Hypopigmented mycosis fungoides (HMF) is a form of cutaneous T-cell lymphoma (CTCL), a heterogeneous group of extranodal non-Hodgkin’s lymphomas. HMF has a unique set of defining features that include light colored to achromic lesions, a predilection for darker skin phototypes, an early onset of disease, and predominance of CD8+ T-cells, among others. In the current review, we detail the known pathways of molecular pathogenesis for this lymphoma and posit that an active Th1/cytotoxic antitumor immune response in part explains why this variant is primarily seen in children/adolescents and young adults, who do not exhibit signs of immunosenescence. As a result of this potent cytotoxic response, HMF patients experience mostly favorable overall prognosis, while hypopigmentation may in fact represent a useful surrogate marker of cytotoxic immunity targeting the malignant cells. Understanding the molecular processes behind the specific features that define HMF may lead to improved diagnostic accuracy, personalized prognosis by risk stratification, and improved management of HMF. Moreover, improving our knowledge of HMF may aid our further understanding of other cutaneous lymphomas.

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.

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.

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BackgroundEsophageal cancer can be subdivided into two main histological subtypes with significant variability in their etiology and epidemiology. The incidence of esophageal adenocarcinoma (AC) is increasing across the developed countries, whereas the incidence of esophageal squamous cell carcinoma (SCC) is declining. Several risk factors have been identified in the pathogenesis of each subtype, however, their epidemiologic characteristics and distribution throughout Canada remain poorly understood.MethodsWe performed a retrospective analysis of demographic data across Canada from 1992 to 2010 using two independent population‐based cancer registries. The incidence of esophageal cancer, for each subtype, was examined at the levels of provinces/territories, cities, and postal codes.ResultsA total of 19 790 patients were diagnosed with esophageal cancer in Canada between 1992 and 2010; 74% were males. The average national incidence rate was 33.5 cases per million individuals per year. Incidence of esophageal AC increased over time, with notable high‐incidence rates on the Vancouver Island, the coasts of the Great Lakes, and the coasts of the Northumberland Strait in the Maritimes. The overall incidence of esophageal SCC has decreased. However, high incidence of esophageal SCC was detected in the Vancouver city, rural eastern Québec, and in the Maritimes. We also report clustering for each subtype using postal codes, which sheds light onto new avenues of research for potential environmental etiologies.ConclusionsThis study, for the first time, provides a detailed analysis on the burden of esophageal cancer in Canada, revealing important geographic clustering trends.

Retinoids are natural and synthetic vitamin A derivatives that are effective for the prevention and the treatment of non-melanoma skin cancers (NMSC). NMSCs constitute a heterogenous group of non-melanocyte-derived skin cancers that impose substantial burdens on patients and healthcare systems. They include entities such as basal cell carcinoma and cutaneous squamous cell carcinoma (collectively called keratinocyte carcinomas), cutaneous lymphomas and Kaposi’s sarcoma among others. The retinoid signaling pathway plays influential roles in skin physiology and pathology. These compounds regulate diverse biological processes within the skin, including proliferation, differentiation, angiogenesis and immune regulation. Collectively, retinoids can suppress skin carcinogenesis. Both topical and systemic retinoids have been investigated in clinical trials as NMSC prophylactics and treatments. Desirable efficacy and tolerability in clinical trials have prompted health regulatory bodies to approve the use of retinoids for NMSC management. Acceptable off-label uses of these compounds as drugs for skin cancers are also described. This review is a comprehensive outline on the biochemistry of retinoids, their activities in the skin, their effects on cancer cells and their adoption in clinical practice.

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.

Gastric cancer is the 5th most common malignancy worldwide, representing ~5–10% of all new cancer cases. Although its incidence is declining, it is estimated that 1 in 98 Canadians will develop gastric cancer in their lifetime. The epidemiology and distribution of gastric cancer throughout Canada, however, remains poorly understood. A retrospective analysis of demographic data across Canada between 1992 and 2010 was performed using 2 population-based cancer registries. The incidence of gastric cancer was examined at the levels of provinces, cities, and postal codes. In addition, 43,955 patients were diagnosed with gastric cancer in Canada between 1992 and 2010; 66% were male and the average age of diagnosis was 68.4 years. The age-adjusted incidence rate was 5.07 cases per 100,000 individuals per year. The incidence decreased over the study period by 30%. High incidence rates were identified in rural areas of Newfoundland and Labrador, New Brunswick, and Quebec. Our study found a significant association between gastric cancer incidence rates and lower socioeconomic status, as well as Hispanic ethnicity. This is the first study to provide a comprehensive analysis of the incidence of gastric carcinoma in Canada, identifying high-risk populations that may benefit from increased primary and secondary prevention.