Incidence and time trends of brain metastases admissions among breast cancer patients in Sweden.

BACKGROUND: While treatment for breast cancer has been refined and overall survival has improved, there is concern that the incidence of brain metastases has increased. METHODS: We identified patients in Sweden with incident breast cancer 1998-2006 in the National Cancer Register, and matched these to the National Patient Register to obtain information on hospital admissions for distant metastases. Hazard ratios (HRs) and 95% confidence intervals (CIs) were computed with Cox regression as estimates of relative risk. RESULTS: Among 50 528 breast cancer patients, 696 (1.4%) were admitted with brain metastases during median 3.5 years of follow-up. Admissions for other metastases were found in 3470 (6.9%) patients. Compared with the period 1998-2000, patients diagnosed with breast cancer 2004-2006 were at a 44% increased risk of being admitted with brain metastases (HR 1.44, 95% CI 1.13-1.85). CONCLUSION: The incidence of admissions with brain metastases in breast cancer patients was increasing in the mid-2000s in Sweden. These findings support a true increase in incidence of brain metastases among breast cancer patients.

p53-independent mechanisms regulate the P2-MDM2 promoter in adult astrocytic tumours.

The MDM2 gene is amplified and/or overexpressed in about 10% of glioblastomas and constitutes one of a number of ways the p53 pathway is disrupted in these tumours. MDM2 encodes a nuclear phosphoprotein that regulates several cell proteins by binding and/or ubiquitinating them, with p53 being a well-established partner. MDM2 has two promoters, P1 and P2 that give rise to transcripts with distinct 5' untranslated regions. Transcription from P2 is believed to be controlled by p53 and a single-nucleotide polymorphism (SNP309, T>G) in P2 is reported to be associated with increased risk for, and early development of, malignancies. The use of P1 and P2 has not been investigated in gliomas. We used RT-PCR to study P1- and P2-MDM2 transcript expression in astrocytic tumours, xenografts and cell lines with known MDM2, TP53 and p14(ARF) gene status. Both promoters were used in all genetic backgrounds including the use of the P2 promoter in TP53 null cells, indicating a p53-independent induction of transcription. Transcripts from the P1 promoter formed a greater proportion of the total MDM2 transcripts in tumours with MDM2 amplification, despite these tumours having two wild-type TP53 alleles. Examination of SNP309 in glioblastoma patients showed a borderline association with survival but no apparent correlation with age at diagnosis nor with TP53 and p14(ARF) status of their tumours. Our findings also indicate that elevated MDM2 mRNA levels in tumours with MDM2 amplification are preferentially driven by the P1 promoter and that the P2 promoter is not only regulated by p53 but also by other transcription factor(s).

Pegylated liposomal doxorubicin as first-line monotherapy in elderly women with locally advanced or metastatic breast cancer: novel treatment predictive factors identified.

We investigated the efficacy and safety of single-agent pegylated liposomal doxorubicin (PLD) as first-line treatment for elderly women with advanced breast cancer and evaluated predictive markers for response and toxicity. Twenty-five women ≥ 65 years received 40 mg/m(2) PLD every 28 days. Time to treatment failure (TTF), response rate, time to progression (TTP) and overall survival (OS) was calculated. The ABCB1 single nucleotide polymorphisms (SNP), tumor MRN complex, and TOPOIIα were analyzed. A mean of 7.4 cycles PLD were administered and TTF was 5.5 months and OS 20.6 months. ABCB1 SNPs were found to correlate to both efficacy and toxicity, while tumor expression of the MRN complex and TOPOIIα correlated to TTP. PLD is a safe and effective treatment for elderly breast cancer patients. Also potential predictive markers were identified.

1p36 is a preferential target of chromosome 1 deletions in astrocytic tumours and homozygously deleted in a subset of glioblastomas.

Astrocytic, oligodendroglial and mixed gliomas are the commonest gliomas in adults. They have distinct phenotypes and clinical courses, but as they exist as a continuous histological spectrum, differentiating them can be difficult. Co-deletions of total 1p and 19q are found in the majority of oligodendrogliomas and considered as a diagnostic marker and a prognostic indicator. The 1p status of astrocytomas has not yet been thoroughly examined. Using a chromosome 1 tile path array, we investigated 108 adult astrocytic tumours for copy number alterations. Total 1p deletions were rare (2%), however partial deletions involving 1p36 were frequently identified in anaplastic astrocytomas (22%) and glioblastomas (34%). Multivariate analysis showed that patients with total 1p deletions had significantly longer survival (P=0.005). In nine glioblastomas homozygous deletions at 1p36 were identified. No somatic mutations were found among the five genes located in the homozygously deleted region. However, the CpG island of TNFRSF9 was hypermethylated in 19% of astrocytic tumours and 87% of glioma cell lines. TNFRSF9 expression was upregulated after demethylation of glioma cell lines. Akt3 amplifications were found in four glioblastomas. Our results indicate that 1p deletions are common anaplastic astrocytomas and glioblastomas but are distinct from the 1p abnormalities in oligodendrogliomas.

Mutations in Rb1 pathway-related genes are associated with poor prognosis in anaplastic astrocytomas.

Anaplastic astrocytoma (AA, WHO grade III) is, second to Glioblastoma, the most common and most malignant type of adult CNS tumour. Since survival for patients with AA varies markedly and there are no known useful prognostic or therapy response indicators, the primary purpose of this study was to examine whether knowledge of the known genetic abnormalities found in AA had any clinical value. The survival data on 37 carefully sampled AA was correlated with the results of a detailed analysis of the status of nine genes known to be involved in the development of astrocytic tumours. These included three genes coding for proteins in the p53 pathway (TP53, p14(ARF)and MDM2), four in the Rb1 pathway (CDKN2A, CDKN2B, RB1 and CDK4) and PTEN and EGFR. We found that loss of both wild-type copies of any of the three tumour suppressor genes CDKN2A, CDKN2B and RB1 or gene amplification of CDK4, disrupting the Rb1 pathway, were associated with shorter survival (P=0.009). This association was consistent in multivariate analysis, including adjustment for age (P=0.013). The findings suggest that analysis of the genes coding for Rb1 pathway components provides additional prognostic information in AA patients receiving conventional therapy.