gastric mass

A 65-year-old male presents with a 3-month history of unintentional weight loss and epigastric discomfort. Endoscopy revealed a gastric mass, and biopsy confirmed a mixed adenoneuroendocrine carcinoma. Staging imaging is shown. His ECOG performance status is 1. Considering the clinical presentation and the findings demonstrated in the provided images, what is the most appropriate initial management strategy for this patient?

A 65-year-old male presents with a 2-month history of fatigue, poor appetite, and 5kg weight loss. He reports mild upper abdominal discomfort. Physical examination is unremarkable. Initial blood tests show mild anaemia. An upper endoscopy revealed a suspicious gastric lesion, with biopsy results pending. A CT scan of the abdomen and pelvis was performed. Given the clinical presentation and the findings on the provided imaging, which of the following statements regarding this patient's likely prognosis and management is most accurate?