Breakdown of immune privilege and spontaneous autoimmunity in mice expressing a transgenic T cell receptor specific for a retinal autoantigen.

Despite presence of circulating retina-specific T cells in healthy individuals, ocular immune privilege usually averts development of autoimmune uveitis. To study the breakdown of immune privilege and development of disease, we generated transgenic (Tg) mice that express a T cell receptor (TCR) specific for interphotoreceptor retinoid-binding protein (IRBP), which serves as an autoimmune target in uveitis induced by immunization. Three lines of TCR Tg mice, with different levels of expression of the transgenic R161 TCR and different proportions of IRBP-specific CD4⁺ T cells in their peripheral repertoire, were successfully established. Importantly, two of the lines rapidly developed spontaneous uveitis, reaching 100% incidence by 2 and 3 months of age, respectively, whereas the third appeared "poised" and only developed appreciable disease upon immune perturbation. Susceptibility roughly paralleled expression of the R161 TCR. In all three lines, peripheral CD4⁺ T cells displayed a naïve phenotype, but proliferated in vitro in response to IRBP and elicited uveitis upon adoptive transfer. In contrast, CD4⁺ T cells infiltrating uveitic eyes mostly showed an effector/memory phenotype, and included Th1, Th17 as well as T regulatory cells that appeared to have been peripherally converted from conventional CD4⁺ T cells rather than thymically derived. Thus, R161 mice provide a new and valuable model of spontaneous autoimmune disease that circumvents the limitations of active immunization and adjuvants, and allows to study basic mechanisms involved in maintenance and breakdown of immune homeostasis affecting immunologically privileged sites such as the eye.

Tangled in the breast cancer web: an evaluation of the usage of web-based information resources by breast cancer patients.

This study describes Internet use by breast cancer patients highlighting search patterns and examining the impact of web-based information on the clinical encounter. From September 2011 to January 2012, breast cancer patients at a cancer center completed a survey. Answers were closed and open-ended. Eighty-one patients were approached and 56 completed the survey. Forty-five (80 %) respondents used the Internet and 32 (71 %) searched for breast cancer information. All used Google as their principal search engine. To evaluate quality, 47 % referred to author credentials and 41 % examined references. Most sought information with respect to treatment or prognosis. Eighty percent felt that the information increased their knowledge and influenced treatment decision making for 53 %. This study highlights search patterns and factors used by breast cancer patients in seeking web-based information. Physicians must appreciate that patients use the Internet and address discrepancies between information sought and that which is available.

Breast-conserving therapy after previous irradiation for lymphoma.

There is an increased risk of breast cancer in patients who have undergone radiation treatment for lymphoma. While this usually precludes further radiotherapy (RT), we report five women who received irradiation for lymphoma and who subsequently received breast-conserving therapy between 1995 and 2007 for early-stage breast cancer. There was an overlap between the two treatment fields in all patients. RT for lymphoma ranged between 29.8 and 40 grays (Gy). The interval between lymphoma and the diagnosis of breast cancer was 11-24 years. All five patients had lumpectomy and received subsequent RT (45 Gy in four patients, 50 Gy in the other). All tolerated breast RT well, and toxicity was limited to grade 1 events. All five patients were alive at last follow-up, and there was no local recurrence in the irradiated breast in any patient. We conclude that previous RT for lymphoma is not necessarily an absolute contraindication to breast-conserving therapy.

Impact of obesity on perinatal outcomes among asthmatic women.

BACKGROUND: Only one study has investigated the combined effect of maternal asthma and obesity on perinatal outcomes; however, it did not consider small-for-gestational age and large-for-gestational age infants. OBJECTIVES: To examine the impact of obesity on perinatal outcomes among asthmatic women. METHODS: A cohort of 1386 pregnancies from asthmatic women was reconstructed using three of Quebec's administrative databases and a questionnaire. Women were categorized using their prepregnancy body mass index. Underweight, overweight and obese women were compared with normal weight women. The primary outcome was the birth of a small-for-gestational-age infant, defined as a birth weight below the 10th percentile for gestational age and sex. Secondary outcomes were large-for-gestational-age infants (birth weight >90th percentile for gestational age) and preterm birth (<37 weeks' gestation). Logistic regression models were used to obtain the ORs of having small-for-gestational-age infants, large-for-gestational-age infants and preterm birth as a function of body mass index. RESULTS: The proportions of underweight, normal weight, overweight and obese women were 10.8%, 53.3%, 19.7% and 16.2%, respectively. Obese asthmatic women were not found to be significantly more at risk for giving birth to small-for-gestational-age infants (OR 0.6 [95% CI 0.4 to 1.1]), large-for-gestational-age infants (OR 1.2 [95% CI 0.7 to 2.2]) or having a preterm delivery (OR 0.7 [95% CI 0.4 to 1.3]) than normal-weight asthmatic women. CONCLUSIONS: No significant negative interaction between maternal asthma and obesity on adverse perinatal outcomes was observed.

Population-based outcomes of boost versus salvage radiosurgery for brain metastases after whole brain radiotherapy.

PURPOSE: We conducted a retrospective population-based study to examine the survival outcomes in patients with brain metastases treated with salvage stereotactic radiosurgery (SRS), compared to boost SRS, after previous whole brain radiotherapy (WBRT). METHODS AND MATERIALS: From January 2000 to June 2011, 191 patients treated with WBRT and SRS for brain metastases in British Columbia were studied. Patients were divided into a boost cohort and a salvage cohort. The criteria used to determine eligibility for SRS were: 1-3 metastases, ≤4cm size, Karnofsky performance status ≥ 70, and control of extracranial disease. RESULTS: Diagnosis by primary site was 84 lung, 47 breast, 15 melanoma, 12 renal, 9 colorectal, and 24 other. There were 113 patients (59%) in the boost cohort and 78 patients (41%) in the salvage cohort. The median overall survival from WBRT for the whole population was 17.7months: 12.1 months for the boost cohort and 22.7 months for the salvage cohort. There was no difference in median survival after SRS for the boost and salvage cohorts (11.2 vs. 11.2 months, p=0.78). CONCLUSIONS: In selected patients with brain metastases treated with WBRT, survival following salvage SRS is as good as survival after WBRT + boost SRS.

Template-based breast IMRT planning for increased workload efficiency.

BACKGROUND: To be less resource intensive, we developed a template-based breast IMRT technique (TB-IMRT). This study aims to compare resources and dose distribution between TB-IMRT and conventional breast radiation (CBR). METHODS: Twenty patients with early stage breast cancer were planned using CBR and TB-IMRT. Time to plan, coverage of volumes, dose to critical structures and treatment times were evaluated for CBR and TB-IMRT. Two sided-paired t tests were used. RESULTS: TB-IMRT planning time was less than CBR (14.0 vs 39.0 min, p < 0.001). Fifteen patients with CBR needed 18 MV, and 11 of these were planned successfully with TB-IMRT using 6 MV. TB-IMRT provided better homogeneity index (0.096 vs 0.124, p < 0.001) and conformity index (0.68 vs 0.59, p = 0.003). Dose to critical structures were comparable between TB-IMRT and CBR, and treatment times were also similar (6.0 vs 7.8 min, p = 0.13). CONCLUSIONS: TB- IMRT provides reduction of planning time and minimizes the use of high energy beams, while providing similar treatment times and equal plans compared to CBR. This technique permits efficient use of resources with a low learning curve, and can be done with existing equipment and personnel.

Influence of smoking status on treatment outcomes after post-operative radiation therapy for non-small-cell lung cancer.

BACKGROUND AND PURPOSE: The role of post-operative radiotherapy in patients with resected non-small-cell lung cancer (NSCLC) is unclear. Modifiable factors, like smoking, may help guide therapy. We retrospectively evaluated the impact of smoking on control in patients undergoing post-operative radiation therapy (PORT) for NSCLC. MATERIALS AND METHODS: Between 1995 and 2007, 152 patients who underwent surgery for NSCLC were analyzed (median follow-up 26 months). Non-smokers were defined as patients who never smoked or who had stopped smoking at the time of initial consultation. Sixty seven percent were non-smokers; 5% never smoked, 40% of the non-smokers had ceased smoking for a year or less, while 55% had stopped for more than a year. RESULTS: On univariate analysis, smokers had worse 5-year local control than non-smokers (70% versus 90%, p=0.001) and locoregional control (52% versus 77%, p=0.002). The 5-year survival rate was 21% for smokers and 31% for non-smokers (p=0.2). On multivariate analysis, smokers maintained a detrimental effect on locoregional control (HR 3.6, p=0.0006). CONCLUSIONS: Smokers at initial consultation have poorer local and locoregional control after PORT than non-smokers. In patients being considered for PORT for NSCLC, quitting smoking before treatment confers additional treatment advantage.