A Review of the Dermatologic Clinical Applications of Topical Photodynamic Therapy.

Topical photodynamic therapy is a widely approved therapy for actinic keratoses and low-risk nonmelanoma skin cancers with a rapidly growing range of emerging indications for other cutaneous diseases. This review summarizes the best-available evidence to provide a clinical update for dermatologists on the approved and emerging indications of photodynamic therapy. The body of evidence suggests that photodynamic therapy is superior or noninferior to other available treatment modalities for actinic keratoses, low-risk basal cell carcinomas, Bowen's disease, skin field cancerization, chemoprevention of keratinocyte carcinomas in organ transplant recipients, photoaging, acne vulgaris, and cutaneous infections including verrucae, onychomycosis, and cutaneous leishmaniasis. There is emerging evidence that photodynamic therapy plays a role in the management of actinic cheilitis, early-stage mycosis fungoides, extramammary Paget disease, lichen sclerosis, and folliculitis decalvans but there are no comparative studies with other active treatment modalities. Common barriers to topical photodynamic therapy include procedural pain, costs, and the time required for treatment delivery. There is significant heterogeneity in the photodynamic therapy protocols reported in the literature, including different photosensitizers, light sources, number of treatments, time between treatments, and use of procedural analgesia. Topical photodynamic therapy should be considered in the management of a spectrum of inflammatory, neoplastic, and infectious dermatoses. However, more comparative research is required to determine its role in the treatment algorithm for these dermatologic conditions and more methodological research is required to optimize photodynamic therapy protocols to improve the tolerability of the procedure for patients.

Cutaneous Melanoma Mortality-to-Incidence Ratio and Its Association With Socioeconomic and Healthcare Factors in Canada: A National Ecological Study.

INTRODUCTION: The mortality-to-incidence ratio (MIR) can be used to approximate healthcare inequities and is helpful to understand/compare cancer survival between geographic regions/jurisdictions. We investigated cutaneous melanoma (CM) outcomes through MIR analysis in Canadian jurisdictions and census divisions (CDs) between 1992 and 2016. METHODS: Data were obtained from the national databases from 1992 to 2016 for all Canadian jurisdictions, except Quebec. Age-standardized overall and median MIRs were calculated per province per year, while crude MIRs were calculated for CDs. Generalized linear regression models were conducted to study the effect of province and year on MIR, while a mixed effect regression model was used to determine how healthcare and socioeconomic factors affect MIR, while accounting for possible clustering effects (eg, year and province). RESULTS: We identified 106,015 CM cases and 20,570 CM deaths between 1992 and 2016. National MIR from 1992 to 2016 demonstrated a significant linear decrease (P value < .0001). The national median MIR was 15.4 (ie, 0.154 × 100), whereby Manitoba (19.9), Ontario (19.5), Saskatchewan (18.5), British Columbia (16.1), and Newfoundland and Labrador (15.9) demonstrated higher MIRs than the Canadian average. CDs with the highest MIRs were commonly identified in the southern regions of provinces. No healthcare or socioeconomic factors were found to be significantly associated with higher MIR at the provincial level. CONCLUSION: MIRs have decreased at the national and provincial levels in recent decades, which is reassuring. Higher MIRs were noted in select rural CDs and in the Canadian territories, reinforcing the importance of proper dermatological care in all parts of the country.

Analysis of Geographic and Environmental Factors and Their Association with Cutaneous Melanoma Incidence in Canada.

BACKGROUND: Over 90% of skin cancers including cutaneous melanoma (CM) are related directly to sun exposure. Despite extensive knowledge on ultraviolet radiation's (UVR) detrimental impact, many still fail to implement sun protection/sun avoidance. Human behavior, attitudes, and cultural norms of individuals and communities heavily depend on the surrounding climate/environment. In many instances, the climate shapes the culture/norms of the society. Canada has vast geographic/environmental differences. METHODS: In the current ecological study, we sought to examine the relationship between various geographic and environmental factors and the distribution of CM incidence by Forward Sortation Area (FSA) postal code across Canada. CM incidence data were extracted from the Canadian Cancer Registry, while environmental data were extracted from the Canadian Urban Environmental Health Research Consortium (greenspace, as measured by the normalized difference vegetation index; annual highest temperature; absolute number and average length of yearly heat events; annual total precipitation [rain and snow]; absolute number and average length of events with precipitation [rain and snow]; and summer UVR index). The above geographic/environmental data by FSA were correlated with the respective CM incidence employing negative binomial regression model. RESULTS: Our analysis highlights that increases in annual average temperature, summer UVR, and greenspace were associated with higher expected incidence of CM cases, while higher number of annual heat events together with highest annual temperature and higher average number of annual rain events were associated with a decrease in CM incidence rate. This study also highlights regional variation in environmental CM risk factors in Canada. CONCLUSIONS: This national population-based study presents clinically relevant conclusions on weather/geographic variations associated with CM incidence in Canada and will help refine targeted CM prevention campaigns by understanding unique weather/geographic variations in high-risk regions.

Non-Melanoma Skin Cancer Distribution in the Russian Federation.

BACKGROUND: Non-melanoma skin cancer (NMSC) incidence has been increasing steadily around the world. The aim of the study is to describe geographic trends in incidence and mortality of NMSC in Russia between 2007 and 2017 and compare findings to other European countries. METHODS: We used geospatial analysis to map the incident cases and descriptive statistical analysis to analyze trends. Additionally, we assessed the relationship between ethnicity, geographic latitude/longitude, and NMSC incidence/mortality rates. We retrospectively analyzed the data from the Moscow Oncology Research Institute, Ministry of Health of the Russian Federation, for 2007-2017. Routine methods of descriptive epidemiology were used to study incidence and mortality rates by age groups, years, and jurisdictions (i.e., Federal Districts and Federal Subjects). RESULTS: In total, 733,723 patients were diagnosed with NMSC in Russia over the period 2007-2017, of whom 63% were women. The overall age-standardized incidence and mortality rates were 29.64/100,000 and 0.70/100,000, respectively. There was a consistent increase in age-standardized incidence rates over the study period, with a decreasing mortality rate. Geographic mapping revealed north-to-south and east-to-west gradients for NMSC. CONCLUSIONS: This study demonstrated longitudinal trends for NMSC incidence in Russia documenting that skin phototype, latitude/longitude, climate zones, and cultural practices remain dominant risk factors defining the epidemiology of NMSC. Moreover, this work identified several regions in the country (i.e., Republic of Adygea, Samara, Krasnodar Krai, etc.), where patient education/sun awareness campaigns will be useful to help reduce the risk of this malignancy.

Epidemiologic trends and geographic distribution of patients with gallbladder and extrahepatic biliary tract cancers in Canada.

BACKGROUND: Gallbladder and biliary tract cancers are rare malignancies that carry a poor prognosis. Research on their epidemiologic trends is scarce. METHODS: We performed a retrospective analysis of the data in Canada using population-based cancer registries from 1992 to 2010. The incidence and mortality of gallbladder and extrahepatic bile duct cancers were examined at the levels of provinces/territories, cities, and Forward Sortation Area (FSA) postal codes. RESULTS: The incidence and mortality rates decreased over the study period. The average national incidence rate of gallbladder and biliary tract cancers was 30.92 cases per million individuals per year. Higher than average incidence rates were observed in Manitoba, Saskatchewan and Québec; there were contiguous regions with high incidence in Saskatchewan and Manitoba that suggest an area of putative case clustering. Higher incidence of gallbladder cancer was observed in women, whereas higher incidence of extrahepatic bile duct cancers was noted in men. Lower socioeconomic status and Hispanic race were found to be risk factors for gallbladder and biliary tract cancers. CONCLUSION: This is the first study to analyze the burden of gallbladder and biliary tract cancers in Canada. The geographic clustering trends present new avenues for research on environmental triggers.

Geographic Variations in Cutaneous Melanoma Distribution in the Russian Federation.

BACKGROUND: Cutaneous melanoma (CM) incidence has been increasing around the world. The goal of this study is to describe geographic trends in incidence and mortality of CM in Russia between 2001 and 2017. METHODS: To achieve this we used geo-informatic technique (mapping) and descriptive statistical analysis. Additionally, we studied the associations between ethnicity, geographic latitude/longitude, and CM incidence/mortality rates. We retrospectively analyzed the data from the Moscow Oncology Research Institute, Ministry of Health of the Russian Federation, for the period of the study. Routine methods of descriptive epidemiology were used to study incidence and mortality rates by age groups, years, and jurisdictions (i.e., Federal Districts and Federal Subjects of Russia). RESULTS: In total, 141,597 patients were diagnosed with melanoma in Russia over the period 2001-2017, of whom 62% were women. The overall age-standardized incidence and mortality rates were 4.27/100,000 and 1.62/100,000, respectively. Geographic mapping revealed north-to-south and east-to-west gradients. As the study was fully descriptive, retrospective, and based on official statistical reports, detailed characteristics of clinical forms, anatomic sites, Breslow depth, and treatments could not be analyzed. CONCLUSIONS: This study outlined the burden of melanoma in the Russian Federation, and the trends were similar to those observed in countries with similar latitudes and skin phenotype. The importance of the skin color gradient and recreational/cultural practices were some of the most important risk factors highlighted in this study for the development of melanoma in Russia.

Epidemiology and Patient Distribution of Oral Cavity and Oropharyngeal SCC in Canada.

BACKGROUND: Oral cavity cancers (OCCs) and oropharyngeal cancers (OPCs) continue to be a major source of morbidity and mortality worldwide requiring the shared effort of numerous specialists. Tobacco and alcohol consumption have long been identified as risk factors for both OCC and OPC. In addition, human papilloma virus (HPV) is gaining its position as the main causal agent for OPC. OBJECTIVE: The objective of this study is to analyze the epidemiology of OCC and OPC in Canada. METHODS: Data pertaining to the year of diagnosis, the patient's sex, age at the time of diagnosis, province/territory, city and postal code of oral cavity, and oropharyngeal malignancies diagnosed during 1992-2010 were extracted from the Canadian Cancer Registry and Le Registre Québécois du Cancer. RESULTS: In total, 21 685 OCC cases and 15 965 OPC cases were identified from 1992 to 2010. Of those, 84.97% were oral cavity squamous cell carcinomas (SCCs), 88.10% were oropharyngeal SCCs, and both had a significant male predominance. While oral cavity SCC incidence stabilized over the study period, oropharyngeal SCC continued to increase. Oral cavity SCC incidence increased with age, while oropharyngeal SCC incidence peaked in the 50- to 59-year age group. Detailed geographic distribution analysis of patients at the provincial/territorial, city, and postal code levels identified several patient clusters. CONCLUSIONS: This work highlights important epidemiological differences in trends between oral and oropharyngeal cancers, identifies high-incidence postal codes for each malignancy, and correlates incidence/mortality with known risk factors including alcohol/tobacco use and HPV infections, therefore providing a comprehensive understanding of epidemiology for these cancers in Canada.

Penile Invasive Squamous Cell Carcinoma: Analysis of Incidence, Mortality Trends, and Geographic Distribution in Canada.

BACKGROUND: Penile invasive squamous cell carcinoma (SCC) is a rare disease with several known risk factors. However, few studies have assessed its incidence, mortality, and temporal trends. OBJECTIVE: Our objectives are to analyze the epidemiology of penile SCC in Canada and to examine patient distribution with this cancer across Canada in order to elucidate population risk factors. METHODS: Three independent cancer registries were used to retrospectively analyze demographic data from Canadian men diagnosed with penile invasive SCC between 1992 and 2010. The Canadian Census of Population was used to calculate incidence and mortality rates at the province and Forward Sortation Area levels. RESULTS: The overall age-adjusted incidence rate was 6.08 cases per million males. Four provinces with statistically significantly higher incidence rates were identified. The national crude incidence rates increased linearly between 1992 and 2010, whereas the age-adjusted incidence rates showed no significant increase during this time period. The overall age-adjusted mortality rate was 1.88 deaths per million males per year. The province of Saskatchewan had significantly higher mortality rates. There was no increase in crude or age-adjusted mortality rates between 1992 and 2010. There was a significant positive correlation between incidence rates and obesity, Caucasian ethnicity, and lower socioeconomic status. CONCLUSION: This study was able to establish geographic variation for this malignancy at the provincial level. Although there are many established risk factors for penile SCC, our results suggest that the increase in crude incidence rates observed is largely due to the aging population.

Analysis of acute myeloid leukemia incidence and geographic distribution in Canada from 1992 to 2010 reveals disease clusters in Sarnia and other industrial US border cities in Ontario.

BACKGROUND: Several risk factors have been implicated in acute myeloid leukemia (AML) leukemogenesis. However, the epidemiologic distribution and precise triggers for AML in Canada remain poorly understood. METHODS: In this study, demographic data for AML patients in Canada from 1992 to 2010 were analyzed using 3 independent population-based cancer registries. The AML incidence and mortality rates were examined at the levels of province/territory, city, and forward sortation area (FSA) postal code. RESULTS: In total, 18,085 patients were identified. AML incidence was documented to be 30.61 cases per million individuals per year (95% confidence interval [CI], 30.17-31.06) from 1992 to 2010. Five industrial cities in Ontario were identified where incidence rates were significantly higher than the national average: Sarnia, Sault Ste. Marie, Thunder Bay, St. Catharines, and Hamilton. Analysis at the FSA postal code level identified significant patient clusters of AML in these cities. Specifically, FSA N7V in Sarnia, Ontario had an incidence of 106.81 (95% CI, 70.96-161.86) cases per million individuals per year, which is >3 times higher than the national average. The pollution from local oil refineries and chemical plants in Sarnia may be implicated as a risk factor for AML in that city. Analysis of mortality rates at the province and city levels corroborated the findings from the incidence data. CONCLUSION: These results provide a comprehensive analysis of AML burden in Canada and reveal striking geographic case clustering in industrial Ontario cities and potentially implicate exposure to materials/pollution from these plants as an important risk factor for developing AML in Canada.

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

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.

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

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.

Analysis of incidence, mortality trends, and geographic distribution of breast cancer patients in Canada.

BACKGROUND/PURPOSE: Breast cancer is the malignancy with the highest incidence rate excluding non-melanoma skin cancers, and the second leading cause of cancer-related deaths among Canadian women. Many modifiable risk factors have been linked to the pathogenesis of this disease. The purpose of this study is to analyze the epidemiology of breast cancer in Canada and to examine its geographic distribution to help identify new risk factors for this disease. METHODS: Three independent population-based cancer registries were used to retrospectively analyze demographic data from Canadian women diagnosed with invasive breast cancer across all provinces and territories between 1992 and 2010. The incidence and mortality rates were assessed at the provincial, city, and forward sortation area (FSA) postal code levels. RESULTS: The overall age-adjusted incidence rate was 114.4 cases per 100,000 females per year. Six provinces and several groups of FSAs had significantly higher incidence rates. There was a significant increase in incidence and decrease in mortality rates between 1992 and 2010. The overall mortality rate was 31.5 deaths per 100,000 females per year. However, three provinces had significantly higher mortality rates. CONCLUSION: By identifying high-incidence areas for breast cancer, our study will help identify patient populations that are at higher risk for this malignancy. It will also act as a foundation for future studies to establish novel risk factors for this disease.

Cutaneous malignant melanoma incidence and mortality trends in Canada: A comprehensive population-based study.

BACKGROUND: The incidence of cutaneous malignant melanoma (CMM) is on the rise in many parts of the world. However, there is limited knowledge on the epidemiology of CMM in Canada. OBJECTIVE: To conduct a comprehensive population-based study of CMM in Canada. METHODS: We examined patient clinical and pathologic characteristics as well as the incidence and mortality trends of CMM in Canada using 3 independent population-based registries. RESULTS: In total, 72,565 Canadian patients were given CMM diagnoses during 1992-2010; 47.5% were women. Average age at the time of diagnosis was 56.5 years for women and 60.4 years for men. We report a steady increase in CMM incidence and mortality rates in both sexes. The overall incidence rate of CMM in Canada was 12.29 cases/100,000 person-years. We also report important differences in the incidence and mortality rates between Canadian provinces and territories; the highest incidence of this cancer was documented in Nova Scotia and Prince Edward Island. LIMITATIONS: Data on race, clinical disease stage, and Breslow depth of CMM was not available. CONCLUSION: This study, for the first time, defines the disease burden of CMM in Canada and highlights important longitudinal, geographic, and spatial differences in the distribution of CMM in this country.

Cutaneous plasmacytosis and multinucleate cell angiohistiocytoma-like lesion in a patient with hepatitis B: A fortuitous triad?

A 28-year-old woman of Chinese descent, with congenital chronic hepatitis B presented with a 7-year history of erythematous-brown papules and plaques on her groins, axillae, and forehead. A first skin biopsy showed findings consistent with two concomitant, yet highly uncommon cutaneous diseases. The presence of lymphoid nodules with germinal centers and clustered polyclonal plasma cells was consistent with cutaneous plasmocytosis. Second, a diffuse proliferation of non-atypical small vessels (CD31+, CD34+, and HHV8-) in a hypercellular stroma peppered with angulated giant cells (CD163+, CD68-) was suggestive of multinucleate cell angiohistiocytoma (MCAH). Interestingly, the second biopsy of a different plaque on the forehead showed only plasmacytosis and the clinical appearance of both plaques and papules alluded to the distinct presence of both concurrent entities. We speculate the immune modulating effects of chronic hepatitis B may have led to a polyclonal plasmacytic proliferation within the dermis. Furthermore, MCAH has been reported in conjunction with other inflammatory skin diseases such as hidradenitis suppurativa and as such we propose that the MCAH lesion in our case may have arisen as a secondary, reactive process to the cutaneous plasmacytosis.

Solitary and multiple epidermolytic acanthoma: A demographic and clinical study of 131 cases.

BACKGROUND: Epidermolytic acanthoma (EA) is a rare, benign acquired cutaneous keratosis displaying epidermolytic hyperkeratosis in more than 50% of its surface. Because of the sparsity of comprehensive studies, little is known on the patient demographics and clinical characteristics of this uncommon entity. We wish to comprehensively characterize the clinical and demographic features of EA and to differentiate it from its mimickers. METHODS: We carried out a retrospective review of 131 cases of EA, recorded clinical and histopathologic features and performed linear regression of yearly incidence rates to assess for possible under-reporting of this entity. RESULTS: EA affected both genders equally. We found 9.08 cases per 100 000 biopsy specimens per year and linear regression analysis showed significantly decreasing incidence rates. Analysis of the anatomical site distribution of EA lesions showed a more frequent genital location in men (39.1% of cases in men, as compared to 11.3% for women). Contrary to previous studies, lesions were most frequently single (91.7%) and the mean age of presentation was 57.8 years. CONCLUSION: The presented largest case series to-date indicates that EA is probably an underdiagnosed entity and establishes the demographic and clinical features of EA.

Successful management of pediatric oral pemphigus vulgaris with topical corticosteroid monotherapy.

Pemphigus vulgaris (PV) is an autoimmune intraepithelial bullous disease that affects the skin and mucous membranes. Typically, the management of PV is challenging, with systemic corticosteroids being the mainstay of treatment. We describe the case of a 14-year-old girl who was diagnosed with oral PV and successfully treated with topical corticosteroids alone. This case details a pediatric mucosal PV case successfully managed solely with topical corticosteroids.

Incidence, Mortality, and Spatiotemporal Distribution of Cutaneous Malignant Melanoma Cases Across Canada.

BACKGROUND: We recently reported a steady increase in the incidence and mortality of cutaneous malignant melanoma (CMM) in Canada during 1992-2010. OBJECTIVES: The objective of this article is to examine the distribution of Canadian CMM patients at the level of provinces, cities, and forward sortation area (FSA) postal codes. METHODS: Using 3 Canadian population-based registries, we conducted an in-depth examination of the incidence and mortality trends for 72 565 Canadian CMM patients over the period 1992-2010. RESULTS: We found that among 20- to 39-year-olds, the incidence of CMM in women (7.17 per 100 000 individuals) was significantly higher than in men (4.60 per 100 000 individuals per year). Women age 80 years and older had an incidence of CMM (58.46 cases per 100 000 women per year) more than 4 times greater than the national average (12.29 cases per 100 000 population per year) and a corresponding high mortality rate (20.18 deaths per 100 000 women per year), when compared with the Canadian melanoma mortality of 2.4 deaths per 100 000 per year. In other age groups men had higher incidence and corresponding melanoma mortality rates. We also studied CMM incidence by province, city, and FSA postal codes and identified several high-incidence communities that were located near the coast/waterfronts. In addition, plotting latitude measures for cities and FSAs vs CMM incidence rate confirmed the inverse relationship between geographical latitude and incidence of melanoma in Canada (slope = -0.22 ± 0.05). CONCLUSIONS: This research may help develop sex-, age- and geographic region-specific recommendations to decrease the future burden of CMM in Canada.

Distribution and Clustering of Cutaneous T-Cell Lymphoma (CTCL) Cases in Canada During 1992 to 2010.

BACKGROUND: Clustering of patients with cutaneous T-cell lymphoma (CTCL) was reported in several jurisdictions around the world. This rare cancer is known to affect spouses and in some cases multiple members of the same family. These combined results suggest the existence of external disease triggers/promoters. We recently conducted the first comprehensive analysis of CTCL incidence and mortality in Canada, which revealed case clustering in several regions. OBJECTIVES: To extend our previous analysis on CTCL incidence across Canada and to provide all the collected data on CTCL patient incidence in Canada during the period of 1992 to 2010. METHODS: Clinical parameters for patients with CTCL in Canada were analyzed using 2 independent population-based cancer registries: Canadian Cancer Registry and Le Registre Québécois du Cancer. The CTCL incidence rates were examined on different geographical levels, including provinces/territories, cities, and forward sortation areas. RESULTS: Our findings further corroborate our earlier observations of higher CTCL incidence in Newfoundland and Labrador, maritime provinces (Nova Scotia and New Brunswick), and prairie provinces (Manitoba and Saskatchewan). Also, most cities with high CTCL incidence were located in these provinces. Extensive mapping of high-incidence postal codes supports case clustering in a number of communities that are located in the proximity of industrial centres and seaports. CONCLUSIONS: Detailed analysis of CTCL incidence in Canada is critical to fully understand the burden of this disease in our country, to begin the search for a possible external trigger for this lymphoma, and to reform how health care resources are distributed throughout the country to better serve Canadian patients with CTCL.

Insights into the Pathophysiology of Hypertrophic Scars and Keloids: How Do They Differ?

GENERAL PURPOSE: To provide information about the clinical presentation of hypertrophic scars and keloids based on their varied structural components. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After completing this continuing education activity, you should be able to: ABSTRACT: Hypertrophic scars and keloids are firm, raised, erythematous plaques or nodules that manifest when the cicatrix fails to properly heal. They result from pathologic wound healing and often cause pain and decreased quality of life. The appearance of such cosmetically unappealing scars affects the confidence and self-esteem of many patients. These scars can also cause dysfunction by interfering with flexion and extension across joints. Both possess some unique and distinct histochemical and physiologic characteristics that set them apart morphologically and at the molecular level. While these entities have been the focus of research for many years, differentiating between them remains challenging for clinicians.This article reviews the clinical presentation of aberrant scars and illustrates how they can be differentiated. It outlines their pathophysiology and emphasizes the unique molecular mechanisms underlying each disorder. It also examines how altered expression levels and the distribution of several factors may contribute to their unique clinical characteristics and presentation. Further research is needed to elucidate optimal treatments and preventive measures for these types of aberrant scarring.

Comprehensive analysis of cutaneous T-cell lymphoma (CTCL) incidence and mortality in Canada reveals changing trends and geographic clustering for this malignancy.

BACKGROUND: Previous reports of geographic clustering of cutaneous T-cell lymphoma (CTCL) in Texas, Pittsburgh, and Sweden as well as the occurrence of CTCL in married couples and family members raise a possibility of the existence of an external and potentially preventable trigger(s) for this rare skin cancer. METHODS: The authors studied CTCL incidence and mortality in Canada using 3 distinct population-based cancer databases. Data on patients' sex, age at the time of diagnosis, subtype of CTCL malignancy, reporting province, city, and postal code were analyzed. CTCL cases were mapped across Canada using geographic information systems software. RESULTS: In total, 6685 patients with CTCL were identified in Canada during 1992 through 2010 (CTCL incidence rate, 11.32 cases per million individuals per year), of which 58% were males. The mean age at diagnosis was 59.4 ± 21.5 years. Geographic analysis of patients revealed increased CTCL incidence on the provincial and city levels in several eastern provinces and in Manitoba. An analysis according to postal codes (Forward Sortation Area [FSA]) identified select communities in which several high-incidence FSAs were contiguous or adjacent. Several of these FSAs were located in industrial regions of Canadian cities. Conversely, 3 of 8 low-incidence FSAs were clustered in Ottawa, Ontario, which has very little industrial presence. An analysis of CTCL mortality in Canada corroborated the current incidence findings. CONCLUSIONS: The current results provide a comprehensive analysis of CTCL burden in Canada and highlight several important areas of geographic case clustering. These findings argue that industrial exposures may play an important role in promoting CTCL pathogenesis. Cancer 2017;123:3550-67. © 2017 American Cancer Society.