¹⁸ F-FDG PET/CT imaging in neuroendocrine prostate cancer: Relation to histopathology and prognosis

Background: This study aimed to evaluate the effectiveness of ¹⁸ F-fluoro-2-deoxy-D-glucose Positron emission tomography/computed tomography (¹⁸ F-FDG PET/CT) in predicting prognosis and characterizing the intratumoral glucose uptake of neuroendocrine prostate cancer (NEPC).

Methods: We retrospectively reviewed 189 NEPC patients from two medical centers between January 2009 and April 2021. Of these, 44 patients met the inclusion criteria. The maximum standardized uptake value (SUVmax) was measured to assess the metabolic state of NEPC and comparison were made between different histopathological subtypes. Kaplan-Meier and Cox regression analyses were performed to evaluate the predictive value of SUVmax on overall survival (OS) and progression-free survival (PFS).

Results: This study analyzed 44 NEPC patients and found that 13 patients had small cell neuroendocrine carcinoma (SCNC), while 31 were diagnosed with adenocarcinoma with neuroendocrine differentiation (Ad-NED) based on histopathology, and a positive correlation was found between SUVmax and SCNC via Spearman correlation test (r_s = 0.60, p < 0.0001). Furthermore, SUVmax demonstrated good diagnostic accuracy in differentiating SCNC from Ad-NED (area under the curve 0.88, 95% confidence interval [CI] 0.76-0.99). Kaplan-Meier survival analyses and univariate analyses revealed that patients with SUVmax > 10.2 had a significantly shorter OS than patients with SUVmax ≤ 10.2 (hazard ratio = 4.83, 95% CI 1.45-16.1, p = 0.01).

Conclusions: The histopathological subtypes in NEPC showed a close correlation with the glucose metabolic activity of primary tumors as assessed by ¹⁸ F-FDG PET/CT. High SUVmax values in primary prostate tumors were associated with a worse OS in NEPC patients.