Günter Hofmann

Comparison of Two Methods for Enumerating Circulating Tumor Cells in Carcinoma Patients

Monitoring of circulating tumor cells (CTCs) in blood of carcinoma patients treated with novel compounds may be a measurement of treatment effectiveness. Before it can be used clinically, a reliably method is needed to enumerate CTCs. We compared two methods for CTC enumeration, OnkoQuick and the CellSearch system.

Survival analysis of 254 patients after manifestation of spinal metastases: evaluation of seven preoperative scoring systems.

Study Design. Retrospective study. Objective. This study analyzed the predictive value of the scoring systems of Bauer, Bauer modified, Tokuhashi, Tokuhashi revised, Tomita, van der Linden, and Sioutos as well as the parameters included in these systems. Summary of Background Data. Metastases of the spinal column are a common manifestation of advanced cancer. Severe pain, pathologic fracture, and neurologic deficit due to spinal metastases need adequate treatment. Besides oncologic aspects and quality of life, treatment decisions should also include the survival prognosis. Methods. Two hundred fifty-four patients with confirmed spinal metastases were investigated retrospectively (treatment 1998–2006; 62 underwent surgery and 192 had conservative treatment only). Factors related to survival, such as primary tumor, general condition (Karnofsky Performance Status Scale), neurologic deficit, number of spinal and extraspinal bone metastases, visceral metastases, and pathologic fracture, were analyzed. The survival period was calculated from date of diagnosis of the spinal metastases to date of death or last follow-up (minimum follow-up: 12 months). For statistical analysis, univariate and stepwise multivariate Cox regression analyses were performed. Results. Median overall survival for all patients was 10.6 months. The following factors showed significant influence on survival in multivariate analysis: primary tumor (P < 0.0001), status of visceral metastases (P < 0.0001), and systemic therapy (P < 0.0001). Using the recommended group assignment for each system, only Bauer and Bauer modified showed significant results for the distinction between good, moderate, and poor prognosis. The other systems failed to distinguish significantly between good and moderate prognosis. The hazard ratio of the absolute score of all analyzed systems was, however, statistically significant, with a better score leading to lower risk of death. Conclusion. According to this analysis, the Bauer and the Bauer modified scores are the most reliable systems for predicting survival. Since the Bauer modified score furthermore consists of only four positive prognostic factors, we emphasize its impact and simplicity.

Association between single nucleotide polymorphisms in the gene for XRCC1 and radiation-induced late toxicity in prostate cancer patients

BACKGROUND AND PURPOSE Polymorphisms in genes responsible for DNA damage signaling and repair might modulate DNA repair capacity and, therefore, affect cell and tissue response to radiation and influence individual radiosensitivity. The purpose of the present prospective investigation was to evaluate the association of single nucleotide polymorphisms in XRCC1 with radiation-induced late side effects in prostate cancer patients treated with radiotherapy. MATERIAL AND METHODS To analyze the role of XRCC1 polymorphisms for late toxicity 603 participants from the Austrian PROCAGENE study treated with three-dimensional conformal radiotherapy were included in the present investigation. Three non-synonymous candidate polymorphisms in the X-ray repair cross-complementing group 1 (XRCC1) gene (Arg194Trp; Arg280His; Arg399Gln) were selected and determined by 5´-nuclease (TaqMan) assays. RESULTS Within a median follow-up time of 35 months, 91 patients (15.7%) developed high-grade late toxicities (defined as late bladder and/or rectal toxicity RTOG≥2). In a Kaplan-Meier analysis, carriers of the XRCC1 Arg280His polymorphism were at decreased risk of high-grade late toxicity (p=0.022), in multivariate analysis including clinical and dosimetric parameters as potential confounders the XRCC1 Arg280His polymorphism remained a significant predictor for high-grade late toxicity (HR=0.221, 95% CI 0.051-0.956; p=0.043). No significant associations were found for the remaining polymorphisms. CONCLUSIONS We conclude that the XRCC1 Arg280His polymorphism may be protective against the development of high-grade late toxicity after radiotherapy in prostate cancer patients.

Single nucleotide polymorphisms in the hypoxia-inducible factor-1 gene and colorectal cancer risk.

With an incidence of about 300 000 new cases colorectal cancer (CRC) is the second leading cause of cancer‐related death in Europe and the United States. Environmental and genetic factors influence CRC risk. Hypoxia‐inducible factor‐1 (HIF‐1), a heterodimeric protein composed of two subunits, HIF‐1 alpha and HIF‐1 beta, plays a critical role in oxygen homeostasis and is involved in angiogenesis and cell proliferation. The gene for the HIF‐1 alpha subunit (HIF1A) carries two common missense mutations—P582S (rs11549465) and A588T (rs11549467)—which both have been related to increased trans‐activation capacity of HIF1A. In our case–control study we investigated the association between these polymorphisms and CRC risk. We investigated 381 patients with histologically confirmed CRC and 2156 control subjects. HIF1A genotypes were determined by exonuclease (TaqMan) assays. For determination of microvessel density (MVD) tumor sections were stained using a mouse monoclonal antibody recognizing the pan‐endothelial marker CD31. In a multivariate logistic regression analysis including age and sex neither the HIF1A 582S allele (Odds ratio: 1.204; 95% confidence interval 0.911–1.592; P = 0.193) nor the 588T allele was significantly associated with CRC (Odds ratio: 0.851; 95% confidence interval 0.444–1.631; P = 0.626). However, in an exploratory analysis, the HIF1A 588T allele was associated with tumor localization (P = 0.016) and tumor size (P = 0.003). MVD was similar in tumors of patients carrying HIF1A 588T allele and patients without this rare allele. We conclude that functional polymorphisms in the HIF1A gene do not modify CRC risk but maybe associated with clinic‐pathological features of the disease.

Integrin alpha-2 and beta-3 gene polymorphisms and breast cancer risk

SummaryIntegrins are cell surface receptors, which mediate cell-to-cell and cell-to-extracellular matrix adhesion. Some of them, e.g. αVβ3, αIIbβ3 and α2β1, have been suggested as key players for cancer development and tumor metastasis. Two polymorphisms in the gene for the α2 component, ITGA2 807C>T and 1648G>A, have been associated with the cell-surface density of integrin α2β1. The 176T>C polymorphism in the ITGB3 gene, encoding the β3 subunit of integrins αIIbβ3 and αVβ3, modifies a variety of traits of β3 expressing cells. To analyze the role of ITGA2 and ITGB3 polymorphisms for breast cancer risk and prognosis, we performed a case-control study including 500 female breast cancer patients and 500 healthy female age-matched control subjects. All study participants were of Caucasian origin (Austria, Middle-Europe). The ITGA2 1648_AA genotype was significantly associated with breast cancer (odds ratio 3.12; 95% confidence interval 1.11–8.77). Carriers of the most common ITGA2 haplotype (807C_1648G, ‘wildtype’) were at decreased risk for breast cancer (odds ratio 0.72; 95% confidence interval 0.53–0.98). A histological grade of 3 or 4 was found more often in ITGA2 807TT subjects (p=0.039 compared to CC+CT genotypes) and carriers of an ITGA2 1648A allele (p=0.017 compared to GG genotype). Carriers of the ITGA2 807C_1648G haplotype were less likely to have a histological grade 3 or 4 compared to non-carriers (p=0.003). The ITGB3 176T>C polymorphisms was not associated with breast cancer susceptibility. In a Cox-regression analysis, carriers of the homozygous ITGB3 176-CC genotype had a higher risk for metastasis (relative risk 2.3; 95% CI 1.3–4.2; p=0.005). We conclude that functional polymorphisms in integrin genes ITGA2 and ITGB3 influence the development and progression of breast cancer, respectively. The precise mechanism remains to be determined, but likely involves dysregulated signaling pathways.

A multigenic approach to predict breast cancer risk.

In the biology of complex disorders, such as breast cancer, interactions among genetic factors may play an important role and theoretical considerations suggest that gene–gene interactions are quite common in such diseases. In this case-control study with 500 breast cancer patients and 500 population-based healthy sex- and age-matched control subjects, we applied a multigenic approach to examine the associations with breast cancer risk of a comprehensive panel of 16 selected polymorphisms in a variety of pathways using classification tree analysis (CART). Overall, 79.6% of all breast cancer patients and 80.6% of all control subjects were correctly classified on the basis of their individual genetic profile by the classification procedure. CART analysis of the data identified the heterozygous vascular endothelial growth factor (VEGF) and matrix metalloproteinase 3 (MMP3) genotype and homozygous cyclooxygenase-2 (PTGS2) mutant as the initial splits, indicating that these genotypes exert the greatest impact on the classification process. Breast cancer patients were primarily indicated by 30 distinct genetic profiles. The odds ratio of these genetic risk profiles for breast cancer was 16.12 (95% confidence interval 11.09–23.49). Five genetic profiles formed homogenous breast cancer subgroups and represented highest risk genetic profiles. This is the first comprehensive study to use a multigenic analysis for breast cancer and the data suggest that individuals with distinct genetic profiles are at an increased risk for breast cancer, confirming the importance of taking a multigenic approach for risk assessment.

The Predictive Value of EGFR and HER-2/neu in Tumor Tissue and Serum for Response to Anthracycline-Based Neoadjuvant Chemotherapy of Breast Cancer

We investigated the predictive value of HER-2/neu and epidermal growth factor receptor (EGFR) in tumor tissue and prechemotherapy serum for histopathologic response in 108 patients with breast cancer undergoing neoadjuvant anthracycline-based chemotherapy. Response to chemotherapy, assessed by histopathologic classification of regression (grade 0 [no therapy effect] to 4 [no residual tumor]), correlated significantly with prechemotherapy serum HER-2/neu levels. Median prechemotherapy serum HER-2/neu levels were significantly higher in patients with regression grades 1 through 4 compared with those in patients with regression grade 0 (9.6 vs 8.55 ng/mL; P = .011; 95% confidence interval [CI], .009-.014). Median pretreatment serum HER-2/neu levels of patients with complete pathologic response (pCR) were significantly higher than in patients with moderate or no treatment response (10.95 vs 9.1 ng/mL; P = .041; 95% CI, .036-.046). Receiver operating characteristic curve analysis revealed a serum HER-2/neu value of more than 10.3 ng/mL to predict a pCR with 80% sensitivity and 69.4% specificity. There was no significant correlation of response with HER-2/neu and EGFR scores in tumor tissue or with serum EGFR levels. Results demonstrate prechemotherapy serum HER-2/neu to be a significant predictor of response to neoadjuvant anthracycline-based chemotherapy for breast cancer.

The Glu228Ala polymorphism in the ligand binding domain of death receptor 4 is associated with increased risk for prostate cancer metastases.

Death receptor 4, encoded by the TNFRSF10A gene, is an important mediator of apoptosis and its dysfunction may be related to cancer development and distant tumor spread. A single nucleotide polymorphism in TNFRSF10A (Glu228Ala, rs20576) within a conserved region of the extracellular cysteine‐rich domain of death receptor 4 has been associated with an increased risk for a variety of tumor entities. Aim of the present study was to evaluate the role of the TNFRSF10A polymorphism in metastatic progression of prostate cancer after radiation therapy.

Integrin alpha-2 and beta-3 gene polymorphisms and colorectal cancer risk

Background and aimsIntegrins such as α2β1, αIIbβ3, and αvβ3 have been suggested as key players for cancer development and progression. Several polymorphisms affecting these molecules, two in integrin α2 (ITGA2 807C>T and 1648G>A) and one in β3 (ITGB3 176T>C), influence their levels, structure, and possibly their function. To analyze the role of ITGA2 and ITGB3 polymorphisms for colorectal cancer risk and clinical presentation, we performed a case–control study.Materials and methodsFour hundred thirty-three colorectal cancer patients and 433 healthy sex- and age-matched control subjects were investigated. ITGA2 and ITGB3 polymorphisms were determined by 5′-nuclease assays.Results/findingsThe ITGA2 807C>T polymorphism was associated with reduced colorectal cancer risk. In a codominant model, the odds ratio for each additional 807-T allele for colorectal cancer was 0.77 (95% confidence interval 0.64–0.94; p = 0.011). The ITGA2 1648G> and the ITGB3 176T>C polymorphism were not associated with colorectal cancer. None of the three polymorphisms investigated was associated with tumor size, histological grade, presence of primary lymph node metastases, tumor stage, or age at diagnosis.Interpretation/conclusionWe conclude that the ITGA2 807C>T polymorphism may be associated with reduced colorectal cancer risk.

Impact of VEGF gene polymorphisms and haplotypes on radiation-induced late toxicity in prostate cancer patients.

Background and PurposeVascular endothelial growth factor (VEGF) is an important determinant of microvascular permeability and angiogenesis and has been shown to be up-regulated during the late phase of radiation injury. The present prospective study was performed to evaluate the role of VEGF gene polymorphisms and haplotypes in the development of radiation-induced late side effects in prostate cancer patients.Patients and MethodsThe association of VEGF gene polymorphisms and haplotypes with high-grade late rectal or urinary toxicity (defined as late toxicity EORTC/RTOG ≥2) was analyzed using 493 prostate cancer patients from the Austrian PROCAGENE study treated with definitive radiotherapy. Seven candidate polymorphisms in the VEGF gene were selected and determined by 5’-nuclease (TaqMan) assays.ResultsWithin a median follow-up time of 48 months, 42 patients (8.6%) developed high-grade late rectal and 47 patients (9.6%) urinary toxicity, respectively. In a Kaplan–Meier analysis, carriers of the VEGF -7C > T polymorphism were at increased risk of high-grade late rectal toxicity (p = 0.003) and in a multivariate analysis including clinical and dosimetric parameters as potential confounders the VEGF -7C > T polymorphism remained a significant predictor (HR = 2.8, 95% CI 1.349–5.813; p = 0.006). Furthermore, the ATTGT haplotype formed by five polymorphisms upstream of the coding sequence demonstrated a significant association with late rectal toxicity grade ≥2 (p = 0.001). No significant associations were found for the remaining polymorphisms and haplotypes.ConclusionWe conclude that genetic variants in the VEGF gene may influence the risk of high-grade late rectal toxicity after definitive radiotherapy for prostate cancer.ZusammenfassungHintergrundVascular endothelial growth factor (VEGF) ist ein wichtiger Regulator der Gefäßpermeabilität und Angiogenese, und in der chronischen Strahlenreaktionsphase wurde die Hochregulation von VEGF gezeigt. Ziel der vorliegenden prospektiven Studie war die Analyse des Zusammenhangs von VEGF-Genpolymorphismen und -Haplotypen mit dem Auftreten von radiogenen Spätfolgen bei Prostatakarzinompatienten.Patienten und MethodenDer Zusammenhang zwischen VEGF-Genpolymorphismen und -Haplotypen und höhergradigen rektalen und urogenitalen Spätfolgen (definiert als Spättoxizität EORTC/RTOG ≥2) wurde bei 493 Prostatakarzinompatienten der PROCAGENE-Studie, die einer definitiven Strahlentherapie unterzogen wurden, untersucht. 7 Kandidatenpolymorphismen wurden ausgewählt und mittels 5´-Nuklease-Assays (TaqMan) analysiert.ErgebnisseWährend einer medianen Nachbeobachtungszeit von 48 Monaten entwickelten 42 Patienten (8,6%) höhergradige rektale und 47 Patienten (9,6%) urogenitale Nebenwirkungen. In der Kaplan-Meier-Analyse zeigten Träger des VEGF -7C > T-Poly-morphismus ein erhöhtes Risiko für höhergradige rektale Spätfolgen (p = 0,003; Abbildung 2) und in der multivariaten Analyse, in welche klinische und dosimetrische Faktoren eingeschlossen wurden, blieb der VEGF -7C > T-Polymorphismus ein signifikanter Prediktor (HR = 28; 95%-CI 1,349–5,813; p = 0,006, Tabelle 4). Zusätzlich zeigte sich für den ATTGT-Haplotyp, bestehend aus 5 vor der kodierenden Sequenz liegenden Polymorphismen, eine signifikante Assoziation mit höhergradiger rektaler Spättoxizität (p = 0,001; Abbildung 3). Keine signifikanten Assoziationen wurden für die übrigen untersuchten Polymorphismen und Haplotypen gefunden (Tabellen 3 und 4).SchlussfolgerungDie vorliegenden Daten zeigen, dass Varianten im VEGF-Gen möglicherweise das Auftreten von höhergradigen rektalen Spätfolgen nach definitiver Radiotherapie des Prostatakarzinoms beeinflussen.