Integrated Analysis of Serum Lymphocytes Develops a Nomogram for Predicting Prognosis of Intracranial Germ Cell Tumors to Chemo-Radiotherapy

Introduction: It is common to evaluate lymphocytes subsets in virus infection, immunodeficiency diseases and cancer. This study retrospectively analyzed serum lymphocyte subsets and survival outcomes in intracranial germ cell tumors (iGCTs) patients. Methods Serum from145 iGCTs patients were collected and lymphocyte subsets were analyzed by flow cytometry. Clinical information was extracted from the database in Sun Yat-sen University Cancer Center and outcomes were confirmed through outpatient visits and telephone follow-up. Results 76 patients were confirmed germinoma, 29 mixed germ cell tumor, 4 teratoma, 9 malignant teratoma, 6 endodermal sinus tumor, 20 choriocarcinoma and 1 embryonal carcinoma. 123(84.8%) patients received comprehensive treatments and 104(71.7%)reached complete or partial response. T lymphocytes (CD3 + ), cytotoxic T cells (CD3 + CD8 + or Tc) and B lymphocytes(CD19 + )decreased(p = 0.033, p = 0.011, and p < 0.001 respectively), while activated cytotoxic T lymphocytes(CD8 + CD25 + ) increased(p < 0.001). Dynamic changes of activated Tc cells were associated with treatment patterns and evaluation of the disease(p = 0.038 and p = 0.043). Median survival was 45.81 months and patients of increased Tc cells, activated T helper cells(CD4 + CD25 + T cells or activated Th cells), activated Tc cells and normal CD4 + /CD8 + ratio presented encouraging outcomes (p = 0.007;0.016;0.028;0.016 respectively). Nomogram and multivariate Cox Regression analysis indicated increased Tc cells was related to reduced risk death(p = 0.001,HR = 0.217 95%CI = 0.085—0.551).) Conclusion Implement of comprehensive treatments led to positive responses. Dynamic monitoring of serum lymphocyte subsets can be used as an auxiliary indicator for prognosis judgment.