Pancreatic mucinous adenocarcinoma has different clinical characteristics and better prognosis compared to non-specific PDAC: A retrospective observational study.

Background: Pancreatic mucinous adenocarcinoma (PMAC) is a rare malignant tumour, and there is limited understanding of its epidemiology and prognosis. Initially, PMAC was considered a metastatic manifestation of other cancers; however, instances of non-metastatic PMAC have been documented through monitoring, epidemiological studies, and data from the Surveillance, Epidemiology, and End Results (SEER) database. Therefore, it is crucial to investigate the epidemiological characteristics of PMAC and discern the prognostic differences between PMAC and the more prevalent pancreatic ductal adenocarcinoma (PDAC). Methods: The study used data from the SEER database from 2000 to 2018 to identify patients diagnosed with PMAC or PDAC. To ensure comparable demographic characteristics between PDAC and PMAC, propensity score matching was employed. Kaplan-Meier analysis was used to analyse overall survival (OS) and cancer-specific survival (CSS). Univariate and multivariate Cox regression analyses were used to determine independent risk factors influencing OS and CSS. Additionally, the construction and validation of risk-scoring models for OS and CSS were achieved through the least absolute shrinkage and selection operator-Cox regression technique. Results: The SEER database included 84,857 patients with PDAC and 3345 patients with PMAC. Notably, significant distinctions were observed in the distribution of tumour sites, diagnosis time, use of radiotherapy and chemotherapy, tumour size, grading, and staging between the two groups. The prognosis exhibited notable improvement among married individuals, those receiving acceptable chemotherapy, and those with focal PMAC (p < 0.05). Conversely, patients with elevated log odds of positive lymph node scores or higher pathological grades in the pancreatic tail exhibited a more unfavourable prognosis (p < 0.05). The risk-scoring models for OS or CSS based on prognostic factors indicated a significantly lower prognosis for high-risk patients compared to their low-risk counterparts (area under the curve OS: 0.81-0.82, CSS: 0.80-0.82). Conclusion: PMAC exhibits distinct clinical characteristics compared to non-specific PDAC. Leveraging these features and pathological classifications allows for accurate prognostication of PMAC or PDAC.

Letrozole ovulation induction: an effective option in endometrial preparation for frozen-thawed embryo transfer.

PURPOSE: To evaluate the clinical efficacy of letrozole on ovulation induction and hormone replacement therapy (HRT) during endometrial preparation for frozen-thawed embryo transfer (FET). METHODS: We analyzed totally 1,230 cycles of patients that underwent FET from October 2010 to September 2012. Seven hundred and thirteen cycles of patients with ovulation disorders that underwent FET were randomly assigned to two groups by case control study. 359 cycles received letrozole ovulation induction and 354 cycles received HRT during endometrial preparation for FET, respectively. In the corresponding period, 517 cycles of patients with normal ovulation in the natural cycle group for FET endometrial preparation served as controls. Reproduction-related clinical outcomes of patients in the three groups were compared. RESULTS: The embryo implantation rate of patients in letrozole group (30.4 %) was significantly higher than the HRT group (22.8 %, P < 0.05). The clinical pregnancy rate of patients in the letrozole group (53.2 %) was significantly higher than the HRT group (44.4 %, P < 0.05), while no significant difference was observed between the letrozole and natural cycle groups (51.3 %, P > 0.05). Estradiol levels on the day of human chorionic gonadotropin administration in the letrozole group were significantly lower than those in the natural cycle group (280.32 ± 125.39 pg/ml and 351.06 ± 123.03 pg/ml, respectively; P < 0.05). The live birth rate of patients in letrozole group (44.6 %) was significantly higher than the HRT group (32.5 %, P < 0.05), while abortion rate (12.0 %) was significantly lower than the HRT group (21.0 %, P < 0.05). There were no significant differences in number of mature follicles, endometrial thickness, duration of follicle growth between the letrozole and the natural cycle groups, and there were no significant differences in twin birth rate and ectopic pregnancy rate among the three groups (all P values >0.05). CONCLUSIONS: Ovulation induction with letrozole during endometrial preparation for FET has a higher rate of pregnancy success and a lower abortion rate than HRT. Letrozole treatment exhibits clinical progression and outcomes similar to those patients undergoing a natural cycle or normal ovulation cycle. Therefore, letrozole treatment may be an effective option in endometrial preparation for FET in patients with ovulation disorders or irregular menstruation.

[Association between H-ras and L-myc gene polymorphisms and susceptibility to colorectal cancer].

OBJECTIVE: To explore the association between the polymorphisms of oncogenes H-ras and L-myc and colorectal cancer risk, and the interaction of those genes. METHODS: The genotypes of H-ras and L-myc genes were determined by polymerase chain reaction-based restriction fragment length polymorphism analysis. Stratified analysis and logistic model were used to detect the gene-gene interaction. The gene-gene interaction was validated by multifactor dimensionality reduction (MDR) analysis. RESULTS: The single SNP model showed that the polymorphisms of H-ras and L-myc genes were not significantly related with colorectal cancer risk (P > 0.05). Stratified analysis revealed that among the L-myc LS + SS genotype carriers, those with H-ras TC + CC genotype showed significantly increased risk of rectal cancer than those with TT genotype (OR = 1.81, P = 0.005). The positive interaction between L-myc and H-ras was detected by logistic regression model. The OR of the interaction effect was 2.74 (P = 0.024). This result was confirmed in the MDR model, with 54.83% testing balanced accuracy and 10/10 cross-validation consistency, and the model was still significant after the 1000 times permutation test (P = 0.001). CONCLUSION: Our findings suggest that the polymorphism of H-ras and L-myc genes is not related to colorectal cancer risk, but there is a synergy between H-ras and L-myc polymorphisms in the development of rectal cancer.

[Application of flexible matching strategy to detect gene-environment interactions for increasing the study power].

INTRODUCTION: Flexible matching has recently been proposed as a method of improving interactions efficiency. In this study, the concept of flexible matching has been introduced, and the applicability of this strategy has also been described based on the power calculation of interaction between HER-2 polymorphism and smoking with breast cancer. A large-sample approximation method is used to estimate the power and efficiency of gene-environment interactions. In the basic scenario, power of interaction between HER-2 polymorphism and smoking of unmatched case-control study appears to be 30% while in the frequency matching case-control study it is 56%. However, when increasing the smoking prevalence in controls, greater power can be obtained (power = 74%). CONCLUSIONS: Flexible matching strategies can increase the power and efficiency of case-control studies to detect and estimate the gene-environment interactions when compared with traditional frequency matching and it is especially useful under those scenarios when low environmental exposure of population, adverse gene-environment interactions or less paired controls are seen. Optimal matching design should be made available by weighing the benefits and loss due to flexible matching.

[Association between HRE-2 gene polymorphism at codon 655 and genetic susceptibility of colorectal cancer].

OBJECTIVE: To explore the distribution of HER-2 genetic polymorphism at codon 655 and its association with susceptibility of colorectal cancer in Chinese. METHODS: A population-based case-control study was carried out. 292 patients with colorectal cancer and 842 healthy controls were interviewed. Meanwhile, the genetic polymorphism of HRE-2 was detected using polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The frequencies of Ile/Val+Val/Val genotypes and Val allele were both higher in cases (25.34% and 13.36%) than those in controls (18.41% and 9.74%) (P<0.05). Compared with Ile/Ile genotype, Ile/Val+Val/Val genotypes were significantly associated with colorectal cancer [ORadjusted=1.54, 95% CI: 1.11-2.14]. The adjusted odds ratio of interactions between this polymorphism and smoking, alcohol drinking were 1.43 (95%CI: 0.88-2.30) and 1.29 (95%CI: 0.73-2.29), respectively. CONCLUSION: The present findings suggest that HER-2 genetic polymorphism at codon 655 may be associated with the risk of colorectal cancer in Chinese. In addition, there are no interactions between this polymorphism and smoking, alcohol drinking, respectively.

[Application of multifactor dimensionality reduction on the interactions between gene-gene, gene-environment and the risk sporadic colorectal cancer in Chinese population].

OBJECTIVE: To identify the association between risk of sporadic colorectal cancer and the common single nucleotide polymorphisms (SNPs) in DNA repairs genes, gene to gene interactions among them and their gene to environment interactions with common environmental factors. METHODS: In this population-based case-control study, 206 primary colorectal cancer cases and 845 cancer-free healthy controls were enrolled. Genotyping was carried out using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, with the status of subjects case or controls unknown. Multifactor dimensionality reduction (MDR) and logistic analysis were both used for association analysis. RESULTS: As compared to the younger age group (> or = 42, < 61 years), the risk of colorectal cancer in older age group (> or = 61 years) increased significantly (OR = 2.04, 95% CI: 1.49-2.80). Similar result was observed in the family cancer history (OR = 1.51, 95% CI: 1.05-2.17). However, no significant association between any single DNA repair gene SNP and colorectal cancer risk was discovered. Results from MDR analysis only showed a significant interaction among the four following factors: age, alcohol drinking, XRCC1 Arg194Trp and OGG1 Ser326Cys (the cross-validation consistency = 10/10, the average testing accuracy = 0.616, P = 0.011). Using a logistic regression model, the "high-risk" individuals had a significantly elevated risk of colorectal cancer compared to those "low- risk" individuals classified by the above MDR model (OR = 2.72, 95% CI: 1.66-4.47). CONCLUSION: The impact of polymorphisms in DNA repair genes on the risk of sporadic colorectal cancer exhibited a low-penetrance characteristics while the intricate interactions existing among them and with environmental factors.

[Correlations of single nucleotide polymorphisms of DNA repair gene XRCC1 to risk of colorectal cancer].

BACKGROUND & OBJECTIVE: X-ray repair cross complementing group 1 (XRCC1) encodes a protein required for DNA base excision repair and single strand break recombination repair. The polymorphisms of XRCC1 affect the function of the protein, therefore, affect the susceptibility of human to cancers. This population-based case-control study was to examine the correlations of the 3 most common single nucleotide polymorphisms (SNPs) of XRCC1 gene, C26304T, G27466A and G28152A, to risk of colorectal cancer. METHODS: XRCC1 genotypes in 207 colorectal cancer patients and 621 matched healthy controls were analyzed by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP). The adjusted odds ratio (OR) and 95% confidence interval (CI) were calculated using unconditional logistic regression model to evaluate the correlations of the 3 genotypes to risk of colorectal cancer. The haplotype distribution was estimated by EH linkage software 1.2. RESULTS: There was no significant differences in selected characteristics, such as age, sex, body mass index, cigarette-smoking and alcohol-drinking status, between the patients and the controls. The frequencies of mutant 26304T, 27466A, and 28152A alleles were 29.95%, 11.22%, and 28.22%, respectively, in the patients, and 32.87%, 12.34%, and 27.27%, respectively, in the controls; there was also no significant difference between the 2 groups. All the polymorphic genotypes met the Hardy-Weinberg equilibrium. No significant correlation of XRCC1 C26304T, G27466A, and G28152A polymorphisms to risk of colorectal cancer was found. Estimated by EH linkage software 1.2, genetic linkage disequilibrium existed both in the patients and the controls, and CGG, CGA, CAG, and TGG were the 4 most common haplotypes. However, there was no significant difference in haplotype distribution between the 2 groups (95.54% vs. 96.64%, P>0.05). CONCLUSIONS: In Han people in southern China, XRCC1 C26304T, G27466A, and G28152A polymorphisms have no correlations to risk of colorectal cancer. However, the genetic linkage disequilibrium exists in these 3 polymorphic sites, and CGG, CGA, CAG, and TGG are the 4 most common haplotypes.

[Study on the application of classification tree model in screening the risk factors of malignant tumor].

OBJECTIVE: To introduce the partitioning algorithm of classification tree model, and to explore the value of this data mining technique applied in data analysis of multifactorial diseases as malignant tumors. METHODS: Data was analyzed from a survey that conducted on 84 breast cancer patients and 273 cancer-free controls selected randomly in Jiashan county. The classification tree model was constructed using Exhaustive CHAID method and evaluated by the Risk statistics and the area under the ROC curve. RESULTS: 9 out of 105 effect risks factors were selected, in which career was the most important factor indicating that workers, teachers and retirees suffered much more risks than others. Nevertheless, the number of pregnancies, breast examination, reasons for menopause, age at menarche, intake of shrimp, crab, kipper, kelp and laver etc were also risk factors on breast cancer. However, physical exercise played different roles on different people. The Risk statistics of model was 0.174, and the area under the ROC curve was 0.872 which was significantly different from 0.5, suggesting that the classification tree model fit the actuality very well. CONCLUSION: The classification tree model could screen out the major affecting factors quickly and effectively and could also identify the cutting-points for continuous and ordinal variables, as well as revealing the complex interaction among the factors at many levels. This model might become a powerful tool to explore the complexities of the risks on diseases.

[Association of single nucleotide polymorphisms and haplotypes in DNA repair gene XRCC1 with susceptibility of breast cancer].

OBJECTIVE: To examine the contribution of the three most common single nucleotide polymorphisms (SNPs) in XRCC1 gene, C26304T, G27466A and G28152A, to susceptibility of breast cancer in Chinese Han population. METHODS: In this population-based case control study, 84 cases with breast cancer and 252 controls, matched to the cases in terms of habitation and age (5 years), were genotyped for the XRCC1 C26304T, G27466A and G28152A polymorphisms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. The haplotype distribution was estimated and compared by EH linkage software 1. 2. RESULT: The distribution of basic characteristics, such as age, alcohol drinking, the family history of malignancy in first and second relatives except cigarette smoking, were not significantly different between cases and controls. However, the percentage of ever or current smokers was significantly higher in cases (7.1%) than that in controls (2.0%). The distributions of allelotype and genotype of C26304T, G27466A and G28152A polymorphisms were also not significantly different between cases and controls. There was no significant association between the risk of breast cancer and these three SNPs of XRCC1 gene. The genetic linkage disequilibrium existed in these three polymorphic sites both in cases and controls, in which the CGG, CGA, CAG and TGG haplotypes were the most common. There was also no significant association of XRCC1 haplotype with risk of breast cancer. CONCLUSION: XRCC1 C26304T, G27466A and G28152A SNPs may not be associated with the susceptibility of breast cancer. The CGG, CGA, CAG and TGG haplotypes might be the most common haplotypes in Chinese Han population.