Combination of anti-PD-1 therapy and stereotactic radiosurgery for a gastric cancer patient with brain metastasis: a case report

Role of savolitinib in advanced gastric adenocarcinoma with meningeal carcinomatosis and cerebellar metastasis: A case report

BACKGROUND

Brain metastases (BM) are very rare in gastric adenocarcinoma (GaC), and patients with BMs have a higher mortality rate due to stronger tumor aggressiveness. However, its pathogenesis remains unclear. Genetic testing revealed cellular-mesenchymal epithelial transition factor receptor (MET) amplification. Therefore, treatment with savolitinib, a small molecule inhibitor of c-Met, was selected.

CASE SUMMARY

A 66-year-old woman was diagnosed with advanced GaC 6 months prior to presentation due to back pain. Cerebellar and meningeal metastases were observed during candonilimab combined with oxaliplatin and capecitabine therapy. The patient experienced frequent generalized seizures and persistent drowsiness in the emergency department. Genetic testing of cerebrospinal fluid and peripheral blood revealed increased MET amplification. After discussing treatment options with the patient, savolitinib tablets were administered. After a month of treatment, the intracranial lesions shrank considerably.

CONCLUSION

BM is very rare in advanced GaC, especially in meningeal cancer, that is characterized by rapid disease deterioration. There are very few effective treatment options available; however, technological breakthroughs in genomics have provided a basis for personalized treatment. Furthermore, MET amplification may be a key driver of BM in gastric cancer; however, this conclusion requires further investigation.

Incidence, clinicopathological characteristics, and therapeutic strategy for gastric cancer patients with metastasis to the central nervous system

AIM

This study aimed to analyze the clinicopathologic features and treatment outcomes of central nervous system (CNS) metastasis from gastric cancer.

METHODS

A total of 419 patients diagnosed with unresectable advanced or recurrent gastric cancer at Kochi Medical School between January 2007 and December 2021 were evaluated. Data of patients were reviewed, and clinicopathological information and survival outcomes of those with CNS metastases were compared to patients without CNS metastases.

RESULTS

In total, 12/419 (2.9%) patients (median age: 66.5 years [range, 41-82 years]) were diagnosed with CNS metastasis from gastric cancer. Eleven had diffuse-type gastric cancer which was significantly more common than in those without CNS metastasis (91% vs. 61%, p = .034). Human epidermal growth factor receptor 2 status was positive in one of the 12 patients. The median survival time was significantly lower for patients with CNS metastasis than for those without CNS metastasis (1.8 months vs. 11.4 months, p < .001). The median survival time for patients who underwent surgical resection, radiation, or chemotherapy for CNS metastasis was significantly higher than those who received only best supportive care (3.5 months vs. .6 months; p = .007).

CONCLUSIONS

CNS metastasis was found in 2.9% (12/419) of patients with unresectable advanced or recurrent gastric cancer. Diffuse-type histology was a risk factor for CNS metastasis. Multidisciplinary treatment, including surgical resection, radiation treatment, or chemotherapy, for CNS metastasis from gastric cancer may benefit selected patients.

Genomic alterations of cerebrospinal fluid cell-free DNA in leptomeningeal metastases of gastric cancer

BACKGROUND

Leptomeningeal metastases (LM) were rare in gastric cancer (GC), and GC patients with LM (GCLM) generally suffer from poor prognosis. Nevertheless, the clinical utility of cerebrospinal fluid (CSF) circulating tumor DNA (ctDNA) was underinvestigated in GCLM.

METHODS

We retrospectively studied 15 GCLM patients, and all patients had paired primary tumor tissue samples and post-LM CSF samples while 5 patients also had post-LM plasma samples. All samples were analyzed using next-generation sequencing (NGS), and the molecular and clinical features were correlated with clinical outcomes.

RESULTS

CSF had higher mutation allele frequency (P = 0.015), more somatic mutations (P = 0.032), and more copy-number variations (P < 0.001) than tumor or plasma samples. Multiple genetic alterations and aberrant signal pathways were enriched in post-LM CSF, including CCNE1 amplification and cell cycle-related genes, and CCNE1 amplification was significantly associated with patients' overall survival (P = 0.0062). More potential LM progression-related markers were detected in CSF samples than in tumor samples, including PREX2 mutation (P = 0.014), IGF1R mutation (P = 0.034), AR mutation (P = 0.038), SMARCB1 deletion (P < 0.001), SMAD4 deletion (P = 0.0034), and TGF-beta pathway aberration (P = 0.0038). Additionally, improvement in intracranial pressure (P < 0.001), improvement in CSF cytology (P = 0.0038), and relatively low levels of CSF ctDNA (P = 0.0098) were significantly associated with better PFS. Lastly, we reported a GCLM case whose CSF ctDNA dynamic changes were well correlated with his clinical assessment.

CONCLUSIONS

CSF ctDNA could more sensitively detect molecular markers and metastasis-related mechanisms than tumor tissues in GCLM patients, and our study sheds light on utilizing CSF ctDNA in prognostic estimation and clinical assessment in GCLM.

Brain metastasis from gastric adenocarcinoma: A large comprehensive population-based cohort study on risk factors and prognosis

Aims

Although brain metastasis from gastric adenocarcinoma (GaC) is rare, it may significantly affect survival and quality of life. The aim of this large, comprehensive, population-based cohort investigation was to investigate factors that were associated with brain metastasis from GaC and to explore the prognostic factors and time-dependent cumulative mortalities among cases with GaC and brain involvement.

Methods

Population-based information on cases with GaC diagnosed from 2010 to 2016 was obtained from a large-scale database. Factors that were associated with brain metastasis were investigated utilizing multivariable logistic regression. Time-dependent tumor-specific mortalities of cases with GaC and brain involvement were then computed utilizing the cumulative incidence functions (CIFs), and mortalities were compared between subgroups utilizing Gray's test. Factors that were associated with death were further evaluated utilizing multivariable Fine-Gray subdistribution hazard regression.

Results

Together, 28,736 eligible cases were included, which comprised 231 (1%) cases with brain metastasis and 10,801 (38%) with metastasis to other sites, encompassing a follow-up of 39,168 person-years. Brain metastasis occurred more often among younger patients (within overall cancers), in cases with stomach cardia tumors, within cases with signet-ring cell carcinoma (within overall cancers), and within cases with positive lymph nodes (within overall tumors); it was less often detected among black people. Brain involvement was associated with more lung and bone metastases. The median survival time of cases having brain metastasis was only 3 months; the 6- and 12-month tumor-specific cumulative mortalities were 57% and 71%, respectively. Among cases with GaC and brain metastasis, those with gastric cardia cancers (when receiving radiotherapy), those undergoing resection, and those receiving chemotherapy had lower mortality risks, while younger patients (when receiving chemotherapy or radiotherapy) and people with positive lymph nodes (when receiving radiotherapy) had higher death hazards.

Conclusion

Among patients with GaC, brain metastasis was correlated with several clinical and pathological variables, including ethnicity, age, cancer histology, location, lymph node involvement, and metastases to other sites. Cases having brain metastasis had poor survival that was correlated with age, cancer location, lymph node metastasis, and management. These findings offer vital clues for individualized patient care and future mechanistic explorations.

Intramedullary spinal cord metastasis of gastric cancer

The incidence of intramedullary spinal cord metastasis (ISCM) has been increasing because the overall survival of patients with cancer has improved thanks to recent advanced therapies, such as molecular targeted drugs, anticancer agents, and various irradiation techniques. ISCM from lung and breast cancer is the most common form among cases of ISCM. We report an extremely rare form of ISCM from gastric cancer. This 83-year-old man who had a past medical history of gastric adenocarcinoma presented with acute onset of paraparesis. Spinal magnetic resonance imaging revealed an intramedullary lesion at the upper thoracic level. Due to rapid worsening of his paresis, we decided to perform tumor extirpation. Gross total resection of the tumor was successfully performed. Pathological examination revealed poorly differentiated adenocarcinoma, suggesting the diagnosis of ISCM from gastric cancer. He demonstrated gradual improvement of paraparesis soon after surgery, although his overall survival was limited to about 6 months after surgery. When examining the etiology of acute paraparesis in elderly patients with a past medical history of cancer, ISCM should be considered in the differential diagnosis. The prognosis of ISCM from gastric cancer is still extremely limited. Unfortunately, there is currently no treatment with proven efficacy. Surgery for ISCM from gastric cancer, although a challenging procedure for spine surgeons, should be considered as a therapeutic option in these patients.

Upregulated expression of SAC3D1 is associated with progression in gastric cancer

SAC3 domain containing 1 (SAC3D1) has been reported to be involved in numerous types of cancer. However, the role of SAC3D1 in GC has not yet been elucidated. In the present study, the mRNA expression level of SAC3D1 between GC and normal tissues were assessed with a continuous variable meta-analysis based on multiple datasets from public databases. The protein expression level of SAC3D1 in GC and normal tissues was assessed by an in-house immunohistochem-istry (IHC). The association between SAC3D1 expression and some clinical parameters was assessed based on the TCGA and IHC data. Survival analysis was performed to assess the association between SAC3D1 expression and the survival of GC patients. The co-expressed genes of SAC3D1 were determined by integrating three online tools, and the enrichment analyses were performed to determine SAC3D1-related pathways and hub co-expressed genes. SAC3D1 was significantly upregulated in GC tumor tissues in comparison to normal tissues with the SMD being 0.45 (0.12, 0.79). The IHC results also indicated that SAC3D1 protein expression in GC tissues was markedly higher than in normal tissues. The SMD following the addition of the IHC data was 0.59 (0.11, 1.07). The protein levels of SAC3D1 were positively associated with the histological grade, T stage and N stage of GC (P<0.001). The TCGA data also revealed that the SAC3D1 mRNA level was significantly associated with the N stage (P<0.001). Moreover, prognosis analysis indicated that SAC3D1 was closely associated with the prognosis of patients with GC. Moreover, 410 co-expressed genes of SAC3D1 were determined, and these genes were mainly enriched in the cell cycle. In total, 4 genes (CDK1, CCNB1, CCNB2 and CDC20) were considered key co-expressed genes. On the whole, these findings demonstrate that SAC3D1 is highly expressed in GC and may be associated with the progression of GC.

Surgical management of metastatic gastric cancer: moving beyond the guidelines

Despite decreasing incidence, gastric cancer remains a major health problem worldwide and is associated with poor survival. The poor survival is mainly attributed to delayed presentation which may cause local or systemic metastases. The standard of care for patients with metastatic gastric cancer (MGC) is palliative chemotherapy with best supportive care. Although the survival has improved owing to advances in chemotherapeutic agents, it is still unsatisfactory, and some perspective changes are needed in the management of MGC to improve the outcomes. Therefore, various alternative treatment strategies for MGC have formed the most important research topics. Liver-directed treatment (LDT) options such as liver resection, radiofrequency ablation (RFA), microwave ablation (MWA), and hepatic artery infusion chemotherapy (HAIC) have been studied in the management of liver metastasis from gastric cancer (LMGC). Intraperitoneal chemotherapy (IPC) in addition to cytoreductive surgery (CRS) aiming to remove all macroscopic tumor focus resulting from peritoneal dissemination is the treatment option for peritoneal metastasis, while para-aortic lymph node dissection is the treatment option for para-aortic lymph node metastasis which is considered to be M1 disease. Conversion surgery is a novel concept aiming at R0 resection for originally unresectable or marginally resectable tumors after a remarkably good response to the chemotherapy. Large amounts of data in the literature have demonstrated the benefits of individualized approaches such as the combination of systemic and local treatment options in selected patient groups. In this review, we aimed to explore the current and future treatment options by reviewing the literature on this controversial topic.

The roles of PD-1/PD-L1 and its signalling pathway in gastrointestinal tract cancers

Cancer immunotherapy has been increasingly applied in the treatment of advanced malignancies. Consequently, immune checkpoints have become a major concern. As PD-1 is an important immunomodulatory protein, the blockade of PD-1 and its ligand PD-L1 is a promising tumour immunotherapy for human carcinoma. In this review, we first discuss the role of the PD-1/PD-L1 interaction in gastrointestinal tract cancers. Targeting PD-1 and PD-L1 in immune cells and tumour cells may show remarkable efficiency in gastrointestinal tract cancers. Second, the PD-1/PD-L1-associated signalling pathway involved in cancer immunotherapy in gastrointestinal tract cancers is discussed. Most importantly, this review summarizes the PD-1/PD-L1-targeted immunotherapy combinations with relevant signalling pathways, which may result in a breakthrough for the treatment of gastrointestinal tract cancers, such as gastric cancer, colorectal cancer and liver cancer. Meanwhile, the review provides a deeper insight into the mechanism of checkpoint blockade immunotherapies.