Residential environment and breast cancer incidence and mortality: a systematic review and meta-analysis

Background: Factors beyond the individual level such as those characterizing the residential environment may be important to breast cancer outcomes. We provide a systematic review and results of meta-analysis of the published empirical literature on the associations between breast cancer risk and mortality and features of the residential environment. Methods: Using PRISMA guidelines, we searched four electronic databases and manually searched the references of selected articles for studies that were published before June 2013. We selected English language articles that presented data on adult breast cancer incidence or mortality in relation to at least one area-based residential (ABR) independent variable. Results: We reviewed 31 eligible studies, and observed variations in ABR construct definition and measurement, study design, and analytic approach. The most common ABR measures were indicators of socioeconomic status (SES) (e.g., income, education, summary measures of several SES indicators or composite SES). We observed positive associations between breast cancer incidence and urbanization (Pooled RR for urban vs. rural: 1.09. 95% CI: 1.01, 1.19), ABR income (Pooled RR for highest vs. lowest ABR income: 1.17, 95% CI: 1.15, 1.19) and ABR composite SES (Pooled RR for highest vs. lowest ABR composite SES: 1.25, 95% CI: 1.08, 1.44). We did not observe consistent associations between any ABR measures and breast cancer mortality. Conclusions: The findings suggest modest positive associations between urbanization and residential area socioeconomic environment and breast cancer incidence. Further studies should address conceptual and methodological gaps in the current publications to enable inference regarding the influence of the residential environment on breast cancer. Keywords: Breast cancer epidemiology Residential environment Socio-economic status Mortality Urbanizatio

Paradoxical Association Between Relative Cerebral Blood Volume Dynamics Following Chemoradiation and Increased Progression-Free Survival in Newly Diagnosed IDH Wild-Type MGMT Promoter Methylated Glioblastoma With Measurable Disease.

Background and purposeWhile relative cerebral blood volume (rCBV) may be diagnostic and prognostic for survival in glioblastoma (GBM), changes in rCBV during chemoradiation in the subset of newly diagnosed GBM with subtotal resection and the impact of MGMT promoter methylation status on survival have not been explored. This study aimed to investigate the association between rCBV response, MGMT methylation status, and progression-free (PFS) and overall survival (OS) in newly diagnosed GBM with measurable enhancing lesions.Methods1,153 newly diagnosed IDH wild-type GBM patients were screened and 53 patients (4.6%) had measurable post-surgical tumor (>1mL). rCBV was measured before and after patients underwent chemoradiation. Patients with a decrease in rCBV >10% were considered rCBV Responders, while patients with an increase or a decrease in rCBV <10% were considered rCBV Non-Responders. The association between change in enhancing tumor volume, change in rCBV, MGMT promotor methylation status, and PFS or OS were explored.ResultsA decrease in tumor volume following chemoradiation trended towards longer OS (p=0.12; median OS=26.8 vs. 16.3 months). Paradoxically, rCBV Non-Responders had a significantly improved PFS compared to Responders (p=0.047; median PFS=9.6 vs. 7.2 months). MGMT methylated rCBV Non-Responders exhibited a significantly longer PFS compared to MGMT unmethylated rCBV Non-Responders (p<0.001; median PFS=0.5 vs. 7.1 months), and MGMT methylated rCBV Non-Responders trended towards longer PFS compared to methylated rCBV Responders (p=0.089; median PFS=20.5 vs. 13.8 months).ConclusionsThis preliminary report demonstrates that in newly diagnosed IDH wild-type GBM with measurable enhancing disease after surgery (5% of patients), an enigmatic non-response in rCBV was associated with longer PFS, particularly in MGMT methylated patients