Cervical cancer histology and tumor differentiation affect ¹⁸F-fluorodeoxyglucose uptake

BACKGROUND: This study aimed to evaluate the variation in cervical cancer glucose metabolism for different tumor histologies and levels of differentiation, as measured by the uptake of ¹⁸F-fluorodeoxyglucose (FDG) by positron emission tomography (PET). METHODS: The study population consisted of 240 patients with International Federation of Gynecology and Obstetrics stages Ib1 through IVb cervical cancer, who underwent a pretreatment FDG-PET. Tumor histology included 221 squamous cell (SC), 4 adenosquamous (AS), and 15 adenocarcinoma (AC) tumors. There were 14 well, 145 moderately, and 81 poorly differentiated tumors. The stage distribution was as follows: 70 stage I tumors (9 AC, 2 AS, and 59 SC), 102 stage II tumors (3 AC, 1 AS, and 98 SC), 64 stage III tumors (3 AC, 1 AS, and 60 SC), and 4 stage IV tumors (4 SC). From the FDG-PET, maximal standardized uptake value (SUV_max) was determined. The variation in SUV_max was analyzed for differences based on tumor histology and differentiation. RESULTS: For all patients, the mean SUV _max was 11.62 (range, 2.50-50.39). The mean SUV_max by histology was as follows: SC, 11.91 (range, 2.50-50.39); AS, 8.85 (range, 6.53-11.26); and AC, 8.05 (range, 2.83-13.92). Squamous versus nonsquamous tumors demonstrated a significant difference in SUV_max (P = .0153). SUV_max and tumor volume were not found to be correlated (R2 = 0.013). The mean SUV_max was 8.58 for well-differentiated, 11.56 for moderately differentiated, and 12.23 for poorly differentiated tumors. The mean SUV_max was significantly different for well-differentiated versus poorly differentiated cervical tumors (P = .0474). CONCLUSIONS: Cervical tumor FDG uptake varied by histology and differentiation. SC tumors demonstrated a significantly higher SUV_max compared with nonsquamous cell tumors, and poorly differentiated tumors also had a higher SUV_max.