Association Between Radiation Tolerance of Lymphocytes and Clinical Outcomes in Cervical Cancer

BACKGROUND/AIM: This study evaluated whether the lymphocyte tolerance factor (LTF) was an indicator of radiation tolerance of lymphocytes (RTL) using the relative lymphocyte count (RLC), and considering clinical outcomes. PATIENTS AND METHODS: A total of 92 cervical cancer patients treated with concurrent chemoradiotherapy (CCRT) were analysed. RLC0 was pre-treatment RLC, and RLC1, and RLC2 were at the first and second week of CCRT, respectively. LTF1 was RLC1:RLC2. LTF2 was the dimension of the convex or concave shape comprising the three RLC vertexes. Patients were divided into three groups: good RTL group, low LTF1; moderate RTL group, high LTF1 and low LTF2; and poor RTL group, high LTF1 and high LTF2. RESULTS: Patients with good tumour response to radiotherapy were mostly included in the good RTL group than in the other groups. The poor RTL group had lower 3-year progression-free survival (57.1% vs. 83.8% and 82%, p=0.01) and 5-year disease-specific survival (71.8% vs. 90.4% and 94.9%, p=0.062) rates than the moderate and good RTL groups. Multivariate analyses showed that poor RTL was a significant survival predictor. CONCLUSION: The poor RTL group according to LTF is a potential predictor of clinical outcome.