Gastric cancer is among the top 5 causes of cancer-related death worldwide. Preoperative chemotherapy has been established as an option in patients with locally advanced gastric cancer. However, chemotherapy yields variable results, owing to the cellular and molecular heterogeneity of this disease. Identifying patients who did or did not respond to preoperative therapy can allow clinicians to alter treatment modalities and provide important information related to prognostication. Pathologic response to preoperative therapies, called Tumor Response Grade (TRG), has been evaluated to quantify treatment response. Multiple systems for TRG have been established. However, literature has demonstrated inconsistent results for TGR systems and prognosis, possibly due to variability in interpretation of tumor response between systems and interobserver variability. Radiographic response to preoperative therapies using RECIST 1.1 criteria and endoscopically-assessed tumor response have demonstrated association with survival; however their use in gastric cancer remains challenging given the inability to accurately and consistently identify and measure the tumor, especially in the setting of neoadjuvant therapy where treatment-related changes can obscure the gastric wall layers. This review is focused on summarizing the available literature related to evaluating TRG in gastric cancer, as well as providing a brief overview on the use of radiographic and endoscopic methods to assess response to preoperative therapies. Lastly, we outline future directions regarding the use of a universal TRG system to guide care and assist with prognosis.

The peptide hormone kisspeptin attenuates liver steatosis, metabolic dysfunction-associated stea-tohepatitis (MASH) and fibrosis in mouse models, by signaling via the kisspeptin 1 receptor (KISS1R). However, whether kisspeptin impacts fibrogenesis in the human liver is not known. We investigated the impact of a potent kisspeptin analog (KPA) on fibrogenesis using human precision cut liver slices (hPCLS) from fibrotic livers from male patients, in human hepatic stellate cells (HSCs), LX-2 and in primary mouse HSCs. In hPCLS, 48 h and 72 h of KPA (3 nM, 100 nM) treatment decreased collagen secretion, and lowered expression of fibrogenic and inflammatory markers. Immunohistochemical studies revealed that KISS1R is expressed and localized to HSCs in MASH/fibrotic livers. In HSCs, KPA treatment reduced transforming growth factor beta (TGFb)-induced expression of fibrogenic and inflammatory markers, in addition to decreasing TGFb induced collagen secretion, cell migration, proliferation and colony formation. Mechanistically, KISS1R signaling downregulated TGFb signaling by decreasing SMAD2/3 phosphorylation, via activation of protein-phosphatases PP2A, that dehosphorylates SMAD 2/3. This study revealed for the first time that kisspeptin reverses human hepatic fibrogenesis thus identifying it as a new therapeutic target to treat hepatic fibrosis.