Occupation and relative risk of cutaneous squamous cell carcinoma (cSCC): A 45-year follow-up study in 4 Nordic countries

Cutaneous Squamous Cell Carcinoma: An Updated Review

Representing the second most common skin cancer, the incidence and disease burden of cutaneous squamous cell carcinoma (cSCC) continues to increase. Surgical excision of the primary site effectively cures the majority of cSCC cases. However, an aggressive subset of cSCC persists with clinicopathological features that are indicative of higher recurrence, metastasis, and mortality risks. Acceleration of these features is driven by a combination of genetic and environmental factors. The past several years have seen remarkable progress in shaping the treatment landscape for advanced cSCC. Risk stratification and clinical management is a top priority. This review provides an overview of the current perspectives on cSCC with a focus on staging, treatment, and maintenance strategies, along with future research directions.

Advances in cutaneous squamous cell carcinoma

Human malignancies arise predominantly in tissues of epithelial origin, where the stepwise transformation from healthy epithelium to premalignant dysplasia to invasive neoplasia involves sequential dysregulation of biological networks that govern essential functions of epithelial homeostasis. Cutaneous squamous cell carcinoma (cSCC) is a prototype epithelial malignancy, often with a high tumour mutational burden. A plethora of risk genes, dominated by UV-induced sun damage, drive disease progression in conjunction with stromal interactions and local immunomodulation, enabling continuous tumour growth. Recent studies have identified subpopulations of SCC cells that specifically interact with the tumour microenvironment. These advances, along with increased knowledge of the impact of germline genetics and somatic mutations on cSCC development, have led to a greater appreciation of the complexity of skin cancer pathogenesis and have enabled progress in neoadjuvant immunotherapy, which has improved pathological complete response rates. Although measures for the prevention and therapeutic management of cSCC are associated with clinical benefit, the prognosis remains poor for advanced disease. Elucidating how the genetic mechanisms that drive cSCC interact with the tumour microenvironment is a current focus in efforts to understand, prevent and treat cSCC.

Incidence of cancer among Nordic police officers

Police work may expose officers to various circumstances that have potential for increasing their risk of cancer, including traffic-related air pollution, night shift work and radiation from radars. In this study, we examined the incidence of cancer among Nordic male and female police officers. We utilize data from the Nordic Occupational Cancer (NOCCA) project, which linked census data on occupations from Finland, Iceland, Norway and Sweden to national cancer registries for the period 1961 to 2005. We report standardized incidence ratios (SIR) and 95% confidence intervals (CI) of selected cancers for each country by sex, age and calendar period. The cohort included 38 523 male and 1998 female police officers. As compared with the general population, male police officers had a 7% (95% CI: 4-9%) excess cancer risk, with elevated SIRs for various cancer sites, including prostate (SIR 1.19, 1.14-1.25), breast (SIR 1.77, 1.05-2.80), colon (SIR 1.22, 1.12-1.32) and skin melanoma (SIR 1.44, 1.28-1.60). Conversely, male police officers had a lower risk of lung cancer than the general population (SIR 0.72, 0.66-0.77). In female police officers, the SIR for cancer overall was 1.15 (0.98-1.34), and there was a slight excess of cancers of the breast (SIR 1.25, 0.97-1.59) and colon (SIR 1.21, 0.55-2.30). In conclusion, cancer incidence among the police officers was slightly higher than in the general population. Notably, SIRs were elevated for cancer sites potentially related to night shift work, namely colon, breast and prostate cancer.

Occupation and cutaneous melanoma: a 45-year historical cohort study of 14·9 million people in five Nordic countries

BACKGROUND

The age-adjusted incidence of cutaneous melanoma (CM) in the Nordic countries has increased during the last 60 years. Few prospective population-based studies have estimated the occupational variation in CM risk over time.

OBJECTIVES

To determine occupational variation in CM risk.

METHODS

A historical prospective cohort study with a 45-year follow-up from 1961 to 2005 (Nordic Occupational Cancer Study, NOCCA) based on record linkages between census and cancer registry data for Nordic residents aged 30-64 years in Denmark, Finland, Iceland, Norway and Sweden. National occupational codes were converted to 53 occupational categories, and stratified into indoor, outdoor and mixed work, and into socioeconomic status. The standardized incidence ratios (SIRs) were estimated as observed number of CM cases divided by the expected number calculated from stratum-specific person-years and national CM incidence rates.

RESULTS

During a follow-up of 385 million person-years, 83 898 incident cases of CM were identified. In all countries combined, men with outdoor work had a low SIR of 0·79 [95% confidence interval (CI) 0·77-0·81] and men with indoor work had a high SIR of 1·09 (95% CI 1·07-1·11). Differences in women pointed in the same direction. High socioeconomic status was associated with an excess risk: SIR 1·34 (95% CI 1·28-1·40) in men and SIR 1·31 (95% CI 1·26-1·36) in women. Technical, transport, military and public safety workers with potential skin exposure to carcinogens had excess risks.

CONCLUSIONS

Occupational variation in CM risk may be partly explained by host, socioeconomic and skin exposure factors. Differences in CM risk across socioeconomic groups attenuated slightly over time.

Occupational Skin Disease in Physicians: A Review of the Literature

OBJECTIVES

Occupational skin disease (OSD) arises from work-related activity. However, there is a paucity of literature on OSD in physicians. The aim of the this review was therefore to examine and summarize what types of symptomatic OSD physicians experience.

METHODS

We conducted a systematic literature search on Cochrane Library, Embase, and Pubmed.

RESULTS

Contact dermatitis from formaldehyde and glutaraldehyde were found in 11.5 and 13.5% of cases, respectively. In total 2.4-14.9% had latex allergy. The reported standardized incidence ratio of squamous cell carcinoma and melanoma was up to 2.15 [95% confidence interval (CI) 1.57-1.95] and 3.2 (95% CI 1.38-6.31). Transmission of human papilloma virus (HPV) particles during carbon dioxide laser wart ablation were found in 70% of samples collected from protective gloves and in 52% of samples from vapors.

CONCLUSIONS

The most frequently reported OSD in physicians is contact dermatitis from allergens in disinfectants and rubber gloves. There is also a risk of cutaneous reactions to latex. The incidence of skin cancer was higher in physicians than in the general population, and the reason for this remains unexplained and potentially biased. There are no reports of transmission of patient HPV to surgeons during wart ablation, possibly because of proper use of protective equipment.

Prediagnostic serum 25-hydroxyvitamin D and melanoma risk

Previous studies of serum 25-hydroxyvitamin D (25(OH)D) in relation to melanoma have shown conflicting results. We conducted a nested case–control study of 708 cases and 708 controls, using prediagnostically collected serum, to study 25(OH)D and melanoma risk in the population-based Janus Serum Bank Cohort. Stratified Cox regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for ultraviolet radiation (UVR) indicators and stratified by ambient UVB of residence and body mass index (BMI). Non-linear associations were studied by restricted cubic splines. Missing data were handled with multiple imputation by chained equations. We found an HR of melanoma risk of 1.01 (95% CI: 0.99, 1.04) and an HR_imputed of 1.02 (95% CI: 1.00, 1.04) per 5-nmol/L increase. The spline model showed exposure-risk curves with significantly reduced melanoma risk between 60 and 85 nmol/L 25(OH)D (reference 50 nmol/L). Non-significant J-shaped curves were found in sub-analyses of subjects with high ambient UVB of residence and of subjects with BMI < 25 kg/m². Our data did not yield persuasive evidence for an association between 25(OH)D and melanoma risk overall. Serum levels within the medium range might be associated with reduced risk, an association possibly mediated by BMI.

Smoking-adjusted risk of kidney cancer by occupation: a population-based cohort study of Nordic men

Background: Evidence suggests that among some occupational groups, there is an elevated risk of kidney cancer. This might, however, derive from a difference in smoking habits across occupational groups. The objective of this study was to determine smoking-adjusted occupational variation in the incidence of kidney cancer in Nordic males.Material and Methods: The source population for this study consisted of 7.4 million men from Denmark, Iceland, Finland, Norway, and Sweden. Data on occupation were obtained from national censuses conducted in the years 1960-1990. Data on cancer cases came from national cancer registries. A proxy for the occupation-specific smoking prevalence among all Nordic men was calculated based on the occupation-specific smoking prevalence and lung cancer incidence data for Finnish men. Smoking-adjusted standardized incidence ratio (SIRadj) with 95% confidence intervals (95%CI) were calculated for each occupational group.Results: The highest SIRadj estimates were observed in dentists (1.32, 95%CI 1.06-1.62), journalists (1.20, 95%CI 1.00-1.42), physicians (1.19, 95%CI 1.03-1.36), public safety workers (1.18, 95%CI 1.10-1.26), administrators (1.17, 95%CI 1.13-1.22), military personnel (1.16, 95%CI 1.05-1.28), and religious workers (1.17, 95%CI 1.09-1.26). The lowest SIRadj was observed among forestry workers (0.82, 95%CI 0.76-0.88).Conclusions: Tobacco smoking plays an important role in the occupational variation in the risk of kidney cancer. The smoking-adjusted incidence of kidney cancer was increased in dentists, physicians, journalists, administrators, and public safety workers.

Socioeconomic inequalities in cancer incidence in Europe: a comprehensive review of population-based epidemiological studies

Background

Since the end of the previous century, there has not been a comprehensive review of European studies on socioeconomic inequality in cancer incidence. In view of recent advances in data source linkage and analytical methods, we aimed to update the knowledge base on associations between location-specific cancer incidence and individual or area-level measures of socio-economic status (SES) among European adults.

Materials and methods

We systematically searched three databases (PubMed, Scopus and Web of Science) for articles on cancer incidence and SES. Qualitative synthesis was performed on the 91 included English language studies, published between 2000 and 2019 in Europe, which focused on adults, relied on cancer registry data and reported on relative risk (RR) estimates.

Results

Adults with low SES have increased risk of head and neck, oesophagogastric, liver and gallbladder, pancreatic, lung, kidney, bladder, penile and cervical cancers (highest RRs for lung, head and neck, stomach and cervix). Conversely, high SES is linked with increased risk of thyroid, breast, prostate and skin cancers. Central nervous system and haematological cancers are not associated with SES. The positive gap in testicular cancer has narrowed, while colorectal cancer shows a varying pattern in different countries. Negative associations are generally stronger for men compared to women.

Conclusions

In Europe, cancers in almost all common locations are associated with SES and the inequalities can be explained to a varying degree by known life-style related factors, most notably smoking. Independent effects of many individual and area SES measures which capture different aspects of SES can also be observed.

Photoaging and actinic keratosis in Danish outdoor and indoor workers

BACKGROUND

The risk of photoaging and actinic keratosis caused by work related solar ultraviolet radiation exposure has not previously been investigated in Nordic countries. The objectives of this study were to describe the occurrence of photoaging, actinic keratosis, and keratinocyte cancer in a population of Danish outdoor and indoor workers, and investigate the association between these clinical findings and semi-objective measures of work related solar ultraviolet radiation exposure in the same population.

METHODS

A clinical cross-sectional study of the occurrence of facial wrinkles, actinic keratosis, keratinocyte cancer, and melanocytic nevi in a population of Danish outdoor and indoor workers and associations with semi-objective measures of work related solar ultraviolet radiation exposure based on a combination of dosimetry and self-report.

RESULTS

Work related solar ultraviolet radiation exposure was significantly positively associated with occurrence of facial wrinkles (α = 0.05). Actinic keratosis was associated to status as outdoor worker (OR = 4.272, CI [1.045-17.471]) and age (P < 0.001, CI [1.077-1.262]) and twice as common in outdoor workers (10.3% CI [0.05, 0.15]) compared to indoor workers (5.1% CI [0.00, 0.10]). Only two cases of keratinocyte cancer were diagnosed (<1%). Older age was negatively associated with occurrence of melanocytic nevi.

CONCLUSION

Outdoor work in Denmark is associated with increased occurrence of facial wrinkles and actinic keratosis from solar ultraviolet radiation exposure, thus justifying sun safety at Danish workplaces from a clinical perspective.

UV exposure, preventive habits, risk perception, and occupation in NMSC patients: A case-control study in Trieste (NE Italy)

BACKGROUND

UV exposure is strongly associated with the incidence of non melanoma skin cancers (NMSCs), both basal and squamous cell carcinomas. The aim of our study was to analyze risk perception, UV exposure, preventive habits, and occupation in 126 subjects affected by NMSC and 187 controls.

METHODS

Consecutive cases with incident NMSC were recruited in Dermatologic Unit at University of Trieste; controls were recruited in Unit of Occupational Medicine. All had a medical examination to define Fitzpatrick skin type and skin lesions, and filled a standardized questionnaire on sun exposure habits, sun protection, occupational exposures, and sunburns in adulthood and childhood.

RESULTS

In multivariate regression analysis, NMSC resulted significantly associated with age (OR: 1.03; 95% CI 1.01-1.05), with a positive feeling for tan (OR: 1.10; 95% CI 1.01-1.20), and sunbath numbers per year (OR: 1.02; 95% CI: 1.001-1.03). A protective effect was demonstrated for Fitzpatrick phototypes III-IV compared to I and II (OR: 0.31; 95% CI: 0.18-0.55), sunscreen use (OR: 0.35; 95% CI: 0.22-0.58), and risk perception (OR: 0.98; 95% CI: 0.97-0.99). In univariate analysis, we demonstrated an increased risk for fishermen, sailors, and lifeguards (OR: 4.3; 95% CI: 1.1-16.4); foundry and metallurgy workers (OR: 5.58; 95% CI: 1.14-27.3); and mechanics, fixers, and welders (OR: 8.2; 95% CI: 1.76-37.9).

CONCLUSIONS

Our study demonstrated that protective behavior must be implemented in people living in Trieste. Workers must avoid direct UV exposure and must use protective equipment. More efforts are needed to increase knowledge on this risk and to raise awareness among at-risk people.

Anthropometric factors and cutaneous melanoma: Prospective data from the population-based Janus Cohort

The aim of the present study was to prospectively examine risk of cutaneous melanoma (CM) according to measured anthropometric factors, adjusted for exposure to ultraviolet radiation (UVR), in a large population-based cohort in Norway. The Janus Cohort, including 292,851 Norwegians recruited 1972-2003, was linked to the Cancer Registry of Norway and followed for CM through 2014. Cox regression was used to estimate hazard ratios (HRs) of CM with 95% confidence intervals (CIs). Restricted cubic splines were incorporated into the Cox models to assess possible non-linear relationships. All analyses were adjusted for attained age, indicators of UVR exposure, education, and smoking status. During a mean follow-up of 27 years, 3,000 incident CM cases were identified. In men, CM risk was positively associated with body mass index, body surface area (BSA), height and weight (all ptrends  < 0.001), and the exposure-response curves indicated an exponential increase in risk for all anthropometric factors. Weight loss of more than 2 kg in men was associated with a 53% lower risk (HR 0.47, 95% CI: 0.39, 0.57). In women, CM risk increased with increasing BSA (ptrend  = 0.002) and height (ptrend  < 0.001). The shape of the height-CM risk curve indicated an exponential increase. Our study suggests that large body size, in general, is a CM risk factor in men, and is the first to report that weight loss may reduce the risk of CM among men.

Skin Cancer Epidemics in the Elderly as An Emerging Issue in Geriatric Oncology

Skin cancer is a worldwide, emerging clinical need in the elderly white population, with a steady increase in incidence rates, morbidity and related medical costs. Skin cancer is a heterogeneous group of cancers comprising cutaneous melanoma and non-melanoma skin cancers (NMSC), which predominantly affect elderly patients, aged older than 65 years. Melanoma has distinct clinical presentations in the elderly patient and represents a challenging question in terms of clinical management. NMSC includes the basal cell carcinoma and cutaneous squamous cell carcinoma and presents a wide disease spectrum in the elderly population, ranging from low-risk to high-risk tumours, advanced and inoperable disease. Treatment decisions for NMSC are preferentially based on tumour characteristics, patient’s chronological age and physician’s preferences and operational settings. Several treatment options are available for NMSC, from surgery to non-invasive/medical therapies, but patient-based factors, such as geriatric comorbidities and patient’s life expectancy, do not frequently modulate treatment goals. In melanoma, age-related variations in clinical management are significant and may frequently lead to under-treatment, limiting access to advanced surgical and medical treatments. Clinical decision-making in the care of elderly skin cancer patient should ideally implement a geriatric assessment, prioritizing patient-based factors and efficiently differentiating fit from frail cancer patients. Current clinical practice guidelines for NMSC and melanoma only partially address geriatric aspects of cancer care, such as frailty, limited life-expectancy, geriatric comorbidities and treatment compliance. We review the recent evidence on the scope and problem of skin cancer in the elderly population as well as age-related variations in its clinical management, highlighting the potential role of a geriatric approach in optimizing dermato-oncological care.

Cancer risks in a population-based study of 70,570 agricultural workers: results from the Canadian census health and Environment cohort (CanCHEC)

BACKGROUND

Agricultural workers may be exposed to potential carcinogens including pesticides, sensitizing agents and solar radiation. Previous studies indicate increased risks of hematopoietic cancers and decreased risks at other sites, possibly due to differences in lifestyle or risk behaviours. We present findings from CanCHEC (Canadian Census Health and Environment Cohort), the largest national population-based cohort of agricultural workers.

METHODS

Statistics Canada created the cohort using deterministic and probabilistic linkage of the 1991 Canadian Long Form Census to National Cancer Registry records for 1992-2010. Self-reported occupations were coded using the Standard Occupational Classification (1991) system. Analyses were restricted to employed persons aged 25-74 years at baseline (N = 2,051,315), with follow-up until December 31, 2010. Hazard ratios (HR) and 95% confidence intervals (CI) were modeled using Cox proportional hazards for all workers in agricultural occupations (n = 70,570; 70.8% male), stratified by sex, and adjusted for age at cohort entry, province of residence, and highest level of education.

RESULTS

A total of 9515 incident cancer cases (7295 in males) occurred in agricultural workers. Among men, increased risks were observed for non-Hodgkin lymphoma (HR = 1.10, 95% CI = 1.00-1.21), prostate (HR = 1.11, 95% CI = 1.06-1.16), melanoma (HR = 1.15, 95% CI = 1.02-1.31), and lip cancer (HR = 2.14, 95% CI = 1.70-2.70). Decreased risks in males were observed for lung, larynx, and liver cancers. Among female agricultural workers there was an increased risk of pancreatic cancer (HR = 1.36, 95% CI = 1.07-1.72). Increased risks of melanoma (HR = 1.79, 95% CI = 1.17-2.73), leukemia (HR = 2.01, 95% CI = 1.24-3.25) and multiple myeloma (HR = 2.25, 95% CI = 1.16-4.37) were observed in a subset of female crop farmers.

CONCLUSIONS

Exposure to pesticides may have contributed to increased risks of hematopoietic cancers, while increased risks of lip cancer and melanoma may be attributed to sun exposure. The array of decreased risks suggests reduced smoking and alcohol consumption in this occupational group compared to the general population.