Detection of minimal residual disease in patients with cancer: a review of techniques, clinical implications, and emerging therapeutic consequences

The issue of minimal residual disease (MRD) manifesting itself by the presence of undetected disseminated isolated tumor cells in both tissues and hematopoietic autografts from patients with early-stage malignancies or from patients in clinical complete remission has been discussed widely during the last decade. Based on the current understanding of the pathogenesis of malignancy, disseminated tumor cells persisting after conventional oncologic treatment modalities or after reinfusion of contaminated autologous hematopoietic cells constitute the source of subsequent recurrence of disease. Accordingly, much emphasis is placed on the detection and characterization of disseminated isolated tumor cells in both basic and clinical research. This effort is aimed at a better understanding of the processes of metastasis and tumor dormancy and, ultimately, the estimation of prognosis, molecular monitoring, and the design of new therapeutic agents in oncology. In our review, we used computerized (MEDLINE, Embase) and manual searches to summarize laboratory and clinical data concerning MRD focusing on the issue of MRD in solid malignancies. We give a detailed overview of the methods used for the detection and molecular characterization of disseminated tumor cells and of the prevalence and prognostic significance of the detection of MRD in patients and hematopoietic autografts. Finally, we discuss the emerging therapeutic consequences of the detection of disseminated tumor cells, with special emphasis on the therapeutic potential of antibodies. We conclude that the detection of MRD represents a hallmark for the diagnosis, monitoring, and treatment of malignant conditions in future clinical trials.     

Intensified Adjuvant IFADIC Chemotherapy for Adult Soft Tissue Sarcoma: A Prospective Randomized Feasibility Trial

Purpose. The present prospective randomized adjuvant trial was carried out to compare the toxicity, feasibility and efficacy of augmented chemotherapy added to hyperfractionated accelerated radiotherapy after wide or marginal resection of grade 2 and grade 3 soft tissue sarcoma (STS).Patients and methods. Fifty-nine patients underwent primary surgery by wide or marginal excision and were subsequently randomized to receive radiotherapy alone or under the addition of six courses of ifosfamide (1500 mg/m(2) , days 1-4), dacarbazine (DTIC) (200 mg/m(2) , days 1-4) and doxorubicin (25 mg/m(2) , days 1-2) administered in 14-day-intervals supported by granulocyte-colony stimulating factor (30 x 10(6) IU/day, s.c.) on days 5-13. According to the randomization protocol, 28 patients received radiotherapy only, whereas 31 patients were treated with additional chemotherapy.Results. The relative ifosfamide-doxorubicin-DTIC (IFADIC) dose intensity achieved was 93%. After a mean observation period of 41+/-19.7 months (range, 8.1-84 months), 16 patients (57%) in the control group versus 24 patients (77%) in the chemotherapy group were free of disease (p>0.05).Within the control group, tumor relapses occurred in 12 patients (43%;six patients with distant metastases, two with local relapse, four with both) versus seven patients (23%; five patients with distant metastases, one with local recurrence, one with both) from the chemotherapy group. Relapse-free survival (RFS) (p=0.1), time to local failure (TLF) (p=0.09), time to distant failure (TDF) (p=0.17) as well as overall survival (OS) (p=0.4) did not differ significantly between the two treatment groups. Treatment-related toxicity was generally mild in both treatment arms.Conclusion. We conclude that the safety profile of intensified IFADIC added to radiotherapy was manageable and tolerable in the current setting. Inclusion of intensified IFADIC was not translated into a significant benefit concerning OS, RFS, TLF andTDF as compared with radiotherapy only, although a potential benefit of chemotherapy for grade 3 STS patients needs to be validated in prospective randomized trials including larger patient numbers.     

Roxatidine versus ranitidine in the treatment of duodenal ulcers: A randomized double-blind controlled multicentre study in Singapore

Roxatidine acetate, a new H₂ receptor antagonist, was compared with ranitidine in the treatment of duodenal ulcers in a double-blind multicentre study. Eighty-four patients with endoscopically proven duodenal ulcer were randomized to receive 150 mg roxatidine acetate or 300 mg ranitidine at bedtime. Repeat endoscopy was performed after 4 weeks (25–33 days) and if the ulcer had not healed, another endoscopy was performed after a further 4 weeks of treatment. Using per protocol analysis 73.6% of ulcers treated with roxatidine healed at 4 weeks compared to 72.2% of ulcers treated with ranitidine (P=NS). The healing rates at 8 weeks were 92% with roxatidine and 83.3% with ranitidine (P=NS). Using equivalence tests, the healing rate of roxatidine was found to be equivalent to that of ranitidine within a 20% region. Roxatidine users took significantly less antacids than ranitidine users (P < 0.05). There were no significant adverse effects due to roxatidine or ranitidine. Roxatidine is a safe effective drug in the treatment of duodenal ulcers with a healing rate comparable to that of ranitidine.     

Hypolipidemic drugs affect monocyte IL-1beta gene expression and release in patients with IIa and IIb dyslipidemia

Because atherosclerosis has been proven to be an inflammatory disease, it became obvious that the proper treatment of dyslipidemic patients should not only correct lipid parameters but also inhibit the inflammatory state. One of the crucial proinflammatory and procoagulant cytokines participating in the pathogenesis of atherosclerosis is interleukin-1beta (IL-1beta). Therefore, the aim of the study was to asses the effect of statin and fibrate therapy (for dyslipidemia IIa and IIb, respectively) on IL-1beta gene expression and monocyte release evaluated in each patient. Additionally, the effect of hypolipidemic therapy on fibrinolysis was evaluated. The study was carried out in 37 patients: 12 with biochemically confirmed type IIa dyslipidemia (treated with atorvastatin), 12 with type IIb dyslipidemia (treated with fenofibrate), and 13 age- and sex-matched normolipidemic persons (control). IL-1beta concentrations in cultured monocytes and PAI-1 (Plasminogen Activator Inhibitor) plasma levels were measured using the ELISA method. To evaluate the expression of IL-1beta gene in monocytes, a semiquantitive RT-PCR procedure was performed. The results were normalized with the expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a housekeeping gene. Although IL-1beta monocyte release was markedly elevated in patients with atherogenic dyslipidemias, IL-1beta gene expression was only slightly and nonsignificantly higher in the studied groups versus control. We have observed significant reduction of IL-1beta mRNA expression after 30-day treatment with the examined drugs (atorvastatin, 2.10 +/- 0.50 versus 1.05 +/- 0.15; P < 0.001, fenofibrate; 2.27 +/- 0.48 versus 1.23 +/- 0.27; P < 0.01). There was no significant difference between statin and fibrate effect on IL-1beta mRNA expression. Similarly, we have noticed significant reduction of IL-1beta release by cultured monocytes after 30-day statin therapy (133.0 +/- 5.7 pg/mL versus 77.0 +/- 3.6 pg/mL; P < 0.01) and fibrate therapy (143.9 +/- 6.5 pg/mL versus 86.2 +/- 5.9 pg/mL; P < 0.01). Besides this antiinflammatory effect, we have observed a 30% reduction of PAI-1 plasma levels in both treated groups. In conclusion, effective 1-month hypolipidemic therapy with atorvastatin or fenofibrate diminished plasma levels of proinflammatory and procoagulatory state markers.     

The effect of censoring on cancer risk estimates based on the Canadian National Dose Registry of occupational radiation exposure

Cohort studies represent an important epidemiological tool for exploring the potential adverse health effects of low-dose exposure to ionizing radiation in the workplace. Analyses of data from the National Dose Registry of Canada have suggested that occupational radiation exposure leads to increased risk of several specific types of cancer, as well as increased overall risk of cancer. An important aspect of such studies is the censoring in recorded exposures induced by dosimetry detection limits. Such a censoring effect can lead to significant underestimation of cumulative doses which, in turn, can result in overestimation of the excess cancer risk associated with occupational radiation exposure. In this article, we present analytic results, supported by a simulation study, on the magnitude of overestimation of risk based on the additive relative risk model used in the analysis of the NDR data that can occur due to censoring. Our results indicate that overestimation of risk is modest, being less than 20% in all situations considered here. Because censoring also results in ovestimation of the precision of the risk estimates, the significance levels of Wald-type statistical tests for increased risk based on the ratio of the estimate to its standard error are virtually unaffected by censoring. These results suggest that although the application of the additive excess relative risk model in the presence of censoring may lead to some overestimation of risk, the model does not lead to invalid conclusions regarding the association between occupational radiation exposure and cancer risk based on data from the NDR.     

Value of a brief ergometric test in the functional evaluation of chronic bronchopneumopathy

The purpose of this work was to study the usefulness of short muscular exercise as part of standard respiratory function testing. A group of 19 patients with chronic bronchitis performed moderate load exercise (30 to 60 watts) on a cycle ergometer for 10 mn. Blood gases and acid-base balance were measured at rest, at the 2nd and the 10th mn of pedaling. In spite of highly significant relationships between resting values (blood gases, spirometry) and exercise data (blood gases), the scattering of the results precludes predicting the latter from the former. In contrast, the comparison between each of the two exercise results (2nd and 10th mn) shows not only a highly significant correlation but also a standard deviation to the regression lines which is objectively diminished. Thus, muscular exercise seems to give specific information that could be a useful component of respiratory function testing. Further, blood gas results obtained at the 2nd mn of muscular exercise suffice, thus obviating the need for a longer exercise programme that might be badly tolerated by patients.