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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.

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.

<b><i>Background:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusions:</i></b> 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.

BackgroundCutaneous melanoma (CM) is one of the most fatal types of skin cancer. Alarmingly, increases in incidence and mortality were noted globally for this malignancy, despite increase in understanding of melanoma pathogenesis and enhanced prevention efforts.MethodsData was extracted for CM patients for provinces and territories (except Quebec) using two independent, population-based registries. Analysis was performed using both clinical and pathological characteristics: tumor morphologic classification, age, sex, anatomic site affected and place of residence. Mortality trends were assessed over a 7-year period. Results were compared to prior findings for 1992–2010.ResultsDuring 2011–2017 39,610 patients were diagnosed with CM, with 5,890 reported deaths. National crude CM incidence was 20.75 (age-standardized incidence: 14.12) cases per 100,000 individuals per year. Females accounted for 45.8% of cases and 37.1% of deaths. While CM incidence rates continue to increase in both sexes, since 2013 the CM mortality is declining. We observed important differences across the provinces/territories, where Nova Scotia, Prince Edward Island, southern Ontario/British Columbia and certain coastal communities of New Brunswick demonstrated higher CM incidence and mortality rates. The observed incidence and mortality trends for 2011–2017 validate and extend earlier observations from 1992 to 2010 for CM.ConclusionThis population-based study highlights that while melanoma's incidence is increasing in Canada, mortality rates are for the first time decreasing since 2013. We detail regional distribution of this cancer highlighting communities in southern/coastal areas, as being most at risk as well as the latest trends of melanoma incidence by age, sex and anatomic site. In males, melanoma is more common on the head/trunk, while in females on the extremities. Notably, Acral Lentiginous Melanoma was the only CM subtype that was more common in females, which primarily affects hands and feet.

Classic adult pityriasis rubra pilaris is a severe papulosquamous disease that tends to resolve in 3–5 years but can have a devastating impact on patients while active. It shares features with psoriasis, but treatment remains largely empiric, based on case reports and series. The condition is often refractory to treatment, especially initially, with topical corticosteroids and oral acitretin the more commonly employed agents. Relatively high doses of acitretin are needed for adequate response, and adverse events often limit adherence. Given the similarity to psoriasis, biologic agents approved for psoriasis have been used with good effect in classic adult pityriasis rubra pilaris and show better tolerance than other agents. In this report, we describe the successful use of a combination of acitretin and ustekinumab in a case of classic adult pityriasis rubra pilaris.

As coronavirus disease (COVID-19) vaccines continue to be administered, dermatologists play a critical role in recognizing and treating the cutaneous manifestations (CM) associated with the vaccines. Adverse cutaneous reactions of COVID-19 vaccines reported in the literature range from common urticarial to rare vesiculobullous reactions. In this study, we performed a (1) scoping review to assess the occurrences of vesicular, papulovesicular, and bullous CMs of COVID-19 vaccines and their respective treatments, and (2) a narrative review discussing other common and uncommon CMs of COVID-19 vaccines. Thirty-six articles were included in the scoping review, and 66 articles in the narrative review. We found that vesicular, papulovesicular, and bullous lesions are infrequent, reported mostly after the first dose of Moderna or Pfizer vaccines. Eleven of the 36 studies reported vesicular reactions consistent with activation or reactivation of the herpes zoster virus. Most vesicular and bullous lesions were self-limited or treated with topical corticosteroids. Other CMs included injection-site, urticarial or morbilliform reactions, vasculitis, toxic epidermal necrolysis, and flaring of or new-onset skin diseases such as psoriasis. Treatments for CMs included topical or oral corticosteroids, antihistamines, or no treatment in self-limited cases. Although most CMs are benign and treatable, the data on the effect of systemic corticosteroids and immunosuppressive therapies on the immunogenicity of COVID-19 vaccines is limited. Some studies report reduced immunogenicity of the vaccines after high-dose corticosteroids use. Physicians may consult local guidelines where available when recommending COVID-19 vaccines to immunosuppressed patients, and when using corticosteroids to manage the CMs of COVID-19 vaccines.