The Relationship Between HER2 Status Acquired From Pathological Data and Metabolic Parameters From Pre-treatment [ 18 F]FDG PET/CT in Gastric Adenocarcinomas

• Published in: Revista Española de medicina nuclear e imagen molecular (English ed.) 2024-12, p.500080
• Main Authors: Acar Tayyar, M N, Tamam, M Ö, Babacan, G B, Can Şahin, M, Özçevik, H, Şengiz Erhan, S, Öztürk, A E
• Format: Article
• Language: English
• ISSN: 2253-8089

Overexpression of Human Epidermal Growth Factor Receptor 2 (HER2) is thought to be more aggressive in gastric cancer. This study aimed to evaluate the predictability of HER2 status and other prognostic pathologic parameters using [ F]FDG PET/CT and to investigate its impact on survival. Pretreatment metabolic parameters measured by [ F]FDG PET/CT as a prognostic factor were retrospectively evaluated in 117 HER2-analysed patients. The relationship between pathological data, tumor metabolic characteristics, and distant metastases was examined, and the effect on survival was investigated. Among the 117 patients, 17.1% were HER2-positive (HER2+), and 82.9% were HER2-negative (HER2-). There was no significant association between PET/CT parameters in the HER2+ and HER2- patient groups. HER2+ patients had higher 1- and 3-year survival expectations than HER2- patients (80%-%37.9; %47.5-%20; respectively). There was no statistically significant difference in overall survival. In Cox-regression analysis, while the presence of vascular invasion, local invasion, and distant metastasis were poor prognostic factors, HER2 was not a prognostic factor. Vascular invasion and local invasion (T3/T4) were also associated with higher SUVmax values. Patients with distant metastases had significantly higher SUVmax, SUVmean, and TLG. This study showed no association between HER2 expression and [ F]FDG PET/CT metabolic parameters. However, regardless of HER2 status, the results indicated distant metastasis, local invasion, and vascular invasion could be associated with primary tumor metabolism. PET/CT parameters predict tumor aggressiveness and disease prognosis better than HER2 status.