Rising prevalence of vascular comorbidities in multiple sclerosis: validation of administrative definitions for diabetes, hypertension, and hyperlipidemia

BACKGROUND

Despite the importance of comorbidity in multiple sclerosis (MS), methods for comorbidity assessment in MS are poorly developed.

OBJECTIVE

We validated and applied administrative case definitions for diabetes, hypertension, and hyperlipidemia in MS.

METHODS

Using provincial administrative data we identified persons with MS and a matched general population cohort. Case definitions for diabetes, hypertension, and hyperlipidemia were derived using hospital, physician, and prescription claims, and validated in 430 persons with MS. We examined temporal trends in the age-adjusted prevalence of these conditions from 1984-2006.

RESULTS

Agreement between various case definitions and medical records ranged from kappa (κ) =0.51-0.69 for diabetes, κ =0.21-0.71 for hyperlipidemia, and κ =0.52-0.75 for hypertension. The 2005 age-adjusted prevalence of diabetes was similar in the MS (7.62%) and general populations (8.31%; prevalence ratio [PR] 0.91; 0.81-1.03). The age-adjusted prevalence did not differ for hypertension (MS: 20.8% versus general: 22.5% [PR 0.91; 0.78-1.06]), or hyperlipidemia (MS: 13.8% versus general: 15.2% [PR 0.90; 0.67-1.22]). The prevalence of all conditions rose in both populations over the study period.

CONCLUSION

Administrative data are a valid means of tracking diabetes, hypertension, and hyperlipidemia in MS. The prevalence of these comorbidities is similar in the MS and general populations.

High-dose glycine impairs the prepulse inhibition measure of sensorimotor gating in humans

An impaired capacity to filter or 'gate' sensory information is a core deficit in cognitive function associated with schizophrenia. These deficits have been linked in part to N-methyl-d-aspartate (NMDA) receptor dysfunction. An association between high levels of glycine, a positive allosteric modulator of the NMDA receptor, and sensorimotor gating impairments (i.e. prepulse inhibition (PPI) deficit) have been reported in animal models of schizophrenia as well as patients with schizophrenia. This study examined the acute effects of modulating the glycine site of the NMDA receptor (with high-dose glycine) on sensory gating as measured by PPI. Sixteen healthy male subjects (final sample size of 12) participated in a double-blind, placebo-controlled, crossover design in which each subject was tested under two acute treatment conditions separated by at least a 5-day washout period; placebo and 0.8 g/kg glycine. PPI was recorded 45 min post treatment using electromyography of the eye-blink response. Relative to placebo, high-dose glycine significantly impaired sensorimotor gating as demonstrated by a decrease in PPI (t(11) = -2.983, p < 0.05). Administration of a high dose of glycine is associated with impairments in PPI supporting earlier observations in animals and patients with schizophrenia. This result, when taken together with findings in patients, suggests that high synaptic levels of glycine may have some clinically relevant detrimental effects and suggests a potential dissociation of clinical symptomatology and sensory information processing as a function of NMDA receptor modulation in schizophrenia.

BCL2 in breast cancer: a favourable prognostic marker across molecular subtypes and independent of adjuvant therapy received

BACKGROUND

Breast cancer is heterogeneous and the existing prognostic classifiers are limited in accuracy, leading to unnecessary treatment of numerous women. B-cell lymphoma 2 (BCL2), an antiapoptotic protein, has been proposed as a prognostic marker, but this effect is considered to relate to oestrogen receptor (ER) status. This study aimed to test the clinical validity of BCL2 as an independent prognostic marker.

METHODS

Five studies of 11 212 women with early-stage breast cancer were analysed. Individual patient data included tumour size, grade, lymph node status, endocrine therapy, chemotherapy and mortality. BCL2, ER, progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) levels were determined in all tumours. A Cox model incorporating the time-dependent effects of each variable was used to explore the prognostic significance of BCL2.

RESULTS

In univariate analysis, ER, PR and BCL2 positivity was associated with improved survival and HER2 positivity with inferior survival. For ER and PR this effect was time dependent, whereas for BCL2 and HER2 the effect persisted over time. In multivariate analysis, BCL2 positivity retained independent prognostic significance (hazard ratio (HR) 0.76, 95% confidence interval (CI) 0.66-0.88, P<0.001). BCL2 was a powerful prognostic marker in ER- (HR 0.63, 95% CI 0.54-0.74, P<0.001) and ER+ disease (HR 0.56, 95% CI 0.48-0.65, P<0.001), and in HER2- (HR 0.55, 95% CI 0.49-0.61, P<0.001) and HER2+ disease (HR 0.70, 95% CI 0.57-0.85, P<0.001), irrespective of the type of adjuvant therapy received. Addition of BCL2 to the Adjuvant! Online prognostic model, for a subset of cases with a 10-year follow-up, improved the survival prediction (P=0.0039).

CONCLUSIONS

BCL2 is an independent indicator of favourable prognosis for all types of early-stage breast cancer. This study establishes the rationale for introduction of BCL2 immunohistochemistry to improve prognostic stratification. Further work is now needed to ascertain the exact way to apply BCL2 testing for risk stratification and to standardise BCL2 immunohistochemistry for this application.

Proton-pump inhibitor use is not associated with osteoporosis or accelerated bone mineral density loss

BACKGROUNDS & AIMS

Recent studies have shown an association between proton-pump inhibitor use (PPI) and hip fracture. The mechanism by which PPI use promotes the development of hip fracture is uncharacterized. Therefore, we sought to determine whether PPI use is associated with osteoporosis or accelerated bone mineral density (BMD) loss.

METHODS

We used the Manitoba Bone Mineral Density Database to determine the relationship between chronic PPI use and osteoporosis on an initial assessment of BMD and on BMD loss between successive assessments of BMD. In the cross-sectional study, cases with osteoporosis at the hip or lumbar vertebrae (T-score < or =-2.5) were matched to 3 controls with normal BMD (T-score > or =-1.0). In the longitudinal analysis, the change in BMD among PPI users and nonusers between successive BMD assessments was assessed. Conditional logistic regression and multivariate linear regression were used to obtain estimates of the association between PPI use and osteoporosis and of the annualized change in BMD associated with PPI use.

RESULTS

PPI use was not associated with having osteoporosis at either the hip (OR, 0.84; 95% CI, 0.55-1.34) or the lumbar spine (OR, 0.79; 95% CI, 0.59-1.06) for PPI use >1500 doses over the previous 5 years. In the longitudinal study no significant decrease was observed in BMD at either site attributable to PPI use.

CONCLUSIONS

PPI use does not appear to be associated with either the presence of osteoporosis or accelerated BMD loss. The association between PPI use and hip fracture is probably related to factors independent of osteoporosis.

Validation of FOXA1 as a Prognostic Marker in Breast Cancer in a Large Population-Based Tissue Microarray

FOXA (Forkhead box protein A) proteins play major roles in development and differentiation. However, recently, FOXA1 has been identified to play a role in controlling nearly 50% of estrogen receptor target genes and has been deemed as a 'pioneer factor'. It is believed to have a dual role in breast cancer: (1) growth promotion by coactivating ERα and (2) growth inhibition by regulating factors like p27Kip1 and E-cadherin. We studied the expression of FOXA1 in a population based tissue microarray of 4,046 invasive breast cancer cases with a median follow- up of 12.4 years using immunohistochemistry and studied its correlation with estrogen receptor and other clinicopathological variables. The percent positivity (P) and intensity (I) of nuclear FOXA1 expression were multiplied to generate a numerical score (S = P × I) that ranged from 0 to 30. Scores between 0 and 3 were defined as low FOXA1 expression and 4 to 30 were defined as high FOXA1 expression. Variable FOXA1 expression was noted in the 3581 interpretable tumors: none (10.6%), weak (3.5%), moderate (19.3%) and strong (55.1%). High level of FOXA1 expression (FOXA1 score greater than 3) was seen in nearly 86% of the tumors. FOXA1 expression correlated positively with ER (p&lt; 0.0001), PR (p&lt; 0.0001), E-cadherin (p&lt;0.0001), age (p&lt; 0.0001) and negatively with basal subtype (p&lt; 0.0001), Ki67 (p&lt;0.0001), tumor size (p&lt; 0.0001) and tumor grade (p&lt;0.0001). Univariate analyses showed small tumor size (T1 tumors), low grade (Grade I), node negative disease, absence of lymphovascular invasion, ER, PR, Her2, cyclin D1 and Ki67 as independent predictors of better overall survival. Patients with Luminal A subtype breast cancers had better overall survival than those with non-Luminal A subtype breast cancers. FOXA1 is found to be a significant predictor of breast cancer specific survival (p=0.012) and locoregional relapse free survival (p=0.0001). However, FOXA1 did not reach statistical significance for disease free survival (p=0.110) and distant relapse free survival (p=0.147). When stratified by molecular subtypes using IHC, FOXA1 did not show any trend for overall survival. In those treated with tamoxifen, low FOXA1 expression was associated with poor overall survival (p&lt;0.0001). In a subset of ERα-positive breast cancer cases, FOXA1 was a significant predictor of breast cancer specific survival (p=0.012). To summarize, FOXA1 expression in ERα-positive breast cancer is of prognostic significance.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2130.

α-basic-crystallin expression in basal-like breast cancer and its association with brain metastasis

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Background: Basal-like breast cancers are high grade tumors with poor prognosis, having propensity for brain and lung metastasis (Perou et al. Nature 406:747–52, 2000, Cheang et al. Clin Cancer Res 14:1368–76, 2008, Luck et al. Clin Oncol (R Coll Radiol) 20:40–5, 2008). α-basic-crystallin (αBC), a small heat shock protein with anti-apoptotic and oncogenic activity, is expressed in about half of basal-like breast cancers but only 6% of other types (Moyano et al. J Clin Invest 116:261–70, 2006). Here we investigate the association of αBC with sites of distant metastasis in a large cohort of breast cancer patients. Methods: Our cohort consists of 4046 early invasive breast cancers referred to the British Columbia Cancer Agency from 1986 to 1992. Archival paraffin tissue blocks were used to construct tissue microarrays. Breast cancer subtypes were defined using a surrogate of six immunohistochemical markers: ER, PR, HER2, Ki-67, epidermal growth factor receptor and cytokeratin 5/6. αBC immunostaining was scored by pre-established, published criteria. All documented sites of distant metastasis were abstracted by chart review according to predefined categories. The null hypothesis was tested using chi-square and Fisher's Exact tests; all tests were two-sided. Results: Among 3,248 cases with interpretable αBC data, 11% were αBC +. Among patients who developed distant metastatic disease, the 10-yr BCSS survival in αBC+ and - tumors was 12% and 29%. Sites of metastatic disease included: brain (15%), lung (35%), liver (35%) and bone (65%). Brain metastasis was significantly more common among αBC positive tumors (Fisher's Exact test p<10e-8). Basal-like tumors with brain metastasis commonly co-expressed αBC (Chi-square p=0.006). Conclusion: αBC is significantly associated with brain metastasis, particularly among basal breast cancers. These findings suggested that αBC may be involved in tumor cell metastasis and may allow early identification of a subset of patients at particularly high risk of brain metastasis.

[Table: see text]

No significant financial relationships to disclose.

Use of proton pump inhibitors and risk of osteoporosis-related fractures

BACKGROUND

The use of proton pump inhibitors has been associated with an increased risk of hip fracture. We sought to further explore the relation between duration of exposure to proton pump inhibitors and osteoporosis-related fractures.

METHODS

We used administrative claims data to identify patients with a fracture of the hip, vertebra or wrist between April 1996 and March 2004. Cases were each matched with 3 controls based on age, sex and comorbidities. We calculated adjusted odds ratios (OR) for the risk of hip fracture and all osteoporosis-related fractures for durations of proton pump inhibitor exposure ranging from 1 or more years to more than 7 years.

RESULTS

We matched 15 792 cases of osteoporosis-related fractures with 47 289 controls. We did not detect a significant association between the overall risk of an osteoportic fracture and the use of proton pump inhibitors for durations of 6 years or less. However, exposure of 7 or more years was associated with increased risk of an osteoporosis-related fracture (adjusted OR 1.92, 95% confidence interval [CI] 1.16-3.18, p = 0.011). We also found an increased risk of hip fracture after 5 or more years of exposure (adjusted OR 1.62, 95% CI 1.02-2.58, p = 0.04), with even higher risk after 7 or more years exposure (adjusted OR 4.55, 95% CI 1.68-12.29, p = 0.002).

INTERPRETATION

Use of proton pump inhibitors for 7 or more years is associated with a significantly increased risk of an osteoporosis-related fracture. There is an increased risk of hip fracture after 5 or more years exposure. Further study is required to determine the clinical importance of this finding and to determine the value of osteoprotective medications for patients with long-term use of proton pump inhibitors.

Underutilization of gastroprotective strategies in aspirin users at increased risk of upper gastrointestinal complications

BACKGROUND

Aspirin use is with an increased risk of upper gastrointestinal complications (UGICs). Proton pump inhibitors (PPIs) decrease the risk of UGICs among aspirin users. The distribution of risk factors for UGIC and PPI utilization among aspirin users remains uncharacterized.

AIM

To determine the prevalence and predictors of PPI use in high-risk aspirin users.

METHODS

Using questionnaires and administrative records, we collected information on aspirin and PPI utilization and risk factors for UGICs from a stratified random sample of subjects with established cardiovascular disease. We calculated the proportion of aspirin users with UGIC risk factors and determined the prevalence of PPI use among aspirin users with risk factors. Regression analysis was used to determine predictors of PPI use among aspirin users.

RESULTS

Overall response rate was 35%, of whom 86% were regular aspirin users. Seventy-one per cent of aspirin users had at least one risk factor (in addition to cardiac disease) for the development of UGICs. Although a history of UGIC was predictive of PPI use, 44% of aspirin users with a prior history of UGICs did not receive a concomitant PPI, and only 23% of subjects with additional UGIC risk factors were prescribed a PPI.

CONCLUSION

There is a high prevalence of UGIC risk factors among aspirin users, and many are not prescribed PPIs as a gastroprotective strategy.