P11.21.B CLINICAL CHARACTERISTICS AND TREATMENT STRATEGIES FOR CANCER CASES PRESENTING WITH CENTRAL NERVOUS SYSTEM SYMPTOMS AS THE INITIAL MANIFESTATION

Abstract BACKGROUND Historically, metastatic brain tumors have been associated with a poor prognosis, with median survival reported at approximately six months. Accordingly, brain metastases have often been regarded as a terminal-stage manifestation of cancer, limiting the consideration of aggressive treatment. However, advances in imaging and systemic therapies have significantly improved the prognosis for various cancers, leading to prolonged survival even in advanced stages. In cases where metastatic brain tumors are discovered as the initial manifestation through neurological symptoms, determining the appropriate treatment strategy remains a clinical challenge. We hypothesize that controlling brain metastases could facilitate subsequent treatment of the primary malignancy and potentially prolong survival. Here, we retrospectively analyzed cancer cases presenting with central nervous system symptoms as the initial presentation treated at our institution over the past 10 years. MATERIAL AND METHODS We retrospectively reviewed 13 cases diagnosed between 2013 and 2022, in which central nervous system symptoms were the initial manifestation of cancer. Clinical data, including age, sex, neurological symptoms, tumor size and number, Karnofsky Performance Status, primary tumor site, presence of extracranial metastases, treatment approaches for brain metastases and primary tumors, and GPA/Lung-mol GPA scores, were collected. Overall survival (OS) was defined as the interval from the diagnosis of brain metastases to death or last follow-up. RESULTS Thirteen cases were identified, with primary tumors originating from lung cancer (n=11), breast cancer (n=1), and esophageal cancer (n=1). Among lung cancer cases, nine were non-small cell lung cancer (NSCLC) and two were small cell lung cancer (SCLC). In NSCLC cases, the median predicted OS based on the Lung-mol GPA was 6.9 months, whereas the actual observed median OS was 53 months. Even among NSCLC cases without driver mutations, the median OS was 24.5 months, exceeding the predicted survival. In SCLC cases, the predicted and observed OS were consistent. CONCLUSION This study demonstrates that NSCLC cases presenting with central nervous system symptoms as the initial manifestation achieved markedly longer survival than predicted by the Lung-mol GPA. Treatment-naïve status at diagnosis and subsequent aggressive therapy targeting the primary tumor may have contributed to the favorable outcomes. These findings suggest that aggressive treatment should still be considered in NSCLC patients without genetic mutations. GPA/Lung-mol GPA scores, which are designed for cases with brain metastases arising after cancer diagnosis, may not accurately predict prognosis in cases where brain metastases are the initial presentation. Multimodal treatment strategies may greatly extend survival in this unique patient population.