Constitutional mutations of the CHEK2 gene are a risk factor for MDS, but not for de novo AML.

CHEK2 plays a key role in cellular response to DNA damage, and also in regulation of mitosis and maintenance of chromosomal stability. In patients newly diagnosed with myelodysplastic syndrome (MDS, n = 107) or acute myeloid leukemia (AML, n = 117) congenital CHEK2 mutations (c.444 + 1G > A, c.1100delC, del5395, p.I157 T) were tested by PCR and sequencing analysis. The karyotype of bone marrow cells of each patient was assessed at disease diagnosis using classical cytogenetic methods and fluorescence in situ hybridization. The CHEK2 mutations were strongly associated with the risk of MDS (p < 0.0001) but not with the risk of de novo AML (p = 0.798). In CHEK2-positive MDS patients, two times higher frequency of aberrant karyotypes than in CHEK2-negative patients was found (71% vs. 37%, p = 0.015). In CHEK2-positive patients with cytogenetic abnormalities, subtypes of MDS: refractory anemia with excess blasts-1 or 2, associated with unfavorable disease prognosis, were diagnosed two times more often than in CHEK2-negative cases with aberrations (78% vs. 44%). In conclusion, the congenital CHEK2 inactivation is strongly associated with the risk of MDS and with a poorer prognosis of the disease. However, the chromosomal instability in AML is not correlated with the hereditary dysfunction of CHEK2.

Screening with magnetic resonance imaging, mammography and ultrasound in women at average and intermediate risk of breast cancer.

BACKGROUND: The addition of MRI to mammography and ultrasound for breast cancer screening has been shown to improve screening sensitivity for high risk women, but there is little data to date for women at average or intermediate risk. METHODS: Two thousand nine hundred and ninety-five women, aged 40 to 65 years with no previous history of breast cancer were enrolled in a screening program, which consisted of two rounds of MRI, ultrasound and mammography, one year apart. Three hundred and fifty-six women had a CHEK2 mutation, 370 women had a first-degree relative with breast cancer (and no CHEK2 mutation) and 2269 women had neither risk factor. Subjects were followed for breast cancer for three years from the second screening examination. RESULTS: Twenty-seven invasive epithelial cancers, one angiosarcoma and six cases of DCIS were identified over the four-year period. Of the 27 invasive cancers, 20 were screen-detected, 2 were interval cancers, and five cancers were identified in the second or third follow-up year (i.e., after the end of the screening period). For invasive cancer, the sensitivity of MRI was 86%, the sensitivity of ultrasound was 59% and the sensitivity of mammography was 50%. The number of biopsies incurred by MRI (n = 156) was greater than the number incurred by mammography (n = 35) or ultrasound (n = 57). Of the 19 invasive cancers detected by MRI, 17 (89%) were also detected by ultrasound or mammography. CONCLUSIONS: In terms of sensitivity, MRI is slightly better than the combination of mammography and ultrasound for screening of women at average or intermediate risk of breast cancer. However, because of additional costs incurred by MRI screening, and the small gain in sensitivity, MRI screening is probably not warranted outside of high-risk populations.

The variant allele of the rs188140481 polymorphism confers a moderate increase in the risk of prostate cancer in Polish men.

A number of single nucleotide polymorphisms (SNPs) in the human genome have been associated with increased risk of prostate cancer. Recently, a single SNP in the region of chromosome 8q24 (rs188140481) has been associated with a three-fold increased risk of prostate cancer in Europe and North America. To establish whether rs188140481 is associated with the risk of prostate cancer in Poland, we genotyped 3467 men with prostate cancer and 1958 controls. The A allele of rs188140481 was detected in 44 of 3467 (1.3%) men with prostate cancer and in seven of 1958 (0.4%) controls (odds ratio=3.6; 95% confidence interval 1.6-7.9; P=0.0006). The allele was present in eight of 390 (2.1%) men with familial prostate cancer (odds ratio=5.8; 95% confidence interval 2.1-16.2; P=0.001). A positive family history of cancers at sites other than the prostate was observed in 27% of men who carried the rs188140481 risk allele and in 44% of noncarriers (P=0.04). No cancer at a site other than the prostate was more common in first-degree or second-degree relatives of carriers of the rs188140481 risk allele than relatives of noncarriers. The rs188140481 polymorphism in the 8q24 region confers a moderate increase in the risk of prostate cancer in Polish men. The SNP does not appear to be associated with susceptibility to cancers of other types.

A risk of breast cancer in women - carriers of constitutional CHEK2 gene mutations, originating from the North - Central Poland.

BACKGROUND: Germline mutations of the CHEK2 gene have been reported to be associated with breast cancer. In this study, we analyzed the association of CHEK2 mutations with the risk of development of breast cancer in women of North-Central Poland. METHODS: 420 women with breast cancer and 435 controls were tested for three protein truncating (IVS2 + 1G > A, 1100delC, del5395) and one missense (I157T) CHEK2 mutation. IVS2 + 1G > A and I157T mutations were identified by RFLP-PCR, 1100delC variant was analyzed using an ASO-PCR and del5395 mutation by multiplex-PCR. The statistical tests: the odds ratio (OR) and Fisher's exact test were used. RESULTS: In 33 out of 420 (7.9%) women consecutively diagnosed with breast cancer, we detected one of four analyzed CHEK2 mutations: I157T, 1100delC, IVS2 + 1G > A or del5395. Together they were not associated with the increased risk of breast cancer (North-Central control group: OR = 1.6, p = 0.124; the general Polish population: OR = 1.4, p = 0.109). This association was only seen for IVS2 + 1G > A mutation (OR = 3.0; p = 0.039). One of the three truncating CHEK2 mutations (IVS2 + 1G > A, 1100delC, del5395) was present in 9 of 420 women diagnosed with breast cancer (2.1%) and in 4 of 121 women (3.3%) with a history of breast cancer in a first- and/or second- degree relatives. Together they were associated with the increased risk of disease in these groups, compared to the general Polish population (OR = 2.1, p = 0.053 and OR = 3.2; p = 0.044, respectively). I157T mutation was detected in 25 of 420 women diagnosed with breast cancer (6.0%) and in 8 of 121 women (6.6%) with a history of breast cancer in first- and/or second- degree relatives. The prevalance of I157T mutation was 4.1% (18/435) in North-Central control group and 4.8% (265/5.496) in the general Polish population. However it was not associated with an increased risk of breast cancer. CONCLUSION: Obtained results suggest that CHEK2 mutations could potentially contribute to the susceptibility to breast cancer. The germline mutations of CHEK2, especially the truncating ones confer low-penetrance breast cancer predisposition that contribute significantly to familial clustering of breast cancer at the population level.

Ten-year survival in patients with BRCA1-negative and BRCA1-positive breast cancer.

PURPOSE: To estimate 10-year overall survival (OS) rates for patients with early-onset breast cancer, with and without a BRCA1 mutation, and to identify prognostic factors among those with BRCA1-positive breast cancer. PATIENTS AND METHODS: A total of 3,345 women with stage I to III breast cancer, age ≤ 50 years, were tested for three founder mutations in BRCA1. Information on tumor characteristics and treatments received was retrieved from medical records. Dates of death were obtained from the vital statistics registry. Survival curves for the mutation-positive and -negative subcohorts were compared. Predictors of OS were determined using the Cox proportional hazards model. RESULTS: Of the 3,345 patients enrolled onto the study, 233 (7.0%) carried a BRCA1 mutation. The 10-year survival rate for mutation carriers was 80.9% (95% CI, 75.4% to 86.4%); for noncarriers, it was 82.2% (95% CI, 80.5% to 83.7%). The adjusted hazard ratio (HR) associated with carrying a BRCA1 mutation was 1.81 (95% CI, 1.26 to 2.61). Among BRCA1 carriers with a small (< 2 cm) node-negative tumor, the 10-year survival rate was 89.9%. Among BRCA1 mutation carriers, positive lymph node status was a strong predictor of mortality (adjusted HR, 4.1; 95% CI, 1.8 to 8.9). Oophorectomy was associated with improved survival in BRCA1 carriers (adjusted HR, 0.30; 95% CI, 0.12 to 0.75). CONCLUSION: The 10-year survival rate among women with breast cancer and a BRCA1 mutation is similar to that of patients without a BRCA1 mutation. Among women with a BRCA1 mutation, survival was much improved after oophorectomy.

Prevalence of the BRCA1 c.68_69delAG (BIC: 185delAG) mutation in women with breast cancer from north-central Poland and a review of the literature on other regions of the country.

AIM OF THE STUDY: Germline mutations in BRCA tumor suppressor genes are strongly associated with breast and ovarian cancer. The lifetime risk of these cancers in women with BRCA1 mutation is 84% and 27%, respectively. Studies on the prevalence of BRCA1 c.68_69delAG congenital mutation, the most frequent in Ashkenazi Jews, among women with breast cancer from north-central Poland and review of the literature on other regions of the country. Evaluation of the c.68_69delAG association with breast cancer risk, with respect to women's age at diagnosis and family history of cancer. MATERIAL AND METHODS: 252 women with breast cancer, without any of the mutations c.5266dupC, c.181T > G, or c.4034delA, regardless of histological type and family history of cancer. The mutation was detected using allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) assay and confirmed by sequence analysis. RESULTS: The c.68_69delAG mutation was disclosed in one out of the 252 women (0.4%), who had been diagnosed with breast cancer at age 43. Family investigations revealed the presence of c.68_69delAG also in the patient's mother, diagnosed with breast cancer at age 68. Sequence analysis confirmed the heterozygous status of the mutation, and family investigation its hereditary character. In the group of families with breast cancer history 1.4% frequency of c.68_69delAG was shown. CONCLUSIONS: Among families with breast cancer aggregation, originating from north-central Poland, c.68_69delAG is a rare BRCA1 alteration, similarly to other central regions of the country, investigated by other authors. However, in northern, north-western and south-western parts of Poland, it occurs 2-4 times more frequently than in our region.

A risk of essential thrombocythemia in carriers of constitutional CHEK2 gene mutations.

Germline mutations of the CHEK2 gene have been reported in some myeloid and lymphoid malignancies, but their impact on development of essential thrombocythemia has not been studied. In 16 out of 106 (15.1%) consecutive patients, newly diagnosed with essential thrombocythemia, we found one of four analyzed CHEK2 mutations: I157T, 1100delC, IVS2+1G>A or del5395. They were associated with the increased risk of disease (OR=3.8; P=0.002). The median age at ET diagnosis among CHEK2+/JAK2V617F+ patients was seven years lower than that among CHEK2-/JAK2V617F+ (52 vs. 59 years; P=0.04), whereas there was no difference in the medians of hematologic parameters between these groups. The results obtained suggest that CHEK2 mutations could potentially contribute to the susceptibility to essential thrombocythemia. The germline inactivation of CHEK2, as it seems, has no direct impact on the development of disease, but it could cause disruption of cell cycle checkpoints and initiate or support the cancerogenic process of essential thrombocythemia at a younger age.

Frequency of CYP1B1 homozygous genotype 355T/T in prostate cancer families from Poland.

A group of 98 families were analyzed for CYP1B1 gene 355T/T homozygous genotype frequency because of prostate cancer history. Molecular investigations were performed using the restriction fragment length polymorphism-PCR method. 355T/T genotype was detected in 14 of the 98 prostate cancer patients (14.3%). Among them, it was found in one man (7.1%) from a family suspected of hereditary prostate cancer (his age at prostate cancer diagnosis was 57 years) and in 13 men (92.9%) originating from families that did not strictly fulfill hereditary prostate cancer criteria (the median age at prostate cancer diagnosis was 60.1 years). Among 14 355T/T genotype-positive families, in 10 (71.4%) other types of cancers, for example, breast, uterus, stomach, colon, ovary, lung, larynx, bladder, pancreas and melanoma other than prostate cancer, were present, and in four (28.6%) only one cancer type, that is, prostate cancer, occurred. In the Polish population, the CYP1B1 355T/T genotype seems to be associated with prostate cancer; the frequency of this genotype was 5.9% higher in prostate cancer patients than in the general population (8.4%). However, it is not associated with prostate cancer family history.

Changes in the MDR1 gene expression after short-term ex vivo therapy with prednisolone have prognostic impact in childhood acute lymphoblastic leukemia.

Multidrug resistance 1 (MDR1) gene expression determined by real-time polymerase chain reaction and results of rhodamine assay were analyzed at diagnosis and after 3 days of ex vivo therapy with prednisolone in 36 pediatric patients with acute lymphoblastic leukemia (ALL). Only 62% patients with de novo ALL had significant decrease of MDR1 expression. These patients had over twofold lower rhodamine retention in the presence of cyclosporine A on day 3 than others and had better probability of disease-free survival. In this study, we have shown that changes in the expression of MDR1 gene after short-term incubation of lymphoblasts with prednisolone may have prognostic value in pediatric de novo ALL patients.

The NOD2 3020insC Mutation in Women with Breast Cancer from the Bydgoszcz Region in Poland. First Results.

The frameshift NOD2 gene mutation 3020insC is predominantly associated with Crohn's disease, but predisposes to many types of common cancers as well. We studied the frequency of this mutant NOD2 allele in 148 breast cancer women from the Bydgoszcz region in Poland. The NOD2 mutation was present in 8.8% of the patients. The mean age at breast cancer diagnosis of the mutation carriers was 43 years. We did not find any mutation in patients diagnosed with breast cancer after the age of 50 years. There was no association of the NOD2 mutation with a strong family history of breast cancer. On the contrary, the mutation frequency (11.4%) was two times higher in women from families with a single case of breast cancer and with aggregation of other common types of cancer, especially digestive tract cancers. Low risk of breast cancer in the mutation carriers seems to be confirmed by finding the 3020insC mutation in three healthy parents of probands aged 73, 74 and 83 years, from three separate families.

A high proportion of founder BRCA1 mutations in Polish breast cancer families.

Three mutations in BRCA1 (5382insC, C61G and 4153delA) are common in Poland and account for the majority of mutations identified to date in Polish breast and breast-ovarian cancer families. It is not known, however, to what extent these 3 founder mutations account for all of the BRCA mutations distributed throughout the country. This question has important implications for health policy and the design of epidemiologic studies. To establish the relative contributions of founder and nonfounder BRCA mutations, we established the entire spectrum of BRCA1 and BRCA2 mutations in a large set of breast-ovarian cancer families with origins in all regions of Poland. We sequenced the entire coding regions of the BRCA1 and BRCA2 genes in 100 Polish families with 3 or more cases of breast cancer and in 100 families with cases of both breast and ovarian cancer. A mutation in BRCA1 or BRCA2 was detected in 66% of breast cancer families and in 63% of breast-ovarian cancer families. Of 129 mutations, 122 (94.6%) were in BRCA1 and 7 (5.4%) were in BRCA2. Of the 122 families with BRCA1 mutations, 119 (97.5%) had a recurrent mutation (i.e., one that was seen in at least 2 families). In particular, 111 families (91.0%) carried one of the 3 common founder mutations. The mutation spectrum was not different between families with and without ovarian cancer. These findings suggest that a rapid and inexpensive assay directed at identifying the 3 common founder mutations will have a sensitivity of 86% compared to a much more costly and labor-intensive full-sequence analysis of both genes. This rapid test will facilitate large-scale national epidemiologic and clinical studies of hereditary breast cancer, potentially including studies of chemoprevention.

Hereditary ovarian cancer in Poland.

There is increasing evidence that hereditary factors play a greater role in ovarian cancer than in any of the other common cancers of adulthood. This is attributable, to a large extent, to a high frequency of mutations in the BRCA1 or BRCA2 genes. In Poland, 3 common founder mutations in BRCA1 account for the majority of families with identified BRCA mutations. Our study was conducted in order to estimate the prevalence of any of 3 founder BRCA1 mutations (5382insC, C61G and 4153delA) in 364 unselected women with ovarian cancer, and among 177 women with ovarian cancer and a family history of breast or ovarian cancer. A mutation was identified in 49 out of 364 unselected women with ovarian cancer (13.5%) and in 58 of 177 women with familial ovarian cancer (32.8%). The majority of women with ovarian cancer and a BRCA1 mutation have no family history of breast or ovarian cancer. The high frequency of BRCA1 mutations in Polish women with ovarian cancer supports the recommendation that all Polish women with ovarian cancer should be offered testing for genetic susceptibility, and that counseling services be made available to them and to their relatives. It is important that mutation surveys be conducted in other countries prior to the introduction of national genetic screening programs.