Prevalence of Human T Cell Lymphotropic Virus 1 Infection in Canada

Alghazawi

et al. 2019

Front. Oncol.

The applications of disease cluster investigations in medicine have developed rather rapidly in recent decades. Analyzing the epidemiology of non-random aggregation of patients with a particular disease fostered identification of environmental and external exposures as disease triggers and promoters. Observation of patient clusters and their association with nearby exposures, such as Dr. John Snow's astute mapping analysis in the mid-1800's, which revealed proximity of cholera patients in London to a contaminated water pump infected with Vibrio cholerae , have paved the way for the field of epidemiology. This approach enabled the identification of triggers for many human diseases including infections and cancers. Cutaneous T-cell lymphomas (CTCL) represent a group of non-Hodgkin lymphomas that primarily affect the skin. The detailed pathogenesis by which CTCL develops remains largely unknown. Notably, non-random clustering of CTCL patients was reported in several areas worldwide and this rare malignancy was also described to affect multiple members of the same family. These observations indicate that external factors are possibly implicated in promoting CTCL lymphomagenesis. Here, we review the epidemiology of CTCL worldwide and the clinical characteristics of CTCL patients, as revealed by global epidemiological data. Further, we review the known risk factors including sex, age, race as well as environmental, infectious, iatrogenic and other exposures, that are implicated in CTCL lymphomagenesis and discuss conceivable mechanisms by which these factors may trigger this malignancy.

Section: Environmental and External Risk Factors Of Ctclmentioning

confidence: 99%

Environmental and Other Extrinsic Risk Factors Contributing to the Pathogenesis of Cutaneous T Cell Lymphoma (CTCL)

Alghazawi

et al. 2019

Front. Oncol.

“…In addition, in accordance with the institutional policy, this study received an exemption from McGill University research ethics board review. This work was performed in a manner similar to that previously reported . Incidence data for MM and PCL were obtained from the Canadian Cancer Registry (CCR) for cases occurring in provinces outside Quebec and from le Registre Québécois du Cancer (LRQC) for cases in Quebec, whereas all mortality data were obtained from the Canadian Vital Statistics (CVS) database.…”

Section: Methodsmentioning

confidence: 99%

“…Accepted risk factors for MM include a positive family history, an advanced age, black race, and male sex, with an elevated risk also being demonstrated for activities leading to obesity or a poor diet and a lower socioeconomic status . Studies assessing environmental and occupational exposures worldwide have consistently shown an elevated risk of MM in farmers and in individuals exposed to pesticides.…”

Section: Introductionmentioning

confidence: 99%

“…7 Accepted risk factors for MM include a positive family history, an advanced age, black race, and male sex, with an elevated risk also being demonstrated for activities leading to obesity or a poor diet and a lower socioeconomic status. [9][10][11][12][13][14][15] Studies assessing environmental and occupational exposures worldwide have consistently shown an elevated risk of MM in Cancer July 15, 2019 farmers and in individuals exposed to pesticides. Studies examining the correlation between MM and farming have shown a relative risk of up to 3-fold or greater, with a large systematic review demonstrating a pooled odds ratio of 1.39 (95% confidence interval [CI], 1.18-1.65) for MM in farmers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multiple myeloma epidemiology and patient geographic distribution in Canada: A population study

Tsang

et al. 2019

Cancer

Background Multiple myeloma (MM) is a malignancy of mature plasma cells. Environmental risk factors identified for this malignancy, among others, include farming and exposure to pesticides. Methods Using 3 independent population‐based databases (the Canadian Cancer Registry, le Registre Québécois du Cancer, and Canadian Vital Statistics), this study analyzed patients’ clinical characteristics and the incidence, mortality, and geographic distribution of MM cases in Canada during 1992‐2015. Results In total, ~32,065 patients were identified, and 53.7% were male. The mean age at the time of diagnosis was 70 ± 12.1 years. The average incidence rate in Canada was 54.29 cases per million individuals per year, and linear regression modeling showed a steady rise in the annual rate of 0.96 cases per million individuals per year. At the provincial level, Quebec and Ontario had significantly higher incidence rates than the rest of Canada. An analysis of individual municipalities and postal codes showed lower incidence rates in large metropolitan areas and in high‐latitude regions of the country, whereas high incidence rates were observed in smaller municipalities and rural areas. Land use analysis demonstrated increased density of crop farms and agricultural industries in high‐incidence areas. A comparison with the available data from 2011‐2015 showed several consistent trends at provincial, municipal, and regional levels. Conclusions These results provide a comprehensive analysis of the MM burden in Canada. Large metropolitan cities as well as high‐latitude regions were associated with lower MM incidence. Higher incidence rates were noted in smaller cities and rural areas and were associated with increased density of agricultural facilities.

“…Demographic and geographic data were obtained from the Canadian Cancer Registry (CCR), Le Registre Québécois du Cancer (LRQC), and the Canadian Vital Statistics (CVS) databases, as described previously. 13,14,[16][17][18][19][20][21][22][23][24][25][26] The CCR is a national database of cancer patients from 12 Canadian provinces and territories (excluding Quebec) who were diagnosed with primary tumors between 1992 and 2014. The LRQC database was used to obtain corresponding data for patients residing in Quebec.…”

Section: Methodsmentioning

confidence: 99%

Identification of significant geographic clustering of polycythemia vera cases in Montreal, Canada

Rahme

et al. 2019

Cancer

Background Polycythemia vera (PV) is a chronic myeloproliferative neoplasm associated at times with debilitating symptoms and a significant mortality rate. Understanding the demographics, epidemiology, and geography of this disease may provide further insight into important risk factors associated with its development. The objective of this study was to analyze patient demographics, incidence, and mortality rates, as well as the geographic distribution of PV patients in Canada between 1992 and 2010. Methods This study was achieved by analyzing the Canadian Cancer Registry, Le Registre Québécois du Cancer, and the Canadian Vital Statistics patient databases. Results A total of 4645 patients were diagnosed with PV between 1992 and 2010. While the annual incidence rate of this cancer fluctuated in Canada, mortality rate analysis indicated a decreasing trend. Geographically, PV incidence rates were notably elevated in the province of Quebec compared with the Canadian average. Further analysis of high‐incidence forward sortation areas indicated a striking clustering of cases in the H4W region encompassing the Côte‐Saint‐Luc borough of Montreal, with an incidence of 102.97 (95% confidence interval, 75.11‐137.79) cases per million per year, which is >13 times the national average. Conclusion The residential area of Côte‐Saint‐Luc is an important PV cluster in Canada, with high concentration of retirement homes and geriatric hospices. Also, Jewish residents comprise >60% of the population in this neighborhood. These findings suggest that an older age and, potentially, an inherent genetic predisposition may be implicated in the pathogenesis of this malignancy. This study provides a comprehensive overview of PV burden/geographic distribution of cases in Canada.