The clinical impact of time to response in de novo accelerated-phase chronic myeloid leukemia

We aimed to describe the impact of time to response on the outcomes of 75 patients with accelerated-phase chronic myeloid leukemia (CML-AP) at diagnosis. Patients had at least 1 feature of AP: blasts ≥15% (n = 2), basophils ≥20% (n = 19), platelets <100 × 10⁹/L (n = 7), cytogenetic clonal evolution (n = 34), or more than one factor (n = 13). Thirty-three patients received imatinib; 42 received a second-generation tyrosine kinase inhibitor (2GTKI) (19 dasatinib and 23 nilotinib). We used chi-square and Kaplan-Meier analyses to determine the impact of various degrees of molecular and cytogenetic response at early time points (3 and 6 months) on rates of overall cytogenetic and molecular response, overall survival (OS), event-free survival (EFS), transformation-free survival (TFS), and failure-free survival (FFS). After a median follow-up of 96 months (range: 18-224 months), the overall rate of complete cytogenetic response was 79%, of major molecular response, 71%, and of molecular reponse (MR)4.5, 59%. Patients who achieved a major cytogenetic response (MCyR) (n = 49) at 3 months had significantly better 3-year OS (94% vs 75%; P = .002), TFS (98% vs 73%; P < .001), EFS (93% vs 42%; P < .001), and FFS (83% vs 25%; P < .001) rates than patients who did not have MCyR at 3 months. Most (67%) who eventually achieved sustained MR4.5 had achieved MCyR at 3 months. In de novo CML-AP, early response at 3 and 6 months is a strong determinant of long-term outcome.     

Occurrence of acute lymphoblastic leukemia and juvenile myelomonocytic leukemia in a patient with Noonan syndrome carrying the germline PTPN11 mutation p.E139D

Noonan syndrome (NS) is a common autosomal dominant condition characterized by short stature, congenital heart defects, and dysmorphic facial features caused in approximately 50% of cases by missense mutations in the PTPN11 gene. NS patients are predisposed to malignancies including myeloproliferative disorders or leukemias. We report a female NS patient carrying a PTPN11 germline mutation c.417 G?>?C (p.E139D), who developed in her second year of life an acute lymphoblastic leukemia (ALL) and after remission, she developed at 4 years of age a juvenile myelomonocytic leukemia (JMML). Molecular genetic analysis of lymphoblastic blasts at the time of the ALL diagnosis revealed the germline mutation in a heterozygous state, while in the myelomonocytic blasts occurring with JMML diagnosis, the mutation p.E139D was found in a homozygous state due to a uniparental disomy (UPD). These findings lead to the suggestion that the pathogenesis of ALL and JMML in our patient is due to different mechanisms including somatically acquired secondary chromosomal abnormalities.     

A newborn with hereditary haemorrhagic telangiectasia and an unusually severe phenotype

Hereditary haemorrhagic telangiectasia (HHT), associated with arteriovenous malformations, is a genetic disease of the vascular system with a frequency of approx. 1:10,000. Genetic diagnosis serves to identify individuals at risk of developing the disease and is a useful tool for genetic counselling purposes. QUESTIONS UNDER STUDY: Here we report on a child presenting severe arteriovenous malformations leading to heart failure. Her mother and grandmother present fewer symptoms of hereditary haemorrhagic telangiectasia. In this study we identify the cause of HHT in the family. METHODS: Clinical examination, PCR, DNA sequencing, quantitative PCR, Southern blot, xray, ultrasound, cardiac catheterisation and angiocardiography. RESULTS: Initially the sequence variant in c.392C>T in the endoglin gene was detected in the grandmother, but not in other affected family members. Further analyses revealed a deletion of exon 1 of endoglin, segregating with the phenotype. CONCLUSIONS: This report points out the need for careful evaluation of molecular genetic findings, particularly in diseases with highly variable phenotype.     

Measurements using the alkaline comet assay predict bladder cancer cell radiosensitivity

In the UK, the two main treatments of invasive bladder cancer are radiotherapy or cystectomy. However, approximately 50% of patients undergoing radiotherapy fail to respond. If tumour radiosensitivity could be predicted in advance, it may be possible to improve control rates significantly by selecting for radiotherapy those patients whose tumours are radiosensitive. Additionally, patients who would benefit from surgery would be identified earlier. The alkaline comet assay (ACA) is a sensitive method for the detection of DNA strand break damage in cells. In the present study, using six bladder cancer cell lines of differing radiosensitivities, cell survival was compared to the manifestation of radiogenic DNA damage as assessed by ACA. For all the cell lines, the extent of comet formation strongly correlates with cell killing (R2>0.96), with a greater response being noted in radiosensitive cells. In repair studies, measures of residual damage correlate with survival fraction at 2 Gy (R2>0.96), but for only five of the cell lines. Finally, cells from human bladder tumour biopsies reveal a wide range of predicted radiosensitivies as determined by ACA. Overall, these studies demonstrate ACA to be a good predictive measure of bladder cancer cell radiosensitivity at low dose, with potential clinical application.