Radiation-Induced Lymphopenia Predicts Poorer Prognosis in Patients with Breast Cancer: A Post-Hoc Analysis of a Randomized Controlled Trial of Postmastectomy Hypofractionated Radiotherapy
Abstract
PURPOSE
The aim of this study was to determine if radiation-induced lymphopenia (RIL) affects survival of patients with breast cancer.
METHODS AND MATERIALS
Post-hoc analysis of data of 598 breast cancer patients from a randomized controlled trial comparing postmastectomy hypofractionated radiotherapy (HFRT; 43.5 Gy in 15 fractions over 3 weeks) with conventional fractionated radiotherapy (CFRT; 50 Gy in 25 fractions over 5 weeks). Mean peripheral lymphocyte count (PLC) at different time points in the two groups were compared by the t-test. Disease-free survival (DFS) and overall survival (OS) were analyzed by the Kaplan-Meier method and compared between groups by the log-rank test.
RESULTS
Baseline PLC (pre-PLC) was comparable between HFRT and CFRT patients (1.60 ± 0.57 × 109/L vs. 1.56 ± 0.52 × 109/L; P = .33). In both groups, the PLC declined steadily during the course of radiotherapy but started to recover at 1 month after radiotherapy. Incidence of lymphopenia was significantly lower in HFRT patients (45.4% vs. 55.7%; P = .01). Nadir PLC (nadir-PLC) was significantly higher in HFRT patients (1.08 ± 0.37 × 109/L vs. 0.97 ± 0.31× 109/L; P < .001), as also the nadir-PLC/pre-PLC ratio (0.72 ± 0.28 vs. 0.67 ± 0.28; P = .02). Median follow-up was for 57.6 months (IQR: 38.5-81.4). The 5-year DFS was significantly lower in patients with nadir-PLC/pre-PLC ratio <0.8 than in those with ratio ≥0.8 (71.8% vs. 82.6%; P = .01); however, OS was comparable between the groups (85.8% vs.…
How strong is the evidence?
Evidence Hub reads this as a secondary / pooled analysis, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 598 participants or records.
Read the paper
Related studies
- Preliminary Toxicity Analysis of 3DCRT versus IMRT on the High Dose Arm of the RTOG 0126 Prostate Cancer Trial
- Adaptive Radiotherapy for Head and Neck Cancer: Initial Clinical Outcomes from a Prospective Trial
- American Association of Physicists in Medicine Task Group 263: Standardizing Nomenclatures in Radiation Oncology
- Motion Management Strategies and Technical Issues Associated with Stereotactic Body Radiotherapy of Thoracic and Upper Abdominal Tumors: A Review from NRG Oncology
- High-dose-rate interstitial brachytherapy as a monotherapy for localized prostate cancer: treatment description and preliminary results of a phase I/II clinical trial
- Highly efficient training, refinement, and validation of a knowledge-based plan quality control system for radiotherapy clinical trials
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.