p16 Expression and Breast Cancer Risk in Women with Atypical Hyperplasia

Background: p16 is a nuclear protein encoded by the p16INK4a gene that regulates the G1-S cell cycle checkpoint. Its overexpression could reflect normal proliferative arrest, but also the evolution of carcinogenic processes that have overcome the p16 block, with progression from hyperplasic lesions to invasive breast cancer. Our aim with this study was to correlate p16 expression, both individually and in combination with expression of COX-2 and Ki67, with subsequent risk of breast cancer among women with atypical hyperplasia. Methods: p16 expression was assessed by immunohistochemical assays in archival paraffin-embedded, formalin-fixed sections from 233 women with atypia whose biopsy specimens were obtained via surgical excision at the Mayo Clinic from January 1, 1967, through December 31, 1991. p16 expression was scored as percent of cells positive and intensity of staining. Risk factor information and follow-up for breast cancer events were obtained via study questionnaire and the medical records. Standardized incidence ratios (SIRs) were used to compare observed numbers of breast cancer events to population-based expected counts, both at 10 years and over the entire course of follow-up. Results: Forty-seven patients (20%) developed breast cancer with a mean follow-up of 14.3 (SD=6.96) years. The overall risk of developing breast cancer was not modified by increasing p16 overexpression (low percent of staining with RR=3.89, 95% CI=2.72 to 5.56; high percent of staining with RR=3.91, 95% CI=2.43 to 6.28; similar results for intensity of staining). However, overexpression of both p16 and COX2 conveyed a stronger risk of breast cancer (SIR=4.01, 95% CI 2.28 to 7.07) as compared to dual low expression (SIR 1.78, 95% CI 0.67-4.74). Moreover, overexpression of both Ki67 and p16 was related to a higher 10-year breast cancer risk (SIR 6.25, 95% CI 2.35-16.6) as compared to low expression of both markers (SIR 0.87, 95% CI 0.22-3.49). Conclusions: although single expression of p16 does not stratify breast cancer risk, its overexpression in concert with biomarkers that reflect other carcinogenic processes (e.g. Ki67 and COX2) could help to define risk of tumor development.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 910.

Results from a phase I safety lead-in study investigating the combination of erlotinib and the histone deacetylase inhibitor entinostat in patients with advanced NSCLC

e14545

Background: Preclinical studies showed the synergistic effect of entinostat with epidermal growth factor tyrosine kinase inhibitors (EGFR-TKI) in NSCLC cell lines. Entinostat (SNDX-275, Syndax Pharmaceuticals) is an oral, class 1 isoform selective HDACi that restores the expression of e-cadherin and sensitivity to EGFR-TKI in NSCLC cell lines. The aim of this study was to determine the safety and feasibility of combining entinostat with erlotinib in advanced NSCLC patients in order to determine the recommended Phase 2 dose. Methods: Patients with recurrent or metastatic NSCLC whose tumors progressed on prior chemotherapy were treated with either 5 or 10mg orally of entinostat once every two weeks and erlotinib 150mg daily. Results: A total of 9 patients were enrolled (3 at entinostat 5mg; 6 at 10mg). Characteristics: Sex: M/F: 6/3; Age range: 46–84 yrs; ECOG PS: 0–1; Smoking status: 1/8 (never/current or prior smokers); Number of prior treatments: 1–2. There was one DLT of grade 3 asthenia. This occurred in one of the six patients in the 10mg dose cohort. The most common adverse events were anorexia, and asthenia. This was more often noted in elderly patients. Of the 9 evaluable patients, one patient had a confirmed partial response and remains on study (>5 cycles) and another patient had stable disease for 8 months. Pharmacokinetic analysis has been completed with both drugs exhibiting levels comparable to historical data. No drug:drug interaction was observed. EGFR FISH, EGFR mutation, and epithelial-to-mesenchymal marker analysis is in progress. Conclusions: This study has established the safety and a recommended phase 2 dose of 10 mg of entinostat once every other week in combination with 150 mg daily of erlotinib in a 28-day cycle in advanced NSCLC patients. A randomized, double blinded phase 2 study has been initiated with 43 patients enrolled to date.

[Table: see text]

Ductal carcinoma in situ of the breast and gene expression markers for prediction of invasive recurrence

550

Background: Ductal carcinoma in situ (DCIS) is a heterogeneous group of non-invasive cancers with varying propensity for recurrence. There are no validated markers that identify patients at risk for invasive recurrence following lumpectomy. HOXB13/IL17BR (H/I) is expressed in both DCIS and invasive cancer (Ma Cancer Cell. 2004) and associated with recurrence in stage I cancer. A 5-gene molecular grade index (MGI) distinguishes outcome in grade II disease (Ma Clin Cancer Res. 2008). We sought to determine whether H/I or MGI was associated with invasive recurrence in resected DCIS. Methods: We identified patients at Mayo Rochester who underwent lumpectomy ± radiation for DCIS between 1988 and 2001 and performed a nested case/control study. Cases were patients with ipsilateral invasive recurrence, matched to controls based on age, surgery date, length of follow-up, and adjuvant radiation. DCIS was macrodissected from paraffin sections and RNA extracted to obtain H/I and MGI RT-PCR profiles. The association of H/I and MGI with case-control status was assessed with conditional logistic regression; results reported are odds ratios (OR) with 95% confidence intervals (CI). The association of H/I and MGI as continuous variables with nuclear grade (low, intermediate, high) was estimated with Spearman's rank correlation. Results: 427 patients underwent lumpectomy for DCIS, and 33 were identified as possible cases. Histologic review excluded 8 (non-sufficient tissue or DCIS recurrence without invasion). 25 cases were matched to 48 controls (2 controls for 23 cases, 1 control for 2 cases). Both H/I (r = 0.43, p = 0.0001) and MGI (r = 0.41, p = 0.0004) were significantly correlated with nuclear grade. Positive H/I was associated with trend towards higher recurrence (OR 1.9; p = 0.22) that was most pronounced in cases/controls (15/28) treated with lumpectomy alone (OR 3.3; CI: 0.8–13.2, p = 0.09). Similarly, positive MGI was associated with a trend towards higher recurrence risk in patients treated with surgery alone (OR 2.0; CI: 0.6–6.4, p = 0.27). Conclusions: These data suggest that both HOXB13/IL17BR and MGI can identify a subset of patients with surgically resected DCIS who are at risk for invasive recurrence. Further studies in larger cohorts are needed to confirm these findings.

[Table: see text]

Results of a randomized phase II trial of amrubicin (AMR) versus topotecan (Topo) in patients with extensive-disease small cell lung cancer (ED-SCLC) sensitive to first-line platinum-based chemotherapy

8028

Background: SCLC presents as ED-SCLC in 60%-70% of patients (pts). AMR, a synthetic anthracycline, is approved for these pts in Japan. We compare the efficacy and safety of single-agent AMR vs topotecan in non-Japanese pts with 2nd-line ED-SCLC sensitive to 1st-line platinum-based chemotherapy. Methods: This phase II, open-label, multicenter study enrolled pts with ED-SCLC sensitive to 1st-line platinum-based chemotherapy (recurrence or progression ≥90 days from 1st-line treatment). Pts aged ≥18 years with ECOG performance status (PS) ≤2 and only 1 prior therapy were eligible. Pts were randomized (2:1) to receive IV AMR 40 mg/m2/d (d, 1–3) or IV topotecan 1.5 mg/m2/d (d 1–5) and treated every 21 days until progression, unacceptable toxicity, or withdrawal. The primary endpoint, overall response rate (ORR, complete + partial response), used RECIST criteria. Secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Results: In all, 76 pts were randomized to AMR (n=50) or topotecan (n=26) with AMR given for a median of 6 cycles (range 1–16) and topotecan 3 cycles (1–16). AMR significantly improved ORR rates vs topotecan (p<0.012; Table ). Median PFS/OS was 4.3 months (95% CI 2.0, 6.1)/9.3 months (95% CI 5.7, 12.0) with AMR vs 3.5 months (95% CI 2.1, 6.3)/8.9 months (95% CI 4.8, 13.8) with topotecan. There was a higher proportion of ECOG PS 2 pts in the AMR group (n=6) vs the topotecan group (n=2). A trend towards improved OS was observed in the ECOG 0–1 subgroup of 68 pts: median OS was 10.5 months with AMR vs 9.7 months with topotecan. The most common grade ≥3 adverse events with AMR vs topotecan were neutropenia (53% vs 74%), thrombocytopenia (31% vs 52%) and leukopenia (27% vs 30%). Three AMR pts (6%) and 1 topotecan pt (4%) died of neutropenic infection. Conclusions: AMR significantly improves ORR and has acceptable tolerability as 2nd-line treatment in pts with sensitive ED-SCLC.

[Table: see text]

[Table: see text]

Evaluation of aromatase expression in mammographically dense and non-dense regions of the breast in healthy women

Abstract #4033

Background: Aromatase activity within the breast is a source of estrogen that may cause breast cancer. Mammographic density (MD) is a risk factor for breast cancer whose biologic basis is unknown. Our study compared aromatase expression in tissue from dense and non-dense areas of the breasts of healthy volunteers.&#x2028; Methods: Participants were 40+ yrs, had a screening mammogram with visible MD, no history of cancer and were not on endocrine therapy. Ultrasound-guided core biopsies were done within 6 months of mammography to obtain three paired cores from mammographically dense and non-dense regions of the breast. Immunostaining for aromatase expression employed the streptavidin-biotin amplification method using the recently developed 677 mouse monoclonal antibody. Immunoreactivity (IR) was scored in terms of proportion of cells staining positive for aromatase (PPC) (0=&lt;1%, 1=1-25%, 2=26-50%, 3=51+% (and 4=75%+ for adipocytes)) and relative immunointensity (0=none, 1=weak, 2=moderate, 3=intense) for each cell type (stroma, normal ductal epithelium, adipocytes). A composite score weighting the PPC by their relative intensity (range 0-9; 0-12 for adipocytes) was also calculated. The sum of the composite score across the three cell types provided a global assessment of aromatase IR. Repeated measures analyses evaluated differences in aromatase IR for dense compared to non-dense tissue within and across cell types. Parameter estimates (β) indicated the average difference between dense and non-dense IR.&#x2028; Results: 18 (37%) of the 49 participants were premenopausal (median age 46 yrs). Summing across cell types, the global composite score showed increased aromatase IR on sections sampled from dense vs. non-dense regions (β=5.3,p&lt;0.001). This global difference reflected increased aromatase IR in the stroma and normal ductal epithelium from dense sections (vs. non-dense). For 42 women with &gt;1% stromal cells on each section, there was evidence for increased IR on dense sections as indicated by the greater PPCs (β=0.9), relative intensity (β=0.7) and composite score (β=2.7)(p's&lt;0.001). Similarly, for 20 women with &gt;1% normal ductal epithelium in both dense and non-dense sections, there was a greater composite score (β=1.4,p=0.004) for cells on dense sections although differences for PPC (β=0.3,p=0.11) and relative intensity (β=0.3,p=0.09) did not reach statistical significance. No differences were seen in IR for adipocytes from the two density regions (46 women). Findings were unchanged with adjustment for covariates, including proportions of each cell type per section.&#x2028; Conclusions: There is strong evidence for increased aromatase expression in the stromal and normal ductal epithelium of dense vs. non-dense tissue. These results support ongoing research into mammographic density as a biomarker of effect of aromatase inhibitors.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4033.

Children and young people with diabetes in Yorkshire: a population-based clinical audit of patient data 2005/2006

AIMS

To provide a population-based clinical audit of children and young people with diabetes, reporting outcomes, including glycaemic control, for named individual units.

METHODS

Clinical audit data on care processes and glycated haemoglobin (HbA(1c)) were collected for 1742 children and young people treated in 16 paediatric units in Yorkshire, from January 2005 to March 2006. The Yorkshire Register of Diabetes in Children and Young People provided information technology support and validation that enhanced data quality. Multi-level linear regression modelling investigated factors affecting glycaemic control.

RESULTS

An HbA(1c) measure was recorded for 91.6% of patients. The National Institute for Clinical Excellence-recommended target level for HbA(1c) of < 7.5% was achieved for 14.7% of patients. HbA(1c) was positively associated with duration of diabetes and later age at diagnosis. Patients living in deprived areas had significantly poorer control compared with those from affluent areas. Significant between-unit variation in HbA(1c) was not reflected by any association with unit size.

CONCLUSIONS

Our population-based clinical audit of children with diabetes is the product of an effective collaboration between those who deliver care and health services researchers. High levels of recording the key care process measuring diabetes control, compared with national figures, suggests collaboration has translated into improved services. The interesting association between poor diabetes control and higher deprivation is noteworthy and requires further investigation. Future audits require recording of clinical management and clinic structures, in addition to resources to record, assemble and analyse data.

Utility of lipid biomarkers in support of bioremediation efforts at army sites

Lipid biomarker analysis has proven valuable in testing the hypothesis that attributes of the extant microbiota can directly reflect the occurrence of contaminant biodegradation. Two past research efforts have demonstrated this utility and are described here. A 4.5 m vertical core was obtained from a diesel fuel oil contamination plume. Core material was assayed for total petroleum hydrocarbons (TPH) and bacterial membrane phospholipids (PLFA) via a single solvent extraction. Microbial viable biomass and the relative abundance of Gram-negative bacterial PLFA biomarkers were found to be significantly correlated with TPH concentration. The core TPH profile also revealed two distinct areas where the average TPH level of 3,000 microg g(-1) fell to near detection limits. Both areas were characterized by a three-fold decrease in the hexadecane/pristane ratio, indicating alkane biodegradation, and a distinct PLFA profile that showed a close similarity to the uncontaminated surface soil. Low-order, incomplete detonations can deposit hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) into training range surface soils. Since surface soils are exposed to temporal and diurnal moisture cycles, we investigated the effect two very different soil moisture tensions had on the in situ microbiota and RDX biodegradation. Saturated soils were characterized by rapid RDX biodegradation, 4 day half-life, a decrease in number of species detected and increase in PLFA biomarkers for Gram-negative proteobacteria (n16:1omega7c, n18:1omega9c, and n18:1omega7c) and Gram-positive firmicutes (i15:0 and a15:0). Terminal restriction fragment length polymorphism (T-RFLP) profiles of endpoint microbial communities indicated a shift from 18 to 36% firmicutes, the loss of gamma-proteobacteria and the emergence of alpha-proteobacteria. These two past research efforts demonstrated the utility of the lipid biomarker analysis in identifying microbial community characteristics that were associated with two very different soil contaminants. Lipid biomarkers defined areas of TPH biodegradation and identified community shifts as a result of soil conditions that affected explosives fate. Information like this can be used to enhance the predictive power of ecological models such as the Army Training and Testing Area Carrying Capacity for munitions model [ATTACC].

Fluoride and casein phosphopeptide-amorphous calcium phosphate

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) slows the progression of caries and remineralizes enamel subsurface lesions. The aim of this study was to determine the ability of CPP-ACP to increase the incorporation of fluoride into plaque and to promote enamel remineralization in situ. Randomized, double-blind, cross-over studies involved mouthrinses and dentifrices containing CPP-ACP and fluoride. The mouthrinses were used for 60 sec, three times/day for 5 days, and supragingival plaque was collected and analyzed for F. The dentifrices were rinsed as a water slurry for 60 sec four times/day for 14 days in an in situ model. The addition of 2% CPP-ACP to the 450-ppm-F mouthrinse significantly increased the incorporation of fluoride into plaque. The dentifrice containing 2% CPP-ACP produced a level of remineralization similar to that achieved with a dentifrice containing 2800 ppm F. The dentifrice containing 2% CPP-ACP plus 1100 ppm F was superior to all other formulations.

Molecular analysis of DNA rearrangements in leukemias and non-Hodgkin's lymphomas

Genetic markers for leukemias and lymphomas include chromosomal translocations and antigen-receptor gene rearrangements. Clonal rearrangements of immunoglobulin or T cell receptor (TCR) genes reflect clonal proliferations of lymphocytes, a characteristic feature of lymphoid neoplasia. These rearrangements can be detected as described in this unit by Southern blot hybridization or, in many instances, the polymerase chain reaction (PCR). Specific chromosomal translocations can also serve as markers for clonality, for malignant transformation, and for various defined subtypes of hematopoietic cancers. PCR protocols are described for detection of the two most commonly assayed translocations, t(9;22) of chronic myelogenous leukemia or acute lymphoblastic leukemia, and t(14;18) of follicular lymphomas.

Human leucocyte antigen class II association in idiopathic bronchiectasis, a disease of chronic lung infection, implicates a role for adaptive immunity

The aetiology of idiopathic bronchiectasis, a lung disease where chronic inflammation and bacterial infection leads to progressive lung damage, is unknown. A possible role for natural killer cells has been highlighted previously. However, a role for adaptive immunity is suggested by the presence of CD4 and CD8 T cells in diseased lung tissue. Evidence of a human leucocyte antigen (HLA) class II disease association would further implicate a role for adaptive immunity. To establish if there is any HLA association, we analysed HLA-A, HLA-B, HLA-DQA1, HLA-DQB1 and HLA-DRB1 alleles in patients with idiopathic bronchiectasis and controls. Genomic DNA from 92 adults with idiopathic bronchiectasis and 101 healthy controls was analysed by polymerase chain reaction with sequence-specific primers. We found an increase in the prevalence of HLA-DRB1*01 DQA1*01/DQB1*05 genes in idiopathic bronchiectasis; that is, the HLA-DR1, DQ5 haplotype (odds ratio 2.19, 95% confidence interval 1.15-4.16, P = 0.0152) compared with control subjects. The association with HLA-DR1, DQ5 implicates a role for CD4 T cells restricted by these molecules in susceptibility to the progressive lung damage seen in this disease. This may operate either through influencing susceptibility to specific pathogens or to self-reactivity and requires further investigation.

Effect of addition of citric acid and casein phosphopeptide-amorphous calcium phosphate to a sugar-free chewing gum on enamel remineralization in situ

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has been shown to remineralize enamel subsurface lesions in situ. The aim of this study was to investigate the effects of CPP-ACP in a fruit-flavoured sugar-free chewing gum containing citric acid on enamel remineralization, and acid resistance of the remineralized enamel, using an in situ remineralization model. The study utilized a double-blind, randomized, crossover design with three treatments: (i) sugar-free gum (2 pellets) containing 20 mg citric acid and 18.8 mg CPP-ACP, (ii) sugar-free gum containing 20 mg citric acid alone, (iii) sugar-free gum not containing CPP-ACP or citric acid. Ten subjects were instructed to wear removable palatal appliances, with 4 half-slab insets of human enamel containing demineralized subsurface lesions and to chew gum (2 pellets) for 20 min 4 times per day for 14 days. At the completion of each treatment the enamel half-slabs were removed and half of the remineralized lesion treated with demineralization buffer for 16 h in vitro. The enamel slabs (remineralized, acid-challenged and control) were then embedded, sectioned and subjected to microradiography to determine the level of remineralization. Chewing with gum containing citric acid and CPP-ACP resulted in significantly higher remineralization (13.0 +/- 2.2%) than chewing with either gum containing no CPP-ACP or citric acid (9.4 +/- 1.2%) or gum containing citric acid alone (2.6 +/- 1.3%). The acid challenge of the remineralized lesions showed that the level of mineral after acid challenge was significantly greater for the lesions exposed to the gum containing CPP-ACP.