Association between MRI-measured bone marrow cellularity and clinical outcomes among cervical cancer patients treated with PD-1 inhibitors

This study aimed to explore the prognostic value of bone marrow cellularity in the clinical outcomes of patients with cervical cancer treated with programmed cell death protein-1 (PD-1) inhibitors. This study retrospectively included patients with locally advanced or advanced cervical cancer receiving PD-1 inhibitor monotherapy or in combination with other therapies at Wuhan Union Hospital from May 2020 to December 2023. The mean signal intensity of the left posterior iliac bone, cerebrospinal fluid, and subcutaneous fat regions were measured on T1-weighted magnetic resonance images to calculate bone marrow cellularity. Optimal cut-off values for bone marrow cellularity and inflammatory indicators were determined using X-tile software. Progression-free survival and overall survival were analyzed using Cox regression and Kaplan-Meier analyses. A total of 167 patients (88 with lower bone marrow cellularity and 79 with higher bone marrow cellularity) were included in this study. There were 124 squamous cell carcinoma, 30 adenocarcinoma, and 13 other pathologic types. Multivariate regression analysis showed that International Federation of Gynecology and Obstetrics stage III (progression-free survival: HR = 3.68, p < .001; overall survival: HR = 10.90, p < .001) and IV (progression-free survival: HR = 3.38, p = .002; overall survival: HR = 7.23, p = .003), other pathologic types (progression-free survival: HR = 2.86, p = .020; overall survival: HR = 3.84, p = .012), systemic immune-inflammation index ≥ 820.8 (progression-free survival: HR = 2.04, p = .029; overall survival: HR = 2.39, p = .045), and lower bone marrow cellularity (progression-free survival: HR = 1.74, p = .026; overall survival: HR = 2.35, p = .011) were significantly associated with poorer prognosis. Neutrophil-to-lymphocyte ratio ≥ 4.1 was an independent factor for overall survival (HR = 2.41, p = .049) but not for progression-free survival. Lower bone marrow cellularity is associated with poorer prognosis in patients with cervical cancer treated with PD-1 inhibitors.