Abstract
Background and purposeWe evaluated the relationship between patient-, tumor-, and treatment-related features and radiation-induced lymphopenia (RIL) and evaluated the correlation between RIL and survival outcome in NPC patients to help improve the treatment strategy.MethodsThis retrospective study included 374 patients with stage II-IVa NPC who had been treated with definitive RT and were enrolled from 2004 to 2015; The associations between the G3–4 RIL (absolute lymphocyte count, ALC < 0.5 × 109 cells/L) during RT and patient-, tumor-, and treatment-related factors were assessed using Cox regression analyses. The correlation between ALC nadir and survival was examined using a Kaplan-Meier analysis, compared with the log-rank test, and confirmed by a Cox proportional hazards analysis.ResultsIn the multivariate analysis, lower baseline ALC and intensity modulated radiation therapy (IMRT) (vs. 2 dimensional-conformal radiation therapy,2D-CRT) were identified as 2 independent factors that were associated with G3–4 RIL. In the multivariate survival analysis, patients with G3–4 ALC nadir had longer local recurrence-free survival durations (LRFS) (vs. G0–2 nadir, HR = 0.548, P = 0.005) and longer progression-free survival durations (PFS) (vs. G0–2 nadir, HR = 0.676, P = 0.022), while patients with G4 ALC nadir had a shorter distant-metastasis-free survival duration (DMFS) (vs. G0–2 nadir, hazard ratio [HR] = 2.567, P = 0.037).ConclusionsIn the study, lymphopenia during RT were affected by baseline ALC and RT modality independently. Moreover, G3–4 ALC nadir was independently linked with longer PFS and LRFS durations, while G4 ALC nadir was independently linked with a shorter DMFS duration.
Highlights
Nasopharyngeal carcinoma (NPC), which is the most common malignancy arising from the nasopharynx epithelium, is especially prevalent in southern China
The eligibility criteria were as follows:(1) biopsyproven World Health Organization 1, 2, or 3, histopathologic type NPC; (2) Stage II-IVa disease according to the eighth edition of the international Union against Cancer/American Joint Committee on Cancer staging system; (3) no evidence of distant metastases before primary treatment; (4) Eastern cooperative Oncology Group performance status grade 0 or 1; and (5) A definitive radiation therapy for NPC was completed without delay
Association between patient characteristics and incidence of high-level radiation-induced lymphopenia (RIL) In the univariate analysis, we found that baseline absolute lymphocyte count (ALC) (HR = 0.591, P < 0.001) and Radiation therapy (RT) modality (IMRT vs. 2DCRT, HR = 1.594, P < 0.001) were significantly associated with the G3–4 RIL (Table 2)
Summary
Nasopharyngeal carcinoma (NPC), which is the most common malignancy arising from the nasopharynx epithelium, is especially prevalent in southern China. The use of concurrent chemotherapy and intensity-modulated radiation therapy (IMRT) has provided a survival benefit [1,2,3], 20–30% of patients still. Radiation therapy (RT) is the primary treatment for NPC. It might directly suppress immune function via the direct destruction of mature circulating lymphocytes, a cell type that exhibits significant DNA fragmentation, even at low radiation doses (< 1 Gy) [5,6,7]. Tang et al [8] found that among patients undergoing chemotherapy, higher lung V5 to V10 exhibited the greatest association with lower lymphocyte nadir (P < 0.001). It is possible that larger RT fields expose more circulating cells to radiation and result in lymphocyte destruction, otherwise known as radiation-induced lymphopenia (RIL). We evaluated the relationship between patient-, tumor-, and treatment-related features and radiation-induced lymphopenia (RIL) and evaluated the correlation between RIL and survival outcome in NPC patients to help improve the treatment strategy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
