Treatment strategies for metastatic gastric cancer: chemotherapy, palliative surgery or radiotherapy?

Aim: This study explored whether chemotherapy combined with palliative surgery and/or radiotherapy is a possible treatment for metastatic gastric cancer. Materials & methods: Patients were divided into groups according to treatments. COX models were used to explore prognostic factors. Kaplan-Meier models and log-rank tests were used to analyze outcomes. Outcomes were analyzed before and after propensity score matching. Results: Chemotherapy combined with gastrectomy or metastasectomy prolongs the survival time compared with chemotherapy alone (p < 0.05). Chemotherapy combined with gastrectomy plus metastasectomy and/or radiation therapy also prolongs the survival time (p < 0.05). Conclusion: Chemotherapy combined with gastrectomy could be a more effective treatment for metastatic gastric cancer. Chemotherapy combined with gastrectomy plus metastasectomy and/or radiation therapy could also be a promising treatment.

Advantages with prophylactic PEG-rhG-CSF versus rhG-CSF in breast cancer patients receiving multiple cycles of myelosuppressive chemotherapy: an open-label, randomized, multicenter phase III study.

BACKGROUND: PEG-rhG-CSF reduces neutropenia and improves chemotherapy safety. In China's registration trial (CFDA: 2006L01305), we assessed its efficacy and safety against rhG-CSF, and prospectively explored its value over multiple cycles of chemotherapy. METHODS: In this open-label, randomized, multicenter phase 3 study, breast cancer patients (n = 569) were randomized to receive PEG-rhG-CSF 100 µg/kg, PEG-rhG-CSF 6 mg, or rhG-CSF 5 µg/kg/d after chemotherapy. The primary endpoints were the incidence and duration of grade 3/4 neutropenia during cycle 1. Secondary endpoints included the incidence and duration of grade 3/4 neutropenia during cycles 2-4, the incidence of febrile neutropenia, and the safety. RESULTS: A once-per-cycle PEG-rhG-CSF at either 100 µg/kg or 6 mg was not different from daily injections of rhG-CSF for either incidence or duration of grade 3/4 neutropenia. Interestingly, a substantial difference was noted during cycle 2, and the difference became bigger over cycles 3-4, reaching a statistical significance at cycle 4 in either incidence (P = 0.0309) or duration (P = 0.0289) favoring PEG-rhG-CSF. A significant trend toward a lower incidence of all-grade adverse events was noted at 129 (68.98%), 142 (75.53%), and 160 (82.47%) in the PEG-rhG-CSF 100 µg/kg and 6 mg and rhG-CSF groups, respectively (P = 0.0085). The corresponding incidence of grade 3/4 drug-related adverse events was 2/187 (1.07%), 1/188 (0.53%), and 8/194 (4.12%), respectively (P = 0.0477). Additionally, PFS in metastatic patients preferred PEG-rhG-CSF to rhG-CSF despite no significance observed by Kaplan-Meier analysis (n = 49, P = 0.153). CONCLUSIONS: PEG-rhG-CSF is a more convenient and safe formulation and a more effective prophylactic measure in breast cancer patients receiving multiple cycles of chemotherapy.

Prognostic performance of pre-treatment NLR and PLR in patients suffering from osteosarcoma.

BACKGROUND: Inflammatory response markers have been proposed to predict the clinical outcomes in various cancers. The aim of this study was to explore the influence of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) on the prognosis of osteosarcoma. METHODS: Three hundred fifty-nine patients who underwent curative surgery for osteosarcoma were enrolled from 2005 to 2010. NLR and PLR were calculated from peripheral blood cell counts taken at pre-treatment. Optimal cutoff values of NLR and PLR were determined on the basis of receiver operating characteristic curve analysis. A predictive model was established to predict the clinical outcome for overall survival, and the predictive accuracy of this model was determined by concordance index (c-index). RESULTS: Our results showed that advanced stage and metastasis at diagnosis were significantly associated with the high NLR and PLR groups. NLR was an independent prognostic indicator for overall survival (HR = 1.80, 95% CI = 1.35-2.41, P < 0.001) and progression-free survival (HR = 1.65, 95% CI = 1.26-2.15, P < 0.001), except for PLR. The nomogram could perform well in the prediction of overall survival in patients with osteosarcoma (c-index 0.829). CONCLUSIONS: Our results suggest that both NLR and PLR can reflect clinical prognosis. NLR is more predictive of overall survival and progression-free survival than PLR.

Association of estrogen receptor-beta (ESR2) polymorphism and cancer risk: a meta-analysis.

Estrogen signal medicated by estrogen receptor (ER), which is involved in various diseases related to steroid hormone, such as cancer. A number of association studies have focused on ESR2 polymorphisms to investigate the relationship with cancer risk. However, the results are inconsistent and inconclusive. To examine this controversy, 33 studies were enrolled for the pooled analysis for three poly-morphisms (rs3020450, rs4986938, and rs1256049) in cancer risk using odds ratios (ORs) with 95% confidence intervals (CIs). Regarding rs4986938, A allele was associated with decreased breast cancer. Ethnicity subgroup analysis observed a decreased risk in both Asian and Caucasian descendent. Regarding rs1256049, cancer type subgroup analysis revealed a significant association with increased prostate and endometrial cancer risk. rs3020450 was not associated with cancer risk in any model. Further studies for clarifying the roles of ESR2 polymorphisms in cancer risk seem of vital importance.

STAT3 inhibitor stattic enhances radiosensitivity in esophageal squamous cell carcinoma.

The radioresistance of esophageal squamous cell carcinoma (ESCC) remains an obstacle for the effective radiotherapy of ESCC. This study aimed to investigate the radiosensitization of ESCC by signal transducer and activator of transcription 3 (STAT3) inhibitor stattic. ECA109, TE13, and KYSE150 cell lines were exposed to hypoxia and treated with stattic or radiation, alone or in combination. Cell proliferation, colony formation, apoptosis, and double-stranded DNA breaks (DSBs) were examined. In addition, ECA109 cells were xenografted into nude mice and treated with radiation and/or stattic. The levels of STAT3, p-STAT3, hypoxia-inducible factor 1α (HIF-1α), and vascular endothelial growth factor (VEGF) in ESCC cells and xenografts were detected by Western blot and immunohistochemical analysis. Our results showed that stattic efficiently radiosensitized ESCC cells and xenografts, especially under hypoxia. Moreover, stattic inhibited STAT3 activation and downregulated HIF-1α and VEGF expression. In conclusion, stattic confers radiosensitivity in ESCC cells in vitro and in vivo and is a potential adjuvant for the radiotherapy of ESCC in the clinical setting.

Clinicopathological significance of SLP-2 overexpression in human gallbladder cancer.

Several studies have indicated that overexpression of stomatin-like protein 2 (SLP-2) has been identified in several types of cancer. However, its role and clinical relevance in gallbladder cancer (GBC) is unknown. The purpose of this study was to reveal the prognostic significance of SLP-2 in GBC. The SLP-2 expression was examined at mRNA and protein levels by real-time quantitative polymerase chain reaction (qRT-PCR), and immunohistochemistry in GBC tissues and adjacent noncancerous tissues. Statistical analyses were applied to test the associations between SLP-2 expression, clinicopathologic factors, and prognosis. Immunohistochemistry and qRT-PCR showed that the protein and mRNA expression levels of SLP-2 were both significantly higher in GBC tissues than in adjacent noncancerous tissues. In addition, immunohistochemistry analysis showed that SLP-2 expression was significantly correlated with histological grade (P <0.001), pathologic T stage (P = 0.019), clinical stage (P = 0.001), and lymph node metastasis (P = 0.026). The Kaplan-Meier survival curves indicated that patients with high expression of SLP-2 had shorter overall survival than those with low expression (P <0.001). Meanwhile, the Cox multivariate analysis indicated that high expressions of SLP-2 were an independent prognostic factor for patients with GBC. These data showed that SLP-2 may play an important role in human GBC tumorigenesis, and SLP-2 might serve as a novel prognostic marker in human GBC.

Meat consumption is associated with esophageal cancer risk in a meat- and cancer-histological-type dependent manner.

BACKGROUND: We conducted a systematic review and meta-analysis of meat intake and esophageal cancer risk, with subgroup analyses based on meat type and histological type of cancer. AIMS: The purpose of this study was to investigate the association between meat intake and risk of esophageal cancer. METHODS: We searched MEDLINE, EMBASE and Cochrane Library (April 2013) for cohort and case-control studies that assessed meat intake and esophageal cancer risk. Random-effect or fixed-effect models were used to pool relative risks (RRs) from individual studies with heterogeneity and publication bias analyses carried out. Seven cohort and 28 case-control studies were included. RESULTS: The summary RRs for esophageal cancer for the highest versus lowest consumption categories were 1.19 (95 % confidence interval [CI] 0.98-1.46) for total meat, 1.55 (95 % CI 1.22-1.96) for red meat, 1.33 (95 % CI 1.04-1.69) for processed meat, 0.72 (95 % CI 0.60-0.86) for white meat, 0.83 (95 % CI 0.72-0.96) for poultry, and 0.95 (95 % CI 0.76-1.19) for fish. When striated by histological subtype, positive associations were seen among esophageal squamous cell carcinoma and red meat, white meat and poultry, and esophageal adenocarcinoma with total meat and processed meat. CONCLUSIONS: Meat consumption is associated with esophageal cancer risk, which depends on meat type and histological type of esophageal cancer. High intake of red meat and low intake of poultry are associated with an increased risk of esophageal squamous cell carcinoma. High meat intake, especially processed meat, is likely to increase esophageal adenocarcinoma risk. And fish consumption may not be associated with incidence of esophageal cancer.

Fruquintinib plus paclitaxel versus placebo plus paclitaxel for gastric or gastroesophageal junction adenocarcinoma: the randomized phase 3 FRUTIGA trial.

The vascular endothelial growth factor pathway plays a key role in the pathogenesis of gastric cancer. In the multicenter, double-blind phase 3 FRUTIGA trial, 703 patients with advanced gastric or gastroesophageal junction adenocarcinoma who progressed on fluorouracil- and platinum-containing chemotherapy were randomized (1:1) to receive fruquintinib (an inhibitor of vascular endothelial growth factor receptor-1/2/3; 4 mg orally, once daily) or placebo for 3 weeks, followed by 1 week off, plus paclitaxel (80 mg/m2 intravenously on days 1/8/15 per cycle). The study results were positive as one of the dual primary endpoints, progression-free survival (PFS), was met (median PFS, 5.6 months in the fruquintinib arm versus 2.7 months in the placebo arm; hazard ratio 0.57; 95% confidence interval 0.48-0.68; P < 0.0001). The other dual primary endpoint, overall survival (OS), was not met (median OS, 9.6 months versus 8.4 months; hazard ratio 0.96, 95% confidence interval 0.81-1.13; P = 0.6064). The most common grade ≥3 adverse events were neutropenia, leukopenia and anemia. Fruquintinib plus paclitaxel as a second-line treatment significantly improved PFS, but not OS, in Chinese patients with advanced gastric or gastroesophageal junction adenocarcinoma and could potentially be another treatment option for these patients. ClinicalTrials.gov registration: NCT03223376 .

Fabrication of two kinds of eight-fold photonic quasi-crystals assisted by a specially designed prism.

We demonstrate that two kinds of 2D eight-fold photonic quasi-crystals (PQCs) can be fabricated by a specially designed prism via single-exposure holographic lithography. The prism with five continuous side surfaces out of common eight symmetrical side surfaces, plus a top surface, is well designed for PQC fabrication. Compared with the traditional method of setting up eight free-space beams in the half-space for an eight-fold PQC fabrication, our specially designed prism reduces the number of beams, avoids the differences of beam-to-beam phases, and simplifies the fabrication process. The theory and computer simulation confirm the patterns of two kinds of PQCs by a single prism illumination recording. Further, these quasi-crystal patterns are successfully verified by experimental results under a scanning electron microscope. In addition, these samples show some good properties, such as uniformity over large area, the implementation of a single defect by underexposure, and symmetry break of the eight dots. Our special prism-assisted holographic lithography technique provides a base for further investigating the optical properties of these novel structures.

[Efficacy and safety of rh-endostatin combined with docetaxel in second-line or intolerant toxicity for first-line treatment in patients with advanced non-small cell lung cancer].

OBJECTIVE: To analyze the efficacy and safety of combination of rh-endostatin (Endostar) with docetaxel treatment on patients of non-small cell lung cancer (NSCLC) who presented PD or intolerable toxicity in/after first-line chemotherapy. METHODS: A randomized, double-blind, placebo-controlled and multi-center clinical trial was conducted. Patients with stage IIIB/IV of NSCLC experienced previous chemotherapy of one-regimen were screened for this trial. A total of 68 cases were included in this study. Single docetaxel and that combined with endostar were conducted in two arms. The response, time to progression (TTP) and adverse effects were observed in both arms. RESULTS: The objective response rate (ORR) and clinical benefit rate (CBR) were 0 and 62.5% in the combined arm, along with 0 and 53.3% in the single docetaxel arm, with a non-significant difference between the two groups (all P > 0.05), respectively. The median TTPs in the combined and single docetaxel arms were 2.63 and 2.07 months, respectively (P = 0.079). The median TTPs of the participants with progressive disease (PD) after first-line chemotherapy were 1.33 and 1.67 months in the combined and single docetaxel arms, respectively (P = 0.946). The median TTPs of the participants with intolerant adverse effects in first-line chemotherapy were 4.70 months and 3.17 months in the combined and single docetaxel arms, respectively (P = 0.070). The median TTPs of the patients with SD after 2 therapeutic cycles in the combined and single docetaxel arms were 6.23 months and 3.27 months, respectively (P = 0.040). The differences between two arms were non-significant in adverse, serious adverse and cardiovascular adverse effects (all P > 0.05). CONCLUSIONS: Endostar may prolong TTP in patients with advanced NSCLC benefited from docetaxel treatment without increased toxicities.

Intrathyroidal Thymic Carcinoma: A Retrospective Case Series Study.

OBJECTIVE: Intrathyroidal thymic carcinoma (ITC) is a rare low-grade malignant thyroid tumor. There is neither sufficient understanding of this tumor nor its clinical treatment. This study is to explore the clinicopathological features, treatment, and prognosis of ITC and thereby provide a reference for the diagnosis and treatment of the disease. METHODS: The clinical, pathological, therapeutic, and prognostic data of 13 patients with ITC were retrospectively analyzed. RESULTS: The case series comprised 7 males and 6 females, with an average age of 51.9 ± 10.1 years. After surgical resection, all patients received post-operative neck radiotherapy at dosages of 60-66 Gy. Five patients with level VI lymph node metastasis additionally received 6 courses of cisplatin chemotherapy. All patients were followed-up for 21-132 months (median = 66 months), and all of them survived without recurrence or metastasis. CONCLUSIONS: The diagnosis of ITC depends mainly on pathological and immunohistochemical results, particularly CD5 positive staining. Surgical resection is the preferred primary treatment modality which can be supplemented with radiotherapy and chemotherapy to reduce the risk of recurrence and metastasis.

A clinical decision support system to predict the efficacy for EGFR-TKIs based on artificial neural network.

BACKGROUND: The efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) was affected by numerous factors. In the study, we developed and validated an artificial neural network (ANN) system based on clinical characteristics and next-generation sequencing (NGS) to support clinical decisions. METHODS: A multicenter retrospective non-interventional study was conducted. 240 patients from three hospitals with advanced non-small cell lung cancer (NSCLC) and EGFR mutation were tested by NGS before the first treatment. All patients received formal EGFR-TKIs treatment. Five different models were individually trained to predict the efficacy of EGFR-TKIs based on one medical center with 188 patients. Two independent cohorts from other medical centers were collected for external validation. RESULTS: Compared with logistic regression, four machine learning methods showed better predicting abilities for EGFR-TKIs. The inclusion of NGS tests improved the predictive power of models. ANN performed best on the dataset with mutations TP53, RB1, PIK3CA, EGFR mutation sites, and tumor mutation burden (TMB). The prediction accuracy, recall and AUC were 0.82, 0.82, and 0.82, respectively in our final model. In the external validation set, ANN still showed good performance and differentiated patients with poor outcomes. Finally, a clinical decision support software based on ANN was developed and provided a visualization interface for clinicians. CONCLUSION: This study provides an approach to assess the efficacy of NSCLC patients with first-line EGFR-TKI treatment. Software is developed to support clinical decisions.

Inducing enhanced neutralizing antibodies against broad SARS-CoV-2 variants through glycan-shielding multiple non-neutralizing epitopes of RBD.

Introduction: Since the outbreak of SARS-CoV-2, vaccines have demonstrated their effectiveness in resisting virus infection, reducing severity, and lowering the mortality rate in infected individuals. However, due to the rapid and ongoing mutations of SARS-CoV-2, the protective ability of many available vaccines has been challenged. Therefore, there is an urgent need for vaccines capable of eliciting potent broadly neutralizing antibodies against various SARS-CoV-2 variants. Methods: In this study, we developed a novel subunit vaccine candidate for SARS-CoV-2 by introducing a series of shielding glycans to the Fc-fused receptor-binding domain (RBD) of the prototypic spike protein. This approach aims to mask non-neutralizing epitopes and focus the immune response on crucial neutralizing epitopes. Results: All modified sites were confirmed to be highly glycosylated through mass spectrometry analysis. The binding affinity of the glycan-shielded RBD (gsRBD) to the human ACE2 receptor was comparable to that of the wildtype RBD (wtRBD). Immunizing mice with gsRBD when combined with either Freund's adjuvant or aluminum adjuvant demonstrated that the introduction of the glycan shield did not compromise the antibody-inducing ability of RBD. Importantly, the gsRBD significantly enhanced the generation of neutralizing antibodies against SARS-CoV-2 pseudoviruses compared to the wtRBD. Notably, it exhibited remarkable protective activity against Beta (B.1.351), Delta (B.1.617.2), and Omicron (B.1.1.529), approximately 3-fold, 7- fold, and 17-fold higher than wtRBD, respectively. Discussion: Our data proved this multiple-epitope masking strategy as an effective approach for highly active vaccine production.

Holographic control of motive shape in plasmonic nanogap arrays.

Here we demonstrate that 4-beam holographic lithography can be utilized to create plasmonic nanogaps that are 70 times smaller than the laser wavelength (488 nm). This was achieved by controlling phase, polarization, and laser beam intensity in order to tune the relative spacing of the two sublattices in the interference pattern of a compound-lattice in combination with the nonlinear resist response. Exemplarily, twin and triplet motive features were designed and patterned into polymer in a single exposure step and then transferred into gold nanogap arrays resulting in an average gap size of 22 nm and smallest features down to 7 nm. These results extend the utility of high-throughput, wafer-scale holographic lithography into the realm of nanoplasmonics.

A Pan-Cancer Study of KMT2 Family as Therapeutic Targets in Cancer.

OBJECTIVE: Exome sequencing studies have shown that the histone-lysine N-methyltransferase 2 (KMT2) gene is one of the most commonly mutated genes in a range of human malignancies and is linked to some of the most common and deadly solid tumors. However, the connection between this gene family's function and tumor type, immunological subtype, and molecular subtype dependency is still unknown. METHODS: We examine the expression patterns of the histone-lysine N-methyltransferase 2 (KMT2) gene, as well as their relationship to patient survival. We also used a pan-cancer analysis to link their function to immunological subtypes, the tumor microenvironment, and treatment sensitivity. RESULTS: Using the TCGA pan-cancer data, researchers looked at and examined KMT2 expression patterns and their links to patient survival and the tumor microenvironment in 33 cancer types. The expression of the KMT2 family changes significantly across and within cancer types, indicating significant inter- and intracancer heterogeneity. Patients' overall survival was often linked to the expression of KMT2 family members. However, the direction of the link differed depending on the KMT2 isoform and cancer type studied. Notably, in all cancer types examined, nearly all KMT2 family members were substantially linked with overall survival in patients with renal clear cell carcinoma (KIRC). Furthermore, all KMT2 genes have a strong relationship with immune infiltrate subtypes, as well as varying degrees of stromal cell infiltration and tumor cell stemness. Finally, we discovered that higher expression of KMT2s, particularly KMT2F and KMT2G, was linked to greater chemotherapeutic sensitivity in several cell lines. CONCLUSIONS: The necessity to investigate each KMT2 member as a distinct entity inside each particular cancer type is highlighted by our comprehensive investigation of KMT2 gene expression and its relationship with immune infiltrates, tumor microenvironment, and cancer patient outcomes. Our research also confirmed the identification of KMT2 as a potential therapeutic target in cancer, but further laboratory testing is required.

Differential expression of Tim3 protein in colorectal cancer associated with MSI and Braf mutation.

Tim3 is a negative immune checkpoint molecule and plays a crucial part in tumor-induced immune suppression. Tim3 is a cell surface molecule expressed on T cells marking dysfunctional CD8+ cells in various kinds of cancers. Tim3 expression was mainly reported in tumor-infiltrating lymphocytes (TILs). There are few studies focusing on the expression of Tim3 in tumor cells. Immunohistochemistry was performed to determine Tim3 expression level. The relationships between Tim3 expression in colorectal cancer cells and in tumor-infiltrating lymphocytes and cilicopathological parameters were statistically analyzed. Tim3 was differentially detected in TILs and in colorectal cancer cells. Positive expression of Tim3 in colorectal cancer cells was associated with tumor location (P=0.001), depth of tumor invasion (P<0.001), lymph node metastasis (P=0.001), TNM stage (P=0.001), MSI (P=0.008), and Braf V600E mutation (P=0.001). On the other hand, positive expression of Tim3 in TILs was only related to depth of tumor invasion (P<0.001). Positive expression of Tim3 in both colorectal cancer cells and TILs was associated with depth of tumor invasion (P<0.001), lymph node metastasis (P=0.002), TNM stage (P=0.002), MSI (P=0.039), and Braf V600E mutation (P=0.009). Kaplan-Meier survival analysis showed that Tim3 expression in colorectal cancer and in TILs was significantly associated with patient overall survival (OS) rate (P=0.039, and 0.001). Tim3 may be a potential prognostic marker and a therapy target for colorectal cancer.

Gut Bacteria Erysipelatoclostridium and Its Related Metabolite Ptilosteroid A Could Predict Radiation-Induced Intestinal Injury.

It is difficult to study the intestinal damage induced by space radiation to astronauts directly, and few prediction models exist. However, we can simulate it in patients with pelvic tumor radiotherapy (RT). Radiation-induced intestinal injury (RIII) is common in cancer patients who receieved pelvic and abdominal RT. We dynamically analyzed gut microbiota and metabolites alterations in 17 cervical and endometrial cancer patients after pelvic RT. In patients who later developed grade 2 RIII, dysbiosis of gut microbiota and metabolites were observed. Univariate analysis showed that Erysipelatoclostridium and ptilosteroid A were related to the occurrence of grade 2 RIII. Notably, a strong positive correlation between gut bacteria Erysipelatoclostridium relative abundance and gut metabolite ptilosteroid A expression was found. Furthermore, combinations of Erysipelatoclostridium and ptilosteroid A could provide good diagnostic markers for grade 2 RIII. In conclusion, gut bacteria Erysipelatoclostridium and its related metabolite ptilosteroid A may collaboratively predict RIII, and could be diagnostic biomarkers for RIII and space radiation injury.

Tunable two-mirror interference lithography system for wafer-scale nanopatterning.

We have designed and analyzed a novel (to the best of our knowledge) two-beam interference lithography system for large-area (wafer-level) nanopatterning with enhanced tunability of pattern periodicities. The tunable feature has been achieved by placing two rotational mirrors in the expanded beam paths at regulated angles for a desired period. Theoretical analyses show that the effective pattern coverage area greater than a 4 in. (10 cm) wafer scale is attainable with a 325 nm (30 cm coherence length) HeCd laser and 4 in. (10 cm) mirrors, while the pattern coverage area is restrained by the overruling effects between the optical coherence and mirror size. The experimental results also demonstrate uniform nanopatterns at varying periods (250-750 nm) on 4 in. (10 cm) substrates, validating the theoretical analyses. The tunable two-mirror interferometer will offer a convenient and robust way to prepare large-area nanostructures on a wafer scale with superior tunability in their pattern periodicities.

Two degrees-of-freedom Lloyd-mirror interferometer for superior pattern coverage area.

In this study, we have developed a tunable Lloyd-mirror interferometer with two degrees of freedom, in contrast to a traditional system with one degree of freedom. This new Lloyd-mirror interferometer allows an angular rotation of the mirror independently from that of a sample stage, resulting in an increased pattern coverage area with tunable pattern periodicity. Both theoretical and experimental results verify that the tunable characteristic of the modified configuration enhances the nanopatterning capabilities of the Lloyd-mirror interference lithography system especially in achieving greater pattern coverage area for larger pattern periodicities.

The association of APE1 -656T > G and 1349 T > G polymorphisms and cancer risk: a meta-analysis based on 37 case-control studies.

BACKGROUND: APE1 (apurinic/apyrimidinic endonuclease 1) is an important DNA repair protein in the base excision repair pathway. Polymorphisms in APE1 have been implicated in susceptibility to cancer; however, results from the published studies remained inconclusive. The objective of this study was to conduct a meta-analysis investigating the association between polymorphisms in APE1 and the risk for cancer. METHODS: The PubMed and Embase databases were searched for case-control studies published up to June, 2011 that investigated APE1 polymorphisms and cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. RESULTS: Two polymorphisms (-656 T > G, rs1760944 and 1349 T > G, rs1130409) in 37 case-control studies including 15, 544 cancer cases and 21, 109 controls were analyzed. Overall, variant genotypes (GG and TG/GG) of -656 T > G polymorphism were associated with significantly decreased cancer risk in homozygote comparison (OR = 0.81, 95%CI: 0.67-0.97), dominant model comparison (OR = 0.89, 95%CI: 0.81-0.97) and recessive model comparison (OR = 0.90, 95%CI: 0.82-0.98), whereas the 1349 T > G polymorphism had no effects on overall cancer risk. In the stratified analyses for -656 T > G polymorphism, there was a significantly decreased risk of lung cancer and among Asian populations. CONCLUSIONS: Although some modest bias could not be eliminated, the meta-analysis suggests that APE1 -656 T > G polymorphism has a possible protective effect on cancer risk particularly among Asian populations whereas 1349 T > G polymorphism does not contribute to the development of cancer.