A.T. van Oosterom

A real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR) to detect breast carcinoma cells in peripheral blood

Summary Background The detection of occult carcinoma cells in patients with breast cancer has been shown to predict disease recurrence and metastasis Materials and methods To improve on molecular detection of breast carcinoma cells in blood, we have developed a sensitive and quantitative assay using real-time quantitative RT–PCR identifying transcripts of the cytokeratin-19 (CK19) gene. Results This real-time quantitative RT–PCR is sensitive, accurate and has a high reproducibihty within a wide dynamic range, which permits simultaneous quantitative analysis of samples with varying input concentrations Furthermore, the procedure offers several technical advantages over classic quantitative PCR methods (competitive RT–PCR, Northern blotting) such as decreased likelihood of contamination due to absence of post-PCR manipulations, high sample throughput because of absence of post-PCR processing time (no agarose gel electrophoresis). In this pilot study, we detected significantly elevated CKI9 transcript levels in 70% of the and stage IV breast cancer patients. Conclusions Analyses using this real time quantitative RTPCR for CK.19 mRNA may prove to have clinical implications in the assessment of circulating tumour cells in peripheral blood, micrometastases in bone marrow or lymph nodes in breast cancer patients Application of this technique in a clinical population may improve diagnosis and monitoring of metastatic breast cancer and its validation is currently ongoing

Comparison of different computer models of the neural control system of the lower urinary tract

This paper presents a series of five models that were formulated for describing the neural control of the lower urinary tract in humans. A parsimonious formulation of the effect of the sympathetic system, the pre‐optic area, and urethral afferents on the simulated behavior are included. In spite of the relative simplicity of the five models studied, behavior that resembles normal lower urinary tract behavior as seen during an urodynamic investigation could be simulated. The models were tested by studying their response to disturbances of the afferent signal from the bladder. It was found that the inhibiting reflex that results from including the sympathetic system or the pre‐optic area (PrOA) only counteracts the disturbance in the storage phase. Once micturition has started, these inhibiting reflexes are suppressed. A detrusor contraction that does not result in complete micturition similar to an unstable detrusor contraction could be simulated in a model including urethral afferents. Owing to the number of uncertainties in these models, so far no unambiguous explanation of normal and pathological lower urinary tract behavior can be given. However, these models can be used as an additional tool in studies of the mechanisms of the involved neural control. Neurourol. Urodynam. 19:289–310, 2000.

Population pharmacokinetic and dynamic analysis of the topoisomerase I inhibitor lurtotecan in phase II studies.

Population pharmacokinetic-dynamic analysiswas prospectively integrated in a broadphase II program of lurtotecan (GI147211),a novel camptothecin derived topoisomeraseI inhibitor, to determine the populationpharmacokinetic profile in a largerpopulation, to estimate individualpharmacokinetic parameters and toinvestigate relationships with clinicaloutcome. A sparse sampling method wasapplied during course one, which involvedtwo sampling time-points. A Bayesianalgorithm was used to estimate individualpharmacokinetic parameters, in particulartotal plasma clearance (CL) and volume ofdistribution. In total, samples werecollected of 109 (63%) of 173 patients.Pharmacokinetic-dynamic evaluation could becarried out successfully in 85 (78%) ofthe sampled patients. CL of lurtotecanshowed substantial variability (mean 87± 28 L/h) and was of the same magnitudeas in the phase I studies where fullpharmacokinetic curves were used. Residualvariability in the population estimate ofCL was 9.9%. No significant relationshipswere observed between exposure parametersand toxicity nor likelihood of tumorresponse, however the latter relationshipmay well have been obscured by theheterogeneity of the studied population.Prospective implementation of large scalepopulation pharmacokinetic-dynamic analysisis feasible and important to establishwhether interpatient variability in drugexposure is a major determinant of toxicityor activity.

Retroperitoneal lymph node dissection as adjuvant therapy in the treatment of non-seminomatous testicular cancer.

Abstract Objective: To assess the results of retroperitoneal lymph node dissection (RPLND) of residual masses in patients with disseminated non-seminomatous germ cell tumour treated with cisplatin-based chemotherapy, both in terms of extension of surgery, morbidity and survival. Patients and methods: Retrospectively, all patients treated for non-seminomatous germ cell tumour at the University Hospital of Antwerp were studied from January 1987 till December 1997. In patients with non-seminomatous testicular cancer more than stage I, the ‘wait and see’ strategy changed and patients were treated with chemotherapy. Patients were assessed at the end of chemotherapy and if a residual masses persisted, a RPLND was performed. If possible, a nerve-sparing lymphadenectomy was performed. Extension of surgery, morbidity and survival were analysed. Results: Sixty patients had a non-seminomatous germ cell tumor of the testis and were analysed. The median follow-up was 78 months (range: 13-144 months). Thirteen patients with stage I disease were treated with orchiectomy only and none of these patients had recurrent disease. Forty-seven patients were treated with cisplatin-based chemotherapy. A complete response was observed in sixteen patients (34%), while 31 patients (66%) achieved a partial response and were treated with a RPLND. Fifteen patients underwent RPLND above the level of the renal trunk. In two patients malignant cells or fibrotic tissue were found above the renal trunk and bilateral. In five patients viable tumour cells were found in the region below the renal trunk. Sixteen patients underwent RPLND below the level of the renal trunk, of which nine had a unilateral resection, containing viable tumour in two patients. Operative mortality was 0%. One patient died six months after RPLND due to metastatic disease. In two patients, an important retroperitoneal bleeding occurred. Resection of adherent organs was performed in two patients. Long term sexual problems were reported by thirteen patients (65%) with bilateral lymphadenectomy versus two patients (18%) in the unilateral group. The survival of the patients treated with a RPLND was 97% and in the whole group of patients with a non-seminoma-tous testicular cancer 98%. Conclusion: RPLND has a place in the treatment of patients with non-seminomatous testicular cancer after chemotherapy in case of residual masses. Although mortality is low, morbidity is acceptable. In a limited number of patients there was a need of resection of adherent organs when a resection above the renal trunk was performed.

Surgical interventions during STI 571 treatment of metastatic GIST: experience in six patients.

Abstract Gastrointestinal stromal tumours (GIST), previously classified as smooth muscle tumours, are the most common mesenchymal tumours of the digestive tract. Since the discovery of KIT (CD 117) expression, these tumours can be diagnosed confidently by pathology. Until recently, surgery was the only treatment available because these tumours were not sensitive to chemotherapy nor radiation therapy. In the long run most of these tumours recurred in the abdominal cavity or in the liver. Recently a new drug STI 573 (Glivec) showed very promising results in metastatic disease with response rates of about 65%. In six patients treated at our center, surgery was indicated during STI therapy because of subobstruction, skin necrosis, abdominal distention, bleeding. Surgery proved to be safe and efficient, allowing continuation of STI therapy in much better circumstances.

Vincristin, Bleomycin, Mitomycin-C und Cisplatin als neoadjuvante Therapie bei der Strahlentherapie von Hochrisikopatientinnen mit Plattenepithelkarzinom der Cervix uteri

Das Karzinom der Cervix uteri, das auf die Zervix beschrankt ist oder die Scheidengewolbe minimal infiltriert hat (FIGO-Stadium I b, II a), kann bei 80% der Patientinnen geheilt werden [3]. Wenn das Zervixkarzinom weiter fortgeschritten ist, bleibt es haufig eine todliche Erkrankung. Die 5-Jahres-Uberlebensrate sinkt bei Patientinnen mit FIGO-Stadium I b und II a, die bei der Erstoperation positive pelvine und paraaortale Lymphknoten haben, auf bis zu 50% oder weniger, selbst wenn eine Lymphonodektomie und/oder Bestrahlung der paraaortalen Region durchgefuhrt werden [2, 5, 7]. Der Anteil der Fernmetastasen ist immer noch hoch [1], auch wenn die moderne Strahlentherapie mittels rechnergestutzter Dosimetrie und interstitieller Implantationen in die Parametrien die lokale Kontrolle uber ein fortgeschrittenes Leiden verbessern konnte. Dies kann nur dadurch erklart werden, das bei diesen Patientinnen bereits bei Beginn der Strahlentherapie eine systemische Ausbreitung der Erkrankung vorliegt. Zur Verbesserung der Uberlebensraten dieser Hochrisikopatientinnen scheint eine zusatzliche systemische Therapie der einzige Weg zu sein, Mikrometastasen auserhalb des Bestrahlungsfeldes zu eliminieren.