Considerations in setting up and conducting epidemiologic studies of cancer in middle‐ and low‐income countries: the experience of a case–control study of inflammatory breast cancer in N orth A frica in the past 10 years

This article illustrates some issues we faced during our experience in conducting an epidemiologic case–control study of inflammatory breast cancer in N orth A frica. We expect that some of the questions we had to ask in order to address these issues might be helpful to others in setting up epidemiologic studies in developing regions. We describe our experience from different angles including the use of multiple sites to achieve adequate sample size, standardizing diagnosis of disease, identifying cancer cases at the time of diagnosis, control selection procedures, logistics of study implementation, questionnaire development and interviewing, biologic specimens, and procedures for protection of human subjects. We have developed a brief checklist to summarize important issues for conducting future epidemiologic studies in these or similar low‐ or middle‐income countries. This article illustrates crucial issues in setting up and conducting epidemiologic studies on cancer in North Africa. The questions we had to ask in order to address these issues might be helpful to others in setting up epidemiologic studies in developing regions. Our experience could improve time and cost efficiency of future epidemiologic studies in this or other regions in low‐ and middle‐income countries.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94458/1/cam436.pd

Reliability of Medical Records in Diagnosing Inflammatory Breast Cancer in Egypt

BACKGROUND: Inflammatory breast cancer (IBC) is a rare, aggressive breast cancer diagnosed clinically by the presence of diffuse erythema, peau d\u27orange, and edema that arise quickly in the affected breast. This study evaluated the validity of medical records in Gharbiah, Egypt in identifying clinical signs/symptoms of IBC. For 34 IBC cases enrolled in a case-control study at the Gharbiah Cancer Society and Tanta Cancer Center, Egypt (2009-2010), we compared signs/symptoms of IBC noted in medical records to those recorded on a standardized form at the time of IBC diagnosis by clinicians participating in the case-control study. We calculated the sensitivity and specificity of medical records as compared to the case-control study for recording these signs/symptoms. We also performed McNemar\u27s tests. RESULTS: In the case-control study, 32 (94.1%) IBC cases presented with peau d\u27orange, 30 (88.2%) with erythema, and 31 (91.2%) with edema. The sensitivities of the medical records as compared to the case-control study were 0.8, 0.5, and 0.2 for peau d\u27orange, erythema, and edema, respectively. Corresponding specificities were 1.0, 0.5, and 1.0. p values for McNemar\u27s test were CONCLUSION: Medical records lacked information on signs/symptoms of IBC, especially erythema and edema, when compared to the case-control study. Deficient medical records could have implications for diagnosis and treatment of IBC and proper documentation of cases in cancer registries

Assessment of diagnosis of inflammatory breast cancer cases at two cancer centers in E gypt and T unisia

The diagnosis of inflammatory breast cancer ( IBC ) is largely clinical and therefore inherently somewhat subjective. The objective of this study was to evaluate the diagnosis of IBC at two centers in N orth A frica where a higher proportion of breast cancer is diagnosed as IBC than in the U nited S tates ( U . S .). Physicians prospectively enrolled suspected IBC cases at the National Cancer Institute ( NCI ) –  C airo, E gypt, and the I nstitut S alah A zaiz ( ISA ), T unisia, recorded extent and duration of signs/symptoms of IBC on standardized forms, and took digital photographs of the breast. After second‐level review at study hospitals, photographs and clinical information for confirmed IBC cases were reviewed by two U . S . oncologists. We calculated percent agreement between study hospital and U . S . oncologist diagnoses. Among cases confirmed by at least one U . S . oncologist, we calculated median extent and duration of signs and S pearman correlations. At least one U . S . oncologist confirmed the IBC diagnosis for 69% (39/50) of cases with photographs at the NCI ‐ C airo and 88% (21/24) of cases at the ISA . All confirmed cases had at least one sign of IBC (erythema, edema, peau d'orange) that covered at least one‐third of the breast. The median duration of signs ranged from 1 to 3 months; extent and duration of signs were not statistically significantly correlated. From the above‐mentioned outcomes, it can be concluded that the diagnosis of a substantial proportion of IBC cases is unambiguous, but a subset is difficult to distinguish from other types of locally advanced breast cancer. Among confirmed cases, the extent of signs was not related to delay in diagnosis. The diagnosis of inflammatory breast cancer ( IBC ) is largely clinical and therefore inherently somewhat subjective. The objective of this pilot study was to evaluate the diagnosis of IBC at two centers in N orth A frica, where a higher proportion of breast cancer is diagnosed as IBC than in the U nited S tates ( U.S. ). The diagnosis of a substantial proportion of IBC cases at the study centers was unambiguous, but a subset was difficult to distinguish from other types of locally advanced breast cancer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97479/1/cam448.pd

White blood cell DNA methylation and risk of breast cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO)

Background Several studies have suggested that global DNA methylation in circulating white blood cells (WBC) is associated with breast cancer risk. Methods To address conflicting results and concerns that the findings for WBC DNA methylation in some prior studies may reflect disease effects, we evaluated the relationship between global levels of WBC DNA methylation in white blood cells and breast cancer risk in a case-control study nested within the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) cohort. A total of 428 invasive breast cancer cases and 419 controls, frequency matched on age at entry (55–59, 60–64, 65–69, ≥70 years), year of entry (on/before September 30, 1997, on/after October 1, 1997) and period of DNA extraction (previously extracted, newly extracted) were included. The ratio of 5-methyl-2’ deoxycytidine [5-mdC] to 2’-deoxyguanine [dG], assuming [dG] = [5-mdC] + [2’-deoxycytidine [dC]] (%5-mdC), was determined by liquid chromatography-electrospray ionization-tandem mass spectrometry, an especially accurate method for assessing total genomic DNA methylation. Results Odds ratio (OR) estimates and 95% confidence intervals (CI) for breast cancer risk adjusted for age at entry, year of entry, and period of DNA extraction, were 1.0 (referent), 0.89 (95% CI, 0.6–1.3), 0.88 (95% CI, 0.6–1.3), and 0.84 (95% CI, 0.6–1.2) for women in the highest compared to lowest quartile levels of %5md-C (p for trend = .39). Effects did not meaningfully vary by time elapsed from WBC collection to diagnosis. Discussion These results do not support the hypothesis that global DNA hypomethylation in WBC DNA is associated with increased breast cancer risk prior to the appearance of clinical disease

Association between Class III Obesity (BMI of 40–59 kg/m2) and Mortality: A Pooled Analysis of 20 Prospective Studies

Background: The prevalence of class III obesity (body mass index [BMI]≥40 kg/m2) has increased dramatically in several countries and currently affects 6% of adults in the US, with uncertain impact on the risks of illness and death. Using data from a large pooled study, we evaluated the risk of death, overall and due to a wide range of causes, and years of life expectancy lost associated with class III obesity. Methods and Findings: In a pooled analysis of 20 prospective studies from the United States, Sweden, and Australia, we estimated sex- and age-adjusted total and cause-specific mortality rates (deaths per 100,000 persons per year) and multivariable-adjusted hazard ratios for adults, aged 19–83 y at baseline, classified as obese class III (BMI 40.0–59.9 kg/m2) compared with those classified as normal weight (BMI 18.5–24.9 kg/m2). Participants reporting ever smoking cigarettes or a history of chronic disease (heart disease, cancer, stroke, or emphysema) on baseline questionnaires were excluded. Among 9,564 class III obesity participants, mortality rates were 856.0 in men and 663.0 in women during the study period (1976–2009). Among 304,011 normal-weight participants, rates were 346.7 and 280.5 in men and women, respectively. Deaths from heart disease contributed largely to the excess rates in the class III obesity group (rate differences = 238.9 and 132.8 in men and women, respectively), followed by deaths from cancer (rate differences = 36.7 and 62.3 in men and women, respectively) and diabetes (rate differences = 51.2 and 29.2 in men and women, respectively). Within the class III obesity range, multivariable-adjusted hazard ratios for total deaths and deaths due to heart disease, cancer, diabetes, nephritis/nephrotic syndrome/nephrosis, chronic lower respiratory disease, and influenza/pneumonia increased with increasing BMI. Compared with normal-weight BMI, a BMI of 40–44.9, 45–49.9, 50–54.9, and 55–59.9 kg/m2 was associated with an estimated 6.5 (95% CI: 5.7–7.3), 8.9 (95% CI: 7.4–10.4), 9.8 (95% CI: 7.4–12.2), and 13.7 (95% CI: 10.5–16.9) y of life lost. A limitation was that BMI was mainly ascertained by self-report. Conclusions: Class III obesity is associated with substantially elevated rates of total mortality, with most of the excess deaths due to heart disease, cancer, and diabetes, and major reductions in life expectancy compared with normal weight. Please see later in the article for the Editors' Summar

Ovarian cancer risk factors by tumor aggressiveness : An analysis from the Ovarian Cancer Cohort Consortium

Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in = 35 vs. 20 to <25 kg/m(2), 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.Peer reviewe