Programmed death 1 (PD-1) and CD4+CD25+FoxP3+ expression in peripheral blood T-cells has been previously reported in various types of cancer. However, the specific variation tendency during surgery and chemotherapy, as well as their relationship in gastric cancer patients, still remain unclear. Understanding this aspect may provide some novel insights for future studies on tumor recurrence and tumor immune escape, and also serve as a reference for determining the optimal timing and dose of clinical anti-PD-1 antibodies.

To observe and analyze the expression characteristics of peripheral lymphocyte PD-1 and FoxP3+ regulatory T cells (FoxP3+ Tregs) before and after surgery or chemotherapy in gastric cancer patients.

Twenty-nine stomach cancer patients undergoing chemotherapy after a D2 gastrectomy provided 10 mL peripheral blood samples at each phase of the perioperative period and during chemotherapy. This study also included 29 age-matched healthy donors as a control group. PD-1 expression was detected on lymphocytes, including CD4+CD8+CD45RO+, CD4+CD45RO+, and CD8+CD45RO+ lymphocytes as well as regulatory T cells.

We observed a significant increase of PD-1 expression on immune subsets and a larger number of FoxP3+ Tregs in gastric cancer patients (P < 0.05). Following D2 gastrectomy, peripheral lymphocytes PD-1 expression and the number of FoxP3+ Tregs notably decrease (P < 0.05). However, during postoperative chemotherapy, we only observed a decrease in PD-1 expression on lymphocytes in the CD8+CD45RO+ and CD8+CD45RO+ populations. Additionally, linear correlation analysis indicated a positive correlation between PD-1 expression and the number of CD4+CD45RO+FoxP3high activated Tregs (aTregs) on the total peripheral lymphocytes (r = 0.5622, P < 0.0001).

The observed alterations in PD-1 expression and the activation of regulatory T cells during gastric cancer treatment may offer novel insights for future investigations into tumor immune evasion and the clinical application of anti-PD-1 antibodies in gastric cancer.

Immune checkpoint inhibitor (ICI) treatment in patients with microsatellite instability-high/mismatch repair deficient (MSI-H/dMMR) tumors holds promise in reshaping organ preservation in rectal cancer. However, the benefits are accompanied by distinctive patterns of response, introducing a dilemma in the response evaluation for clinical decision-making.

Patients with locally advanced rectal cancer with MSI-H/dMMR tumors receiving neoadjuvant ICI (nICI) treatment (n=13) and matched patients receiving neoadjuvant chemoradiotherapy (nCRT; n=13) were included to compare clinical response and histopathologic features.

Among the 13 patients receiving nICI treatment, in the final radiologic evaluation prior to surgery (at a median of 103 days after initiation of therapy), progressive disease (n=3), stable disease (n=1), partial response (n=7), and complete response (n=2) were observed. However, these patients were later confirmed as having pathologic complete response, resulting in pseudoprogression and pseudoresidue with incidences of 23.1% (n=3) and 76.9% (n=10), respectively, whereas no pseudoprogression was found in the 13 patients receiving nCRT. We further revealed the histopathologic basis underlying the pseudoprogression and pseudoresidue by discovering the distinctive immune-related regression features after nICI treatment, including fibrogenesis, dense lymphocytes, and plasma cell infiltration.

Pseudoprogression and pseudoresidue were unique and prevalent response patterns in MSI-H/dMMR rectal cancer after nICI treatment. Our findings highlight the importance of developing specific strategies for response evaluation in neoadjuvant immunotherapy to identify patients with a good response in whom sphincter/organ-preserving or watch-and-wait strategies may be considered.

Angiogenesis inhibitors are of considerable interest for treating metastatic colorectal cancer (mCRC). This trial evaluated the efficacy and safety of apatinib in chemotherapy-refractory mCRC. Apatinib 500 mg was administered daily to patients who had progressed after two or more lines of standard fluorouracil-based chemotherapy. Primary endpoint was progression-free survival (PFS). Secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), and toxicity. Overall, 48 patients were enrolled. ORR and DCR were 8.3% (4/48) and 68.8% (33/48), respectively. Median PFS and OS were 4.8 (95% confidence interval [CI], 3.653-5.887) and 9.1 months (95% CI, 5.155-13.045), respectively, and did not differ between subgroups stratified by previous anti-angiogenic therapies. The most prevalent grade 3-4 adverse events were hypertension (12.5%), hand-foot syndrome (HFS, 10.4%), thrombocytopenia (10.4%), and proteinuria (8.3%). Low baseline neutrophil/lymphocyte ratio (NLR, hazard ratios [HR], 0.619; P = 0.027), early carbohydrate antigen 19-9 (CA19-9) decrease (HR, 1.654; P = 0.016), and HFS (HR, 2.087; P = 0.007) were associated with improved PFS. In conclusion, apatinib monotherapy demonstrated encouraging efficacy with manageable toxicities in chemotherapy-refractory mCRC. Previous anti-angiogenic therapies did not influence outcomes. Baseline NLR, early CA19-9 decrease, and HFS could predict the efficacy of apatinib.

MMP12 is mainly secreted by macrophages, is involved in macrophage development, and decomposes the extracellular matrix. Herein, we investigated whether macrophages would change in the intestinal tumor microenvironment after MMP12 knockout. Apc^Min/+;MMP12^-/-mice were obtained by crossbreeding Apc^Min/+ mice with MMP12 knockout mice (MMP12^-/- mice). The data showed that the number and volume of intestinal tumors were significantly increased in Apc^Min/+;MMP12^-/- mice compared with Apc^Min/+ mice. Additionally, the tumor biomarkers CA19-9, CEA, and β-catenin appeared relatively early in intestinal tumors in Apc^Min/+;MMP12^-/- mice. The results demonstrated that knocking out MMP12 accelerated the tumor growth and pathological process. On further investigation of its mechanism, the proportions of M2 macrophages in the spleen and among peritoneal macrophages were significantly up-regulated in Apc^Min/+;MMP12^-/- mice. Expression of M2 macrophage-related genes was up-regulated in tumor and peritoneal macrophages. The M2-related cytokine levels of IL-4 and IL-13 were increased in the serum of Apc^Min/+;MMP12^-/-mice. In vitro, bone marrow-derived M2 macrophages were obtained by treating bone marrow cells with IL-4 and IL-13, and these M2 macrophages secreted cytokines being changed. This finding reveals the crucial role of MMP12 in macrophage development and provides a new target for the control of macrophage polarization. Knocking out MMP12 causes intestinal M2 macrophage accumulation in tumor microenvironment, promoting the growth of intestinal tumors in Apc^Min/+ mice.

The measurement of serum tumour markers is a simple and non-invasive method for assessing the response to systemic therapies in metastatic colorectal cancer (mCRC) and estimation of prognosis. The aim of our retrospective study was to evaluate the association of baseline serum levels of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), thymidine kinase (TK) and tissue polypeptide specific antigen (TPS) with outcome of patients with mCRC treated with combination of chemotherapy and monoclonal antibodies against epidermal growth factor receptor (anti-EGFR mAbs) in the first line. In our study, the cohort included 102 patients treated with therapy based on anti-EGFR mAbs between years 2011 and 2017 at Department of Oncology and Radiotherapy, Medical School and University Hospital in Pilsen, Czech Republic. Serum samples were collected within one month before the initiation of treatment. In multivariate Cox analysis that included serum tumour markers and clinical baseline parameters show that high baseline serum CA 19-9 was significantly associated with worse progression-free survival (HR=1.871, p=0.0330) and also overall survival (HR=3.903, p=0.0006). We have not demonstrated association of baseline levels of CEA, TK and TPS with patients' outcome. CA 19-9 is commonly used serum tumour marker which is simple and readily available and its candidate prognostic importance in the setting of anti-EGFR therapy deserves to be studied in prospective trials.

The aim of our retrospective study was to analyze the association of selected tumor markers (TMs) including serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), thymidine kinase, and tissue polypeptide specific antigen with outcomes in patients with metastatic colorectal cancer (mCRC) treated with bevacizumab. There is an increasing body of evidence from retrospective/observational studies that some serum TMs may be predictive of effect of targeted therapies in mCRC. In our study, the cohort included 152 patients treated with bevacizumab-based therapy between years 2005 and 2014 at Department of Oncology and Radiotherapy, Medical School and Teaching Hospital Pilsen. Serum samples for measurement of TMs were collected within 1 month before the initiation of bevacizumab-based treatment. In multivariate Cox analysis that included serum tumor markers and clinical baseline parameters, the number of metastatic sites (hazard ratio [HR] = 2.00, p = 0.001) and CEA levels (HR = 2.80, p < 0.001) were significantly associated with progression-free survival, whereas CA 19-9 levels (HR = 2.25, p = 0.008) were the only studied parameter associated with overall survival. Quantification of serum CEA and CA 19-9 is simple and readily available, and their candidate prognostic importance in the setting of antiangiogenesis therapy deserves to be studied in prospective trials.

The purpose of this study was to analyze the predictive value of neutrophil/lymphocyte ratio (NLR) to better clarify which patient groups will benefit the most from particular treatments like bevacizumab.

A total of 245 treatment-naive metastatic colorectal cancern (mCRC) patients were retrospectively enrolled and divided into 2 groups: 145 group A patients were treated with chemotherapy in combination with bevacizumab, and 100 group B patients were treated as above without bevacizumab.

Group A patients had better median overall survival (OS) and progression-free survival (PFS) (24.0 and 9.0 months) than group B patients (20 and 6.0 months) (p=0.033; p=0.015). In patients with low NLR, OS and PFS were significantly longer in group A patients (27 vs 18 months, p=0.001; 11 vs 7 months, p=0.017).

We conclude that NLR, a basal cancer related inflammation marker, is associated with the resistance to bevacizumab- based treatments in mCRC patients.

The prognostic and predictive values of carbohydrate antigen 19-9 (CA19-9) levels in metastatic colorectal cancer (mCRC) remain unclear. We reviewed all mCRC patients at a single institution to evaluate the relationship between CA19-9 levels and survival.

Two hundred and fifty-two patients underwent first-line chemotherapy using oxaliplatin-based regimens between April 2005 and December 2009. The relationship between baseline CA19-9 levels and survival was analyzed. Moreover, we evaluated the relationship between baseline CA19-9 levels and clinicopathological factors.

One hundred and fifty patients had elevated baseline CA19-9 levels (elevated group), and 79 patients had normal baseline CA19-9 (normal group) levels. Both KRAS and BRAF mutation rates were higher in the elevated group than in the normal group. Elevated CA19-9 level was a poor prognostic factor compared with normal CA19-9 levels (P = 0.0021). In the elevated group, the median survival time with bevacizumab was significantly longer with bevacizumab than without it (median OS, 27.8 vs. 15.3 months, P = 0.0019). However, the median survival time was not different with or without bevacizumab in the normal group (median OS, 36.5 vs. 38.0 months, P = 0.9515).

Our results suggest that baseline CA19-9 level is an independent prognostic factor in mCRC patients, and it correlated with the KRAS/BRAF mutation status. Bevacizumab exhibits clinical activity only for high CA19-9 levels in mCRC.

CD45RO, PD-1, and TLR4 immune pathways have proven pivotal in regulating antitumor response and correlate with survival for localized colorectal cancer (CRC). We evaluated if their peripheral expression was associated with outcome in metastatic CRC (mCRC). Thirty-one mCRC patients were eligible for this prospective study ( clinicaltrial.gov NCT01533740) and treated with first-line FOLFIRI-B. Blood was drawn before the first and third cycle and analyzed by flow cytometry for frequency (%) of CD4+, CD8+, CD45RO+, and PD1+ mononuclear cells and for TLR4 expression on neutrophils. Two cycles of chemotherapy determined changes in immune variables that were prognostically meaningful. Pre-third-cycle (ptc) CD45RO+CD8+cell% displayed a statistically significant association with progression-free survival (PFS) (median PFS 22.4 vs. 9.4 months for patients with CD45RO+CD8+cell%> vs. Collapse

Colorectal cancer (CRC) is among the most frequently diagnosed cancers and a major cause of cancer-related mortality worldwide. The aim of the present study was to determine whether there was an improvement in the time to disease progression (TTP) in patients with metastatic colorectal cancer (mCRC) treated with first-line bevacizumab plus chemotherapy, according to tumor characteristics and metastatic sites. Tumor characteristics and tumor burden were considered to be predictive markers of the therapeutic efficacy of bevacizumab. The medical records of 705 patients with mCRC were retrospectively reviewed in three oncology centers between January, 2005 and September, 2012. A total of 101 patients completed their first-line bevacizumab-containing treatment. The median TTP was 6.93 months [interquartile range (IQR)=4.20-9.80 months] in patients treated with irinotecan, 5-fluorouracil (5-FU) and bevacizumab vs. 7.42 months (IQR=6.08-10.68 months) in those treated with oxaliplatin, 5-FU and bevacizumab (P=0.589). When we compared patients with pulmonary metastases (median TTP, 9.9000 months) or other metastatic patients without pulmonary metastasis (median TTP, 6.9000 months), we observed a statistically significant difference (P=0.046). However, when the efficacy of bevacizumab was compared in terms of other tumor characteristics (tumor grade, size and lymph node involvement) and metastatic sites, the differences were not significant (P>0.05). We concluded that bevacizumab may be effective in all subgroups of patients with mCRC. Furthermore, bevacizumab with combination chemotherapy may be superior to combination chemotherapy only as the first-line treatment of patients with mCRC and pulmonary metastasis.

In certain cell culture studies, significant CEA expression was observed in K-ras mutant cells. However, the relationship between high CEA levels and K-ras status has not been sufficiently investigated. In the present study, we aimed to determine the prognostic role of initial CEA and CA 19-9 values in metastatic colorectal cancer patients according to the status of K-ras. Between 2000 and 2010, a total of 215 patients with metastatic colorectal cancer who were treated and followed up in our oncology center were analyzed. Smokers were excluded from the study. The clinicopathological findings and initial CEA and CA19-9 values were determined. K-ras mutation analysis was performed using quantitative PCR evaluation of the DNA from the tumor tissues. Eighty-two patients (38.1 %) were female and 133 (61.9 %) were male, with a median age of 59 years (range 27-83). Based on tumor localization, 127 patients (59 %) were classified as colon cancer patients and 88 patients (41 %) were classified as rectal cancer patients. The majority of patients (83.3 %) had pure adenocarcinoma histology, while 36 cases (16.7 %) had mucinous adenocarcinoma. The initial CEA levels were detected to be high (>5 ng/mL) in 108 of the patients (50.2 %), while high levels of initial CA 19-9 (>37 ng/mL) were found in 90 patients (41.8 %). K-ras mutations were detected in 99 of the patients (46 %). K-ras was found to be wild type in 116 patients (54 %). Significant differences were detected between the K-ras wild-type and mutant groups with respect to age and the initial serum CEA levels. Patients with K-ras mutations were younger (p = 0.04) and had higher initial CEA levels (p = 0.02) compared to patients with K-ras wild type. The median overall survival (OS) time and 3-year OS rate for patients with a high initial CEA level (>5 ng/mL) were significantly shorter than those of patients with a low initial CEA level (<5 ng/mL) (50.5 months and 61.8 % vs. 78.6 months and 79.1 %, p = 0.014). Furthermore, the patients with low initial CA 19-9 levels (<37 ng/mL) had a significant better median OS interval and 3-year OS rate (76.1 months and 80.1 %) compared to patients with high initial CA 19-9 levels (>37 ng/mL) (37.6 months and 55.7 %, p = 0.04). Multivariate analysis indicated that stage at the time of diagnosis (p < 0.001) and low initial serum CEA level (p = 0.037) were independent prognostic factors of OS. For K-ras mutant patients, the stage at diagnosis (p = 0.017), low initial serum CEA level (p = 0.001), and low initial serum CA 19-9 level were found to be independent prognostic indicators of OS. Our findings demonstrate for the first time that the presence of a K-ras mutation correlated with high initial CEA and CA 19-9 levels in patients with metastatic colorectal cancer. Patients with high initial CEA and CA 19-9 levels may potentially predict the presence of a K-ras mutation, and this prediction may guide targeted therapies in these patients.

Angiopoietin 2 (Ang-2) has an important role in tumor angiogenesis. In this study, Ang-2 levels of serum and bronchioloalveolar lavage fluids (BALF) in patients with lung cancer were measured and correlated with clinical and biochemical parameters.

Thirty-five cases newly diagnosed with lung cancer and 18 controls with non-cancerous lung diseases were included in the study. Tumor histology, staging, metastasis, tumor markers, biochemical and clinical parameters were all recorded.

Serum Ang-2 levels were significantly higher in the lung cancer group compared to the control (lung cancer median: 2.42 ng/mL [2.19-2.98], control 0.67 [0.31-1.10]; P < 0.001), whereas Ang-2 levels in BALF were lower in the lung cancer group compared to the control (lung cancer median 0.41 ng/mL [0.22-0.79], control 0.67 [0.46-1.03]; P = 0.02). In the cancer group, higher serum Ang-2 levels (r = 0.52, P < 0.001) were associated with the stage of cancer. No significant correlation was observed between BALF Ang-2 levels and non-small cell lung cancer stages and small-cell lung cancer advanced stage (P = 0.793, r = 0.07). Serum Ang-2 levels were significantly higher in distant metastasis (M1) versus no distant metastasis (M0) (M1: 2.57 ng/mL [2.38-2.87], M0: 2.22 [1.49-2.40], P = 0.01). No significant correlation was observed between BALF Ang-2 levels and M1 (r = 0.11, P = 0.53).

Serum Ang-2 levels were significantly higher in lung cancer patients and positive correlations were observed between serum Ang-2, tumor stage, and metastasis.

The process of new blood vessel formation, or angiogenesis, has become an important target for therapeutic intervention in many cancers, including metastatic colorectal cancer (mCRC). The growth and metastasis of primary tumors is dependent upon their ability to acquire and maintain an adequate blood supply; however, angiogenesis in tumors is an irregular process leading to chaotic and hyperpermeable vessels that may result in increased intratumoral pressure and poor exchange of macromolecules and oxygen. It has been hypothesized that inhibition of angiogenesis in tumors can both impair the formation of new tumor blood vessels and possibly 'normalize' the existing tumor vasculature, causing a more efficient delivery of cytotoxic chemotherapies (CTs). Over the last decade, therapies that target vascular endothelial growth factor (VEGF) have become a component of treatment for several cancers. In particular, the combination of bevacizumab with established chemotherapeutic regimens for mCRC has been shown to improve overall and progression-free survival, as well as response rates, over CT alone. Agents that target various members of the VEGF family, as well as signaling by the VEGF receptors and their tyrosine kinase components, are currently under development and evaluation in clinical trials. Integration of these new therapies into the treatment of mCRC will ultimately increase the available therapeutic options for patients. Still, many challenges remain, including identifying and validating relevant biomarkers to guide the optimal use of antiangiogenesis agents.

We evaluated the changes of the tumor markers CEA and CA19.9 as early predictors of progression in metastatic colorectal cancer (mCRC) patients participating in a clinical study and receiving chemotherapy and bevacizumab (Bev). Seventy-two patients had high baseline CEA or CA19.9 serum levels. By ROC analyses, the areas under the curves were 0.83 for variable CEA cutoff values for distinguishing progressive disease (PD) versus stable disease (SD)/partial remission (PR)/complete remission (CR), and 0.80 for variable CA19.9 cutoff values for distinguishing PD versus SD/PR/CR. Rises in CEA and CA19.9 may early signal the occurrence of progression in mCRC patients receiving chemotherapy and Bev.

The aim of this study is to evaluate the influence of germline vascular endothelial growth factor (VEGF) gene polymorphisms (VGPs) on the efficacy of the anti-VEGF antibody bevacizumab (Bev) in metastatic colorectal cancer (MCRC) patients.

Forty MCRC patients eligible for a first-line therapy were enrolled in this prospective trial and treated with FOLinate/Fluorouracil/Irinotecan (FOLFIRI) + Bev (male/female = 22:18, age (median) = 61 years). Eight VGPs within the promoter/5'UTR region were evaluated in patient blood samples. Primary endpoint was association between VGPs and median progression-free survival (mPFS). Overall radiological response rate (ORR), overall survival (OS), and toxicity were assessed as secondary outcomes.

VGPs -2578, -1512, -1451, -1411, and -460 were in complete linkage disequilibrium and therefore analyzed as haplotype (two variants: Haplo1: A-18 bp insertion-T-4G-C and Haplo2: C-18 bp deletion-C-5G-T, respectively). Seventeen patients Haplo2/Haplo2 had significantly shorter mPFS compared to 23 patients Haplo1/Haplo1 or Haplo1/Haplo2 (mPFS, 9 vs. 15.4 months, respectively, p = 0.02; hazard ratio (HR), 2.64). Also, VGPs -152 (G/G vs. G/A + A/A) and -1154 (G/G vs. G/A + A/A) were significantly associated with PFS (mPFS, 8.9 vs. 15.4 months, p = 0.007; HR, 3.53 and 9.8 vs. 16 months, p = 0.03, HR, 2.32, respectively). In the multivariate analysis including also biochemical variables known to influence prognosis, VGP -1154 retained an independent predictive value for mPFS (G/G over G/A + A/A = HR, 4.43; p = 0.02). With regard to ORR, only VGP -634 was significantly associated with response (G/G vs. G/C + C/C = 64% vs. 14%, p = 0.03). No significant influence on OS and toxicity by the investigated VGPs was observed.

Although these data need to be confirmed in larger trials, investigation of germline VGPs may help identify patients who are more sensitive to anti-VEGF agents.

The addition of bevacizumab to cytotoxic chemotherapy has demonstrated a progression-free survival (PFS) benefit in the first-line and second-line treatment of advanced or metastatic breast cancer (MBC). However, the addition of bevacizumab to capecitabine in heavily pretreated MBC patients did not show a PFS benefit (AVF2119g phase III trial). The aim of this study was to evaluate the expression of novel putative biomarkers as predictors of benefit from bevacizumab in retrospective subset analyses of the AVF2119g trial.

In the AVF2119g trial, 462 patients with MBC were randomly assigned to receive capecitabine or capecitabine plus bevacizumab. Primary tumor tissue and outcome data were available for 223 patients. Biomarker expression was assessed by in situ hybridization (VEGF-A, VEGF-B, thrombospondin-2 and Flt4) or immunohistochemistry (VEGF-C, PDGF-C, neuropilin-1, delta-like ligand (Dll) 4, Bv8, p53 and thymidine phosphorylase) on formalin-fixed, paraffin-embedded tissue. PFS was associated with these variables in retrospective subset analyses.

Patients with low scores for Dll4, VEGF-C, and neuropilin-1 showed trends toward improvement in PFS associated with the addition of bevacizumab to capecitabine (P values = 0.01, 0.05, and 0.07, respectively). These observations were not statistically significant following correction for multiple hypothesis testing.

These retrospective subset analyses suggest that expression of Dll4, VEGF-C, and neuropilin-1 may predict benefit from bevacizumab. Such observations are not conclusive but warrant additional testing.