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Perioperative systemic treatment is standard of care for Caucasian patients with locally advanced, resectable gastric adenocarcinoma. The prognostic relevance of the microsatellite instability (MSI) status in patients undergoing neoadjuvant chemotherapy followed by resection is unclear. We analyzed the association of the MSI status with histological regression and clinical outcome in patients undergoing neoadjuvant systemic treatment. Tumor tissue from patients undergoing neoadjuvant chemotherapy followed by resection for gastric or gastroesophageal‐junction adenocarcinoma was analyzed for MSI status using a mononucleotide marker panel encompassing the markers BAT25, BAT26, and CAT25. Histological regression, relapse‐free survival and overall survival were calculated and correlated with MSI status. We identified the MSI‐H phenotype in 9 (8.9%) out of 101 analyzed tumors. Though a poor histological response was observed in eight out of nine MSI‐H patients, overall survival was significantly better for patients with MSI‐H compared to MSS tumors (median overall survival not reached vs. 38.6 months, log‐rank test p = 0.014). Among MSI‐H patients, an unexpected long‐term survival after relapse was observed. Our data indicate that the MSI‐H phenotype is a favorable prognostic marker in gastric cancer patients undergoing neoadjuvant treatment. The benefit of perioperative cytotoxic treatment in patients with MSI‐H gastric cancer, however, remains questionable. Future trials should stratify patients according to their MSI status, and novel treatment modalities focusing on MSI‐H tumors should be considered.

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Response of the primary tumor does not guarantee recurrence-free long-term survival, but histopathological complete responders have better prognosis compared to partial responders. Established prognostic factors strongly influence the outcome, which could, in the future, be used for stratification of adjuvant treatment approaches. Increasing the rate of histopathological complete responders is a valid endpoint for future clinical trials investigating new drugs.

VEGFR-2 is expressed on tumor vasculature and a target for anti-angiogenic intervention. VXM01 is a first in kind orally applied tumor vaccine based on live, attenuated Salmonella bacteria carrying an expression plasmid, encoding VEGFR-2. We here studied the safety, tolerability, T effector (Teff), T regulatory (Treg) and humoral responses to VEGFR2 and anti-angiogenic effects in advanced pancreatic cancer patients in a randomized, dose escalation phase I clinical trial. Results of the first 3 mo observation period are reported. Locally advanced or metastatic, pancreatic cancer patients were enrolled. In five escalating dose groups, 30 patients received VXM01 and 15 placebo on days 1, 3, 5, and 7. Treatment was well tolerated at all dose levels. No dose-limiting toxicities were observed. Salmonella excretion and salmonella-specific humoral immune responses occurred in the two highest dose groups. VEGFR2 specific Teff, but not Treg responses were overall increased in vaccinated patients. We furthermore observed a significant reduction of tumor perfusion after 38 d in vaccinated patients together with increased levels of serum biomarkers indicative of anti-angiogenic activity, VEGF-A, and collagen IV. Vaccine specific Teff responses significantly correlated with reductions of tumor perfusion and high levels of preexisting VEGFR2-specific Teff while those showing no antiangiogenic activity had low levels of preexisting VEGFR2 specific Teff, showed a transient early increase of VEGFR2-specific Treg and reduced levels of VEGFR2-specific Teff at later time points - pointing to the possibility that early anti-angiogenic activity might be based at least in part on specific reactivation of preexisting memory T cells.

The proposed PRSC clearly identifies three subgroups with different outcomes and may be more helpful for guiding further therapeutic decisions than the UICC staging system.

BackgroundEsophageal cancer is often marked by aggressive tumor growth and poor prognosis. Patient groups who benefit from perioperative therapy are not yet defined. The tumor microenvironment and circulating factors as possible predictors of response and prognosis gain interest. This study aimed to investigate cytokines in patients’ serum and tumor tissue with regard to response and prognosis.ResultsMedian survival between SCC and AC was not different (published previously). Lower levels of CCL11 (Eotaxin-1) and CXCL10 (IP-10) in the tumor tissue were associated with a better prognosis (p = 0.022; p = 0.002). In the AC subgroup higher concentrations of TGF-β3 in serum and corresponding tumor tissue were associated with adverse prognosis (p = 0.035; p = 0.006). An association with histopathological response was found for IL-12(p70) and CXCL10 in patients’ sera (p = 0.041; p = 0.032). The tissue levels of TGF-β1 and TGF-β2 were significantly lower in histopathological responders than in nonresponders (p = 0.033; p = 0.007). A similar trend was seen for TGF-β3, without statistical significance (p = 0.097).Materials and MethodsPreoperative serum samples and corresponding tumor tissue (n = 54), only serum (n = 20) or only tissue (n = 4) were collected from patients undergoing surgery for cT3/4 esophageal squamous cell cancer (SCC) (n = 34) and adenocarcinoma (AC) (n = 44). All samples were taken after neoadjuvant treatment. All patients received perioperative chemo(radio)therapy. Cytokine levels of 17 different cytokines were measured by multiplex immunoassay and correlated with clinicopathological factors.ConclusionsTwo chemokines (CCL11 and CXCL10) in posttherapeutic tumor tissue were associated with prognosis in patients with esophageal cancer, lower levels indicating a better prognosis. Lower levels of TGF-β were associated with better response and prognosis in patients with AC.

After PSM, standardized follow-up by a specialized center significantly improved OS. Cross-sectional imaging and treatment of recurrence were associated with better outcome. Regular follow-up by cross-sectional imaging especially during the first 3 years should be recommended by national guidelines, since early detection might help select patients for treatment of recurrence and even resection in few designated cases.