Epidemiologic studies have demonstrated a relationship between selenium status and cancer risk among those with low selenium levels. It is of interest to prospectively evaluate the relationship ...between selenium and cancer among women who reside in a region with ubiquitously low selenium levels.
We performed a nested case-control study of baseline serum selenium levels and cancer risk using data and biological samples from 19,573 females that were participants in a biobanking initiative between 2010 and 2014 in Szczecin Poland. Cases included women with any incident cancer (
= 97) and controls (
= 184) were women with no cancer at baseline or follow-up. Serum selenium was quantified using mass spectroscopy.
The odds ratio associated being below the cutoff of 70.0 μg/L compared to a level above 70.0 μg/L was 2.29 (95% CI 1.26-4.19;
= 0.007). The risks for women in the two middle categories were similar and suggests that the normal range be between 70 μg/L and 90 μg/L. There was evidence for an increased risk of cancer among women in the highest category of selenium levels (i.e., > 90 μg/L), but this association did not achieve statistical significance (OR = 1.63; 95%CI 0.63-4.19;
= 0.31).
Results from this study suggest that suggest that the optimum serum level of selenium in women living in Poland should be between 70 μg/L and 90 μg/L.
Melanoma is one of the most aggressive human malignancies. The determination of prognostic biomarkers is important for the early detection of recurrence and for the enrollment of the patients into ...different treatment regimens. Herein, we report the 10-year survival of 375 melanoma patients depending on their serum selenium levels. The study group was followed up from the date of melanoma diagnosis until death or 2020. Patients were assigned to one of four categories, in accordance with the increasing selenium level (I–IV quartiles). The subgroup with low selenium levels had a significant lower survival rate in relation to patients with high selenium levels, HR = 8.42; p = 0.005 and HR = 5.83; p = 0.02, for uni- and multivariable models, respectively. In the univariable analysis, we also confirmed the association between Breslow thickness, Clark classification and age at melanoma prognosis. In conclusion, a low serum selenium level was associated with an increased mortality rate in the 10 years following melanoma diagnosis. Future studies in other geographic regions with low soil selenium levels should be conducted to confirm our findings.
To investigate the contribution of a founder deletion in the CHEK2 gene to the burden of breast cancer in Poland we studied 4,454 women with breast cancer and 5,496 population controls. Cases and ...controls were genotyped for the presence of a 5,395 bp founder deletion that removes exons 9 and 10 of the CHEK2 gene. This deletion has recently been described in a Czech and Slovak population. The cases and controls had previously been tested for two protein-truncating (IVS2 + 1G > A and 1100delC) and one missense CHEK2 mutation (I157T) which are characteristic for the population. The exons 9 and 10 deletion was present in 0.4% of the controls, in 1.0% (19 of 1,978) of unselected breast cancer cases (OR=2.2; 95% CI: 1.2-4.0; p = 0.01) and in 0.9% (28 of 3,228) of the early-onset cases (OR=2.0; 95% CI: 1.3-1.8; p = 0.02). One of the three truncating CHEK2 mutations (del5395; 1100delC or IVS2 + 1G > A) was seen in 101 of 4,454 (2.3%) cases and in 58 of 5,496 controls (1.1%) (OR=2.2; 95% CI: 1.6-3.0 p < 0.0001). A 5,395 bp founder deletion contributes to the burden of breast cancer in Poland. The deletion was present in 0.9% of the women with breast cancer diagnosed under the age of 51 and in 0.9% of women with breast cancer over the age of 50. This is one of the most common protein-truncating CHEK2 variants in Poland. Overall, 2% of all breast cancers in Poland can be attributed to one of three protein-truncating mutations in CHEK2.
Some experimental evidence suggests that BRCA1 plays a role in repair of oxidative DNA damage. Selenium has anticancer properties that are linked with protection against oxidative stress. To assess ...whether supplementation of BRCA1 mutation carriers with selenium have a beneficial effect concerning oxidative stress/DNA damage in the present double-blinded placebo control study, we determined 8-oxodG level in cellular DNA and urinary excretion of 8-oxodG and 8-oxoGua in the mutation carriers. We found that 8-oxodG level in leukocytes DNA is significantly higher in BRCA1 mutation carriers. In the distinct subpopulation of BRCA1 mutation carriers without symptoms of cancer who underwent adnexectomy and were supplemented with selenium, the level of 8-oxodG in DNA decreased significantly in comparison with the subgroup without supplementation. Simultaneously in the same group, an increase of urinary 8-oxoGua, the product of base excision repair (hOGG1 glycosylase), was observed. Therefore, it is likely that the selenium supplementation of the patients is responsible for the increase of BER enzymes activities, which in turn may result in reduction of oxidative DNA damage. Importantly, in a double-blinded placebo control prospective study, it was shown that in the same patient groups, reduction in cancer incidents was observed. Altogether, these results suggest that BRCA1 deficiency contributes to 8-oxodG accumulation in cellular DNA, which in turn may be a factor responsible for cancer development in women with mutations, and that the risk to developed breast cancer in BRCA1 mutation carriers may be reduced in selenium-supplemented patients who underwent adnexectomy.
Familial pancreatic cancer describes families with at least two first-degree relatives with pancreatic cancer that do not fulfil the criteria of other inherited tumor syndromes with increased risks ...of pancreatic cancer. Although much has been learned regarding the aggregation of pancreatic cancer in some families, the genetic basis for this familial aggregation is poorly understood. This study evaluated the prevalence of 10 Polish founder mutations in four genes among individuals from families with diagnosed familial pancreatic cancer syndrome and assessed their possible association with the familial pancreatic cancer (FPC) risk in Poland.
In this study, 400 FPC individuals and 4,000 control subjects were genotyped for founder mutations in
(5382insC, 4153delA, C61G),
(1100delC, IVS2+1G>A, del5395, I157T),
(657del5), and
(509_510delGA, 172_175delTTGT) genes.
A statistically significant association was observed between the 172_175delTTGT mutation of the
gene and an increased risk of FPC syndrome (odds ratio OR, 10.05; p=0.048). In addition, an increased risk of cancer was observed in the FPC family members with a
mutation (OR, 6.72; p=0.006). Novel associations were found between the FPC family members with cancer and
mutations (OR, 2.26; p=0.008) with a noticeable contribution of the missense variant, I157T of
(OR, 2.17; p=0.026).
The founder mutations in the genes,
,
, and
, cause a small percentage of familial pancreatic cancer syndrome in the Polish population. Following confirmation in larger studies, these mutations can be added to the panel of genes to be tested in families with a diagnosis of FPC syndrome.
In following study we examined whether blood arsenic (As) levels combined with specific polymorphisms in MT1B, GSTP1, ABCB1, NQO1, CRTC3, GPX1, SOD2, CAT, XRCC1, ERCC2 can be used as a marker for the ...detection of colorectal cancer (CRC) among Polish women. A retrospective case-control study of CRC included 83 CRC cases and 78 healthy controls. From each study participant pre-treatment peripheral blood was collected for As level measurement by inductively coupled–plasma mass spectrometry (ICP-MS). We estimated the odds ratio (OR) of the association between blood-As levels and CRC using multivariable unconditional logistic regression models. A low blood-As level (0.27–0.67 µg/L) was associated with an increased frequency of CRC (OR: 3.69; p = 0.005). This correlation was significantly greater when participants carried particular gene variants: CAT, rs1001179-nonCC (OR: 19.4; p = 0.001); ABCB1 rs2032582–CC (OR: 14.8; p = 0.024); GPX1 rs1050450-CC (OR: 11.6; p = 0.002) and CRTC3 rs12915189-nonGG (OR: 10.3; p = 0.003). Our study provides strong evidence that low blood-As levels are significantly associated with increased CRC occurrence and that particular gene variants significantly enhanced this correlation however, due to the novelty of these findings, we suggest further validation before a definitive statement that the combined effect of low blood-As levels with specific gene polymorphisms is a suitable CRC biomarker.
Breast and ovarian cancer penetrance in BRCA1 mutation carriers is estimated to be between 15% and 80% by age 70 years. At present, it is not possible to predict with any certainty who is most likely ...to develop disease or which age it will develop. Previous studies have tried to correlate the sites of BRCA1 mutations with disease risk; however, the results have not yielded any definitive association. An alternative explanation that could account for differences in the penetrance of BRCA1 mutations is the action of modifier genes. In this study, we have investigated the role of the RAD51_135_G>C polymorphism in breast and ovarian cancer case-control populations of Polish women who have been matched for BRCA1 mutation and year of birth. The results reveal that women who harbor the C allele have almost twice the reduction in breast and ovarian cancer risk compared with women who harbor only the G allele. These findings suggest that the effect of the RAD51 C allele is an important risk modifier for malignancies occurring on a background of BRCA1 mutations. In addition, we were able to show that the site of the BRCA1 mutation does not influence the effect of the RAD51 C allele, indicating that this polymorphism contributes to prevention of disease in BRCA1 carriers. In conclusion, the RAD51 C allele seems to protect against both breast and ovarian cancer in women harboring BRCA1 mutations.
CYP1B1 is a P450 enzyme which is involved in the activation of pro-carcinogens to carcinogens as well as sex hormone metabolism. Because differences in the activity of the enzyme have been correlated ...with variant alleles of single nucleotide polymorphisms (SNPs), it represents an attractive candidate gene for studies into colorectal cancer susceptibility.
We genotyped 597 cancer patients and 597controls for three CYP1B1 SNPs, which have previously been shown to be associated with altered enzymatic activity. Using the three SNPs, eight different haplotypes were constructed. The haplotype frequencies were estimated in cases and controls and then compared. The odds ratio for each tumour type, associated with each haplotype was estimated, with reference to the most common haplotype observed in the controls.
The three SNPs rs10012, rs1056827 and rs1056836 alone did not provide any significant evidence of association with colorectal cancer risk. Haplotypes of rs1056827 and rs10012 or rs1056827 and rs1056836 revealed an association with colorectal cancer which was significantly stronger in the homozygous carriers. One haplotype was under represented in the colorectal cancer patient group compared to the control population suggesting a protective effect.
Genetic variants within the CYP1B1 that are associated with altered function appear to influence susceptibility to a colorectal cancer in Poland. Three haplotypes were associated with altered cancer risk; one conferred protection and two were associated with an increased risk of disease. These observations should be confirmed in other populations.
To evaluate the extent of distal intramural spread (DIS) after preoperative radiotherapy for rectal cancer.
A total of 316 patients with T(3-4) primary resectable rectal cancer were randomized to ...receive either preoperative 5x5 Gy radiation with immediate surgery or chemoradiation (50.4 Gy, 1.8 Gy per fraction plus boluses of 5-fluorouracil and leucovorin) with delayed surgery. The slides of the 106 patients who received short-course radiation and of the 86 who received chemoradiation were available for central microscopic evaluation of DIS.
The length of DIS did not differ significantly (p = 0.64) between the short-course group and the chemoradiation group and was 0 in 47% vs. 49%; 1 to 5 mm in 41% vs. 42%; 6 to 10 mm in 8% vs. 9%, and greater than 10 mm in 4% vs. 0, respectively. Among the 11 clinically complete responders, DIS was found 1 to 5 mm from the microscopically detected ulceration of the mucosa in 5 patients. The discontinuous DIS was more frequent in the chemoradiation group as compared with the short-course group (i.e., 57% vs. 16% of cases, p < 0.001).
Approximately 1 out of 10 advanced rectal cancers after preoperative radiotherapy or radiochemotherapy was characterized by DIS of over 5 mm. No significant difference was seen in the length of DIS between the 2 groups.
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