40-year trends in skin cancer in British Columbia, Canada, 1973 to 2003

Incidence and profile of skin cancers in patients following ultraviolet phototherapy without psoralens: A retrospective cohort study

BACKGROUND

Psoralen + ultraviolet-A (PUVA) is associated with photocarcinogenesis. However, carcinogenic risk with other ultraviolet phototherapies remains unclear.

OBJECTIVE

Evaluate whether phototherapy without psoralens increases skin cancer risk.

METHODS

Retrospective cohort study of patients treated at a teaching-hospital phototherapy center (1977-2018). Skin cancer records were validated against pathology reports. Age-standardized incidence rates (ASIRs) of skin cancer were evaluated for gender, skin phototype, diagnosis, ultraviolet modality, anatomical site; and compared to provincial population incidence rates (2003).

RESULTS

In total, 3506 patients treated with broadband-ultraviolet-B, narrowband-UVB and/or combined UVAB were assessed with a mean follow-up of 7.3 years. Majority of patients had psoriasis (60.9%) or eczema (26.4%). Median number of treatments was 43 (1-3598). Overall, 170 skin cancers (17 melanoma, 33 squamous cell carcinoma and 120 basal cell carcinoma) occurred in 79 patients. Patient-based and tumor-based ASIR of skin cancer was 149 (95% CI: 112-187)/100,000 and 264 (219-309)/100,000 person-years, respectively. There was no significant difference between tumor-based ASIRs for melanoma, squamous cell carcinoma, and basal cell carcinoma compared to the general population; or in phototherapy patients with-psoriasis or eczema; or immunosuppressants. No cumulative dose-response correlation between UVB and skin cancer was seen.

LIMITATIONS

Treatment and follow-up duration.

CONCLUSION

No increased risk of melanoma and keratinocyte cancer was found with phototherapy.

Incidence and mortality rates of keratinocyte carcinoma from 1998-2017: a population-based study of sex differences in Ontario, Canada

Background:

Keratinocyte carcinoma is the most common malignant disease, but it is not captured in major registries. We aimed to describe differences by sex in the incidence and mortality rates of keratinocyte carcinoma in Ontario, Canada.

Methods:

We conducted a population-based retrospective study of adults residing in Ontario between Jan. 1, 1998, and Dec. 31, 2017, using linked health administrative databases. We identified the first diagnosis of keratinocyte carcinoma using a validated algorithm of health insurance claims, and deaths related to keratinocyte carcinoma from death certificates. We calculated the incidence and mortality rates of keratinocyte carcinoma, stratified by sex, age and income quintile. We evaluated trends using the average annual percentage change (AAPC) based on joinpoint regression.

Results:

After decreasing from 1998 to 2003, the incidence rate of keratinocyte carcinoma increased by 30% to 369 per 100 000 males and 345 per 100 000 females in 2017 (AAPC 1.9%, 95% confidence interval [CI] 1.7 to 2.1 from 2003 to 2017). The incidence rate was higher in females younger than 55 years, but higher in males aged 55 years or older. Between 2008 and 2017, the incidence rate rose faster in females than males aged 45–54 years (AAPC 1.2% v. 0.5%, p = 0.01) and 55–64 years (1.2% v. 0.1%, p < 0.01). The incidence was higher in males than females in the higher income quintiles. Between 1998 and 2017, the mortality rate of keratinocyte carcinoma was 1.8 times higher in males than females, on average, and rose 4.8-fold overall (AAPC 8.9%, 95% CI 6.4 to 11.4 in males; 8.0%, 95% CI 5.3–10.8 in females).

Interpretation:

The population burden of keratinocyte carcinoma is growing, and the incidence and mortality rates rose disproportionately among certain sex- and age-specific groups. This warrants further investigation into causal factors and renewed preventive public health measures.

Basal cell carcinoma: an emerging epidemic in women in Iceland

BACKGROUND

An epidemic of basal cell carcinoma (BCC) has led to a significant healthcare burden in white populations.

OBJECTIVES

To provide an update on incidence rates and tumour burden in an unselected, geographically isolated population that is exposed to a low level of ultraviolet radiation.

METHODS

This was a whole-population study using a cancer registry containing records of all cases of BCC in 1981-2017. We assessed BCC incidence according to age, residence and multiplicity and assessed trends using join-point analysis. Age-standardized and age-specific incidence rates were calculated along with cumulative and lifetime risks.

RESULTS

During the study period, the age-standardized incidence rates increased from 25·7 to 59·9 for men, and from 22·2 to 83·1 for women (per 100 000). Compared with the single-tumour burden, the total tumour burden in the population was 1·72 times higher when accounting for multiplicity. At the beginning of the study period, the world-standardized rates in men and women were similar, but by the end of the study period the rates were 39% higher in women (83·1 per 100 000, 95% confidence interval 77·9-88·3) than in men (59·9 per 100 000, 95% confidence interval 55·6-64·2). This increase was most prominent in women on sites that are normally not exposed to ultraviolet radiation in Iceland: the trunk and legs.

CONCLUSIONS

This is the only reported population in which the incidence of BCC is significantly higher in women than in men. The period of notable increase in BCC lesions correlates with the period of an increase in tanning beds and travel popularity. The high multiplicity rates suggest that the total tumour burden worldwide might be higher than previously thought. What is already known about this topic? Basal cell carcinoma (BCC) is becoming an increasing healthcare burden worldwide, especially in white populations. Recent population studies have reported a rapid increase in incidence among younger individuals, especially women. What does this study add? Iceland is the only reported population in which the incidence of BCC is significantly higher in women than in men, and there does not seem to be a clear relationship between latitude and BCC incidence in Europe. Men might be comparatively protected in the northern low-ultraviolet environment, with tanning beds and travel abroad likely playing important roles in the observed incidence increase, especially in women. The high multiplicity rates suggest that the total tumour burden worldwide might be higher than previously thought. Linked Comment: Pandeya. Br J Dermatol 2020; 183:799-800.

National incidence of eyelid cancer in Ireland (2005-2015)

AIMS

We report on the incidence of cutaneous eyelid tumours in Ireland over the 11-year-period from 2005 to 2015, we identify associations between demographic factors and cutaneous eyelid tumour risk.

METHODS

Skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), melanoma, and other cancers, located on the eyelid or canthus according to ICD-10 coding, as registered by the National Cancer Registry of Ireland (NCRI), were captured from the period 2005 to 2015. Age standardised rates (ASR) were calculated according to the European Standard Population (2013). Longitudinal data analysis using linear regression, and associations with age and sex were evaluated with the statistics program R.

RESULTS

There were 4824 patients diagnosed with eyelid BCC during the study period, the ASR in men and women was mean 15.87 and 13.49 per 100,00, respectively. The relative risk for eyelid BCC in men compared with women was 1.18, age was associated with incidence. There were 528 patients diagnosed with SCC; the ASR of eyelid SCC in men and women was 2.10 and 1.39 per 100,000, respectively, and increased in women annually (β = 0.07, p = 0.0005). The relative risk for eyelid SCC in men compared with women was 1.51, and age was exponentially associated with SCC. Melanoma and other eyelid tumours were uncommon-50 and 55 cases, respectively.

CONCLUSION

Incidence of both BCC and SCC increases with age and male sex. The incidence of eyelid SCC is increasing in women, and under age 50, eyelid BCC is more common in women than men.

SYNOPSIS

We describe the recent incidence of eyelid cancers in Ireland, from National Cancer Registry Data. We find eyelid BCC, and also SCC, are associated with increased age. Rate of eyelid SCC is increasing in women.

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.

A 13-Year Retrospective Study of Basal Cell Carcinoma in a Canadian Dermatology Practice: A Comparison Between Anatomical Location and Histopathologic Subtypes

BACKGROUND

It is unknown whether the histologic subtypes of basal cell carcinoma (BCC) arise from a common progenitor cell or whether other factors play a role in their development.

OBJECTIVE

To investigate the relationship between the different BCC histopathologic subtypes and anatomical distribution of BCCs in a Canadian dermatology practice.

METHODS

The charts of all patients diagnosed with BCC between 1993 and 2005 from a single private dermatology practice in Vancouver, Canada, were reviewed. Descriptive data analysis was undertaken to look at the distribution of histologic subtypes based on age, gender, and anatomical location.

RESULTS

Nodular BCCs accounted for 58% of all tumors. Sixty-six percent of these were situated on the head/neck (odds ratio [OR] = 3.0, 95% confidence interval [CI] = 2.1-4.3, P < .0001). Infiltrative (OR = 2.4, 95% CI = 1.5-4.1, P = .0003) and superficial BCCs were more common in women (OR = 3.7, 95% CI = 2.5-5.7, P < .0001), affected the trunk (OR = 3.2, 95% CI = 2.1-4.9, P < .0001), and appeared in younger individuals (OR = 1.8, 95% CI = 1.2-2.7, P = .004).

CONCLUSION

Our results show a preference of distinct BCC subtypes for certain anatomical locations.

Trends in Non-Melanoma Skin Cancer (Basal Cell Carcinoma and Squamous Cell Carcinoma) in Canada

Background:

Despite its increased incidence and status as the most prevalent cancer in Canada, there is a paucity of epidemiological data on non-melanoma skin cancer (NMSC).

Objective:

To assess trends of keratinocyte carcinomas (KC) in Canada over 5 decades.

Methods:

Articles published from 1960 to 2015 on NMSC in Canada were identified through MEDLINE. Six articles met our search criteria.

Results:

Overall, KC has increased. However, the rate of increase in the past decade has slowed down and decreased in younger age cohorts. Men had higher incidences of KC. In both sexes, the basal cell carcinoma and squamous cell carcinoma ratio was ≥2.5:1. Keratinocyte carcinomas were most commonly located on the head and neck, and increasing rates are occurring on the trunk.

Limitations:

The methods of registering skin cancer cases vary among different provinces.

Conclusion:

Keratinocyte carcinomas incidence is overall increasing; however, there may be evidence that the incidence is leveling off and decreasing in younger age cohorts.

Skin health in older age

As people age, their skin undergoes changes which result in reduced elasticity, increased fragility and an altered immune response; in essence it becomes frail. As life expectancy is increasing the health of older skin is becoming a progressively more important facet of overall care. In addition to the consequences of ageing for otherwise healthy skin, the relative incidence of some dermatological conditions is age-dependent. In particular, xerosis (dry skin), cutaneous malignancies and skin injuries are more common in older people. In this review we describe the functional consequences of skin ageing and discuss the current evidence on how skin health may be maintained and dermatological conditions prevented in an ageing population. The future of dermatological health-care provision in the older population relies on the development of coordinated pathways of care, which start from a young age. Better quality research coordinated by the establishment of institutions dealing with skin health and ageing would be a method of addressing these needs.