Socioeconomic status and the prevalence of melanoma in Ontario, Canada

The sociological basis of the skin cancer epidemic

Given the precipitous rise in its incidence in recent decades, skin cancer has been recognized as a growing epidemic. We explore the sociological underpinnings of this epidemic, including: (1) aging of the demographic; (2) human ecologic factors (residing in areas with high ambient ultraviolet levels and a depleted ozone layer); (3) large-scale European migration to more equatorial latitudes; (4) social structures that for centuries minimized miscegenation and maximized segregation; (5) gender-based differences in sunbathing, tanning, sunscreen use, and clothing choice; (6) occupational ultraviolet exposure; (7) the complex interplay of socioeconomic status, race, and urbanization on skin cancer incidence and mortality; (8) the effects of war on skin cancer incidence; (9) cultural shifts in clothing, travel, outdoor sports, recreation, and attitudes towards being tan; and (10) the indirect effects of religion. We show that without these sociological factors, the most common type of cancer would not be nearly as common.

Socioeconomic Status and Melanoma in Canada: A Systematic Review

As melanoma is one of the leading cancers in average years of life lost per death from disease, screening and early diagnosis are imperative to decrease morbidity and mortality. Socioeconomic status (SES) has been shown to be associated with melanoma incidence. However, it is unclear if this association holds true in universal healthcare systems where screening, diagnostic, and treatment services are available to all patients. The objective of this systematic review was to evaluate the evidence on the association of SES and melanoma incidence in Canada. A comprehensive search of PubMed and EMBASE yielded 7 studies reporting on melanoma incidence or outcomes with respect to SES in Canada. High SES was associated with increased melanoma incidence across all studies, which encompassed all Canadian provinces, and time periods spanning from 1979 to 2012. Studies also reported an increasing incidence of melanoma over time. There were substantial discrepancies in melanoma incidence across Canadian provinces, after controlling for SES and demographic characteristics. Populations of lower SES and living within certain healthcare regions had increased risks of advanced melanoma at diagnosis. This review highlights the potential for inequities in access to care even within a universal healthcare system. Future research is needed to characterize specific risk factors within different patient groups and within the universal health system context in order to implement targeted strategies to lower melanoma incidence, morbidity, and mortality.

Melanoma incidence, stage, and survival after solid organ transplant: A population-based cohort study in Ontario, Canada

BACKGROUND

Risk of melanoma is increased with potentially worse outcomes after solid organ transplant.

OBJECTIVE

To estimate the incidence, stage, and survival in transplant recipients with melanoma.

METHODS

Population-based, retrospective, observational study using linked administrative databases. Adults receiving their first solid organ transplant from 1991 through 2012 were followed to December 2013.

RESULTS

We identified 51 transplant recipients with melanoma, 11 369 recipients without melanoma, and 255 matched patients with melanoma from the nontransplant population. Transplant recipients were at increased risk of melanoma (standardized incidence ratio, 2.29; 95% confidence interval [CI], 2.07-2.49) and more likely to be diagnosed at stages II through IV (adjusted odds ratio, 4.29; 95% CI, 2.04-9.00) compared with the nontransplant population. Melanoma-specific mortality was increased in transplant recipients compared with the nontransplant population (adjusted hazard ratio, 1.93; 95% CI, 1.03-3.63). Among transplant recipients, all-cause mortality was increased after melanoma compared with those without melanoma (stage T1/T2: adjusted hazard ratio, 2.18; 95% CI, 1.13-4.21; T3/T4: adjusted hazard ratio, 4.07; 95% CI, 2.36-7.04; III/IV: adjusted hazard ratio, 7.92; 95% CI, 3.76-16.70).

LIMITATIONS

The databases did not contain data on immunosuppressive drugs; ascertainment of melanoma metastasis relied on pathology reports.

CONCLUSION

Melanoma after solid organ transplant is more often diagnosed at a later stage and leads to increased mortality, even for early-stage tumors.

Is Access to Care Associated With Stage at Presentation and Survival for Melanoma Patients?

BACKGROUND

Melanoma incidence increases with socioeconomic status but the effect of rurality and access to primary care or dermatology on patient outcomes is unclear.

OBJECTIVES

The objectives of this study were to determine whether access to care, rurality, or socioeconomic status are associated with melanoma stage at presentation and prognosis.

METHODS

Linked administrative databases from Ontario, Canada, were retrospectively analyzed to identify a population-based cohort of patients diagnosed with melanoma between 2004 and 2012. Rurality was assessed using the rural index of Ontario (RIO) score, and the number of visits to dermatology and primary care was used to evaluate access to care.

RESULTS

We identified 18 776 melanoma patients, of whom 9591 had completed pathological staging. Patients with higher RIO scores, living further from a cancer center or in a rural community, were less likely to see a dermatologist in the year prior to diagnosis (P < .001 for all). Patients seen by a dermatologist within 365 days prior to diagnosis were less likely to present with stage III or IV disease (odds ratio 0.63, P < .001) and had improved overall survival (hazard ratio [HR] for death 0.77, P < .001). There was a nonlinear association between number of family physician visits and melanoma prognosis, with patients who had 3 to 5 visits per year having the best overall survival (HR 0.88, P = .003).

CONCLUSION

Our findings strengthen the known association between access to dermatology and melanoma outcomes by linking individual patients' prediagnosis access to care to pathological stage at diagnosis and overall survival.

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.

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.

Melanoma patterns of care in Ontario: A call for a strategic alignment of multidisciplinary care

BACKGROUND AND OBJECTIVES

Variability in melanoma management has prompted concerns about equitable and timely treatment. We investigated patterns of melanoma diagnosis and treatment using population-level data.

METHODS

Patients with invasive cutaneous melanoma were identified retrospectively from the Ontario Cancer Registry (2003-2012) and deterministically linked with administrative databases to identify incidence, disease characteristics, geographic origin, and multimodal treatment within a year of diagnosis. Melanoma treatment was categorized as inadequate or adequate based on multidisciplinary clinical algorithms. Multivariable logistic regression was used to model factors associated with treatment adequacy.

RESULTS

From 2003 to 2012, 22 918 patients with invasive melanoma were identified with annual age/sex standardized incidence rates of 11.7-14.3/100 000 for females and 13.4-15.9/100 000 for males. Melanoma occurred at median age of 62 and primarily on extremities (43.9%). Within 1 year after diagnosis, 86.7% of patients received surgery as primary therapy. A total of 2312 (10.6%) patients received inadequate or no treatment after diagnosis. Receiving adequate treatment was associated with consultation with dermatology (OR 1.92, CI 1.71-2.14), plastic surgery (OR 4.80, CI 4.32-5.34), or general surgery (OR 2.15, CI 1.94-2.38).

CONCLUSIONS

Significant variation exists in melanoma management and nearly one in nine patients is inadequately treated. Referral to sub-specialized providers is critical for ensuring appropriate care.

Burden of illness for metastatic melanoma in Canada, 2011-2013

BACKGROUND

Detailed epidemiology for patients with advanced metastatic melanoma in Canada is not well characterized. We conducted an analysis of patients with this disease in the province of Ontario, with the aim being to study the presentation, disease characteristics and course, and treatment patterns for malignant melanoma.

METHODS

In this Canadian observational prospective and retrospective study of patients with malignant melanoma, we used data collected in the Canadian Melanoma Research Network (cmrn) Patient Registry. We identified patients who were seen at 1 of 3 cancer treatment centres between April 2011 and 30 April 2013. Patient data from 2011 and 2012 were collected retrospectively using chart records and existing registry data. Starting January 2013, data were collected prospectively. Variables investigated included age, sex, initial stage, histology, mutation type, time to recurrence, sites of metastases, resectability, and previous therapies.

RESULTS

A cohort of 810 patients with melanoma was identified from the cmrn registry. Mean age was 58.7 years, and most patients were men (60% vs. 40%). Factors affecting survival included unresectable or metastatic melanoma, initial stage at diagnosis, presence of brain metastasis, and BRAF mutation status. The proportion of surviving patients decreased with higher initial disease stages.

CONCLUSIONS

Using registry data, we were able to determine the detailed epidemiology of patients with melanoma in the Canadian province of Ontario, validating the comprehensive and detailed information that can be obtained from registry data.

Incidence of cutaneous malignant melanoma by socioeconomic status in Canada: 1992-2006

BACKGROUND

There are no nationwide studies documenting changes in cutaneous malignant melanoma incidence or association of incidence with socioeconomic status (SES) in Canada. We sought to determine whether melanoma incidence increased from 1992 to 2006 and if there was an association between SES and melanoma incidence. Additionally, we studied whether there was a correlation between province of residence and melanoma incidence.

METHODS

Cases from the Canadian Cancer Registry were reviewed. Demographic and socioeconomic information were extracted from the Canadian Census of Population data. Cases were linked to income quintiles by postal code. A negative binomial regression was performed to identify relationships among these variables.

RESULTS

Overall incidence of melanoma in Canada increased by 67 % from 1992 to 2006 (p < 0.0001). The increase in incidence was greater for melanoma in situ compared with invasive melanoma (136 % versus 52 % [p < 0.0001]). Incidence was positively correlated with higher income quintiles; the incidence rates among patients in the lowest income quintiles were 67 % of that for the highest income quintiles (p < 0.0001).

DISCUSSION

A wide variety of explanations have been postulated for an increased incidence in melanoma among persons of higher SES, including access to and awareness of screening, more access to vacations in sunny climates, and increased leisure time. Variations in incidence of melanoma by urban vs. rural location and province may indicate differences in access to dermatologists across Canada.

CONCLUSIONS

Melanoma incidence is increasing in Canada and is higher among people in high SES groups. This rise is likely due to a combination of factors including a true rise in incidence due to increases in sun exposure, and also an increased detection rate, particularly in those who are more aware of the disease and have access to resources for detection.

A checklist for ascertaining study cohorts in oncology health services research using secondary data: report of the ISPOR oncology good outcomes research practices working group

OBJECTIVES

The ISPOR Oncology Special Interest Group formed a working group at the end of 2010 to develop standards for conducting oncology health services research using secondary data. The first mission of the group was to develop a checklist focused on issues specific to selection of a sample of oncology patients using a secondary data source.

METHODS

A systematic review of the published literature from 2006 to 2010 was conducted to characterize the use of secondary data sources in oncology and inform the leadership of the working group prior to the construction of the checklist. A draft checklist was subsequently presented to the ISPOR membership in 2011 with subsequent feedback from the larger Oncology Special Interest Group also incorporated into the final checklist.

RESULTS

The checklist includes six elements: identification of the cancer to be studied, selection of an appropriate data source, evaluation of the applicability of published algorithms, development of custom algorithms (if needed), validation of the custom algorithm, and reporting and discussions of the ascertainment criteria. The checklist was intended to be applicable to various types of secondary data sources, including cancer registries, claims databases, electronic medical records, and others.

CONCLUSIONS

This checklist makes two important contributions to oncology health services research. First, it can assist decision makers and reviewers in evaluating the quality of studies using secondary data. Second, it highlights methodological issues to be considered when researchers are constructing a study cohort from a secondary data source.

Socioeconomic factors and diagnosis of uveal melanoma in the mid-southern United States

PURPOSE

To establish the base incidence of uveal melanoma in the mid-southern United States and to explore the regional frequency of uveal melanoma diagnosis as a function of area-based socioeconomic measures (ABSM) aggregated at the level of small geographic units delimited by Zoning Improvement Plan (ZIP) codes.

METHODS

Based on a retrospective chart review (1996-2007) of patients seen at our institutions with the diagnosis of uveal melanoma, the number of uveal melanoma cases was calculated for each ZIP-code in Arkansas, Mississippi, western Tennessee and Louisiana. The base incidence of uveal melanoma was calculated using the population size reported in the 2000 census as the population at risk for each geographic area. Data on the average house value and average household income reported in the 2000 census were used in a Poisson regression analysis to examine their effect on the frequency of uveal melanoma diagnosis.

RESULTS

There were 327 (of 1,669) regional ZIP-codes that were the source of 457 patients with uveal melanoma. Higher ABSM, defined as greater average house value or household income, were positively associated with the number of observed melanoma cases per ZIP-code. The annualized incidence of uveal melanoma was at least 3.5 cases per million in the areas studied.

CONCLUSION

Higher ABSM were associated with the increased frequency of uveal melanoma diagnosis in the regions studied. Extrapolating from similar trends observed with non-ocular cancers, this may signify a need for increased access to ophthalmologic care to ensure timely diagnosis.