Radiotherapy in the SIOP (international society of pediatric oncology) nephroblastoma studies: A review

For decades radiation has generally been accepted as a valuable supplement to surgery in the treatment of Wilms' tumor; unfortunately, it may produce undesirable late effects. It turned out, however, that when treatment is adjusted to known variables, the risk for late sequelae can be diminished in some groups of children. SIOP clinical trials have been based on children with unilateral tumors of standard histology and free of metastasis at diagnosis. The first two clinical trials, SIOP-1 (started in 1971) and SIOP-2 (started in 1974), established the beneficial effect (such as less ruptures, lower stage) of preoperative radiation and actinomycin D (AMD) in SIOP-2, with all children having radiation therapy either pre-operatively, postoperatively, or both. In the SIOP-5 trial (started in 1977), preoperative radiation therapy and AMD were compared with preoperative chemotherapy resulting in only 50% of children having radiation. The result permitted disuse of preoperative radiation in the SIOP-6 trial (started in 1980), where only one-third of the patients received postoperative radiation therapy. At present, in the SIOP-9 trial (started in 1987), fewer than 20% of children are having radiotherapy. The survival rates meanwhile have been increasing steadily from 64% in SIOP-1 to 84% in SIOP-6 for stages I, II, and III combined. © 1994 Wiley-Liss, Inc.     

Diagnosis of variants of hyperphenylalaninemia by determination of pterins in urine

Assessment of urinary pterins is proposed as a rapid method for recognition of the variants of hyperphenylalaninemia. This is achieved by means of oxidation of pterins by iodine in acidic and alkaline solutions and then by high performance liquid chromatography on a cation-exchange column with fluorimetric detection.

In biopterin-synthetase deficiency, only neopterin accumulated; in dihydropteridine-reductase (DHPR) deficiency and in phenylketonuria, high levels of pterins are found, but BH₄ levels, absent in the former and high in the latter, allow a differential diagnosis. Phenylalanine loads in the controls also lead to increased elimination of pterins, but with a pattern different from that found in phenylketonuria.

This method can be used before dietary treatment and thus can be proposed for all newly detected hyperphenylalaninemic babies.     

Prognostic and predictive relevance of microsatellite instability in colorectal cancer

Microsatellite instability (MSI) is the phenotypic hallmark of a deficient DNA mismatch-repair system, observed in 10-20% of sporadic colorectal cancers (CRC). Since the prognostic and predictive value of this genetic alteration has been assessed mainly in non-randomised, uncontrolled studies, we investigated the potential of MSI to predict patient survival and response to adjuvant chemotherapy in tumour specimens from a randomised trial of the Swiss Group for Clinical Cancer Research (SAKK) that tested the value of 5-fluorouracil/mitomycin adjuvant chemotherapy. MSI status was determined in matched normal and tumour tissue samples from 160 patients using a panel of 9 microsatellite markers. There was no correlation between high frequency MSI (MSI-H) and overall (OS) or disease-free survival (DFS) in the untreated control group of patients (HR=1.13, p=0.80; and HR=0.89, p=0.81, respectively). Furthermore, MSI-H phenotype did not predict for a larger benefit of adjuvant chemotherapy on OS or DFS (HR=0.49, p=0.41; HR=0.49, p=0.41, respectively), making a potential value of this molecular marker as a predictive factor in CRC unlikely. Our data do not confirm the prognostic relevance of MSI-H status in colorectal cancer patients found in some other studies. In addition, microsatellite instability did not correlate with the extent of chemotherapy benefit, although we observed a statistically non-significant favourable impact of 5-FU-based treatment in the MSI-H group compared to MSI-L/MSS patients. Larger prospective randomised trials are required to conclusively establish a potential clinical significance of MSI in colorectal cancer.     

Prognostic significance of a combined clinicopathologic score for response to primary systemic therapy in locally advanced breast cancer

The response to chemotherapy is one of the best indicators of prognosis in locally advanced breast cancer (LABC). The pathologic response (pR) of 108 LABC patients was analysed and compared with their clinical response (cR). Our aim was to define a new combined clinicopathologic response score (cpR) and to explore its correlation with survival data. The 108 stage IIB to IIIB breast carcinomas were first treated with high-dose anthracycline-based chemotherapy. Standard criteria were used to assess cR. Pathologic analysis of surgical specimens allowed the definition of 5 types of pR. Three groups of combined clinicopathologic response were defined. Twenty-two patients (20%) had complete or almost complete pR. Most patients (88, 81%) had partial cR. This large group of partial cR was very heterogeneous, ranging from pR1 to pR5 and from cpR1 to cpR3. In univariate analysis, pR and cpR both strongly correlated with EFS. cR, pR and cpR all correlated with OS. Subgroups of incomplete pathologic responses were not prognostically different. In multivariate analysis, only cpR correlated strongly with both EFS and OS (p<0.002), identifying good (20%), intermediate (61%) and poor (19%) prognosis patients. In conclusion, in 108 stage IIB to IIIB breast cancer patients initially treated by high-dose chemotherapy, combined grading of clinical and pathologic responses in a single score allowed accurate prediction of outcome.     

Drug related falls: a study in the French Pharmacovigilance database

OBJECTIVE: To investigate the risk of falls associated with drugs among the French population using data reported to the French spontaneous reporting system and recorded in the French Pharmacovigilance database. METHODS: All cases including a fall were searched in the French Pharmacovigilance database between 1995 and 1999. Drugs involved and characteristics of patients were investigated. In a second step, we estimated the risk associated with psychotropic and cardiovascular drugs in a case/non case comparison, where cases were reports including a fall and non cases all other reports. This risk was estimated by calculation of crude and age and gender adjusted reporting odds ratios (ROR). RESULTS: During this period, 328 reports including a fall were reported (0.4% of the database). Patients were female in 70%. Mean age was 76 +/- 18 years. Comparisons between cases and non cases showed that cases were more likely to be women (OR: 1.9; 95% confidence interval (CI) [1.5-2.4]) and older. After adjustment on age and gender, falls remained significantly associated with exposure to benzodiazepines (4.7 [3.7-5.9]), imipraminic antidepressants (3.6 [2.5-5.1]), serotonin reuptake inhibitor (SRI) antidepressants (2.2 [1.5-3.1]) or nitrates (1.9 [1.2-2.8]). CONCLUSION: This study confirms that taking psychotropic drugs strongly increases the risk of falls. The role of cardiovascular drugs (except nitrates) remains not significant when confounding factors are taken into account. According to the very high prevalence of psychotropic drug use in the French elderly, further study are needed to investigate the relative effect of some drugs on falls, like for example SRIs or short acting benzodiazepines.     

Regulation of telomeres length: making the telomeres accessible?

Under a normal state, the extremities of chromosomes, telomeres, are protected against undesired fusion events. Alterations of the telomere structure are associated with genetic instability, while erosion of the telomeric repeats, occurring at each cell division, provides a mechanism controlling the long-term proliferation of somatic cells. Although the structure and composition of the human telomerase enzyme are now well characterized, the protein partners regulating the stability and conformation of its DNA substrate, the telomeric end, are much less known. A functional link has been recently evidenced between proteins that bind the double-stranded telomere repeats and those recruited at the 3' G-rich telomeric overhang. This review presents an update on these telomeric factors controlling telomere lengthening and discuss the actual models proposed for its regulation.