Correlation Between Semiquantitative Metabolic Parameters After PET/CT and Histologic Prognostic Factors in Laryngeal and Pharyngeal Carcinoma

Positron emission tomography/computed tomography (PET/CT) has shown prognostic significance in head and neck cancer patients. The underlying pathologic features that could explain the mechanisms associated with this observation are not clear. To analyze the correlation between 18-F-fluoro-2-deoxy-d-glucose (18F-FDG) uptake assessed by PET/CT in head and neck cancer and histopathologic prognostic factors. Ninety-nine patients with laryngeal and pharyngeal squamous cell carcinoma were retrospectively reviewed for pretreatment PET/CT measurements, namely standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The corresponding histologic material was evaluated for tumor stroma-related prognostic factors such as the amount and type of stroma, lymphocytic response, tumor budding activity, and size of tumor cell nests in the tumor core area and tumor front. TLG and MTV were associated with tumor localization, as they were higher in oropharyngeal tumors. These values were also associated with tumor cell nest size in the tumor core with higher values corresponding to tumors with smaller nests. MTV40% was marginally associated with fibroblastic stroma type and higher budding activity. SUVmax was not associated with the histological factors in the whole sample, but higher values trended with higher tumor budding activity and stroma-rich tumors of the oropharynx. 18F-FDG PET measurements in head and neck squamous cell carcinomas are associated with prognostic histopathologic factors and suggest a possible correlation of glucose metabolism to epithelial-to-mesenchymal transition.