Lymphopenia is an independent predictor of inferior outcome in clear cell renal carcinoma.

OBJECTIVE

A low absolute lymphocyte count is a likely index of poor systemic immunity that may be associated with aggressive features and inferior survival in patients with clear cell renal cell carcinoma.

METHODS

To determine the absolute lymphocyte count we retrospectively analyzed the preoperative blood count of 430 patients with a mean age of 60 years treated with primary surgical resection at our cancer center. Absolute lymphocyte count values as a continuous variable and at a level below 1,300 cells per μl, which was our lowest reference value, were correlated with nuclear grade, pathological stage and TNM stage. We used the Kaplan-Meier method to estimate overall survival, stratified by absolute lymphocyte count status.

RESULTS

As a continuous variable, low absolute lymphocyte count was associated with higher grade (p = 0.009), and higher pT stage (p = 0.034) and TNM stage (p <0.0001). Lymphopenia below 1,300 cells per μl was associated with high grade (p = 0.0043), pT stage (p = 0.051) and TNM stage (p <0.0001). At a median followup of 33.5 months lymphopenia was associated with inferior overall survival in a univariate model (p <0.0001), and on multivariate analysis independent of pT, N and M stages, patient age, grade, smoking history and comorbidities (p = 0.0102). Lymphopenia was also associated with inferior overall survival in a subset of young patients (age 60 years or less) with no distant metastasis (p = 0.014).

CONCLUSIONS

In 430 patients with clear cell renal cell carcinoma lymphopenia was associated with lower overall survival independent of pT and TNM stages, nuclear grade, age, tobacco smoking and comorbidity index.