Appendiceal tumors and pseudomyxoma peritonei: current recommendations for clinical practice.

Appendiceal tumors and pseudomyxoma peritonei (PMP) are rare tumors. Perforated epithelial tumors of the appendix are the most common source of PMP. This disease is characterized by the presence of mucin of varying degrees of consistency, partially adherent to the surfaces. Appendiceal mucoceles themselves are also very rare and usually their treatment involves only a simple appendectomy. The aim of this study was to provide an up-to-date review of the recommendations for the diagnosis and treatment of these malignancies according to the current guidelines of The Peritoneal Surface Oncology Group International (PSOGI) and the Blue Book of the Czech Society for Oncology of the Czech Medical Association of J. E. Purkyne (COS CLS JEP).

Enzyme replacement following total pancreatectomy; population analysis

Introduction: Total pancreatectomy (TPE) inevitably leads to absolute exocrine pancreatic insufficiency (EPI). No specific recommendations are available for enzyme replacement in such cases. The aim of our analysis was to explore the actual EPI replacement rates among patients following TPE after a certain period of time from the surgery. Methods: This retrospective analysis of living patients who had undergone TPE more than 2 years ago was done using a simple questionnaire to investigate the following: BMI prior to TPE, 3 months after TPE and at the time of data collection (in 2022), together with the actual number of daily bowel movements; and the replacement characteristics ­ the daily dose, its scheme and subjective satisfaction evaluation. Results: In total, we obtained data from 26 living patients with the history of TPE with their median follow up of 56 months (30­157). Malignant disease was confirmed in 69% patients based on histology; a benign tumor was present in the rest, although malignancy had been suspected preoperatively. Median BMI decreased from preoperative 27.4 (19.1­41.1) to 24.1 (19.8­33.7) 3 months following TPE, and median BMI value of 25.5 (21.2­34.5) was established at 30­157 months from TPE. The mean number of daily bowel movements was 2.2 (median 2, range 1­8) and the mean daily replacement dose was 182,000 units of lipase (median 175,000 u., range 0­250,000 u.) at the time of our investigation. Subjective satisfaction was reported by 85% responders and a lack of satisfaction despite maximum EPI replacement was expressed by 15% responders. Conclusion: BMI decreased shortly after TPE. In the long term, up to 80% of the patients achieved preoperative BMI values ±10% after TPE. Due to persistent steatorrhea and more frequent bowel movements despite enzyme replacement, 15% of the patients remained subjectively dissatisfied after TPE, but 85% of the patients did not perceive even more frequent bowel movements as unpleasant and were satisfied with their condition. The need of individualized enzyme replacement therapy of EPI following TPE is evident.

Germline BRCA2 K3326X and CHEK2 I157T mutations increase risk for sporadic pancreatic ductal adenocarcinoma.

Rare truncating BRCA2 K3326X (rs11571833) and pathogenic CHEK2 I157T (rs17879961) variants have previously been implicated in familial pancreatic ductal adenocarcinoma (PDAC), but not in sporadic cases. The effect of both mutations in important DNA repair genes on sporadic PDAC risk may shed light on the genetic architecture of this disease. Both mutations were genotyped in germline DNA from 2,935 sporadic PDAC cases and 5,626 control subjects within the PANcreatic Disease ReseArch (PANDoRA) consortium. Risk estimates were evaluated using multivariate unconditional logistic regression with adjustment for possible confounders such as sex, age and country of origin. Statistical analyses were two-sided with p values <0.05 considered significant. K3326X and I157T were associated with increased risk of developing sporadic PDAC (odds ratio (ORdom ) = 1.78, 95% confidence interval (CI) = 1.26-2.52, p = 1.19 × 10-3 and ORdom = 1.74, 95% CI = 1.15-2.63, p = 8.57 × 10-3 , respectively). Neither mutation was significantly associated with risk of developing early-onset PDAC. This retrospective study demonstrates novel risk estimates of K3326X and I157T in sporadic PDAC which suggest that upon validation and in combination with other established genetic and non-genetic risk factors, these mutations may be used to improve pancreatic cancer risk assessment in European populations. Identification of carriers of these risk alleles as high-risk groups may also facilitate screening or prevention strategies for such individuals, regardless of family history.

KRAS pathway expression changes in pancreatic cancer models by conventional and experimental taxanes.

The KRAS signalling pathway is pivotal for pancreatic ductal adenocarcinoma (PDAC) development. After the failure of most conventional cytotoxic and targeted therapeutics tested so far, the combination of taxane nab-paclitaxel (Abraxane) with gemcitabine recently demonstrated promising improvements in the survival of PDAC patients. This study aimed to explore interactions of conventional paclitaxel and experimental taxane SB-T-1216 with the KRAS signalling pathway expression in in vivo and in vitro PDAC models in order to decipher potential predictive biomarkers or targets for future individualised therapy. Mouse PDAC PaCa-44 xenograft model was used for evaluation of changes in transcript and protein levels of the KRAS signalling pathway caused by administration of experimental taxane SB-T-1216 in vivo. Subsequently, KRAS wild-type (BxPc-3) and mutated (MiaPaCa-2 and PaCa-44) cell line models were treated with paclitaxel to verify dysregulation of the KRAS signalling pathway gene expression profile in vitro and investigate the role of KRAS mutation status. By comparing the gene expression profiles, this study observed for the first time that in vitro cell models differ in the basal transcriptional profile of the KRAS signalling pathway, but there were no differences between KRAS mutated and wild-type cells in sensitivity to taxanes. Generally, the taxane administration caused a downregulation of the KRAS signalling pathway both in vitro and in vivo, but this effect was not dependent on the KRAS mutation status. In conclusion, putative biomarkers for prediction of taxane activity or targets for stimulation of taxane anticancer effects were not discovered by the KRAS signalling pathway profiling in various PDAC models.

Hedgehog pathway overexpression in pancreatic cancer is abrogated by new-generation taxoid SB-T-1216.

The Hedgehog pathway is one of the major driver pathways in pancreatic ductal adenocarcinoma. This study investigated prognostic importance of Hedgehog signaling pathway in pancreatic cancer patients who underwent a radical resection. Tumors and adjacent non-neoplastic pancreatic tissues were obtained from 45 patients with histologically verified pancreatic cancer. The effect of experimental taxane chemotherapy on the expression of Hedgehog pathway was evaluated in vivo using a mouse xenograft model prepared using pancreatic cancer cell line Paca-44. Mice were treated by experimental Stony Brook Taxane SB-T-1216. The transcript profile of 34 Hedgehog pathway genes in patients and xenografts was assessed using quantitative PCR. The Hedgehog pathway was strongly overexpressed in pancreatic tumors and upregulation of SHH, IHH, HHAT and PTCH1 was associated with a trend toward decreased patient survival. No association of Hedgehog pathway expression with KRAS mutation status was found in tumors. Sonic hedgehog ligand was overexpressed, but all other downstream genes were downregulated by SB-T-1216 treatment in vivo. Suppression of HH pathway expression in vivo by taxane-based chemotherapy suggests a new mechanism of action for treatment of this aggressive tumor.

The role of ABC transporters in progression and clinical outcome of colorectal cancer.

Worldwide, colorectal cancer (CRC) is the third most common cancer, with the highest mortality rates occurring in Central Europe. The use of chemotherapy to treat CRC is limited by the inter-individual variability in drug response and the development of cancer cell resistance. ATP-binding cassette (ABC) transporters play a crucial role in the development of resistance by the efflux of anticancer agents outside of cancer cells. The aim of this study was to explore transcript levels of all human ABCs in tumours and non-neoplastic control tissues from CRC patients collected before the first line of treatment by 5-fluorouracil (5-FU)-containing regimen. The prognostic potential of ABCs was evaluated by the correlation of transcript levels with clinical factors. Relations between transcript levels of ABCs in tumours and chemotherapy efficacy were also addressed. The transcript profile of all known human ABCs was assessed using real-time polymerase chain reaction with a relative standard curve. The majority of the studied ABCs were down-regulated or unchanged between tumours and control tissues. ABCA12, ABCA13, ABCB6, ABCC1, ABCC2 and ABCE1 were up-regulated in tumours versus control tissues. Transcript levels of ABCA12, ABCC7 and ABCC8 increased in direction from colon to rectum. Additionally, transcript levels of ABCB9, ABCB11, ABCG5 and ABCG8 followed the reverse significant trend, i.e. a decrease in direction from colon to rectum. The transcript level of ABCC10 in tumours correlated with the grade (P = 0.01). Transcript levels of ABCC6, ABCC11, ABCF1 and ABCF2 were significantly lower in non-responders to palliative chemotherapy in comparison with responders. The disease-free interval of patients treated by adjuvant chemotherapy was significantly shorter in patients with low transcript levels of ABCA7, ABCA13, ABCB4, ABCC11 and ABCD4. In conclusion, ABCC11 may be a promising candidate marker for a validation study on 5-FU therapy outcome.

Polymorphisms in metabolizing enzymes and the risk of head and neck squamous cell carcinoma in the Slavic population of the central Europe.

The question of susceptibility to squamous cell carcinoma of head and neck (SCCHN) in the environmental context was addressed by analysis of functional polymorphisms in enzymes metabolizing smoke constituents and/or alcohol (CYP2A13, CYP1B1, EPHX1, NQO1, GSTM1, GSTP1, GSTT1, ADH1B and ADH1C). Case-control study of 122 age- and sex-matched pairs of subjects was performed using so far unexplored Central European Slavic population with high level of tobacco and alcohol abuse. Age-, gender-, smoking- and alcohol-adjusted logistic regression failed to demonstrate any significant association of the analyzed polymorphisms with the SCCHN risk. When interactions between potential modifiers of effect, i.e. smoking and alcohol were tested, drinkers seemed to be at lower risk than nondrinkers when carrying the heterozygous genotype Ile/Val in codon 432 of CYP1B1 (OR=0.42; 95% CI=0.21-0.83; p=0.013 vs. OR=1.02; 95% CI=0.34-2.94; p=0.977). Similarly, drinkers were at lower risk than nondrinkers when carrying the heterozygous genotype Pro/Ser in codon 187 of NQO1 (OR=0.41; 95% CI=0.19-0.88; p=0.022 vs. OR=0.96; 95% CI=0.29-3.12; p=0.948). More interestingly, drinkers carrying the rare homozygous genotype Val/Val in codon 350 of ADH1C were at significantly higher risk than nondrinkers carrying this genotype (OR=4.01; 95% CI=1.61-10.01; p=0.003 vs. OR=0.93; 95% CI=0.25-3.57; p=0.919). This result confirmed findings of previously published studies. Smoking did not significantly modify the effect of genotypes. Our data thus demonstrate that genetic susceptibility to SCCHN shall be further followed on populations with different genetic background and lifestyle.

[The role of membrane transporters in cellular resistance of pancreatic carcinoma to gemcitabine]. / Role membránových transportéru v chemorezistenci karcinomu pankreatu pri terapii gemcitabinem.

BACKGROUNDS: Pancreatic carcinoma is one of the most serious forms of cancer, with a very high mortality rate, and is the fourth leading cause of cancer-related death in the Czech Republic. The etiology and molecular pathogenesis of the disease is still poorly understood. Gemcitabine is a cytotoxic nucleoside analog, which is widely used in the treatment of malignancies, and in particular in pancreatic carcinoma. Interindividual differences in gemcitabine pharmacokinetics and pharmacodynamics have been demonstrated, which can significantly influence the outcome of the therapy in thus treated patients. Resistance developed to nucleoside analogs limits their clinical use, just like in the case of any other cytostatics. AIM: This review summarizes available data concerning the membrane proteins involved in the transport mechanism of gemcitabine through cellular membrane, and their role in the cellular resistance of pancreatic carcinoma to gemcitabine.

The association between glutathione S-transferase gene polymorphisms and pancreatic cancer in a central European Slavonic population.

In the first case-control study on pancreatic cancer conducted on 253 cases and 403 controls in the Czech Republic we observed that the GSTP1-codon 105 Val variant allele and the GSTT1-null genotype were associated with an elevated risk for pancreatic cancer (OR = 1.38; 95%CI = 0.96-1.97 and OR = 1.56; 95%CI = 0.93-2.61, respectively). Combination of GSTT1-null and GSTP1-codon 105 Val variants further increased the risk for pancreatic cancer (OR = 2.50; 95%CI = 1.20-5.20). In conclusion, this study suggests population-specific associations of polymorphisms in key biotransformation genes with elevated risk for pancreatic cancer.