Main Session
Sep
29
PQA 06 - Genitourinary Cancer, Gynecological Cancer, and Health Care Access and Engagement
3785 - Association Between Survival and Dynamic Changes in Peripheral Lymphocyte Count During Radiotherapy in Older Patients with Locally Advanced Cervical Cancer
Presenter(s)
Takeshi Fujisawa, MD, PhD - University of Tsukuba, Tsukuba City 305-8575, Ibaraki
T. Fujisawa1, T. Sumiya1, T. Sawada1, K. Baba2, T. Ishida1, M. Harada1, M. Goto1, M. Nakamura3, T. Saito4, H. Numajiri1, K. Nakai2, M. Mizumoto2, and H. Sakurai5; 1Departement of Radiation Oncology and Proton Medical Research Center, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan, 2Department of Radiation Oncology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan, 3University of Tsukuba, Tsukuba City 305-8575, Japan, 4Tsukuba University, Tsukuba, Japan, 5Department of Radiation Oncology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
Purpose/Objective(s):
In patients with locally advanced cervical cancer, definitive radiotherapy (RT) can potentially decrease peripheral lymphocyte counts during and after treatment. Previous studies suggest that patients with less severe lymphopenia during treatment and better post-treatment recovery have higher survival rates; nonetheless, evidence in older patients is limited. We hypothesized that greater post-RT lymphocyte recovery relative to baseline would be associated with improved overall survival (OS) in older patients. This retrospective study aimed (1) to determine whether changes in lymphocyte count during and after RT are associated with OS in patients aged =70 and (2) to identify clinical factors associated with lymphocyte recovery.Materials/Methods:
We retrospectively reviewed data from patients aged =70 years who received definitive RT for cervical cancer at our institution between March 2013 and October 2024 (IRB: R07-209). OS was evaluated by stratifying patients according to the proportion of lymphocyte decline during RT (low vs. high nadir) and the proportion of post-RT recovery relative to baseline (low vs. high recovery). Clinical factors (age, concurrent chemotherapy, V10Gy of bone marrow at WPRT, and V45Gy of bowels at WPRT) associated with the recovery from the nadir in peripheral lymphocyte count were assessed using univariate analyses (Wilcoxon rank–sum test), and variables with p < 0.05 were entered into a multivariate linear regression model.Results:
Sixty-eight 68 patients were included in the study. The median age was 76 years (range: 70–96 years). All patients received a total RT dose of 50 Gy whole-pelvic RT (WPRT), with (n=66) or without center shielding (n=2), and a median brachytherapy dose of 24 Gy (range, 6–30 Gy). Twenty-nine patients received either cisplatin or gemcitabine during RT. The median follow-up time was 45 months (95% confidence interval [CI]: 31–58 months). There was no significant difference in 3-year OS between the low and high nadir groups (81% [95% CI: 67–98] vs. 77% [95% CI: 62–95], p = 0.3). Conversely, 3-year OS was significantly higher in patients with high recovery than in those with low recovery (92% [95% CI: 83–100] vs. 66% [95% CI: 48–91], p = 0.03). Univariate analysis revealed that younger patients (p < 0.01), those receiving chemotherapy during RT (p < 0.01), and those with a lower bone marrow V10 Gy (p = 0.04) had a higher rate of increase from the nadir. In multivariate analysis, only younger age remained significantly associated with a greater increase in lymphocyte count after RT (p = 0.01).Conclusion:
Greater post-RT recovery of peripheral lymphocyte count is associated with improved OS in patients aged =70 years with cervical cancer. Peripheral lymphocyte counts in older patients are less likely to show a lower recovery rate after RT compared to younger patients.