Validation of a Metastatic Assay using biopsies to improve risk stratification in patients with prostate cancer treated with radical radiation therapy.

Background: Radiotherapy is an effective treatment of intermediate/high-risk locally advanced prostate cancer, however, >30% of patients relapse within 5 years. Clinicopathological parameters currently fail to identify patients prone to systemic relapse and those whom treatment intensification may be beneficial. The purpose of this study was to independently validate the performance of a 70-gene Metastatic Assay in a cohort of diagnostic biopsies from patients treated with radical radiotherapy and androgen deprivation therapy. Patients and methods: A bridging cohort of prostate cancer diagnostic biopsy specimens was profiled to enable optimization of the Metastatic Assay threshold before further independent clinical validation in a cohort of diagnostic biopsies from patients treated with radical radiotherapy and androgen deprivation therapy. Multivariable Cox proportional hazard regression analysis was used to assess assay performance in predicting biochemical failure-free survival (BFFS) and metastasis-free survival (MFS). Results: Gene expression analysis was carried out in 248 patients from the independent validation cohort and the Metastatic Assay applied. Ten-year MFS was 72% for Metastatic Assay positive patients and 94% for Metastatic Assay negative patients [HR = 3.21 (1.35-7.67); P = 0.003]. On multivariable analysis the Metastatic Assay remained predictive for development of distant metastases [HR = 2.71 (1.11-6.63); P = 0.030]. The assay retained independent prognostic performance for MFS when assessed with the Cancer of the Prostate Assessment Score (CAPRA) [HR = 3.23 (1.22-8.59); P = 0.019] whilst CAPRA itself was not significant [HR = 1.88, (0.52-6.77); P = 0.332]. A high concordance [100% (61.5-100)] for the assay result was noted between two separate foci taken from 11 tumours, whilst Gleason score had low concordance. Conclusions: The Metastatic Assay demonstrated significant prognostic performance in patients treated with radical radiotherapy both alone and independent of standard clinical and pathological variables. The Metastatic Assay could have clinical utility when deciding upon treatment intensification in high-risk patients. Genomic and clinical data are available as a public resource.

Molecular basis of chemosensitivity of platinum pre-treated ovarian cancer to chemotherapy.

BACKGROUND: Ovarian cancer shows considerable heterogeneity in its sensitivity to chemotherapy both clinically and in vitro. This study tested the hypothesis that the molecular basis of this difference lies within the known resistance mechanisms inherent to these patients' tumours. METHODS: The chemosensitivity of a series of 31 ovarian tumours, all previously treated with platinum-based chemotherapy, was assessed using the ATP-based tumour chemosensitivity assay (ATP-TCA) and correlated with resistance gene expression measured by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) in a TaqMan Array following extraction of mRNA from formalin-fixed paraffin-embedded tissue. The results were standardised against a housekeeping gene (PBGD), and assessed by multiple linear regression. RESULTS: Predictive multiple linear regression models were derived for four single agents (cisplatin, gemcitabine, topotecan, and treosulfan), and for the combinations of cisplatin+gemcitabine and treosulfan+gemcitabine. Particularly strong correlations were obtained for cisplatin, gemcitabine, topotecan, and treosulfan+gemcitabine. No individual gene expression showed direct correlation with activity in the ATP-TCA. Genes involved in DNA repair and apoptosis were strongly represented, with some drug pumps also involved. CONCLUSION: The chemosensitivity of ovarian cancer to drugs is related to the expression of genes involved in sensitivity and resistance mechanisms.

Comparing histopathological classification with MYCN, 1p36 and 17q status detected by fluorescence in situ hybridisation from 14 untreated primary neuroblastomas in Singapore.

INTRODUCTION: Neuroblastoma is the most common extracranial solid tumour in children, accounting for about 5.3 percent of all childhood cancers in Singapore. Several genetic abnormalities have been reported as prognostic markers, including amplification of the MYCN gene, deletion of the short arm of chromosome 1 (1p) and gain of the long arm of chromosome 17 (17q). However, the correlation between tumour histology and these genetic parameters remains to be established in our local population. METHODS: 14 untreated primary neuroblastoma tumours, diagnosed consecutively in our hospital between 2003 and 2007, were included for this study. Tumour tissues were classified histologically as favourable or unfavourable, according to the modification of World Heath Organization Classification of Tumours, by associating the degree of differentiation and mitotic-karyorrhectic index of the neuroblastoma to the age of the patient. Fluorescence in situ hybridisation analysis for MYCN, 1p status and 17q status were subsequently performed on tumour touch imprints. RESULTS: Five tumours with favourable histology were all negative for the three genetic parameters being investigated. The other nine tumours showing unfavourable histology exhibited one or more of the three genetic parameters. All MYCN amplified tumours either had additional 1p deletion and/or 17q gain. CONCLUSION: Our limited data suggests that 1p deletion and 17q gain are reliable independent parameters correlating with an unfavourable histology and poor clinical outcome. The use of 1p deletion and 17q gain studies, in addition to MYCN amplification studies, should be considered routinely in predicting prognosis in neuroblastomas.

Combination chemotherapy in advanced gastrointestinal cancers: ex vivo sensitivity to gemcitabine and mitomycin C.

Advanced or metastatic disease is common in both oesophagogastric and colorectal cancers, with poor 5-year survival despite palliative chemotherapy. We have investigated the sensitivity of gastrointestinal tumours to gemcitabine in combination with mitomycin C (GeM), using a modified ex vivo ATP-based tumour chemosensitivity assay (ATP-TCA). Tumour material from 41 colorectal and 22 oesophagogastric cancers were assessed. The GeM combination showed variable but definite activity in most of the samples tested. The results show that GeM achieves >95% inhibition at concentrations within the range achievable clinically in 60% of colorectal tumours (21 out of 35) and 38% of oesophagogastric tumours (five out of 13) tested. We did not identify any significant difference in sensitivity using concurrent or sequential exposure of tumour-derived cells to these two drugs. The results from this study suggest that GeM may be a useful combination in the treatment of advanced gastrointestinal malignancy.

Variants of chromosome 9 in phenotypically normal individuals.

The human chromosome 9 displays the highest degree of structural variability. Four different types of variants are described including pericentric inversion, extra G-positive band in the q arm, additional G-positive band in the p arm and duplication of band 9q21-q22. It is important to demonstrate inheritance from a phenotypically normal individual in order to differentiate between a variant chromosome and an abnormal chromosome.

Partial monosomy for chromosome 22 in a girl with mental retardation.

This report describes a 5-year 6-month-old Chinese girl with partial monosomy for the long arm of chromosome 22. The karyotype was 46,XX/46,XX,del (22) (q13.2). She presented with global developmental delay. Clinical features include seizures, failure-to-thrive, prominent ears, long philtrum and abnormal skin pigmentation on the face and limbs.

Subtle translocation (18;21) confirmed by FISH in a patient with Down syndrome.

The patient presented with the typical features of Down syndrome; hypotonia, brachycephaly, flattened occiput, bilateral prominent medical epicanthic folds, flat nasal bridge, protruding tongue, low-set dysplastic ears, short broad hands, bilateral clinodactyly and simian crease. The karyotype of this child was originally reported as normal. High-resolution chromosomes revealed extra material on the long arm of chromosome 18. The mother's karyotype showed a reciprocal translocation between the long arm of 18 and the long arm of 21 at band q23 and q22.1, respectively. FISH performed separately with two different 21q cosmid probes gave two signals on the mother's metaphases and three signals on the proband. These findings confirmed that the proband is trisomic for the long arm of chromosome 21 at loci D21S65 and D21S19.

Fanconi's anaemia and recurrent squamous cell carcinoma of the oral cavity: a case report.

Fanconi's anaemia is a rare genetic disorder and majority of the patients die of haematologic complications in their second or third decades of life. Others who have mild or no cytopenias survive long enough to develop malignancies. This is a report of a 44-year-old woman who presented with recurrent oral squamous cell carcinoma during her adulthood, without clinical haematological problem. Despite treatment with cis-retinoic acid, she developed a third squamous cell carcinoma 6 months later. In a review of the literature, only in 1 reported case was the patient treated with low-dose retinoids but he developed recurrent anal cancer after 14 months.

Del(3) (p25.3) without phenotypic effect.

A terminal deletion of chromosome 3 at p25.3 was observed during prenatal diagnosis. A similar deletion is also present in the phenotypically normal mother. The deletion was confirmed by FISH. The breakpoint is distal to the region responsible for the 3p- syndrome. A normal baby girl was born with no apparent phenotypic abnormalities.

Extra G positive band on the long arm of chromosome 9.

Various heteromorphisms of the 9q heterochromatic area have been reported. In most instances, the extra G positive band is accompanied by an extra C band. We describe a family where the extra G band is totally euchromatic and does not include an extra C band. It is not clear whether these two types of variant chromosome 9 arose from a similar mechanism.

Higher-order factors assessed by the ISI and PRF.

The Interpersonal Style Inventory and the Personality Research Form were administered to 327 adolescents in order to test hypotheses with regard to the second-order factors that they share in common. The 37 scale scores were intercorrelated and factored by the principal axes method and rotated to an oblique solution. The seven correlated factors were interpreted as Impulse Control, Extraversion-Introversion, Autonomy, Level of Socialization, Achievement Motivation, Liking New Experience, and Adventure Seeking. These confirmed four of the hypothesized factors.

Mosaic inversion duplication of chromosome 15 without phenotypic effect: occurrence in a father and daughter.

A mosaic marker chromosome was observed in 2 generations. Multiple staining techniques identified it as an inverted duplication of chromosome 15 (inv dup 15) derived from the paternal grandmother. Although this inv dup 15 included a central R band, there was no noticeable phenotypic effect.

Prenatal diagnosis of 45,X/46,XX mosaicism: true mosaicism in only one of four primary cultures.

45,X/46,XX mosaicism was found in only one of four primary amniotic fluid cultures. Repeat amniocentesis revealed 45,X/46,XX mosaicism in all four primary cultures. Mosaicism was confirmed in tissues from the abortus.

Multiple karyotypic changes in retinoblastoma tumor cells: presence of normal chromosome No. 13 in most tumors.

There are conflicting reports on the frequency in retinoblastoma tumor cells of aberrations involving chromosome No. 13. To quantitate the frequency of various chromosome aberrations, we analyzed the karyotypes from the retinoblastoma tumors; all tumors contained chromosome abnormalities. Chromosome No. 13 was altered in only two tumors, but the aberrations in these two cases affected different portions of the chromosome. We have concluded that chromosome aberrations affecting chromosome No. 13 are relatively infrequent in retinoblastoma tumors. Chromosome No.1 was involved in rearrangements in eight tumors; in six tumors the rearrangements lead to trisomy of 1q25-1q32. Seven tumors had aberrations resulting in trisomy of the long arm of chromosome No. 17; the most common aberration was an i(17q) chromosome. Every tumor showed trisomy of the long arm of either chromosome No. 1 or 17. These changes in chromosomes No. 1 and 17 have been observed by others in many different tumors and are not unique to retinoblastoma. In summary, chromosome abnormalities were present in all retinoblastoma tumors studied, but no aberration common to all tumors was found.

Familial retinoblastoma: segregation of chromosome 13 in four families.

Fluorescent markers on chromosome 13 have been used to study familial retinoblastoma. One family showed concordant segregation of a particular chromosome 13 and retinoblastoma from the affected parent to the affected children. In three other families, segregation was discordant. Meiotic crossing over with recombination is proposed as the explanation.

Absence of chromosome breakage in patients with retinoblastoma.

Mixed lymphocyte cultures were employed to assess the degree of spontaneous chromosome fragility in patients with retinoblastoma. There was no difference between the patients and their controls. If chromosome instability plays a role in the inherited tumour, more sensitive methods need be employed to elucidate it.