Prevalence of calreticulin exon 9 indel mutations in vascular risk patients.

INTRODUCTION: Acquired JAK2 as well as calreticulin (CALR) mutations are involved in the development of Philadelphia-negative myeloproliferative neoplasms (MPN). We previously showed that the JAK2 V617F mutation could also been found in coronary patients and in patients with peripheral arterial disease (PAD). However, prevalence of CALR mutations is unknown in vascular risk patients and its evaluation subject of the present study. MATERIALS AND METHODS: We determined the prevalence of CALR exon 9 indel mutations in a cohort of 1052 angiographied coronary patients, including 141 patients with PAD, and, additionally, 86 patients with PAD, but without coronary angiography. CALR mutation analysis was performed using PCR fragment analysis and JAK2 V617F mutation analysis with allele-specific real-time PCR. RESULTS: From included 1138 patients, 18 individuals were tested positive for the JAK2 V617F mutation. CALR exon 9 mutations were not detected in any of our patients. CONCLUSIONS: We conclude that CALR exon 9 mutations are infrequent in vascular risk patients. Routine testing for the presence of CALR mutations is not recommended for unselected patients with vascular disease. Future studies are warranted to define a putative pathologic role of CALR mutations in patients without MPN.

Evaluation of BRCA1/2 mutational status among German and Austrian women with triple-negative breast cancer.

PURPOSE: Testing for BRCA1 and BRCA2 mutations in breast cancer patients is used to identify the risk of second primary cancers and the risk of cancer in the patients' family. Women with triple-negative breast cancer (TNBC) are thought to be more likely to be BRCA1/2 mutation carriers, but most national guidelines for genetic testing, including those used in Germany and Austria, do not consider receptor triple negativity. METHODS: We determined the prevalence of BRCA1 and BRCA2 mutations within a cohort of 100 unselected TNBC cases, including patients from Germany and Austria to identify those BRCA-positive patients with a masked family history and who would have been missed due to respective current national guidelines. Double-stranded Sanger sequencing of all exons of BRCA1 and BRCA2, respectively, was performed. RESULTS: We identified a total of 13 deleterious mutations in BRCA1 and a total of four deleterious mutations in BRCA2. The total rate of deleterious BRCA1/2 mutation carriers was 21 % in our cohort. Six novel mutations, including two deleterious mutations, have been identified, which have not been described in public mutation databases so far. According to current German and Austrian national guidelines for genetic testing, 38.1 and 52.4 %, respectively, of BRCA1/2 mutation carriers would have been overlooked. CONCLUSIONS: We conclude that the prevalence of BRCA1 and BRCA2 mutations is high in TNBC patients and that BRCA1/2 mutations are not restricted to young women or patients with a positive family history. Receptor triple negativity should therefore be considered in BRCA1/2 genetic testing guidelines.

Occurrence of the JAK2 V617F mutation in patients with peripheral arterial disease.

The acquired JAK2 V617F mutation is common in patients with myeloproliferative neoplasms. We previously showed that JAK2 V617F is also found in coronary patients, most of them affected by coronary atherosclerosis. Peripheral arterial disease (PAD) is another important manifestation of atherosclerosis. However, prevalence of the JAK2 V617F mutation and its effect on clinical or hematologic characteristics is unknown in PAD patients. In the present study we determined the prevalence of JAK2 V617F in a cohort of 287 patients with sonographically proven PAD and compared mutation frequency with mutational status of 997 healthy people from the KORA F4 study. JAK2 V617F screening and quantification of allele burden in both cohorts was performed with same allele-specific quantitative real-time PCR method. From a total of 287 PAD patients, 9 individuals were tested positive for the JAK2 V617F mutation. One patient showed elevated hemoglobin values, indicating polycythemia vera. Observed JAK2 V617F frequency (3.1%) in PAD patients showed a 5-fold, highly significant increase compared with healthy people (P < 0.001). Furthermore, occurrence of the mutation in PAD patients was significantly decreased in patients using aspirin (P = 0.003). We conclude that the prevalence of JAK2 V617F mutation is significantly increased in PAD patients compared to the general population. Future studies are warranted to confirm our observations and to define the underlying mechanisms behind our findings.

Significant survival impact of MACC1 polymorphisms in HER2 positive breast cancer patients.

BACKGROUND: Deregulation of hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (MET) signalling has been associated with poor clinical outcome in breast cancer and other cancers. The recently discovered metastasis-associated in colon cancer-1 (MACC1) gene is a key regulator of the HGF/MET pathway. Potential links between genetic variants of the MACC1 gene and survival in breast cancer patients are unknown. In the present study, we therefore aimed to investigate the influence of MACC1 polymorphisms on event-free and overall survival in patients with human epidermal growth factor 2 (HER2)-positive breast cancer. METHODS: The present study included 164 consecutive white patients with HER2-positive breast cancer. Three MACC1 polymorphisms, rs1990172, rs975263 and rs3735615, already associated with cancer prognosis or with potential functional effects, were genotyped by the 5' nuclease assay. RESULTS: Multivariate Cox regression analysis adjusted for age and tumour stage showed increased risk for progression or death for carriers of the rare allele (G-allele) of single nucleotide polymorphism (SNP) rs1990172 (hazard ratios (HR) = 2.26; p = 0.004 and HR = 3.13; p = 0.001 for event-free survival and overall survival, respectively). In addition, we were able to demonstrate an adverse effect on cancer prognosis for carriers of the rare allele (T-allele) of SNP rs975263 (HR = 2.17; p = 0.007 and HR = 2.80; p = 0.003 for event-free survival and overall survival, respectively). The rare allele (C-allele) of SNP rs3735615 showed a significant protective impact on event-free survival as well as overall survival (HR = 0.25; p = 0.001, and HR = 0.16; p = 0.001, respectively). CONCLUSIONS: This study provides first evidence that MACC1 polymorphisms are associated with clinical outcome for HER2-positive breast cancer patients. Further studies are warranted to validate these findings.

Evaluation of the prevalence and prospective clinical impact of the JAK2 V617F mutation in coronary patients.

The JAK2 V617F mutation is not only found in the majority of patients with myeloproliferative neoplasms (MPN), including essential thrombocythemia (ET), but also has been reported in individuals without overt MPN. A close relation of the JAK2 V617F mutation to atherothrombotic events has been described, at least in patients with MPN. The prevalence of the JAK2 V617F mutation and its clinical impact in coronary patients is unknown. To address this issue, DNA samples from 1,589 subjects undergoing coronary angiography with up to 11 years of follow up were genotyped using allele-specific real-time PCR assays. Prevalence of the JAK2 V617F mutation was 1.32% (n = 21) in coronary patients. Two JAK2 V617F positive patients showed baseline platelet counts indicative for ET and a third patient developed ET during follow up, finally resulting in a percentage of 0.188% of ET cases. This corresponds to an up to fivefold accumulation of ET cases in coronary patients compared with the general population. Our study showed no impact of the JAK2 V617F mutation on future atherothrombotic events or overall survival (HR = 1.04 [0.33-3.27]; P = 0.949 and HR = 0.35 [0.05-2.46]; P = 0.288, respectively). Therefore, our data suggest that JAK2 V617F positive coronary patients are not at increased risk for future atherothrombotic complications. Routine mutation screening in coronary patients is, therefore, not warranted. However, number of ET cases appears to be accumulated in coronary patients. For this reason, we recommend JAK2 V617F testing only in coronary patients showing abnormal blood cell counts for further clarification.

Association of a common genetic variant of the IGF-1 gene with event-free survival in patients with HER2-positive breast cancer.

PURPOSE: Insulin-like growth factor 1 (IGF-1) stimulates mitosis and inhibits apoptosis. High circulating IGF-1 levels are linked with an increased risk of colorectal and breast cancer. Recently, IGF-1 single nucleotide polymorphisms (SNPs), especially variant rs2946834, have been associated with poor clinical outcome in patients with colorectal cancer. In the present study, we aimed to investigate the influence of IGF1 polymorphisms associated with IGF-1 plasma levels on event-free survival in patients with HER2-positive breast cancer. METHODS: The present study included 161 consecutive white patients with HER2-positive breast cancer. Event-free survival was calculated as the time from cancer diagnosis to either relapse or death from any cause. Genomic DNA was extracted from archived formalin-fixed paraffin-embedded tumor tissue samples; five IGF-1 polymorphisms (rs2946834, rs6220, rs1520220, rs5742694, and rs5742678), all associated with IGF-1 levels, were genotyped by SNaPshot assays. RESULTS: Kaplan-Meier analysis showed a poorer clinical outcome for carriers of the rare allele of SNP rs2946834 (log-rank test, p = 0.020). Concordantly, in univariate Cox regression analyses, the rare allele of SNP rs2946834 was significantly associated with a decreased event-free survival (HR = 3.06 [1.14-8.22]; p = 0.027). Multivariate analysis adjusted for age and tumor stage confirmed this result (HR = 4.02 [1.36-11.90]; p = 0.012). Other investigated polymorphisms of the IGF1 gene were not significantly associated with event-free survival (all p values >0.05). CONCLUSIONS: This study provides first evidence that IGF1 rs2946834 polymorphism is associated with clinical outcome of HER2-positive breast cancer patients. Further studies are warranted to validate these findings.

A common variant of the MACC1 gene is significantly associated with overall survival in colorectal cancer patients.

BACKGROUND: The newly discovered metastasis-associated in colon cancer-1 (MACC1) gene is a key regulator of the HGF/MET pathway. Deregulation of HGF/MET signaling is reported as a prognostic marker for tumorigenesis, early stage invasion, and metastasis. High expression levels of MACC1 have been associated with colon cancer metastasis and reduced survival. Potential links between the genetic diversity of the MACC1 locus and overall survival are unknown. We therefore investigated the association between MACC1 tagging single nucleotide polymorphisms (SNPs) and overall survival in a large cohort of colorectal cancer patients. METHODS: The study included 318 subjects with histopathologically proven colorectal cancer at the Academic Teaching Hospital Feldkirch, Austria. Survival data were provided by the federal agency for statistics in Austria. Genomic DNA was isolated from formalin-fixed paraffin-embedded specimens; six tagging SNPs (rs1990172, rs3114446, rs10275612, rs3095007, rs3095009, and rs7780032), capturing most of the common variants of the MACC1 locus, were genotyped by SNaPshot assays. RESULTS: Over a mean follow up period of 5.3 (± 1.0) years, 94 deaths were recorded. Carriers of the G-allele of SNP rs1990172 showed a significantly decreased overall survival (additive HR = 1.38 [1.05-1.82]; p = 0.023). Multivariate analysis adjusted for age and UICC tumor stage confirmed this result (HR = 1.49 [1.12-1.98]; p = 0.007). Other investigated genetic variants of the MACC1 gene were not significantly associated with overall survival (p-values > 0.05). CONCLUSIONS: For the first time, our study investigated the influence of MACC1 tagging polymorphisms on overall survival suggesting SNP rs1990172 as a predictor for reduced overall survival in colorectal cancer patients. Further studies will be required to validate our findings.

Optimized allele-specific real-time PCR assays for the detection of common mutations in KRAS and BRAF.

Mutations in the oncogenes KRAS and BRAF have been identified as prognostic factors in patients with colorectal diseases and as predictors of negative outcome in epidermal growth factor receptor-targeted therapies. Therefore, accurate mutation detection in both genes, KRAS and BRAF, is of increasing clinical relevance. We aimed at optimizing allele-specific real-time PCR assays for the detection of common mutations in KRAS and the BRAF Val600Glu mutation using allele-specific PCR primers for allelic discrimination and probes (TaqMan) for quantification. Each reaction mix contains a co-amplified internal control to exclude false-negative results. Allele-specific real-time PCR assays were evaluated on plasmid model systems providing a mutation detection limit of 10 copies of mutant DNA in proportions as low as 1% of the total DNA. Furthermore, we analyzed 125 DNA samples prepared from archived, formalin-fixed, paraffin-embedded colorectal carcinomas and compared results with those obtained from direct-sequence analysis. All mutations determined by sequence analysis could be recovered by allele-specific PCR assays. In addition, allele-specific PCR assays clearly identified three additional samples affected by a mutation. We propose these allele-specific real-time PCR assays as a low-cost and fast diagnostic tool for accurate detection of KRAS and BRAF mutations that can be applied to clinical samples.

Treatment of severe cancer pain by low-dose continuous subcutaneous morphine.

In a prospective and intraindividually controlled trial, we have compared the efficacy and safety of a continuous subcutaneous morphine infusion with conventional intermittent oral or subcutaneous morphine application. Twenty-eight in-patients with cancer pain received a short-term infusion lasting 2-42 days, and 8 out-patients underwent long-term infusion from 49 to 197 days during the terminal stage of their disease. Continuous subcutaneous morphine infusion significantly (P less than 0.001) improved both pain and quality of life when compared to conventional morphine application. With continuous infusion, 5-48 mg (median 19 mg) of morphine was required daily, significantly (P less than 0.001) less than the 10-90 mg (median 50 mg) necessary with conventional use. As a result of lower dosage, side effects under continuous infusion were infrequent and mild. Constipation occurred in 3 of the 36 patients and was always controlled by the addition of laxatives; no nausea, sedation or respiratory depression were observed. Signs of tolerance developed in 2 patients on long-term infusion, but the use of continuous subcutaneous methadone for 2 weeks reversed the tolerance. The study presented indicates that low-dose continuous subcutaneous morphine provides a valuable treatment modality for severe terminal cancer pain exhibiting a high degree of both efficacy and safety.