Longitudinal profiling identifies co-occurring BRCA1/2 reversions, TP53BP1, RIF1 and PAXIP1 mutations in PARP inhibitor-resistant advanced breast cancer

BACKGROUND

Resistance to therapies that target homologous recombination deficiency (HRD) in breast cancer limits their overall effectiveness. Multiple, preclinically validated, mechanisms of resistance have been proposed, but their existence and relative frequency in clinical disease are unclear, as is how to target resistance.

PATIENTS AND METHODS

Longitudinal mutation and methylation profiling of circulating tumour (ct)DNA was carried out in 47 patients with metastatic BRCA1-, BRCA2- or PALB2-mutant breast cancer treated with HRD-targeted therapy who developed progressive disease-18 patients had primary resistance and 29 exhibited response followed by resistance. ctDNA isolated at multiple time points in the patient treatment course (before, on-treatment and at progression) was sequenced using a novel >750-gene intron/exon targeted sequencing panel. Where available, matched tumour biopsies were whole exome and RNA sequenced and also used to assess nuclear RAD51.

RESULTS

BRCA1/2 reversion mutations were present in 60% of patients and were the most prevalent form of resistance. In 10 cases, reversions were detected in ctDNA before clinical progression. Two new reversion-based mechanisms were identified: (i) intragenic BRCA1/2 deletions with intronic breakpoints; and (ii) intragenic BRCA1/2 secondary mutations that formed novel splice acceptor sites, the latter being confirmed by in vitro minigene reporter assays. When seen before commencing subsequent treatment, reversions were associated with significantly shorter time to progression. Tumours with reversions retained HRD mutational signatures but had functional homologous recombination based on RAD51 status. Although less frequent than reversions, nonreversion mechanisms [loss-of-function (LoF) mutations in TP53BP1, RIF1 or PAXIP1] were evident in patients with acquired resistance and occasionally coexisted with reversions, challenging the notion that singular resistance mechanisms emerge in each patient.

CONCLUSIONS

These observations map the prevalence of candidate drivers of resistance across time in a clinical setting, information with implications for clinical management and trial design in HRD breast cancers.

Abstract P2-04-07: Immune profiling of post neoadjuvant high metastatic risk (RCB-II/III) residual disease in patients with early triple negative breast cancers

Background: Poor prognosis in TNBC can be predicted in the significant fraction of patients with large volume residual cancer burden (RCB-II/III) after neoadjuvant chemotherapy (NACT). Whilst residual disease has been characterised to identify “driver” mutations and copy number variations, the contribution of the immune response within its tumour microenvironment remains unclear. Here we aimed to: 1) assess the potential spatial heterogeneity of immune transcript related gene expression between areas of tumour approximately 1cm apart as might still occur with a radiologically guided biopsy through the residual disease; and 2) assess the immune stroma composition of the TNBC high metastatic risk RCB II/III disease.

Method: 12 TNBC post NACT RCB II/III residual cases were identified from the KHP biobank. H&E sections were reviewed and areas of tumor 1cm apart within a residual resection specimen marked as area A and area B. HistoQuest analysis software was used to quantify the proportion of tumor infiltrating lymphocytes (per total cell count) within both areas. RNA was extracted from both areas and immune gene expression profiling performed using a Nanostring nCounter® on all 24 samples. The immune PanCancer panel consisted of 770 genes combining markers for different immune cell populations. Differential genes between paired samples were compared and unsupervised hierarchical clustering using 770 genes and immune cell types performed.

Results:Quantitative comparison of the tumour infiltrating lymphocytes (TILS) between area A and B revealed that 73% (8/11) of the cases had a <2-fold difference in the percentage of TILS within a residual specimen; and 27% (3/11) displayed a >2-fold (range 2.03-3.16) difference in the TILS. When comparing the 770 gene expression profiles between sampling areas in the same tumour, we found little spatial heterogeneity with areas A/B clustering together in 10 out of 12 cases. Interestingly, the two cases that revealed spatial heterogeneity within the paired samples displayed little immune cell heterogeneity histologically (i.e. <1-fold change in the TILS percentage score between area A and B). Comparing patient samples by immune gene expression profiling divided the patients into two groups: i) those with immunologically enriched tumors in whom gene signatures for majority of the immune cell types (DC, Macrophages, CD8+T-cells, T-helper cells (Th17, Th2, Th1), Tregs, NK, B-cells, Neutrophils, Mast cells) were highly expressed and ii) those with immunologically inert tumors in whom the immune cell signatures were not highly expressed. Within our patient cohort, patients with immunologically enriched gene expression profiles were also seen to display higher TILS score (ranging between 28.17% to 40.66%) as compared to patients with immunologically inert gene expression with scores ranging from 11.82% to 16.80%.

Conclusion: The findings that high metastatic risk residual disease can be further characterized as either “immunologically inert” or “immunologically enriched” at the level of extensive immunological transcript gene expression and by histological assessment of TILS requires further investigation; and is being validated in a larger sample set.

Citation Format: Irshad S, Cheang M, Gazinka P, Naidoo K, Buus R, Pinder S, Dowsett M, Tutt A. Immune profiling of post neoadjuvant high metastatic risk (RCB-II/III) residual disease in patients with early triple negative breast cancers [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-04-07.

Prognostic and predictive value of ERβ1 and ERβ2 in the Intergroup Exemestane Study (IES)-first results from PathIES†

BACKGROUND

Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2-3 years from tamoxifen to exemestane. PathIES aimed to assess the potential prognostic and predictive value of ERβ1 and ERβ2 expression in primary tumours in order to determine benefit in the two treatment arms.

PATIENTS AND METHODS

Primary tumour samples were available for 1256 patients (27% IES population). ERβ1 and ERβ2 expression was dichotomised at the median IHC score (high if ERβ1 ≥ 191, ERβ2 ≥ 164). Hazard ratios (HRs) were estimated by multivariable Cox proportional hazards models adjusting for clinicopathological factors. Treatment effects with biomarker expressions were determined by interaction tests. Analysis explored effects of markers both as a continuous variable and with dichotomised cut-offs.

RESULTS

Neither ERβ1 nor ERβ2 were associated with disease-free survival (DFS) or overall survival (OS) in the whole cohort. In patients treated with continued tamoxifen, high ERβ1 expression compared with low was associated with better DFS [HR = 0.38:95% confidence interval (CI) 0.21-0.68, P = 0.001]. DFS benefit of exemestane over tamoxifen (HR = 0.40:95% CI 0.22-0.70) was found in the low ERβ1 subgroup (interaction P = 0.01). No significant difference with treatment was observed for ERβ2 expression in either DFS or OS.

CONCLUSION

In the PathIES population, exemestane appeared to be superior to tamoxifen among patients with low ERβ1 expression but not in those with high ERβ1 expression. This is the first trial of its kind to report a parameter potentially predicting benefit of an aromatase inhibitor when compared with tamoxifen and an independent validation is warranted.

NEOCENT: a randomised feasibility and translational study comparing neoadjuvant endocrine therapy with chemotherapy in ER-rich postmenopausal primary breast cancer

Neoadjuvant endocrine therapy is an alternative to chemotherapy for women with oestrogen receptor (ER)-positive early breast cancer (BC). We aimed to assess feasibility of recruiting patients to a study comparing chemotherapy versus endocrine therapy in postmenopausal women with ER-rich primary BC, and response as well as translational endpoints were assessed. Patients requiring neoadjuvant therapy were randomised to chemotherapy: 6 × 3-weekly cycles FE₁₀₀C or endocrine therapy: letrozole 2.5 mg, daily for 18-23 weeks. Primary endpoints were recruitment feasibility and tissue collection. Secondary endpoints included clinical, radiological and pathological response rates, quality of life and translational endpoints. 63/80 patients approached were eligible, of those 44 (70, 95% CI 57-81) were randomised. 12 (54.5, 95% CI 32.2-75.6) chemotherapy patients showed radiological objective response compared with 13 (59.1, 95% CI 36.4-79.3) letrozole patients. Compared with baseline, mean Ki-67 levels fell in both groups at days 2-4 and at surgery [fold change: 0.24 (95% CI 0.12-0.51) and 0.24; (95% CI 0.15-0.37), respectively]. Plasma total cfDNA levels rose from baseline to week 8 [fold change: chemotherapy 2.10 (95% CI 1.47-3.00), letrozole 1.47(95% CI 0.98-2.20)], and were maintained at surgery in the chemotherapy group [chemotherapy 2.63; 95% CI 1.56-4.41), letrozole 0.95 (95% CI 0.71-1.26)]. An increase in plasma let-7a miRNA was seen at surgery for patients with objective radiological response to chemotherapy. Recruitment and tissue collection endpoints were met; however, a larger trial was deemed unfeasible due to slow accrual. Both regimens were equally efficacious. Dynamic changes were seen in Ki-67 and circulating biomarkers in both groups with increases in cfDNA and let-7a miRNA persisting until surgery for chemotherapy patients.

Tumor Ki67 Proliferation Index within 4 Weeks of Initiating Neoadjuvant Endocrine Therapy for Early Identification of Non-Responders

Background: The Preoperative Endocrine Prognostic Index (PEPI) scores the independent prognostic effects of tumor pathologic staging and expression levels of ER and the “proliferation” marker Ki67 in the surgical sample to predict long term outcomes after completion of neoadjuvant endocrine treatment (Ellis et al JNCI 100:1380, 2008). A limitation of the PEPI is that the prognostic information becomes available only after 4 months of treatment. We therefore evaluated the value of an early assessment of the Ki67 level in a tumor biopsy sample taken two to four weeks after initiating treatment in two neoadjuvant endocrine therapy trials for the purposes of the early identification of non- respondersMethods: A Ki67 cut point of greater than 10% for poor outcome in ER+ breast cancer was derived by comparing the PAM50 intrinsic subtype profile using a qRT-PCR assay with Ki67 data in a 700+ sample data set. A baseline level of 10% or less correlated most closely with a PAM50-based definition of LumA breast cancer and above 10% LumB breast cancer. We subsequently applied the 10% cut point to the baseline and early on-treatment Ki67 data in two trials, POL (Olson et al JACS 208:906, 2009) and IMPACT (Smith et al JCO: 23, 5108, 2005).Results: At baseline the dichotomized Ki67 definition was not significantly predictive for surgical Ki67 level, PEPI score or RFS in this modest size sample set. In contrast, in a result that emphasizes the enhaced prognostic properties of the on-treatment Ki67 approach, the one month POL sample Ki67 values (62 patients) predicted a higher level of Ki67 in the surgical samples at four months after treatment initiation (P=.01), a poorer PEPI score (P=0.01), a smaller number of patients in the PEPI risk point zero group (P=0.08) and worse relapse free survival (P=0.003). The IMPACT data (153 patients) confirmed that a two week Ki67 >10% predicted higher Ki67 in the surgical specimen (P=0.001), a poorer PEPI score (P=0.001), smaller numbers of patients in the PEPI 0 risk point group (P= 0.004) and worse relapse free survival (P=0.008).Ki67 and OutcomePOL 4W Ki67% PEPI 0RFS (events)10%>1/19 (5%)5/21 (23%)10%≤10/36 (28%)1/41 (2.4%)P ValueP=0.08 (Fisher)P=0.003 (log rank)IMPACT 2W Ki67% PEPI 0RFS (events)10%>0/32 (0%)9/35 (26%)10%≤21/101 (21%)13/118 (11%)P ValueP=0.004 (Fisher)P=0.008 (log rank) Conclusions: A tumor Ki67 assessment taken a short time (2 to 4 week window) after the initiation of neoadjuvant AI identifies patients with poor outcome ER+ disease. Amendment 6 of the neoadjuvant endocrine therapy protocol ACOSOG Z1031 will triage patients with an “on treatment” Ki67 value above 10% to chemotherapy in order to assess the pathological response rate to cytotoxic therapy in this important tumor subset.Supported by R01 CA095614, Avon PFP award 3P50 CA68438-07S2, U01 CA114722, ACOSOG U10 CA 76001, Breakthrough Cancer UK and AstraZenica (IMPACT trial).

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 78.

Breast cancer molecular profiles and tumor response of neoadjuvant doxorubicin and paclitaxel: The I-SPY TRIAL (CALGB 150007/150012, ACRIN 6657)

LBA515

Background: I-SPY is a multi-center trial designed to identify predictive markers of pathological complete response (pCR) and survival of women with locally advanced breast cancers (3cm or greater). Women received neoadjuvant doxorubicin and cyclophosphamide then paclitaxel. Methods: 237 women enrolled, 216 completed serial imaging and core biopsies. Pre-treatment assays include: Agilent expression arrays, MIP aCGH, p53 gene chip and sequencing, IHC and reverse phase protein arrays (RPMA). Response to therapy was measured by serial MRI, pCR and residual cancer burden (RCB). Associations among molecular markers, pCR, RCB and survival were evaluated using chi-square test, Kaplan-Meier curves and log-rank test. Results: Median tumor size was 6cm, % pCR and RCB 0/1 was 27% and 36% for the entire study; % pCR rate for the 144 Agilent arrays was 25%. Distribution, rates of pCR and RCB 0/1 are shown in the Table for molecular and IHC markers. DFS and OS will be presented. Several molecular subtypes, including NKI 70 gene low, luminal A, 21 gene set low and IHC HR+, define 15–28% of patients with 3–10% pCR, yet excellent early survival. Wound healing, most discriminatory for prognosis, is not predictive of chemotherapy response. By RPMA, patients with pCR had increased phosphorylation of 4EBP1, eNOS, cAbl, STAT5, EGFR, AKT (p<0.05). In ER+ patients with poor MR response, pIRS, pIGFR, p706S were activated (p<0.05). RCB is a more refined way to measure pCR and was more predictive of DFS and OS (p=0.01) than pCR alone with a mean follow up of 3.9 years. MR volume is highly predictive of pCR and RCB. For specific subtypes, e.g. basal, RCB is predictive of DFS (p<0.00001). Conclusions: LABC have aggressive biology. Response to therapy and outcome can be predicted by many biomarkers. The I-SPY data set provides a platform to compare, contrast and combine marker signatures to tailor therapy and demonstrates the power of the neoadjuvant setting. Support: ACRIN U01 CA079778 ; CALGB CA31964, CA33601; NCI SPORE CA58207.

[Table: see text]

[Table: see text]

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

1025

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.

Anthracyclines in basal breast cancer: The NCIC-CTG trial MA5 comparing adjuvant CMF to CEF

519

Background: MA5 randomized premenopausal women with node-positive early breast cancers to cyclophosphamide- methotrexate-fluorouracil (CMF) or cyclophosphamide-epirubicin-fluorouracil (CEF) adjuvant chemotherapy. This and other trials have shown that adjuvant regimens containing anthracyclines confer significant survival benefit to breast cancer patients. Meta-analyses have revealed most benefit in women with HER2(+) or TOPO2 (+) tumors. Population-based data suggest that patients with a core basal phenotype (negative for hormone receptors and HER2, positive for CK5/6 or EGFR) conversely have worse survival on anthracycline containing vs. CMF regimens. Here we test the hypothesis specified a priori that for basal breast cancers anthracyclines may be inferior, using data from MA5. Methods: From 710 patients in MA5, blocks suitable for tissue microarray construction were recovered for 549. Immunohistochemistry for ER, PR, HER2, Ki67, CK5/6 and EGFR was obtained, allowing stratification of 511 cases into intrinsic biological subtypes by published methods (Cheang MC et al. Clin Cancer Res 2008;14:1368–76). Prespecified analyses were conducted independently by the NCIC- CTG statistical centre. Results: In the CEF arm, patients with core basal tumors had a hazard ratio of 1.8 (log rank p=0.02) for overall survival (OS) relative to the other biological subtypes. In the CMF arm, there was no significant difference (HR 0.9, p = 0.7). The interaction between core basal status and treatment was borderline significant (p=0.06). Relapse free survival differences did not reach significance. Conclusions: Data from this randomized trial supports the hypothesis that anthracycline containing adjuvant chemotherapy regimens are inferior to adjuvant CMF in women with basal breast cancer.

[Table: see text]

No significant financial relationships to disclose.

Breast cancer molecular profiles and tumor response of neoadjuvant doxorubicin and paclitaxel: The I-SPY TRIAL (CALGB 150007/150012, ACRIN 6657)

LBA515

The full, final text of this abstract will be available in Part II of the 2009 ASCO Annual Meeting Proceedings, distributed onsite at the Meeting on May 30, 2009, and as a supplement to the June 20, 2009, issue of the Journal of Clinical Oncology.

[Table: see text]

Insulin like growth factor in breast cancer subtypes

Abstract #3048

Background: Insulin Like Growth Factor -1 Receptor (IGF-1R) is an important new therapeutic target expressed in all cancer types. IGF-1R supports cell survival pathways implicated in resistance to cancer therapy. Knowledge of the pattern of IGF-R1 expression among breast cancer subtypes and its impact on prognosis may enhance development of therapeutics targeting this pathway.&#x2028; Methods: Patients with early breast cancer cases, stage I-III, referred to the BC Cancer Agency from 1986 to 1992 were included. Archival paraffin tissue blocks were used to construct a tissue microarray. Among 4,046 patients with early stage on the TMA, 1,238 patients (30.6 %) were excluded due to missing subtype biomarkers, IGFR staining or both. Breast cancer subtypes were defined as Luminal A (ER/PR+, HER2- and Ki67 &lt;19%), Luminal B (ER/PR+,and HER2- and Ki67 &gt;19%), Luminal HER2+ (HER2+ and ER/PR+), HER2 (HER2+ and ER-and PR-), and Basal {HER2-,ER-PR- and (CK 5/6+ and/or EGFR+)}. IGF-1R staining was done with Santa Cruz antibody and was scored negative if there was no or weak staining and positive if staining was moderate or strong. Chi-square and Kaplan-Meier Survival analysis were done to compare IGF-1R expression among subtypes and determine impact on Breast Cancer Specific (BCSS) and Overall Survival (OS).&#x2028; Results: A total of 2,808 evaluable cases were included with a median follow-up of 12.5 years. IGF-1R staining was scored positive in 86.4%, and negative in 13.6%. Cases with Luminal A (1,676), Luminal B (426), Luminal HER2+ (199), HER2 (206 ) and Basal (301 ) had an IGF-1R+ rate of 89.9%, 94.4 %, 83.4%, 59.2% and 76.1%, respectively (p&lt;0.0001). 10 year BCSS was 68% (95% CI 66.0%-70.0%) in IGF-R1+ and 63% (95% CI 59.1%-66.9%) in IGF-R1 - group. Among subtypes, IGF-1R positivity was associated with improved BCSS only in Luminal A patients (p=0.015 ) and was not prognostic in other subtypes.&#x2028; Conclusion: Luminal breast cancer subtypes are associated with high rates of IGF1-R expression, while non-luminal groups have lower rates of expression. The prognostic impact of IGF-R1 expression supports the role of this pathway as a therapeutic target particularly among hormone receptor positive breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3048.

The pattern of metastatic spread among breast cancer sub-types

Abstract #2025

Background: Although breast cancer subtypes are associated with differing relapse risks, the patterns of metastatic spread are less well defined, particularly for more than the first site of metastasis. We describe the sites of all diagnosed metastases among breast cancer subtypes in a large series of women diagnosed with breast cancer to further define patterns of spread.&#x2028; Methods: Subjects with early stage breast cancer referred to the British Columbia Cancer Agency from 1986 to 1992 were included. Archival paraffin tissue blocks were used to construct a tissue microarray. Breast cancer subtypes were defined as Luminal A (ER/PR+ and HER2- and Ki67 &lt;19%), Luminal B (ER/PR+, and HER2- and Ki67 &gt;19%), LuminalHer2 (Her2+ and ER/PR+), HER2 (HER2+ and ER- and PR-), and Basal (HER2-ER-PR- and CK 5/6+and/orEGFR+). All documented sites of distant metastasis were abstracted by chart review according to predefined categories.&#x2028; Results: 3526 eligible women were classified according to Luminal A (2109), Luminal B (514), LuminalHER2 (252), HER2 (276) and Basal (375) and 30%,47%, 48%, 50% and 42% in each subgroup were diagnosed with distant metastasis. Median Survival with metastatic disease was 2.2, 1.6 and 1.3 years in Luminal A, B and LuminalHER2 groups and 0.7 and 0.5 years in the HER2 and Basal types, respectively. Bone was the predominant site of metastasis for luminal groups A (76%), B (73%) and LuminalHER2 (70%). The distribution was more heterogeneous in HER and Basal groups. High rates of brain metastasis were observed in the HER2 (30%) and Basal (27%) and less frequently in the LuminalHER2 (17%) and other groups (p &lt;0001).&#x2028; &#x2028; Conclusion: Molecular breast cancer subtypes are associated with specific distributions of metastasis which may lead to specific prophylactic therapies to modify this risk. New systemic therapies, including trastuzumab, may impact these patterns and survival after recurrence.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2025.

Variation in mortality rates among long-term care facilities for residents with lower respiratory tract infection

OBJECTIVE

To identify variables contributing to interfacility differences in mortality among residents of long-term care facilities who have lower respiratory tract infection.

DESIGN

Multicenter, prospective, 1-year observational study.

SETTING

Twenty-one long-term care facilities in 4 geographic areas of Canada.

PARTICIPANTS

Residents of long-term care facilities prescribed antimicrobials for treatment of lower respiratory tract infection.

METHODS

Mortality rates were calculated for 3 definitions of lower respiratory tract infection: episodes with a clinical or radiographic diagnosis and treated with antimicrobials (definition 1); episodes with a physician diagnosis of pneumonia (definition 2); and episodes with chest radiography findings consistent with pneumonia (definition 3). Multilevel modeling was used to evaluate variables describing premorbid resident status, clinical presentation, management, and facility characteristics. Multivariable models were developed to identify independent predictors of mortality and determine whether facility-level variables remained independently associated with mortality rate after incorporation of individual-level variables.

RESULTS

Facility mortality rates varied from 0% to 17.8% for definition 1, from 0% to 47.1% for definition 2, and from 0% to 37.5% for definition 3. There were significant differences in mortality rate depending on which definition was used; for definitions 1 and 2, there were significant differences in mortality rate across facilities. Poorer premorbid resident status and a more severe presentation remained independent predictors of mortality in the multivariable analysis. There were also significantly increased mortality rates for episodes in which a fluoroquinolone was prescribed for initial treatment. For definitions 1 and 3, facility-level variables remained independently associated with mortality rate in the final multivariable model.

CONCLUSIONS

Rates of mortality due to lower respiratory tract infection varied among long-term care facilities and differed within a facility, depending on the definition applied. Variables describing premorbid resident status, severity of presentation, and management did not fully explain the variation in mortality rate. Some facility-level variables remained independent predictors of mortality.

Foot abnormalities in Canadian Aboriginal adolescents with Type 2 diabetes

AIMS

To determine the profile of foot abnormalities in Canadian Aboriginal adolescents with Type 2 diabetes and the risk factors associated with these abnormalities.

METHODS

Aboriginal adolescents with Type 2 diabetes underwent an interview, medical record review and foot examination in a tertiary care, paediatric hospital diabetes clinic and two geographically remote outreach clinics. The notes of 110 subjects were reviewed [mean age 15 +/- 3 years; mean duration of diabetes, 30 +/- 20 months; 71 (66%) female and 39 (34%) male] and 77 (70%) of the subjects were examined.

RESULTS

Foot abnormalities were identified by either interview or notes review, and included poor toenail condition in 85 (77%), paronychia in 29 (26%), ingrowing toenails in 16 (15%) and neuropathic symptoms in 13 (12%) subjects. Foot abnormalities were identified by examination in many subjects, including poor toenail condition in 38 (49%), calluses in 34 (44%) and paronychia in 13 (17%) subjects. Eighteen (24%) of 75 subjects did not have running water in the home. Factors that significantly increased the presence of foot abnormalities included: foot care provided by a person other than self; absence of running water in the home; decreased frequency of bathing; and decreased frequency of nail clipping. A greater percentage of subjects living on a reservation or rural community had specialized consultations for retinal examination, footwear, or both than of those living in an urban or unknown residence.

CONCLUSIONS

A high prevalence of foot abnormalities was noted in Aboriginal adolescents with Type 2 diabetes. These findings highlight the associated comorbidities in this population, emphasizing the need for early detection and intervention.

Ki-67 is a Luminal B marker that identifies a high-risk subgroup in hormone receptor positive and node negative breast cancer

10521

Background: Gene expression profiling studies have revealed prognostically significant intrinsic breast cancer subtypes, designated Luminal A, Luminal B, Basal and Her2. Expression of ER and associated genes characterizes the luminal breast cancers. The Lum B subgroup is associated with poor outcome, but we lack immunohistochemical (IHC) markers to distinguish Lum A and Lum B subgroups. MKI67 is one gene known to be highly expressed in Lum B tumors, encoding the Ki-67 protein, a robust marker of cell proliferation. In this study, we perform IHC analysis of Ki-67 in a large breast cancer tissue microarray. Methods: Our patient cohort consists of 2222 consecutive cases of invasive breast cancer referred to the BC Cancer Agency from 1986 to 1992. Archival paraffin tissue blocks were used to construct a tissue microarray that was then stained for Ki-67 using a commercially available mouse monoclonal antibody. Ki-67 staining was scored quantitatively by automated image analysis and a tumor was positive if the percent positive nuclei was >30%’ Results: Of the 2,222 patients, there are 1,437 Luminal tumors as defined by IHC (ER or PR positive). As Her2 positive status is an established marker of poor prognosis, we excluded these tumors from our analysis. Of the remaining tumors, 9% were Ki-67 positive when using a ki-67 cut off of 30% positive nuclei. In survival analysis of patients ER/PR positive and Her2 negative, we found that Ki-67 identifies a population with poor prognosis (10-yr BCSS 60% vs. 80%). In a multivariate Cox regression we found that Ki-67 is independently prognostic. We repeated Cox regression analysis including only node negative patients and again found that Ki-67 is an independent predictor of poor outcome. Conclusions: Ki-67 has prognostic significance on multivariate survival analysis. Hormone receptor positive and node negative status is typically associated with a favorable outcome for breast cancer. However, Ki-67 is able to identify a small, but clinically significant subgroup with a particularly poor outcome. Defining the Luminal B subtype as (ER or PR) positive and (HER2 or Ki-67) positive, results in a subgroup that contains 18% of hormone receptor positive breast cancers with 10-yr BCSS of 61%.

No significant financial relationships to disclose.

Kidney transplantation outcomes in Canadian aboriginals

Aboriginal populations experience a very high rate of end-stage renal disease (ESRD); however, little is known about the outcomes of transplantation in this population. We performed a retrospective database review to determine the short- and long-term outcomes of kidney transplantation in Aboriginals. Adult Aboriginal (AB) and Caucasian (C) individuals receiving primary kidney transplants between 1969 and 2003 in Manitoba, Canada were examined. A total of 705 recipients were included (126 AB and 579 C). AB recipients were younger, had different etiologies of ESRD, longer cold-ischemic times for deceased donor transplants, and higher peak panel reactive antibody levels. At 1 year post-transplant, there was no difference in serum creatinine, acute rejection or graft survival between AB and C recipients. However, AB recipients experienced greater weight gains early post-transplant and were more likely to develop post-transplant diabetes mellitus. AB recipients exhibited inferior 10-year graft (AB 26% vs. C 47%, p < 0.01) and patient survival (AB 50% vs. 75%, p < 0.01). When graft survival was censored for death with a functioning graft, there was no difference between the two groups. Multivariate analysis revealed AB race to be an independent predictor of premature graft failure and patient death. In conclusion, kidney transplant outcomes have historically been inferior in the Manitoba population of Canadian Aboriginals.

p63 Expression in Lung Carcinoma

p63 is a recently discovered member of the p53 family that has been shown to be important in the development of epithelial tissues. p63 may also play a role in squamous cell carcinomas of the lung, head and neck, and cervix, and its expression is increased in these tumors. The purpose of this study was to investigate the expression of p63 in a broad spectrum of histologic types of lung tumors. A total of 441 cases of primary lung tumors with follow-up data were identified, and the paraffin-embedded tissue blocks were used to construct a duplicate core tissue microarray. After review of the tissue cores, 408 cases, consisting of 123 squamous cell carcinomas, 93 adenocarcinomas, 68 large cell carcinomas, 68 classic carcinoids, 31 atypical carcinoids, 11 large cell neuroendocrine carcinomas, and 14 small cell carcinomas, were adequate for analysis. Immunohistochemistry was performed at 2 different laboratories using monoclonal antibody 4A4 to detect the expression of p63, using different staining protocols. p53 expression was also studied with immunohistochemistry using monoclonal antibody DO-7. Kaplan-Meier curves were plotted to compare the survival of p63-expressing versus nonexpressing tumors. A large proportion of squamous cell carcinomas expressed p63 (96.9%), most showing strong positive nuclear immunoreactivity. Expression in other nonsmall cell lung cancers was also present. Thirty percent of adenocarcinomas and 37% of large cell carcinomas showed p63 expression. In the neuroendocrine tumors, an increasing proportion of tumors stained for p63 as tumor grade increased; 1.9% of classic carcinoids, 30.8% of atypical carcinoids, 50% of large cell neuroendocrine carcinomas, and 76.9% of small cell carcinomas were positive. Approximately half of the positively staining neuroendocrine cases showed strong staining. Expression of p63 was of prognostic significance in neuroendocrine tumors (P < 0.0001), with higher-grade tumors more likely to express p63. Correlation between p63 and p53 expression was not observed (P = 0.18) in nonsmall cell lung cancer; however, a significant correlation between the 2 markers was found in neuroendocrine tumors (P < 0.0001). p63 staining was repeated with a different staining protocol, yielding similar results overall but a lower percentage of positive cases (34.2% vs. 48.4% of tumors positive). In conclusion, p63 expression is consistently expressed in squamous cell carcinoma in the lung, but is also expressed in a subset of adenocarcinomas and large cell carcinomas. Pulmonary neuroendocrine tumors also show p63 staining in some instances, particularly in higher-grade tumors, and the majority of small cell carcinomas are p63-positive. These results suggest that p63 may be involved in oncogenesis in a broader range of tumors than was previously thought.

Evaluation of immunohistochemical markers in non-small cell lung cancer by unsupervised hierarchical clustering analysis: a tissue microarray study of 284 cases and 18 markers

This study has investigated a panel of immunomarkers in non-small cell lung carcinoma (NSCLC). Unsupervised hierarchical clustering analysis was used to investigate the possibility of identifying different subgroups in NSCLC based on their molecular expression profile rather than morphological features. A tissue microarray consisting of 284 cases of NSCLC was constructed. Immunohistochemistry was used to detect the presence of 18 biomarkers including synaptophysin, chromogranin, bombesin, NSE, GFI1, ASH-1, p53, p63, p21, p27, E2F-1, cyclin D1, Bcl-2, TTF-1, CEA, HER2/neu, cytokeratin 5/6, and pancytokeratin. Univariate analysis of all 18 markers for prognostic significance was performed. Immunohistochemical scoring data for NSCLC were analysed by unsupervised hierarchical clustering analysis. Kaplan-Meier survival curves were plotted for the different cluster groups of lung tumours identified by this method. Analysis of the three different World Health Organization (WHO) subtypes (adenocarcinoma, squamous cell carcinoma, large cell carcinoma) of NSCLC individually showed that different markers were significant in different subtypes. For example, p53 and p63 were significant for squamous cell carcinoma (p = 0.007 and p = 0.03, respectively), whereas cyclin D1 and HER2/neu were significant prognostic markers for adenocarcinoma (p = 0.025 and p = 0.015, respectively). These markers were not significant prognostic predictors for NSCLC as a group. Hierarchical clustering analysis of NSCLC produced four separate cluster groups, although the vast majority of cases were found in two cluster groups, one dominated by squamous cell carcinoma and the other by adenocarcinoma. The clinical outcomes of cases from the four cluster groups were not significantly different. Prognostic indicators vary between different morphological subtypes of NSCLC. Unsupervised hierarchical clustering analysis, based on an extended immunoprofile, identifies two main cluster groups corresponding to adenocarcinoma and squamous cell carcinoma; cases of large cell carcinomas are assigned to one of these two groups based on their molecular phenotype.

Mental disorders and public safety of the community at large--does the Tarasoff principle apply in Singapore?

The Tarasoff Principle is a legal ruling arising out of the Tarasoff case in California, in which 2 therapists were found by a court to be negligent for not warning an intended victim of a threat to her by their mentally disordered patient, and she was subsequently killed. The 2 therapists were deemed to have an obligation to protect an intended victim of a patient who presented a serious danger of violence. The question is whether this would apply under Singapore law, and whether an act of disclosure to protect a victim would be a breach of confidentiality and the doctor-patient relationship.

HLA-A and HLA-B in Kenya, Africa: allele frequencies and identification of HLA-B*1567 and HLA-B*4426

HLA-A and HLA-B alleles of a population from Kenya, Africa were examined by sequencing exon 2 and exon 3 DNA and typing using a Taxonomy-based Sequence-analysis (TBSA) method. Extensive diversities were observed at both HLA-A and HLA-B loci in this population. Forty-one HLA-A alleles were identified from 159 unrelated individuals. The most frequently observed alleles were A*6802 (11.64%), A*02011/09 (9.75%), A*7401/02 (9.43%), A*3001 (7.86%), A*3002 (7.23%) and A*3601 (6.6%). Forty-nine HLA-B alleles were identified in 161 unrelated individuals, including two novel alleles, B*1567 and B*4426. The most frequently observed HLA-B alleles were B*5301 (9.01%), B*5801 (8.38%), B*4201 (7.76%), B*1503 (7.14%), B*1801 (6.21%), and B*5802 (5.90%). The most frequently observed HLA-A-B haplotypes were A*3601-B*5301 (3.55%) and A*3001-B*4201 (3.19%), followed by A*7401/02-B*5801 (2.84%), A*7401/02-B*5802 (2.84%) and A*02011/09-B*1503 (2.13%). Linkage disequilibrium and chi2 analysis showed the association of these HLA-A-B haplotypes at the antigen level to be significant. The frequencies of HLA-A and HLA-B alleles from the Kenyan population were compared with that of a population from Cameroon. The difference in allele and haplotype frequency distributions partly reflected the different ethnic composition of these two African populations.

Fractal or biologically variable delivery of cardioplegic solution prevents diastolic dysfunction after cardiopulmonary bypass

OBJECTIVE

To determine whether myocardial protection is improved by restoring physiologic variability to the cardioplegia pressure signal during cardiopulmonary bypass, we compared cardiac function in pigs in the first hour after either conventional cold-blood cardioplegia (group CC) or computer-controlled biologically variable pulsatile cardioplegia (group BVC).

METHODS

Invasive monitors and sonomicrometry crystals were placed, and cardiopulmonary bypass was initiated. The aorta was crossclamped, and cold blood cardioplegic solution was infused intermittently through the aortic root with either conventional cardioplegia (n = 8) or biologically variable pulsatile cardioplegia (n = 8; mean pressure, 75 mm Hg for 85 minutes). The crossclamp was released, cardiac function was restored, and separation from cardiopulmonary bypass was completed. With stable temperature and arterial blood gases, hemodynamics and systolic and diastolic indices were compared at 15, 30, and 60 minutes after cardiopulmonary bypass.

RESULTS

Diastolic stiffness doubled from 0.027 +/- 0.016 mm Hg/mm (mean +/- SD) at baseline to 0.055 +/- 0.036 mm Hg/mm (P =.003) at 1 hour after bypass in group CC, associated with increased left ventricular end-diastolic pressure from 9 +/- 2 to 11 +/- 2 mm Hg (P =.001), mean pulmonary artery pressure from 14 +/- 2 to 20 +/- 3 mm Hg (P =.003), and serum lactate levels from 2.0 +/- 0.5 to 5.6 +/- 2.3 mmol/L (P =.008). Systolic function was not affected. In group BVC diastolic stiffness, left ventricular end-diastolic pressure, and pulmonary artery pressure values were not different from control values at any time after bypass, and serum lactate levels were significantly less than with conventional cold blood cardioplegia. Peak pressure variability with biologically variable pulsatile cardioplegia fit a power-law equation (exponent = -3.0; R(2) = 0.97), indicating fractal behavior.

CONCLUSION

Diastolic cardiac function is better preserved after cardiopulmonary bypass with biologically variable pulsatile cardioplegia and fractal perfusion. This may be attributed to enhanced microcirculatory perfusion with improved myocardial protection. A model supporting these results is presented.

Evaluation of primary hemostasis in neonates with a new in vitro platelet function analyzer

With the use of the PFA-100 platelet function analyzer to evaluate primary hemostasis in whole blood, measured as closure time (CT), neonates had shorter CTs than members of an adult control group. Multivariate analysis of measures that contribute to primary hemostasis showed that higher hematocrits and increased ristocetin cofactor activity were the best correlates for CTs of cord blood. These 2 factors may also enhance primary hemostasis in vivo and compensate for the impaired platelet function of the newborn.

Association of Chlamydia trachomatis heat-shock protein 60 antibody and HLA class II DQ alleles

A total of 113 female commercial sex workers had individual alleles for HLA class II genes determined by using labeled sequence-specific oligonucleotide probes to hybridize to polymerase chain reaction products of amplified DNA. Women also had microimmunofluorescent (MIF) antibody titers to Chlamydia trachomatis elementary bodies and ELISA antibody to recombinant chlamydial heat-shock protein 60 (Chsp60) determined. Women were prospectively followed at monthly intervals over 2 years for incident C. trachomatis infection and acute pelvic inflammatory disease (PID). HLA DQA1*0401 and DQB1*0402 alleles were statistically associated with increased prevalence and amount of antibody to Chsp60 but not MIF antibody. However, these alleles did not alter the risk for chlamydial PID. The potential role that HLA DQ may play in chlamydial disease pathogenesis requires further study.

Herpes zoster and multiple sclerosis

BACKGROUND

Clinical experience suggests that young multiple sclerosis patients may have herpes zoster (HZ) earlier and more often than the general population. As there is evidence of a relationship between varicella zoster virus (VZV) and MS, a study of HZ and MS was undertaken.

METHODS

Eight hundred and twenty-nine patient-members of the Manitoba Chapter of the Canadian Multiple Sclerosis Society were surveyed by mail. Six hundred and thirty-three (76%) responded. Questions included: age at diagnosis of MS, history of HZ (yes, no, probably), number of episodes of HZ and age at each occurrence, date of birth, and sex of respondent. The controls were consecutive patients with other neurological diseases (OND) attending local neurological or neurosurgical clinics, plus practice-based and population-based surveys of herpes zoster without reference to any other disease. The OND controls were assessed at the time of their outpatient visits.

RESULTS

In the MS group with a positive/probable history of HZ, the HZ/MS rate was 106/633 (16.8%); in the practice-based survey the rate was 192/3534 (5.4%); and among the patients with OND it was 42/616 (6.8%). The HZ occurred at an earlier age in the MS group. The majority of male patients had HZ prior to the diagnosis of MS. The date of diagnosis is more likely to be a precise memory as opposed to the onset of symptoms. More than one attack of HZ was also more common in the MS group.

CONCLUSIONS

This survey adds to the evidence that patients with MS have a unique relationship with the herpes zoster virus.

HLA associations of seropositive rheumatoid arthritis in a Cree and Ojibway population

OBJECTIVE

To determine the HLA associations of seropositive rheumatoid arthritis (RA) in a Cree and Ojibway population; to determine whether specific alleles distinguish juvenile or adult onset.

METHODS

HLA-A, B, C, and DRB1 alleles were analyzed in 23 Ojibway and Cree patients with RA seen in a single tertiary care center. Comparisons were made with published results of controls and with results of 18 patients with rheumatoid factor (RF) positive polyarticular juvenile rheumatoid arthritis (JRA) from the same population.

RESULTS

Comparisons among patients with RA, patients with RF positive polyarticular JRA, and controls showed increased frequencies of the RA shared epitope in patients with RA and of DRB1*0901 in patients with seropositive polyarticular JRA, while the frequency of DRB1*08 alleles was decreased in patients with RF positive polyarticular JRA.

CONCLUSION

In this population, DRB1*0901 may promote while DRB1*08 alleles may protect against a juvenile onset of RA specifically. In contrast, the RA shared epitope may have a greater effect on the risk of adult onset seropositive RA. Due to the small patient numbers, these results require confirmation.

Beneficial effects of treatment of early subclinical rejection: a randomized study

The prevalence of subclinical rejection, by the Banff criteria, is approximately 30% in the first 3 mo in renal transplant recipients. A randomized study was performed to determine whether the treatment of subclinical rejection with corticosteroids was associated with improved outcomes in these patients. Seventy-two patients, stratified by donor source, were randomized to biopsies at 1, 2, 3, 6, and 12 mo (Biopsy group), or to 6- and 12-mo biopsies only (Control group). Patients were analyzed by "intent to treat" and were followed for a minimum of 2 yr. Patients in the Biopsy arm of the study had a significant decrease in early (months 2 and 3) and late (months 7 to 12) acute rejection episodes, a reduced chronic tubulointerstitial score at 6 mo, and a lower serum creatinine at 24 mo than did patients in the Control arm. There was a trend toward an increase in infectious morbidity, but no increase in mortality, in the patients randomized to the Biopsy group. The results of this study suggest that early protocol biopsies and the treatment of subclinical rejection with corticosteroids may lead to better histologic and functional outcomes in renal transplant recipients.

Juvenile rheumatoid arthritis in a Canadian First Nations (aboriginal) population: onset subtypes and HLA associations

OBJECTIVE

To determine onset subtypes and HLA associations of juvenile rheumatoid arthritis (JRA) in a First Nations (aboriginal) population; to determine whether population frequencies of HLA antigens may explain the distribution of subtypes of JRA in this population.

METHODS

All patients were children from Manitoba and Northwestern Ontario seen in a single pediatric rheumatology clinic between 1975 and 1996. Patients were identified from a clinic registry. Controls were adults of Algonkian Cree and Ojibway heritage. Class I and II major histocompatibility (HLA) typing was performed for First Nations patients and controls.

RESULTS

There were a total of 74 First Nations patients with JRA. The relative frequency of rheumatoid factor (RF) positive polyarticular JRA was higher and that of pauciarticular JRA was lower in First Nations compared with Caucasian patients (42 versus 3% and 22 versus 58%, respectively; p = 0.00000). HLA-DRB1*04 (63%), 08 (43%), and 1402 (25%) were the most common DRB1 antigens among controls. The main subtypes of DRB1*04 were 0404 (33% of controls) and 0407 (23%). HLA typing was performed for 39 First Nations patients; 27 were Cree or Ojibway, 4 were from other tribes, and 8 were part First Nations. Among Cree and Ojibway, 59% of controls and 63% of patients with RF positive polyarticular JRA (n = 16) had HLA-DRB1 antigens bearing the rheumatoid arthritis (RA) shared epitope (OR 1.16, 95% CI: 0.38, 3.48). The OR for polyarticular RF positive JRA in those with DRB1*0802 and 0901 were 0.15, 95% CI: 0.02; and 1.24 and 5.83, 95% CI: 1.58, 28.38, respectively.

CONCLUSION

There was a high frequency of the RA shared epitope represented by both HLA-DRB1*0404 and 1402 in this Algonkian population. This high frequency may explain the high frequency of RF positive polyarticular JRA. DRB1*0802 may be protective, whereas DRB1*0901 may increase the risk for this subtype of JRA.

Identification of clinical and histopathologic risk factors for diminished renal function 2 years posttransplant

The aim of this study was to identify early clinical and pathologic variates that independently predict diminished renal allograft function at 24 mo posttransplant. A clinical pathologic data base was prospectively derived from 71 patients in whom protocol renal biopsies were performed at 1, 2, 3, 6, and 12 mo posttransplant. The major end point was the 24-mo serum creatinine. Variates correlating independently (r2 = 0.67) with the 24-mo serum creatinine were the chronic biopsy scores (months 3 and 6), late rejections (months 4 to 6), cyclosporin A (CsA) levels (months 1 to 2), and delayed graft function. The adjusted odds ratio (OR) and 95% confidence interval (CI) for having a serum creatinine > or = 130 mumol/L at 24 mo increased for every year the donor age increased (OR = 1.07; 95% CI, 1.02 to 1.13; range, 9 to 55) or for each late rejection episode (OR = 5.9; 95% CI, 1.7 to 20.1), whereas a mean CsA level > 300 micrograms/L from months 1 to 3 was protective (OR = 0.07; 95% CI, 0.01 to 0.43). Variates correlating independently (r2 = 0.53) with the change in serum creatinine from 6 to 24 mo (delta Cr6-24) were the chronic biopsy scores at months 3 and 6. The adjusted OR of the delta Cr6-24 rising > or = +20 mumol/L increased for every year the donor age increased (OR = 1.09; 95% CI, 1.02 to 1.16; range 9 to 56) or when the 6-mo chronic biopsy score was > or = 2 (OR = 6.6; 95% CI, 1.2 to 36.4). An estimate of the relative risk for diminished renal function at 2 yr can be assigned within 6 mo of transplant based on chronic pathology, late acute rejections, CsA levels, and donor age.

Quantification of the placebo response in ulcerative colitis

BACKGROUND & AIMS

There is consistently a measurable benefit noted among placebo users in treatment trials of ulcerative colitis (UC). The aim of this study was to define the placebo response in active UC and identify study features that influence the placebo response.

METHODS

MEDLINE database was searched for placebo-controlled treatment studies of active UC. Data extraction was performed by two reviewers, and one separate investigator reviewed all trials and data extraction before data tabulation. Placebo remission and benefit rates were determined for clinical, endoscopic, and histological outcomes. Synthesis analysis on the weighted proportions from the different studies explored the placebo response as it related to eight study variables.

RESULTS

Thirty-eight of 44 studies identified were included in the analysis. The clinical remission rate was 9.1% (confidence interval [CI], 6.6-11.6) and the benefit rate was 26.7% (CI, 24.1-29.2). Similar rates were observed endoscopically and histologically. The number of study visits (< or =3 vs. >3) modified placebo response as assessed by clinical benefit (P = 0.05), endoscopic remission (P = 0.02), and histological remission (P = 0.04). Other study variables were not significant placebo response modifiers.

CONCLUSIONS

In trials of active UC, the placebo remission rate is approximately 10% and the placebo benefit rate is approximately 30%. These rates are consistent regardless of assessment end point. The placebo response is greater in trials with more frequent study visits (more than three).

Varicella zoster antibodies after herpes zoster, varicella and multiple sclerosis

BACKGROUND

We previously showed that Manitoba Hutterites seek physician care for varicella zoster virus infection significantly less than non-Hutterites. The current study was undertaken to measure varicella zoster virus seroprevalence for Hutterite and non-Hutterite controls.

METHODS

Blood was obtained from 315 Hutterites and 259 similar age and sex controls at the time of blood donations to The Canadian Red Cross Society. The controls were from the same or a contiguous postal code area and were collected at the same time as the Hutterite samples. The immune status of the specimens was determined by the ELISA method (enzyme linked immunosorbent assay).

RESULTS

Twenty-eight per cent of 315 Hutterites had no immunity and an additional 25% had only marginal immunity. Among the 259 controls, 10% had no immunity and an additional 10% had only marginal immunity (p < .0001).

CONCLUSIONS

Manitoba Hutterites have significantly decreased seroprevalence to varicella zoster virus infection. This study of serum varicella zoster virus antibodies verifies a previous population based study that demonstrated the relative rarity of varicella and herpes zoster among a particular population group.

Antibody to chlamydial hsp60 predicts an increased risk for chlamydial pelvic inflammatory disease

To determine whether serum antibody to Chlamydia trachomatis antigens alters the risk of C. trachomatis pelvic inflammatory disease (PID), 280 female sex workers were prospectively evaluated over a 33-month period for incident C. trachomatis and Neisseria gonorrhoeae cervical infection and for clinical PID. At enrollment, women were tested for antibody to C. trachomatis elementary bodies by an indirect microimmunofluorescence assay and to recombinant chlamydial hsp60 (Chsp60) by an ELISA format. At each follow-up visit, women were tested for cervical chlamydial and gonococcal infection and were identified as having clinical PID if they complained of lower abdominal pain and were found to have uterine and adnexal tenderness on pelvic examination. The data demonstrate that antibody to Chsp60 predicts a 2- to 3-fold increased risk for C. trachomatis PID.

A citywide analysis of the utilization of common laboratory tests and imaging procedures in ICUs

OBJECTIVE

To identify and discriminate between patient and institutional determinants of investigation costs in the ICU.

DESIGN

Retrospective survey.

SETTING

All seven hospitals in the city of Winnipeg, Manitoba, Canada.

PARTICIPANTS

One hundred consecutive admissions to each of 11 ICUs. Two teaching hospitals (TH1 and TH2) each have three units (medical, surgical, and coronary care), the five community hospitals (CHs) have single combined units. TH1 operates an information-based management system.

MEASUREMENTS

Each admission was categorized as MEDICAL, SURGICAL, or CARDIAC. The frequency and cost of 17 laboratory or imaging procedures were collected for each admission. Demographic data included age, length of ICU stay, APACHE II (acute physiology and chronic health evaluation) score, therapeutic intervention scoring system (TISS) data, and ICU survival. The primary diagnosis on admission and acquisition of significant problems or complications after admission were collected.

RESULTS

Multivariate models revealed that length of stay, TISS score, and acquisition of a problem after ICU admission were strongly associated with increased costs in all categories (p=0.0001). Admission to TH2 was associated with greater costs in all categories (p=0.0001 MEDICAL and CARDIAC; p=0.0016 SURGICAL). Admission to a CH was associated with lower cost for SURGICAL admissions (p=0.0014), but costs at CHs were not significantly lower than at TH1 for MEDICAL (p=0.18) or CARDIAC (p=0.22) admissions.

CONCLUSIONS

ICU investigation costs vary significantly between institutions and are not always linked to patient-dependent factors. Acquisition of nosocomial and iatrogenic events during ICU admission increases costs dramatically. Costs are not necessarily greater in teaching hospitals.

Common infectious diseases in a population with low multiple sclerosis and varicella occurrence

A previous study revealed the rarity of varicella zoster virus (VZV) diseases among 5601 Hutterite Brethren living in a high-risk area for these diseases. The current study was established to determine the frequency of other common infectious diseases. The information was gathered from a population-based study of a unique group of Manitoba citizens and compared with an equal number of their age and sex-matched neighbors. The data were contained in the records of the Manitoba Health Services Commission (MHSC). The MHSC, the sole paying agency for medical diseases in Manitoba, contained 94,383,972 records for all of Manitoba for the years 1985 to 1991 inclusive. From these, the records of a cohort of 5601 Hutterites and an equal number of non-Hutterite age- and sex-matched controls were examined for the frequency of 14 diseases of interest. To be eligible a Hutterite subject must have one of the 22 unique family names and live on a Colony with the precise address. A control must be age (within 10 years) and sex-matched, live in the same or a contiguous postal code, and use the same medical practitioners. There were no interventions or identification of any member of the study. Mumps, acute coryza, and rubella are of the same frequency among the two groups. Only herpes simplex and cellulitis are more common among the Hutterites. All of the other nine common infectious diseases are significantly more common among the controls. The VZV diseases are not exclusively less common among the Hutterite Brethren. Nine other common infectious diseases are also less common but the degree of significant difference does not reach the level of the VZV diseases. The reduction in numbers of these diseases among the Hutterites is not related to the vaccination habits of the group and is not due to physical isolation. The Hutterites appear to have a more effective immune system relative to their neighbors.

The varicella zoster virus: a pilot trial of a potential therapeutic agent in multiple sclerosis

There are a number of similarities in the geographic, latitudinal, and epidemiological features of multiple sclerosis (MS) and varicella (V). In the experimental model of MS, repeated high antigen doses (myelin basic protein) have deleted both the clinical and pathological manifestations of the disease. Therefore, it seemed appropriate to explore the effects of varicella zoster vaccine on patients with MS. Fifty patients with chronic progressive MS were vaccinated with attenuated varicella virus vaccine and followed for one year. Fourteen patients improved, four became worse, and twenty-nine were unchanged. All patients were seropositive for varicella before vaccination and all had a rise in varicella antibodies after the vaccinations. There were no major untoward results from the vaccine. Four patients developed mild chicken-pox after vaccination. This was a short-term pilot trial without control subjects. Thus, the apparently favourable clinical and magnetic imaging changes must be assessed with caution, as must the lack of adverse effects.

Epidemiology of chronic arthritis in childhood

This study was performed to review reports of the descriptive epidemiology of chronic arthritis in childhood and to analyze the factors that may explain differences in its reported frequency. Articles were retrieved by searching MEDLINE and EMBASE under the following index terms: juvenile rheumatoid arthritis (JRA), juvenile chronic arthritis (JCA), spondyloarthropathy, epidemiology, prevalence, and incidence. For reports published between 1977 to 1982, the Index Medicus was used. All original articles that provided prevalence or incidence rates, population size, or number of cases, were reviewed and entered into the analysis. Variables analyzed were disease prevalence and incidence. Modifier variables investigated were diagnostic criteria, source population, geographic origin of the report (Europe or North America), duration of the study, and race of the population studied. Diagnostic criteria had no effect on reported prevalence or incidence rates. Prevalence per 100,000 at risk obtained from population studies (132, 95% CI: 119, 145) was significantly higher than values derived from practitioner- (26, 95% CI: 23, 29) or clinic-based studies (12, 95% CI: 10, 15) (P = .02). North American clinic-based studies had higher prevalence values compared with European reports (32, 95% CI: 26, 38 versus 8, 95% CI: 5, 11, P = .009). None of the factors analyzed accounted for the variability in reported incidence rates. An effect of race was detected only in the distribution of patients among onset subsets. Thus, the percentage of patients with pauciarticular JRA was highest in series of North American and European caucasian patients (58, 95% CI: 56, 60) compared with series of East Indian (25, 95% CI: 20, 31), native North American Indian (26, 95% CI: 15, 37), or other races (31, 95% CI: 28, 35) (P = .001). In contrast, the percentage of patients with polyarticular JRA was lowest in the former (27, 95% CI: 25, 28) compared with the other racial groups (East Indian, 61, 95% CI: 55, 66; native North American Indian, 64, 95% CI: 53, 76; other races, 34, 95% CI: 30, 38) (P = .004). Although an effect of source population on reported prevalence was confirmed, the effect of geographic origin suggests that environmental or ethnic differences also may influence the prevalence of chronic arthritis in children. Differences in the percentages of patients with pauciarticular and polyarticular JRA may reflect racial differences in the prevalence of these conditions.

Risk factors for Chlamydia trachomatis pelvic inflammatory disease among sex workers in Nairobi, Kenya

Among 302 female sex workers in Nairobi, Kenya, who were followed for 17.6 +/- 11.1 months, 146 had one or more infections with Chlamydia trachomatis; 102 had uncomplicated cervical infection only, 23 had C. trachomatis pelvic inflammatory disease (PID), and 21 had combined C. trachomatis and Neisseria gonorrhoeae PID. As determined by multivariate logistic regression analysis, risk factors for C. trachomatis PID included repeated C. trachomatis infection (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.4; P = .0004), antibody to C. trachomatis heat-shock protein 60 (OR, 3.9; CI, 1.04-14.5; P = .04), oral contraceptive use (OR, 0.28; 95% CI, 0.08-0.99; P = .048), and number of episodes of nongonococcal nonchlamydial PID (OR, 1.7; 95% CI, 1.1-2.7; P = .02). Among human immunodeficiency virus (HIV)-seropositive women, a CD4 lymphocyte count of <400/mm3 was an additional independent risk factor for C. trachomatis PID (OR, 21.7; 95% CI, 1.2-383; P = .036); among HLA-typed women, HLA-A31 was independently associated with C. trachomatis PID (OR, 5.6; 95% CI, 1.1-29.4; P = .043). The results suggest an immune-mediated pathogenesis for C. trachomatis PID.

The epidemiology of Chlamydia trachomatis within a sexually transmitted diseases core group

Female sex workers in Nairobi were prospectively evaluated for risk factors of incident Chlamydia trachomatis infection. Independent risk factors included cervical ectopy (P=.007), gonococcal infection (P=.002), human immunodeficiency virus (HIV) seropositivity (P=.003), HIV seroconversion (P=.001), and duration of prostitution (P=.002). Eighteen different C. trachomatis outer membrane protein (omp1) genotypes were identified, with the allelic composition of the C. trachomatis population changing significantly over time (P=.005). Seventeen of 19 reinfections > or = 6 months apart were with different C. trachomatis omp1 genotypes. Women with HIV infection had an increased proportion of visits with C. trachomatis infection (P=.001) and an increased risk of reinfection (P=.008). Overall, the data demonstrate significant fluctuations in the genotype composition of the C. trachomatis population and a reduced rate of same-genotype reinfection consistent with the occurrence of strain-specific immunity.

The M1 gene is associated with differences in the temperature optimum of the transcriptase activity in reovirus core particles

The reovirus core is a multienzyme complex that contains five different structural proteins and 10 segments of double-stranded RNA. The core is responsible for transcribing mRNA from the enclosed double-stranded RNA. The reovirus transcriptase has an unusual temperature profile, with optimum transcription occurring at approximately 50 degrees C and little activity occurring below 30 or above 60 degrees C. Purified reovirus serotype 1 Lang (T1L) cores transcribed most efficiently at 48 degrees C. The transcriptase temperature optimum of purified reovirus serotype 3 Dearing (T3D) cores was 52 degrees C. In addition, T1L cores produced more mRNA per particle than did T3D cores at their respective temperature optima. Core particles were purified from T1L x T3D reassortants and were used to map these differences. The M1 gene, which encodes minor core protein mu 2, was uniquely associated with the difference in temperature optimum of transcription (P = 0.0003). The L1 gene, which encodes minor core protein lambda 3 (previously implicated as the RNA polymerase), and the M1 gene were associated with the difference in absolute amounts of transcript produced (P = 0.01 and P = 0.0002, respectively). These data suggest that minor core protein mu 2 also plays a role in reovirus transcription.

Long-term outcome of radical radiation therapy for prostatic carcinoma: 1967-1987

PURPOSE

This study was done to review long-term results of radical radiotherapy for prostate cancer.

METHODS AND MATERIALS

The records of 674 patients with Stage T1a, T1b, T2a, T2b, T3, and any T,N1,M0 disease, treated with external beam radiotherapy between January 1, 1967 and December 1987, were reviewed. These patients were treated to an average total dose of 66 Gy, with an average fractional dose of 2.05 Gy, using megavoltage. The duration of follow-up for surviving patients ranged from a minimum of 7 years to more than 20 years.

RESULTS

The survival for 151 Stage T1a,T1b patients was 98.5% at 5 years, 93.6% at 10 years, and 75.2% at 15 years. Survival for 346 Stage T2a,b patients was 94.4% at 5 years, 67.9% at 10 years, and 41.5% at 15 years. Survival for 92 Stage T3 patients was 87.3% at 5 years, 54% at 10 years, and 26.6% at 15 years. The survival for 85 any T,N1,M0 patients was 73.9% at 5 years, 34.4% at 10 years, and 8.5% at 15 years. At 15 years, 75.2% of Stage T1a,b patients, 41.5% of Stage T2a,b patients, 21.7% of Stage T3 patients, and 8.5% of Stage T,N1,M0 patients remained free of local recurrence and distant metastases. The elevation of prostatic acid phosphatase prior to radiotherapy was an unfavorable prognostic factor, with impact on both loco-regional recurrences and survival.

CONCLUSIONS

The external beam radiotherapy for localized carcinoma of the prostate produced a good loco-regional control, NED, and overall survival. Patients with smaller tumors and low grade fared better than the ones with more aggressive and/or bulky tumors. The weakness of this study is the absence of serial prostate-specific measurements, which were not available during the period under study. The complication rate requiring surgical intervention was low, i.e. 0.4%.

Analysis of Tcrvb8, Il4, and Ifg as genetic predisposition factors for atopic IgE response in a murine model

Allergen-induced synthesis of lgE Abs in genetically predisposed individuals constitutes the hallmark of allergic diseases; however, the molecular basis of this genetic predisposition remains unknown. T cell cytokines lL-4 and IFN-gamma reciprocally regulate lgE synthesis and are potential genetic factors governing atopy. To examine the inheritance patterns of IgE responsiveness and address the role of these cytokines as genetic predisposition factors, in this study we established a MHC-identical mouse colony comprising crosses between two inbred strains of mouse, A.SW and SJL, respectively representing high and low IgE responder phenotypes. Segregation analysis with 149 [(A.SW x SJL)F1 x SJL] backcross and 148 [(A.SW x SJL)F1 x F1]F2 mice suggested that persistent high IgE responsiveness was inherited as a simple Mendelian dominant trait under the control of a single non-MHC, autosomal gene of major effect in these strains. Since SJL lacked Tcrvb8 genes, we examined the possibility of Tcrvb8 as a candidate gene for IgE responsiveness. The results suggested association of neither the Tcrvb8 gene nor its expression with allergen-induced IgE phenotype. Furthermore, microsatellite marker and gene sequencing analyses revealed that neither of the ll4 and lfg genes was associated with IgE phenotype. Moreover, correlation studies between IgE and cytokine levels in splenocyte cultures indicated that IgE levels were moderately to poorly correlated with IL-4 and IFN-gamma levels. It is concluded that even though expression of Tcrvb8, II4, and Ifg genes may play pivotal roles in IgE regulation, these genes per se do not contribute to genetic predisposition of allergen-induced IgE hyperresponsiveness in these strains of mice.

Analysis of Tcrvb8, Il4, and Ifg as genetic predisposition factors for atopic IgE response in a murine model

Allergen-induced synthesis of lgE Abs in genetically predisposed individuals constitutes the hallmark of allergic diseases; however, the molecular basis of this genetic predisposition remains unknown. T cell cytokines lL-4 and IFN-gamma reciprocally regulate lgE synthesis and are potential genetic factors governing atopy. To examine the inheritance patterns of IgE responsiveness and address the role of these cytokines as genetic predisposition factors, in this study we established a MHC-identical mouse colony comprising crosses between two inbred strains of mouse, A.SW and SJL, respectively representing high and low IgE responder phenotypes. Segregation analysis with 149 [(A.SW x SJL)F1 x SJL] backcross and 148 [(A.SW x SJL)F1 x F1]F2 mice suggested that persistent high IgE responsiveness was inherited as a simple Mendelian dominant trait under the control of a single non-MHC, autosomal gene of major effect in these strains. Since SJL lacked Tcrvb8 genes, we examined the possibility of Tcrvb8 as a candidate gene for IgE responsiveness. The results suggested association of neither the Tcrvb8 gene nor its expression with allergen-induced IgE phenotype. Furthermore, microsatellite marker and gene sequencing analyses revealed that neither of the ll4 and lfg genes was associated with IgE phenotype. Moreover, correlation studies between IgE and cytokine levels in splenocyte cultures indicated that IgE levels were moderately to poorly correlated with IL-4 and IFN-gamma levels. It is concluded that even though expression of Tcrvb8, II4, and Ifg genes may play pivotal roles in IgE regulation, these genes per se do not contribute to genetic predisposition of allergen-induced IgE hyperresponsiveness in these strains of mice.

Varicella zoster virus and multiple sclerosis in a Hutterite population

There are similarities between multiple sclerosis and varicella. They are common in the same parts of the world and both are scarce in other areas. Immigration studies suggest the environmental cause of multiple sclerosis (MS) must be contracted prior to age 15 years and will usually remain dormant for years. At age 10 years varicella has occurred in greater than 95% of children living in the high-risk areas for both of these diseases. The varicella zoster virus (VZV) could be etiologically important in multiple sclerosis. The known host containment of the virus for decades with recrudescence and the variable cell-mediated immunity of the host, which can wax and wane without clinical manifestations, all lend themselves to the natural history of multiple sclerosis. A population-based study of the medical records of 5601 Hutterite Brethren was performed to determine the occurrence of multiple sclerosis, varicella, and herpes zoster. Compared to their matched non-Hutterite neighbors who acted as controls, these events were significantly less common among the Hutterites. Included in the study was an assessment of other common neurological diseases and "autoimmune" diseases among the Hutterites and the controls. There is evidence of a relationship between MS and VZV that may not be coincidental.

Haemodynamic instability and myocardial ischaemia during carotid endarterectomy: a comparison of propofol and isoflurane

The purpose of this study was to compare two anaesthetic protocols for haemodynamic instability (heart rate (HR) or mean arterial pressure (MAP) < 80 or > 120% of ward baseline values) measured at one-minute intervals during carotid endarterectomy (CEA). One group received propofol/alfentanil (Group Prop; n = 14) and the other isoflurane/alfentanil (Group Iso; n = 13). Periods of haemodynamic instability were correlated to episodes of myocardial ischaemia as assessed by Holter monitoring (begun the evening before surgery and ceasing the morning of the first postoperative day). In Group Prop, anaesthesia was induced with alfentanil 30 micrograms.kg-1 i.v., propofol up to 1.5 mg.kg-1 and vecuronium 0.15 mg.kg-1, and maintained with infusions of propofol at 3-12 mg.kg-1.hr-1 and alfentanil at 30 micrograms.kg-1.hr-1. In Group Iso, anaesthesia was induced with alfentanil and vecuronium as above, thiopentone up to 4 mg.kg-1 and maintained with isoflurane and alfentanil infusion. Phenylephrine was infused to support MAP at 110 +/- 10% of ward values during cross-clamp of the internal carotid artery (ICA) in both groups. Emergence hypertension and/or tachycardia was treated with labetalol, diazoxide or propranolol. Myocardial ischaemia was defined as ST-segment depression of > or = 1 mm (60 msec past the J-point) persisting for > or = one minute. For the entire anaesthetic course (induction to post-emergence), there was no difference between groups for either duration or magnitude outside the < 80 or > 120% range for HR or MAP. However, when the period of emergence from anaesthesia (reversal of neuromuscular blockade to post-extubation) was assessed, more patients were hypertensive (P = 0.004) and required vasodilator therapy in Group Iso (10/13 vs 5/14; P = 0.038 Fisher's Exact Test). The mean dose of labetalol was greater in Group Iso (P = 0.035). No patient demonstrated myocardial ischaemia during ICA cross-clamp. On emergence, 6/13 patients in Group Iso demonstrated myocardial ischaemia compared with 1/14 in Group Prop (P = 0.029). Therefore, supporting the blood pressure with phenylephrine, during the period of ICA cross-clamping, appears to be safe as we did not observe any myocardial ischaemia at this time. During emergence from anaesthesia, haemodynamic instability was associated with myocardial ischaemia. Under these specific experimental conditions, with emergence, hypertension and myocardial ischaemia were more prevalent with more frequent pharmacological interventions in patients receiving isoflurane.

Geographic similarities between varicella and multiple sclerosis: an hypothesis on the environmental factor of multiple sclerosis

The environmental factor causing multiple sclerosis (MS) is unknown. Kurtzke et al. (Neurology 1979; 29: 1228-1235) depicted a north to south diminishing gradient in the case/control ratios for MS among American veterans in the United States. A similar, but less precise, gradient emerged when the incidence rates of varicella from 37 states during 1978-91 were compared. A loose correlation appears to exist between the mean incidence of varicella and the MS risk ratio (n = 0.344 Spearman rank correlation coefficient, p = 0.037). Further, the data on the fat of migrants moving from a high risk MS country to a low risk country and the reverse, plus the great importance of the age at migration, raise the question of a possible connection between the two diseases. Because of these epidemiological and other similarities between the two diseases a further comparative study was suggested.