Waiting times for radiotherapy: consequences of volume increase for the TCP in oropharyngeal carcinoma.

BACKGROUND AND PURPOSE: Waiting lists for radiotherapy have become longer over the past years. Apart from the psychological distress for the patient we are concerned about tumour growth during this waiting time, which may worsen prognosis. The purpose of this pilot study was to investigate tumour growth in the waiting time and to obtain an indication of its clinical consequences for patients with oropharyngeal carcinoma. A tumour control probability (TCP) model was applied to evaluate consequences for outcome. METHODS AND MATERIALS: Increase in tumour volume was measured for 13 patients with oropharyngeal carcinoma by outlining the tumour on the diagnostic as well as on the treatment planning CT scan. Waiting time was defined as time between histopathological diagnosis and start of radiotherapy. For each tumour we calculated the increase in tumour volume and the tumour doubling time. The potential increase in TCP was calculated for each tumour for the situation without treatment delay. RESULTS: The mean increase in tumour volume was 70%. The mean waiting time was 56 days. Expected TCP with incorporation of delay was 47%, without delay it might have been 63-66%. CONCLUSION: This study shows tumour progression during the time between the diagnostic CT scan and the treatment planning CT scan in oropharyngeal cancer. As a consequence of waiting time, which allows tumour volume increase, there may be an average control loss of 16-19 % for these tumours during the total waiting time before radiotherapy.     

Adenoviral vectors expressing siRNAs for discovery and validation of gene function

RNA interference is a powerful tool for studying gene function and for drug target discovery in diverse organisms and cell types. In mammalian systems, small interfering RNAs (siRNAs), or DNA plasmids expressing these siRNAs, have been used to down-modulate gene expression. However, inefficient transfection protocols, in particular, for primary cell types, have hampered the use of these tools in disease-relevant cellular assays. To be able to use this technology for genome-wide function screening, a more robust transduction protocol, resulting in a longer duration of the knock-down effect, is required. Here, we describe the validation of adenoviral vectors that express hairpin RNAs that are further processed to siRNAs. Infection of cell lines, or primary human cells, with these viruses leads to an efficient, sequence-specific, and prolonged reduction of the corresponding target mRNA, resulting in a reduction of the encoded protein level in the cell. For knock-down of one of the targets, GalphaS, we have measured inhibition of ligand-dependent, G-protein-coupled signaling. It is expected that this technology will prove to be of great value in target validation and target discovery efforts.     

Simultaneous mapping of human papillomavirus integration sites and molecular karyotyping in short-term cultures of cervical carcinomas by using 49-color combined binary ratio labeling fluorescence in situ hybridization

Infection with high-risk type human papillomavirus (HPV) is a necessary causal factor in the pathogenesis of cervical carcinoma. In most invasive cervical cancers, HPV is integrated in the host cell genome, and additional genetic aberrations are observed among which are chromosomal aberrations. To analyze in detail such often complex chromosomal changes and simultaneously map HPV integration sites, we extended the multiplicity of the combined binary ratio labeling fluorescence in situ hybridization (COBRA-FISH) technique to 49 by inclusion of a large Stokes' shift fluorochrome as the third binary label. The technique allows mapping of the integrated HPV genome in the context of p- and q-arm COBRA-FISH, with a sensitivity of one copy of the HPV genome as tested for HPV 16 in SiHa cells. We investigated the molecular karyotypes and integration patterns of HPV types 16 and 18 in metaphase spreads from short-term cultures of primary cervical carcinomas (n=5). Of the tested cervical carcinomas, two contained integrated HPV at 8q24, one of which in addition harbored the integrated virus near a translocation breakpoint. Two carcinomas had integrated HPV at 17q21 through 23 in a morphologically normal chromosome 17. One carcinoma contained HPV at 1q42 in a morphologically normal chromosome 1. Our data illustrate the efficacy of 49-color COBRA-FISH to resolve complex karyotypes and simultaneously map specific sequences in metaphases obtained from short-term solid tumor cultures.     

Schistosomin,a peptide present in the haemolymph ofLymnaea stagnalis infected withTrichobilharzia ocellata,is produced only in the snail's central nervous system

A peptide, schistosomin, is present in haemolymph ofLymnaea stagnalis infected withTrichobilharzia ocellata. There are indications that schistosomin is produced by the central nervous system (CNS) of the snail. Schistomin inhibits the effects of the snail's gonadotropic hormones, e.g. calfluxin (CaFl). CaFl stimulates Ca²⁺ influx into the mitochondria of the albumen gland, as shown using the ultracytochemical potassium pyroantimonate precipitation technique. We investigated the question as to whether schistosomin is produced only by the snail or by both the snail and the parasite. Several types of extract of stages of the parasite and of the CNS of the snail were tested for their capability to inhibit the CaFl response. Acid extracts of cercariae and of CNS showed an inhibitory effect, suggesting that both contain schistosomin. From these extracts, material was obtained that showed the same HPLC characteristics as schistosomin. This material was tested again. The hormone response was inhibited only by material derived from the CNS of the snail, indicating that the parasite does not produce schistosomin.     

DGGE-based whole-gene mutation scanning of the dystrophin gene in Duchenne and Becker muscular dystrophy patients

Duchenne and Becker muscular dystrophy (DMD and BMD) are caused by mutations in the dystrophin gene. Large rearrangements in the gene are found in about two-thirds of DMD patients, with approximately 60% carrying deletions and 5-10% carrying duplications. Most of the remaining 30-35% of patients are expected to have small nucleotide substitutions, insertions, or deletions. To detect these subtle changes within the coding and splice site determining sequences of the dystrophin gene, we established a semiautomated denaturing gradient gel electrophoresis (DGGE) mutation scanning system. The DGGE scan covers the dystrophin gene with 95 amplicons, PCRed either individually or in a multiplex setup. PCR and pooling were performed semiautomatically, using a pipetting robot and 384-well plates, enabling concurrent amplification of DNA of four patients in one run. Amplification of individual fragments was performed using one PCR program. The products were pooled just before gel loading; DGGE requires only a single gel condition. Validation was performed using DNA samples harboring 39 known DMD variants, all of which could be readily detected. DGGE mutation scanning was applied to analyze 135 DMD/BMD patients and potential DMD carriers without large deletions or duplications. In DNA from 25 out of 44 DMD patients (57%) and from 5 out of 39 BMD patients (13%), we identified clear pathogenic changes. All mutations were different, with the exception of one DMD mutation, which occurred twice. In DNA from 10 out of 44 potential DMD carriers, including four obligate carriers, we detected causative changes, including one pathogenic change in every obligate carrier. In addition to these pathogenic changes, we detected 15 unique unclassified variants, i.e., changes for which a pathogenic nature is uncertain.     

Correction to: Neurocognitive functioning and health‑related quality of life of children after pediatric intensive care admission: a systematic review

Quality of Life Research -     

Temporomandibular disorders. The role of the otolaryngologist

Earache, tinnitus, dizziness and hearing loss are frequent complaints of patients with temporomandibular disorder (TMD). Certain patients, therefore, have to be examined by an otolaryngologist. All ear symptoms have to be meticulously described and evaluated by audiometry and vestibular examination. This is obligatory for the evaluation of treatment results and further exploration of the possible relation between these complaints and TMD.     

Ki-67 and p53 in T2 laryngeal cancer

Objective: To study the relationship between the proliferative capacity, represented by the immunohistochemical labeling index (LI) of proliferation marker Ki-67, and the p53 status, as in theory an intact p53 cell cycle checkpoint system should result in a lower proliferative capacity. Study Design: From a group of 128 patients with a T2 laryngeal carcinoma, presented from 1989 to 1993 at the University Hospital Utrecht, 20 patients with recurrent disease and 16 patients without recurrent disease were randomly selected. All patients received primary irradiation. Methods: Denaturing gradient gel electrophoresis and immunohistochemistry determined the p53 status. MIB-1 staining was used to determine the Ki-67 LI. Results: In 36% of specimens we found a p53 mutation with overexpression (LI, 31%). In 8% a p53 mutation without p53 overexpression was found (LI, 18%). Forty-two percent showed no mutation but, nevertheless, overexpression (LI, 35%). Neither mutation nor overexpression was found in 14% (LI, 38%). No correlation exists between p53 status and proliferative capacity of tumors (analysis of variance [ANOVA]; P = .104). The proliferation rate as established with Ki-67 LI positively correlates with response to radiotherapy (P = .006). Conclusions: 1. Overexpression of wild-type p53 protein does not result in cell cycle arrest measurable by a lower Ki-67 LI in comparison with cases overexpressing mutant type p53 protein. 2. A high Ki-67 LI correlates with a favorable response to radiotherapy. Laryngoscope, 108:1548–1552, 1998     

Simultaneous radio‐ and chemotherapy for squamous cell carcinoma of the head and neck in daily clinical practice: 5 years experience in a University Hospital

Several randomized studies and meta‐analyses have shown that simultaneous radio‐ and chemotherapy prolongs survival in patients with unresectable squamous cell carcinoma of the head and neck as compared with conventional radiotherapy. We assessed the feasibility and effectiveness of simultaneous radiotherapy (35 × 2 Gy) and chemotherapy [cisplatinum 100 mg/m² or carboplatin (AUC 6) on days 1, 22 and 43] in daily clinical practice in a cohort of 87 patients treated at our institute between 1998 and 2002. Eighty patients completed radiotherapy according to schedule. Eighty patients received two courses of chemotherapy and 50 patients three courses. Nephrotoxity, bone marrow suppression and ototoxicity were the most frequent side‐effects. Median weight loss was 8.5%. Median survival was 15 months and 44% of the patients were alive at 2 years. Patients receiving three courses of chemotherapy had a better survival than patients receiving two or less courses. Treatment with simultaneous radio‐ and chemotherapy for advanced head and neck cancer is a demanding, but feasible treatment in daily clinical practice. Survival seems to be comparable with the results achieved in patients selected for clinical trials.     

Preoperative evaluation of patients with primary head and neck cancer using dual-head 18fluorodeoxyglucose positron emission tomography

OBJECTIVE: To evaluate the value of 18fluorodeoxyglucose (FDG) positron emission tomography (PET) in primary head and neck cancer. BACKGROUND DATA: Head and neck carcinomas tend to metastasize to regional lymph nodes rather than to spread hematogenously. With nodal metastases, cure rates decrease by approximately 50%. Moreover, in approximately 3% of the patients, a second primary tumor is found at initial presentation. METHODS: Fifty-four consecutive patients (31 men and 23 women; mean age 60 years, range 34-81 years) with previously untreated squamous cell carcinomas of the oral cavity or oropharynx were studied. Before surgery and within a period of 3 weeks, clinical examination, chest x-ray, computed tomography (CT), ultrasonography with fine-needle aspiration cytology (US/ FNAC), and FDG-PET were performed. All study results were scored per neck side and were also classified as 0 (no metastases), 1 (single metastasis), or 2 (multiple metastases). RESULTS: The sensitivity for the detection of lymph node metastases per neck side was 96%, 85%, and 64% for FDG-PET, CT, and US/FNAC, respectively. The specificity was 90%, 86%, and 100% for FDG-PET, CT, and US/FNAC, respectively. In terms of the classification, FDG-PET showed the best correlation with the histologic data. Finally, in nine patients (17%), a second primary tumor was detected by FDG-PET and confirmed by histologic evaluation. CONCLUSION: Because of the high prevalence of second primary tumors detected by FDG-PET and the decreased error rate in the assessment of lymph node involvement compared with CT and US, FDG-PET should be routinely performed in patients with primary head and neck cancer.