Is serum survivin expression a predictive biomarker in locally advanced gastric cancer patients treated with neoadjuvant chemotherapy?

Biomarker evaluation in radically resectable locally advanced gastric cancer treated with neoadjuvant chemotherapy: an evidence reappraisal

Neoadjuvant chemotherapy (NAC) significantly improved the prognosis of patients with locally advanced resectable gastric cancer but, despite important progresses, relapse-related death remains a major challenge. Therefore, it appears crucial to understand which patients will benefit from peri-operative treatment. Biomarkers such as human epidermal growth factor receptor-2 (HER2), microsatellite instability (MSI), and Epstein-Barr Virus (EBV) have been widely studied; however, they do not yet guide the choice of perioperative treatment in clinical practice. We performed a narrative review, including 23 studies, addressing the value of tissue- or blood-based biomarkers in the neoadjuvant setting. Ten studies (43.5%) were prospective, and more than half were conducted in East-Asia. Biomarkers were evaluated only post-NAC (on surgical samples or blood) in seven studies (30.4%), only pre-NAC (on endoscopic specimens or blood) in 10 studies (43.5%), and both pre- and post-NAC (26.1%) in six studies. Among the high variety of investigated biomarkers, some of these including MSI-H or enzymatic profile (as TS, UGT1A1, MTHFR, ERCC or XRCC) showed promising results and deserve to be assessed in methodologically sound clinical trials. The identification of molecular biomarkers in patients treated with NAC for locally advanced resectable gastric or EGJ cancer remains crucial.

Molecular Bases of Mechanisms Accounting for Drug Resistance in Gastric Adenocarcinoma

Gastric adenocarcinoma (GAC) is the most common histological type of gastric cancer, the fifth according to the frequency and the third among the deadliest cancers. GAC high mortality is due to a combination of factors, such as silent evolution, late clinical presentation, underlying genetic heterogeneity, and effective mechanisms of chemoresistance (MOCs) that make the available antitumor drugs scarcely useful. MOCs include reduced drug uptake (MOC-1a), enhanced drug efflux (MOC-1b), low proportion of active agents in tumor cells due to impaired pro-drug activation or active drug inactivation (MOC-2), changes in molecular targets sensitive to anticancer drugs (MOC-3), enhanced ability of cancer cells to repair drug-induced DNA damage (MOC-4), decreased function of pro-apoptotic factors versus up-regulation of anti-apoptotic genes (MOC-5), changes in tumor cell microenvironment altering the response to anticancer agents (MOC-6), and phenotypic transformations, including epithelial-mesenchymal transition (EMT) and the appearance of stemness characteristics (MOC-7). This review summarizes updated information regarding the molecular bases accounting for these mechanisms and their impact on the lack of clinical response to the pharmacological treatment currently used in GAC. This knowledge is required to identify novel biomarkers to predict treatment failure and druggable targets, and to develop sensitizing strategies to overcome drug refractoriness in GAC.

Neoadjuvant therapy strategies for advanced gastric cancer: Current innovations and future challenges

Gastric cancer, which has a high incidence and poor prognosis, remains a therapeutic challenge. Recently, neoadjuvant therapy has attracted increasing attention due to high recurrence rate and low survival rate after resection in most patients with advanced stage. Clinical trials show that neoadjuvant approaches confer a significant survival advantage for resectable locally advanced gastric cancer. The specific advantages of chemoradiotherapy compared with chemotherapy have not been clarified; optimal regimens and cycles, particularly in the preoperative setting, should be studied further; and trials aimed at determining the role of targeted and immunological therapies should be conducted.

SPAG5 contributes to the progression of gastric cancer by upregulation of Survivin depend on activating the wnt/β-catenin pathway

The sperm-associated antigen 5 (SPAG5) plays a key role in controlling cellular processes, including cell cycle progression and proliferation. However, the role of SPAG5 in gastric cancer (GC) remains unclear. Herein, our study showed that upregulation of SPAG5 was detected frequently in GC tissues, and was associated with significantly worse survival in patients with GC. Multivariate analyses revealed that high SPAG5 expression was an independent predictive marker for the poor prognosis of GC patients. Further, SPAG5 knockdown notably inhibited the proliferation abilities of GC in vivo and in vitro. Moreover, our results indicate that SPAG5 promotes cell progression by increasing Survivin expression, which has been reported to control the progression of GC. Moreover, our data demonstrate that Survivin is crucial for SPAG5-mediated GC cell progression in vitro and in vivo. Mechanistically, we demonstrated that SPAG5 promotes the progression of GC via enhancing the Wnt/β-catenin/Survivin axis. Collectively, our data suggest that SPAG5 plays a crucial oncogenic role in GC tumorigenesis, and we provide a novel evidence that SPAG5 may be serve as a prognostic and therapeutic target for GC patients.