-analysis

Abstract

Background: To evaluate the prognostic value of pretreatment lymphocyte counts with respect to clinical outcomes in patients with solid tumors. Methods: Systematic literature search of electronic databases (Pubmed, Embase and Web of Science) up to May 1, 2018 was carried out by two independent reviewers. We included Eligible studies assessed the prognostic impact of pretreatment lymphocytes and had reported hazard ratios (HR) with 95% confidence intervals (CIs) for endpoints including overall survival (OS) and progression-free survival (PFS). Only English publications were included. Results: A total of 42 studies comprising 13,272 patients were included in this systematic review and meta-analysis. Low pretreatment lymphocyte count was associated with poor OS (HR = 1.27, 95% CI 1.16-1.39, P < 0.001, I 2 = 58.5%) and PFS (HR = 1.27, 95% CI 1.15-1.40, P < 0.001, I 2 = 25.7%). Subgroup analysis disaggregated by cancer type indicated that low pretreatment lymphocytes were most closely associated with poor OS in colorectal cancer followed by breast cancer and renal cancer. Conclusions: Low pretreatment lymphocyte count may represent an unfavorable prognostic factor for clinical outcomes in patients with solid tumors.

Evaluation of lymphocyte apoptosis in patients with oral cancer

“…[4][5][6] Low lymphocyte counts (lymphopenia) may lead to a decrease in immune system's ability to inhibit cancer development, promoting tumor growth and worsening prognosis. 7 OC has an immune-escape mechanism. Malignant cells are associated with immune suppression, enabling cancer cells to evade the host's immune surveillance.…”

“…Malignant cells are associated with immune suppression, enabling cancer cells to evade the host's immune surveillance. 7,8 The impaired function of the immune system might be directly associated with head and neck squamous cell carcinomas (HNSCC) growth and metastasis. 8 It has also been reported that tumor cells can escape immune surveillance, inhibit immune function, 9 and induce immunogenic cell death and lymphocyte apoptosis, changing lymphocyte homeostasis.…”

“…8 It has also been reported that tumor cells can escape immune surveillance, inhibit immune function, 9 and induce immunogenic cell death and lymphocyte apoptosis, changing lymphocyte homeostasis. 7 Apoptosis is a form of programmed cell death 13 A previous study on cancer tissues found that the expression of Bax is strongly correlated with good clinical outcomes in HNSCC patients. 14 Takemura and Noguchi 15 (2002) corroborate with these results, reporting that patients with OSCC along with Bax expression had better prognosis than those without Bax expression.…”

“… 4 - 6 Low lymphocyte counts (lymphopenia) may lead to a decrease in immune system’s ability to inhibit cancer development, promoting tumor growth and worsening prognosis. 7 …”

Association of neutrophil-to-lymphocyte ratio, neutrophil count, and VEGF on metastasis in patients with nasopharyngeal carcinoma

“…Neutrophils initiate interactions between cancer cells and endothelial cells in the vicinity of the primary tumor microenvironment to expedite metastasis via the release of growth factors such as vascular endothelial growth factor (VEGF) and proteases [13]. Lymphocytes act to prevent tumor cell proliferation and migration [14]. However, whether alterations in these cell counts result in elevated NLR during NPC progress is controversial [15,16].…”