Nynke Zwart

Prognostic Significance of Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand and Its Receptors in Adjuvantly Treated Stage III Colon Cancer Patients

PURPOSE In preclinical models, there is synergism between chemotherapy and recombinant human tumor necrosis factor (TNF) -related apoptosis-inducing ligand (TRAIL) on apoptosis induction in tumor cells. Therefore, the prognostic relevance was analyzed of the expression of TRAIL and its death receptors DR4 and DR5 on disease-free survival and overall survival in stage III colon cancer patients treated with adjuvant chemotherapy. METHODS Tissue microarrays were constructed of primary tumor tissue from 376 stage III colon cancer patients treated in a randomized adjuvant chemotherapy study (fluorouracil/levamisole v fluorouracil/levamisole/leucovorin) and stained immunohistochemically for TRAIL, DR4, and DR5. Log-rank tests and Cox proportional hazard analysis, with adjustment for treatment arm, sex, age, N stage, microsatellite instability status, and p53 mutation status, were performed. RESULTS The majority of tumors showed high expression of TRAIL (83%), DR4 (92%), and DR5 (87%). Median follow-up was 43 months. High DR4 expression was associated with worse disease-free survival (odds ratio [OR] = 2.19; 95% CI, 1.06 to 4.53; P = .03), worse overall survival (OR = 2.22; 95% CI,1.03 to 4.81; P = .04) and shorter time to recurrence (P = .02) compared with those with low DR4 expression. TRAIL or DR5 expression had no prognostic value. CONCLUSION High DR4 expression is associated with worse disease-free and overall survival in stage III adjuvant-treated colon cancer patients. Evaluation of DR4 expression in stage III colon cancer patients may identify a subset requiring more aggressive adjuvant treatment.

Early development of the metabolic syndrome after chemotherapy for testicular cancer

BACKGROUND The metabolic syndrome (MS) might increase the risk of cardiovascular disease in testicular cancer (TC) survivors. We investigated its prevalence, development, vascular implications, and the role of gonadal function. METHODS TC survivors treated with chemotherapy and follow-up ≥3 years (N = 370, study I) were retrospectively evaluated for the development of cardiovascular risk factors. A subgroup followed 3-20 years (N = 173, study II) was compared with controls (N = 1085) for MS prevalence and evaluated for vascular function. RESULTS In TC survivors (study I), 24% developed overweight, 24% hypercholesterolemia, and 30% hypertension, after median follow-up of 1.7, 0.9, and 5.1 years, respectively. At the median follow-up of 5 years (study II), 25% of survivors have the MS {odds ratio (OR) 2.2, [95% confidence interval (CI) 1.5-3.3] compared with controls}. Survivors with MS have features of inflammation and prothrombotic state, increased carotid artery intima-media thickness. Survivors with testosterone levels <15 nmol/l (22%) have an increased risk of the MS (OR 4.1, 95% CI 1.8-9.3). CONCLUSIONS The current data suggest that the MS occurs at earlier age in TC survivors treated with chemotherapy compared with controls and is accompanied by early signs of atherosclerosis. As low testosterone may have a causal role, it is a target for interventions.

Variation in Bleomycin Hydrolase Gene Is Associated With Reduced Survival After Chemotherapy for Testicular Germ Cell Cancer

PURPOSE Response to chemotherapy may be determined by gene polymorphisms involved in metabolism of cytotoxic drugs. A plausible candidate is the gene for bleomycin hydrolase (BLMH), an enzyme that inactivates bleomycin, an essential component of chemotherapy regimens for disseminated testicular germ-cell cancer (TC). We investigated whether the single nucleotide polymorphism (SNP) A1450G of the BLMH gene (rs1050565) is associated with survival. PATIENTS AND METHODS Data were collected on survival and BLMH genotype of 304 patients with TC treated with bleomycin-containing chemotherapy at the University Medical Center Groningen, the Netherlands, between 1977 and 2003. Survival according to genotype was analyzed using Kaplan-Meier curves with log-rank testing and Cox regression analysis with adjustment for confounders. RESULTS BLMH gene SNP A1450G has a significant effect on TC-related survival (log-rank P = .001). The homozygous variant (G/G) genotype (n = 31) is associated with decreased TC related survival compared with the heterozygous variant (A/G; n = 133) and the wild-type (A/A; n = 140). With Cox regression the G/G genotype proves to be an unfavorable prognostic factor, in addition to the commonly used International Germ Cell Consensus Classification prognosis group, with a hazard ratio of 4.97 (95% CI, 2.17 to 11.39) for TC-related death. Furthermore, the G/G genotype shows a higher prevalence of early relapses. CONCLUSION The homozygous variant G/G of BLMH gene SNP A1450G is associated with reduced survival and higher prevalence of early relapses in TC patients treated with bleomycin-containing chemotherapy. This association is hypothesis generating and may eventually be of value for risk classification and selection for alternative treatment strategies in patients with disseminated TC.

Catecholamine-synthesizing enzymes in carcinoid tumors and pheochromocytomas

BACKGROUND Serotonin is the principal endocrine product of carcinoid tumors, but simultaneously increased production of catecholamines has been described in these tumors. As it is not clear whether these tumors contain specific enzymes for catecholamine synthesis, we aimed to detect catecholamine-synthesizing enzymes [tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH), and phenylethanolamine-N-methyltransferase (PNMT)] in midgut carcinoid tumors and pheochromocytoma and to correlate enzyme expression to serotonin production as well as catecholamines and metabolites excreted in urine. METHODS Paraffin-embedded tumor specimens from 21 midgut carcinoid patients and 20 pheochromocytoma patients (10 sporadic and 10 MEN type IIa-related tumors) were stained for TH, DBH, and PNMT, using a three-step biotin-avidin-peroxidase method. RESULTS TH was demonstrated in 9 (43%) of 21 carcinoids and in all (100%) of 20 pheochromocytomas, DBH in 8 (38%) carcinoids and in 15 (75%) pheochromocytomas, and PNMT in 7 (33%) carcinoids and in 13 (65%) pheochromocytomas. Increased urinary excretion of catecholamines and metabolites was observed in 10 (48%) carcinoid patients and in all pheochromocytoma patients. No clinically relevant association between enzyme expression and urinary excretion of catecholamines and metabolites was found. CONCLUSIONS Catecholamine-synthesizing enzymes are present in many carcinoid tumors. This finding possibly indicates the existence of a catecholamine-synthesizing pathway in carcinoids similar to that found in pheochromocytoma.

Proliferation rate of colonic mucosa in normal subjects and patients with colonic neoplasms: a refined immunohistochemical method.

An increased colonic epithelial proliferation rate and an increase of the cryptal proliferative zone are probable markers of increased susceptibility to colonic cancer. In this study an immunohistochemical method using 5-bromo-deoxyuridine (BrdUrd) to measure the proliferation rate of colonic mucosa in vitro was used. Fresh endoscopic colonic biopsy specimens were incubated with BrdUrd and then processed for immunohistochemistry using a monoclonal antibody. Essential procedures with respect to the equal distribution of nuclei stained with BrdUrd in the biopsy specimens proved to be the cutting of the specimens before incubation and the use of a microwave oven at the beginning of incubation. The use of the procedure of the running average showed that 12 length cut crypts are sufficient to determine reliably the proliferation rate, expressed as the labelling index (LI). This was determined in the biopsy specimens of 10 subjects without organic colonic disease, eight patients with adenomatous colonic polyps, and in six patients with (recent) colonic carcinoma. Mean LI in the controls was significantly lower than in patients with colonic polyps and in those with colon cancer. It is concluded that this method is promising for screening persons at risk for colon cancer and will be of great potential in performing dietary intervention studies in these subjects.

Systolic and diastolic dysfunction in long-term adult survivors of childhood cancer.

AIM To assess systolic and diastolic function in adult childhood-cancer survivors (CCS) after treatment entailing potential cardiovascular toxicity. METHODS The study cohort consisted of 277 adult CCS (median age 28 [range 18-48]years), who had been treated with anthracyclines, platinum, and/or radiotherapy between 1976 and 1999, along with 130 healthy sibling controls. The assessments included echocardiography, baroreflex sensitivity measurement, and plasma N-terminal pro-brain natriuretic peptide (NT-proBNP). Echocardiography measurements were shortening fraction (SF) (abnormal<29%) for systolic function and tissue velocity imaging of early diastole (TVI Et) (abnormal<8.00)cm/sec for diastolic function; systolic function was also assessed by the wall motion score index (WMSI). RESULTS At 18 (5-31)years post-treatment, the prevalence of both impaired SF and abnormal WMSI was increased in CCS compared to controls (p=0.003 and p<0.001, respectively). CCS also had an increased prevalence of diastolic dysfunction compared to the controls (12% versus 1%, p<0.001). Abnormal SF and/or abnormal diastolic function were found in 43% of CCS. NT-proBNP was higher in CCS and was associated to increased WMSI. Baroreflex sensitivity was lower in CCS and was associated with diastolic dysfunction. Systolic as well as diastolic dysfunction was associated with cumulative dose of anthracyclines and mediastinal irradiation. CONCLUSION After treatment with potential cardiovascular toxic therapies, the risk of systolic and diastolic dysfunction in CCS is considerable. Since these abnormalities, in particular diastolic dysfunction, are age related, the observed effects might be considered a sign of precocious cardiac ageing.

The willingness of general practitioners to be involved in the follow-up of adult survivors of childhood cancer.

BackgroundLong-term follow-up of childhood cancer survivors is mainly organised by paediatric oncologists and until now general practitioners (GPs) are rarely involved. To ensure appropriate follow-up for all survivors into adulthood, a combined effort of paediatric oncologists and general practitioners might be the solution. We investigated the willingness of GPs, who had followed a postgraduate course on late effects of cancer treatment, to participate in a shared care model for follow-up of adult childhood cancer survivors as well as what their requirements would be in case of participation.MethodsFrom the Northern Netherlands, 358 GPs participated in a postgraduate course on late effects in paediatric cancer survivors. After the course, they were asked to complete a 10-item questionnaire on motivation to participate in the regular follow-up of adult childhood cancer survivors as well as their conditions to participate.ResultsThe response rate was 65%. Of the responders, 97% were willing to participate in a shared care model for follow-up and 64% felt that it was their responsibility to be in charge of childhood cancer survivors. The main requirements for participation were the availability of guidelines (64%), sufficient information about the patient’s medical history (37%), and short communication lines (45%). The main barriers to participate were workload (16%), lack of knowledge (15%), and lack of communication (13%).ConclusionA significant number of GPs are ready to participate in the long-term follow-up of adult childhood cancer survivors if adequate guidelines and medical information is provided and communication lines are clear.

Role of metallothionein in cisplatin sensitivity of germ-cell tumours

Cisplatin (CDDP) is an extremely active drug in the treatment of germ‐cell tumours. Earlier, we found an unexpected inverse correlation between the total amount of sulfhydryl groups and CDDP sensitivity in a panel of 3 human germ‐cell‐tumour and 3 colon‐carcinoma cell lines. Major components of the sulfhydryl groups are glutathione and metallothionein (MT). We further investigated a possible role of MT in the CDDP sensitivity of germ‐cell tumours. MT levels and functionality of the germ‐cell‐tumour and colon‐carcinoma cell lines were found to be inversely correlated with CDDP sensitivity. No difference in sub‐cellular localization of MT could be observed among the types of cell lines. In agreement with the in vitro data, immunohistochemical detection of MT was high in 11/14 primary human germ‐cell tumours and low in 7/7 human colon carcinomas. MT‐protein expression in primary germ‐cell tumours did not discriminate between responding and non‐responding patients. As compared with the primary tumours, MT‐protein expression decreased in 5/7 post‐chemotherapy residual vital tumours or remained undetectable (2/7). MT‐protein expression in the germ‐cell tumours was not related to total p53‐protein expression. In summary, over‐expression of MT was found in germ‐cell tumours, both in cell lines and in human tumours. Although MT‐protein over‐expression seems to be associated with the CDDP sensitivity of germ‐cell tumours, MT‐protein expression in primary germ‐cell tumours did not differ between responding and non‐responding patients and therefore cannot be used to predict response to chemotherapy. Int. J. Cancer 85:777–781, 2000.

Sulindac Inhibits β-Catenin Expression in Normal-Appearing Colon of Hereditary Nonpolyposis Colorectal Cancer and Familial Adenomatous Polyposis Patients

Sulindac reduces colorectal cancer risk in genetically susceptible humans and animals. The molecular mechanisms underlying these effects are incompletely understood. Many studies suggest an important role for induction of apoptosis involving the mitochondrial pathway and the death receptor pathway. Alternatively, mechanisms involving the APC-β-catenin-Wnt pathway have been suggested, possibly mediated by p21. We determined the effects of sulindac on apoptosis and expression of death receptor (DR)-4 and DR5, β-catenin, and p21 in normal-appearing colorectal epithelium. Biopsies were obtained before and after sulindac treatment during two chemoprevention studies. Patients (n = 18) with hereditary nonpolyposis colorectal cancer (HNPCC) received 150 mg sulindac bd for 4 weeks in a placebo-controlled crossover design. Patients (n = 6) with familial adenomatous polyposis (FAP) received 150 mg sulindac bd for 6 months. Apoptosis was assessed by M30 staining and expression patterns of DR4, DR5, β-catenin, and p21 were studied immunohistochemically. In HNPCC patients, apoptotic indices were similar following placebo and sulindac. Also in FAP patients, apoptotic indices were not different after sulindac compared with pretreatment values. Expression of DR4 and DR5 was observed in all samples with no consistent differences between placebo/baseline and sulindac. Intensity of membranous β-catenin staining was lower in HNPCC samples following sulindac compared with placebo (P < 0.001). Similar results were obtained in FAP samples (P < 0.01). p21 expressions before and after sulindac treatment were similar in both patient groups. In conclusion, sulindac inhibits β-catenin expression in normal colorectal epithelium from HNPCC and FAP patients without affecting apoptotic indices and DR4, DR5, and p21 expression.

TRAIL Induces Apoptosis in Human Colorectal Adenoma Cell Lines and Human Colorectal Adenomas

Purpose: Recombinant human (rh) tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) is a potential new anticancer drug which can induce apoptosis in colorectal cancer cell lines. The aim of this study was to investigate whether it is possible to induce apoptosis in human adenoma cell lines and human adenomas using rhTRAIL. Experimental Design: Two human adenoma cell lines were exposed to 0.1 μg/mL of rhTRAIL for 5 hours. Apoptosis and caspase activation in cell lines were evaluated using immunocytochemistry, fluorimetric caspase assays, and Western blotting. Short-term explant cultures were established from freshly removed human adenomas (n = 38) and biopsies of normal colon epithelium (n = 15), and these were incubated for 5 hours in the presence or absence of 1 μg/mL of rhTRAIL. Apoptosis was determined in paraffin-embedded tissue using morphologic criteria and cleaved caspase-3 staining. Results: In the adenoma cell lines, rhTRAIL induced up to 55% apoptosis. This coincided with caspase-8 and caspase-3 activation and could be inhibited by a pan-caspase inhibitor. rhTRAIL induced caspase-dependent apoptosis in adenomas with high-grade dysplasia (n = 21) compared with the paired untreated counterparts (apoptotic index, 34 ± 5% versus 17 ± 2%, mean ± SE; P = 0.002), but not in adenomas with low-grade dysplasia (n = 17) or in normal colon epithelium (n = 15). Conclusions: Colorectal adenoma cell lines and adenomas with high-grade dysplasia are sensitive to rhTRAIL-induced apoptosis, whereas normal colon epithelium is not. This suggests the potential application of rhTRAIL in the treatment of adenomas with high-grade dysplasia.