Christian Marth

A concept for the standardized detection of disseminated tumor cells in bone marrow from patients with primary breast cancer and its clinical implementation

Numerous single‐institutional studies and a large pooled analysis have demonstrated that the presence of disseminated tumor cells (DTCs) in the bone marrow (BM) from patients with primary, nonmetastatic breast cancer (Stages I‐III) is associated with impaired prognosis. To date, sampling of BM and assessment of DTCs is not considered a routine procedure in the clinical management of breast cancer patients; however, emerging data suggest a future role for risk stratification and monitoring of therapeutic efficacy. Because these clinical options need to be evaluated in trials to verify the principle of this concept in the clinical setting, agreement on the standardized detection of DTCs is necessary. Consequently, the German, Austrian, and Swiss Societies for Senology recently formed a panel 1) to review and discuss the existing methodologies, 2) to find a consensus for a standardized detection of DTCs, and 3) to explore the options for its clinical implementation. Cancer 2006.

Why did p53 gene therapy fail in ovarian cancer

Promising preclinical and clinical data led to the initiation of an international randomised phase II/III trial of p53 gene-therapy trial for first-line treatment of patients with ovarian cancer. In that trial, replication-deficient adenoviral vectors carrying wild-type p53 were given intraperitoneally in combination with standard chemotherapy to patients with ovarian cancers harbouring p53 mutations. The study was closed after the first interim analysis because an adequate therapeutic benefit was not shown. In this review, we discuss the possible reasons for failure of p53 gene therapy, which include the multiple genetic changes in cancer and epigenetic dysregulations leading to aberrant silencing of genes. These complex interactions lead us to conclude that repair of single genes might not be a suitable strategy for the treatment of cancer. Moreover, dominant negative cross talk between ectopic wild-type p53 and recently identified dominant p53 mutants and splice variants of p63 and p73--which are frequently overexpressed in ovarian cancers--could seriously compromise the effectiveness of p53 gene therapy. Other substantial problems in targeting tumour cells with adenoviral vectors are the heterogeneity or lack of expression of coxsackie-adenovirus receptors and integrin co-receptors in ovarian tumours and the presence of adenovirus-neutralising antibodies in ovarian cancer-related ascites.

Pregnancies after adjustable gastric banding.

Background: We evaluated outcome of pregnancies of morbidly obese women who are within the first 2 years after laparoscopic adjustable gastric banding. Methods: 215 morbidly obese women of reproductive potential (age 18-45 years), who had agreed to remain on reliable contraceptives for 2 years after surgery, were retrospectively analyzed following bariatric surgery. Results: 7 unexpected pregnancies were observed. 5 pregnancies were full-term (3 vaginal and 2 cesarean deliveries). The birth weights ranged from 2110 g to 3860 g. 2 women had first trimester miscarriages. All gastric bands were completely decompressed due to nausea and vomiting, resulting in further weight gain. 2 serious band complications were observed (1 intragastric band migration and 1 balloon defect), which required re-operation. Conclusions: Pregnancy in morbidly obese women soon after adjustable gastric banding may occur unexpectedly during a period of weight loss. Prophylactic fluid removal from the band eliminates the efficacy of the obesity treatment. Moreover, this cohort shows an increased incidence of spontaneous abortions and band-related complications.

CDH1 and CDH13 methylation in serum is an independent prognostic marker in cervical cancer patients.

Cervical cancer is the principal cause of death due to cancer in women. Five‐year survival rate ranges from 15–80%, depending on the extent of the disease. New predictive markers for relapse may increase survival rates by improving treatment of patients at high risk for relapse. The gene products of CDH1 and CDH13, namely E‐cadherin and H‐cadherin, play a key role in cell–cell adhesion. Inactivation of the cadherin‐mediated cell adhesion system, caused by aberrant methylation, is a common finding in human cancers. To test the hypothesis that CDH1/CDH13 methylation is a prognostic marker in cervical cancer we determined the methylation status of CDH1/CDH13 in serum samples from 93 cervical cancer patients. Methylation analysis was carried out using MethyLight. Aberrant methylation of the 5′‐region of CDH1 or CDH13 was observed in 43% (40 of 93) of the patients. Cervical cancer patients with unmethylated CDH1/CDH13 in serum samples showed significantly better disease‐free survival in univariate and multivariate analysis. Median disease‐free survival for CDH1/CDH13 methylation negative and positive patients was 4.3 years and 1.2 years, respectively. Our results suggest that detection of aberrant methylation of CDH1/CDH13 may be of potential use as a marker for selecting cervical cancer patients at high risk for relapse who could benefit from additional systemic therapy.

Epigenetic downregulation of the retinoic acid receptor-beta2 gene in breast cancer.

A growing body of evidence supports the hypothesis that the retinoic acid receptor β2 (RAR-β2) gene is a tumor suppressor gene which induces apoptosis and that the chemopreventive and therapeutic effects of retinoids are due to induction of RAR-β2. During breast cancer progression, RAR-β2 is reduced or even lost. It is known from studies of other tumor-suppressor genes that methylation of the 5′-region is the cause of loss of expression. Several groups demonstrated that this is also true for the RAR-β2 in breast cancer by treating breast cancer cell lines with a demethylating agent and examining expression of the RAR-β2 gene in response to a challenge with retinoic acid. Studies using sodium bisulfite genomic sequencing as well as methylation specific PCR showed that a number of breast cancer cell lines as well as breast cancer tissue showed signs of methylation. The RAR-β2 gene was unmethylated in non-neoplastic breast tissue as well as in other normal tissues. A combination of retinoic acid with demethylating agents as well as with histone deacetylase inhibitors acts synergistically to inhibit growth. This review presents data that suggest that treatment of cancer patients with demethylating agents followed by retinoic acid may offer a new therapeutic modality. Both the time of commencement of chemoprevention and the choice of substances that are able either to prevent de novo methylation or to reverse methylation-caused gene silencing may be important considerations.

Immunohistochemical determination of HER2 expression in breast cancer from core biopsy specimens: a reliable predictor of HER2 status of the whole tumor.

HER2 overexpression in breast cancer is associated with a poor prognosis, resistance to endocrine therapy and chemosensitivity to anthracyclines and paclitaxel. Moreover, trastuzumab (HerceptinR) shows therapeutic benefit in patients with HER2 overexpressing tumors. Therefore, knowledge of the pretherapeutical HER2 status allows an optimal selection of patients for treatment. In addition to a definitive histological diagnosis, core biopsies of tumors offer the opportunity to evaluate the HER2 status preoperatively. In 64 patients with invasive breast cancer, sections of core biopsies and of the subsequently removed whole tumor were investigated immuno-histochemically with the DAKO HercepTestTM. Fifteen tumors (23%) revealed HER2 overexpression, and 44 tumors (69%) were negative in both, the core biopsy and the whole tumor sections. Two core biopsies were negative whereas the corresponding final specimen was 2+ positive. In 3 cases weak overexpression was observed in the core biopsy, but the whole tumor was negative. The overall concordance of the results achieved at core biopsy and whole tumor sections was 92% κ=0.8). A negative HER2 result on core biopsy was never associated with a score 3+ tumor specimen nor was there a case of negative whole tumor specimen with a preceding 3+ score in the biopsy. If one demands the highest degree of overexpression (3+), 100% of our study patients would have been selected correctly using the results on core biopsy alone. We thus conclude, that the immunohistochemical investigation of core biopsies offers the opportunity for a valid preoperative estimation of HER2 overexpression.

Determination of molecules regulating gene delivery using adenoviral vectors in ovarian carcinomas

Gene therapeutic approaches currently favor adenoviral vectors over alternatively available vector systems. Ovarian cancer represents an attractive model for an intraperitoneal adenovirus-based gene therapy, which is now under intensive clinical investigation. Adenovirus-mediated gene transfer depends on adequate virus uptake and thus on the presence of sufficient amounts of high-affinity coxsackie-adenovirus receptor (CAR) and αvβ3- and αvβ5 integrins on target cells. This fact has been ignored in most ongoing clinical trials. This investigation, therefore, determined expression of CAR by immunohistochemistry in 37 ovarian carcinomas and compared it with that of αvβ3 and αvβ5 integrins. In all samples, except one undifferentiated carcinoma, CAR was immunohistochemically demonstrable. Grade 1 tumors exhibited stronger CAR immunostaining as compared with higher-grade cancers (P < 0.03). Integrins αvβ3 and αvβ5 were detectable in 62% and 65% of carcinomas, respectively, and staining for both classes correlated positively (P < 0.005). Cancers classified as undifferentiated completely lacked αvβ3 expression. Furthermore, in undifferentiated and grade 3 carcinomas the three molecules studied exhibited marked distributional heterogeneity with regard to focal positivity and negativity within the same tumor. Either the absence of CAR, αvβ3 and αvβ5 or the pronounced heterogeneity in their expression might seriously compromise the efficiency of adenovirus-based gene therapy in ovarian cancer.

Favorable prognostic value of SOCS2 and IGF-I in breast cancer

BackgroundSuppressor of cytokine signaling (SOCS) proteins comprise a protein family, which has initially been described as STAT induced inhibitors of the Jak/Stat pathway. Recent in vivo and in vitro studies suggest that SOCS proteins are also implicated in cancer. The STAT5 induced IGF-I acts as an endocrine and para/autocrine growth and differentiation factor in mammary gland development. Whereas high levels of circulating IGF-I have been associated with increased cancer risk, the role of autocrine acting IGF-I is less clear. The present study is aimed to elucidate the clinicopathological features associated with SOCS1, SOCS2, SOCS3, CIS and IGF-I expression in breast cancer.MethodsWe determined the mRNA expression levels of SOCS1, SOCS2, SOCS3, CIS and IGF-I in 89 primary breast cancers by reverse transcriptase PCR. SOCS2 protein expression was further evaluated by immuno-blot and immunohistochemistry.ResultsSOCS2 expression inversely correlated with histopathological grade and ER positive tumors exhibited higher SOCS2 levels. Patients with high SOCS2 expression lived significantly longer (108.7 vs. 77.7 months; P = 0.015) and high SOCS2 expression proved to be an independent predictor for good prognosis (HR = 0.45, 95% CI 0.23 – 0.91, P = 0.026). In analogy to SOCS2, high IGF-I expression was an independent predictor for good prognosis in the entire patient cohort. In the subgroup of patients with lymph-node negative disease, high IGF-I was a strong predictor for favorable outcome in terms of overall survival and relapse free survival (HR = 0.075, 95% CI 0.014 – 0.388, P = 0.002).ConclusionThis is the first report on the favorable prognostic value of high SOCS2 expression in primary mammary carcinomas. Furthermore a strong association of high IGF-I expression levels with good prognosis was observed especially in lymph-node negative patients. Our results suggest that high expression of the STAT5 target genes SOCS2 and IGF-I is a feature of differentiated and less malignant tumors.

Tumor marker CA-125 in tissues of the female reproductive tract and in serum during the normal menstrual cycle

OBJECTIVEnTo further elucidate the origin of the physiological CA-125 amounts that lead to cyclic changes in CA-125 serum levels in normally menstruating women.nnnDESIGNnFifty-three normal endometria, 13 fallopian tubes, 25 ovaries, and nine isolated corpora lutea were prospectively investigated for their CA-125 content in a sandwich solid-phase RIA and by immunohistochemistry. In addition, endometrial CA-125 tissue content was compared with the actual CA-125 serum levels of the study patients.nnnRESULTSnCytosolic CA-125 concentrations were 20-fold and twofold higher in the endometrium than those measured in the ovary and the fallopian tube, respectively. Moreover, only in the endometrium did CA-125 content show significant cyclic changes, with the highest concentrations during the early proliferative and middle secretory phase. The lowest tissue concentrations were measured during the early secretory phase. Furthermore, during the early and middle secretory phases cytosolic CA-125 was negatively associated with CA-125 serum levels. In immunohistochemistry, marked distributional changes in OC-125 reactivity were revealed in the basalis and the functionalis throughout the menstrual cycle and the postovulatory loss of CA-125 expression was found to be strongly connected with early secretory transformation of glandular epithelium.nnnCONCLUSIONnOur findings indicate that the CA-125 amounts responsible for cyclic changes in serum levels in normally menstruating women seem to be a product of normal endometrium.

Prognostic value of CD44 splice variant expression in ovarian cancer

In 44 ovarian cancers, CD44 variant (CD44v) expression was investigated immunohistochemically using a variant-specific polyclonal antibody. Patients with CD44v-positive carcinomas had a significantly shorter disease-free survival than patients with CD44v-negative tumors. Overall survival was also significantly reduced for stages III and IV of the International Federation of Gynecology and Obstetrics. Furthermore, a highly significant inverse correlation was observed between CD44v expression and preoperative platelet count. Urinary neopterin concentration, a marker of cell-mediated immunostimulation, did not differ between CD44v-positive and -negative ovarian cancer patients. Moreover, in seven ovarian carcinoma cell lines, modulation of CD44v expression was analyzed by living cell radioimmunoassay. Interferon-alpha, interferon-gamma, tumor necrosis factor, transforming growth factor-beta, all-trans retinoic acid and cisplatin did not affect CD44v expression.