Brain metastases in gastro-esophageal cancers: Survival and prognostic insights from an Asian cohort.

Abstract

323 Background: Brain metastases (BrM) from gastro-esophageal cancers are rare and often associated with poor prognosis. Accounting for up to 3% of all cases, overall survival (OS) can be as low as 3 months compared to 17 months in patients without BrM. We describe the clinico-demographic factors, treatment patterns, survival, and prognostic factors of gastro-esophageal cancer patients with BrM. Methods: A multi-center retrospective cohort study of patients with BrM from gastro-esophageal cancers was performed across 4 hospitals in Singapore. Data from Feb 2006-Sep 2022 was analysed, with total 73 patients included. Primary endpoint of interest was median OS (measured from the date of diagnosis of BrM). Secondary endpoints include treatment patterns and prognostic variables. Results: Among 73 patients, 72.6% were male and 82.2% Chinese. Mean age at diagnosis was 59.9 years. The primary cancer sites were gastric (41.1%), esophageal (30.1%) and gastro-esophageal junction (28.8%). Adenocarcinoma accounted for 58.8%, while squamous cell carcinoma 13.2%. BrM were found at primary diagnosis in 26.0% of patients. Most lesions were supratentorial (56.2%), with multiple lesions (60.0%) and leptomeningeal disease present in 19.7% Median follow-up was 323 days. Median OS from BrM diagnosis was 82 days (95% CI 53.2-108.8), with 1-year OS of 15%. Treatments included radiotherapy (RT) alone (37.0%), best supportive care (26.0%), resection + RT (13.7%), systemic therapy + RT (11.0%), systemic therapy alone 8.2% and finally resection alone 2.7%. Of RT recipients, 52.2% received whole brain RT and 28.3% stereotactic radiosurgery. Amongst systemic therapy patients, majority received chemotherapy alone (74.2%), 4.1% chemo-immunotherapy, 19.2% chemotherapy and targeted therapy. In our cohort, esophageal tumor (p=0.010), leptomeningeal disease (p=0.028) were significantly associated with poorer survival. Multimodality treatment improved survival compared to RT alone (2.07 months) in the multivariable analysis: RT + systemic therapy (11.51 months, HR 0.022 , p=0.001), RT + resection + systemic therapy (12.66 months, HR 0.029 , p=0.004). Conclusions: Patients with gastro-oesophageal cancers and brain metastases continue to have poor prognoses despite advances in systemic therapy. Our findings suggest that a multimodality approach - surgery, RT, and systemic therapy - offers the greatest survival benefit, with median overall survival of about 12 months in selected patients.