Effect of Peripheral Blood Lymphocytes on Prognosis of Multiple Cancers

In the era of immunotherapy, the immune function of patients with cancer has attracted increasingly more attention. The immune scoring system is an important supplement to the classical tumor staging and classification process. The immune system plays a controversial role in the development of cancer. Meanwhile, the prognostic significance of peripheral blood lymphocytes is still controversial. The present study aimed to assess the prognostic significance of peripheral blood lymphocytes in eight types of cancers.

We performed a retrospective analysis of 32731 patients with cancer hospitalized in Shanxi Cancer Hospital from January 2012 to December 2016. The percentages of CD3⁺, CD4⁺, CD8⁺, CD19⁺, CD56⁺, and CD127+ lymphocytes in the peripheral blood of all patients were examined using flow cytometry. The immune cell subsets of patients with cancer were classified into three groups using the K-means clustering method via the R language software. Differences in the overall survival rate were analyzed using the Kaplan-Meier method. The Cox regression model was utilized for univariate and multivariate analysis.

The mean survival time of patients with liver cancer, rectal cancer, gastric cancer, breast cancer, esophageal cancer, colon cancer, ovarian cancer, and lymphoma was 30.25, 21.74, 37.67, 16.28, 21.62, 30.25, 31.43, and 34.27 months, respectively. The survival curves showed that the most prognostically beneficial immune state of the patients was when the expression of the immune cells in the peripheral blood was in equilibrium. Moreover, Cox proportional hazards regression model analysis revealed that the factors affecting the overall survival (OS) of patients with eight different kinds of cancer were not identical. However, CD19⁺ lymphocytes had the most significant impact on the prognosis of these patients.

Cancer occurrence and development were associated with the density of lymphocyte infiltration. Thus, immune homeostasis could be an effective indicator to evaluate prognosis and judge cancer treatment.