Associations between absolute neutrophil count and lymphocyte-predominant breast cancer

Tumor-infiltrating lymphocytes (TILs) might be associated with host-cell mediated immunity, which could be partly reflected by peripheral blood cell counts. In addition, lymphocyte-predominant breast cancer (LPBC), which was defined as tumors having high TIL levels, showed a favorable prognosis among triple-negative breast cancer or HER2-positive breast cancer. We aimed to investigate whether peripheral blood cell counts are associated with LPBC.

We evaluated the percentage of stromal TILs in breast cancer patients who underwent primary surgery, using the standardized methodology proposed by the international TIL Working Group. Lymphocyte-predominant breast cancer (LPBC) was defined as tumors having high TIL levels (≥50%). Peripheral blood cell counts including absolute neutrophil counts (ANC), absolute lymphocyte counts (ALC) and neutrophil-to-lymphocyte ratio (NLR) was obtained from pretreatment laboratory data.

Of the 810 patients, 132 (16.3%) had LPBC, and 678 (83.7%) had non-LBPC. In a comparison of 3 markers of peripheral blood counts, LPBC had a significantly lower mean ANC than non-LPBC (3,304 vs. 3,564; P = 0.023), but the other means were not different. In multivariable analysis, each 1K increment in ANC corresponded to an odds ratio of 0.790 (95% CI, 0.642 to 0.971) for LPBC. In the ER-negative and high-Ki67 subgroups identified by interaction tests, significant inverse correlations between continuous ANC and TILs were noted.

Low peripheral ANC could be linked with LPBC, supporting the hypothesis that systemic immune cell counts might be associated with the tumor-immune microenvironment.