Trends in Skin Cancer Incidence in Neuchâtel, 1976-98

A systematic review of worldwide incidence of nonmelanoma skin cancer

BACKGROUND

  Nonmelanoma skin cancer (NMSC) is the most common cancer affecting white-skinned individuals and the incidence is increasing worldwide.

OBJECTIVES

This systematic review brings together 75 studies conducted over the past half century to look at geographical variations and trends worldwide in NMSC, and specifically incidence data are compared with recent U.K. cancer registry data.

METHODS

Following the development of a comprehensive search strategy, an assessment tool was adapted to look at the methodological quality of the eligible studies.

RESULTS

Most of the studies focused on white populations in Europe, the U.S.A. and Australia; however, limited data were available for other skin types in regions such as Africa. Worldwide the incidence for NMSC varies widely with the highest rates in Australia [>1000/100, 000 person-years for basal cell carcinoma (BCC)] and the lowest rates in parts of Africa (< 1/100, 000 person-years for BCC). The average incidence rates in England were 76·21/100, 000 person-years and 22·65/100, 000 person-years for BCC and squamous cell carcinoma (SCC), respectively, with highest rates in the South-West of England (121·29/100, 000 person-years for BCC and 33·02/100, 000 person-years for SCC) and lowest rates by far in London (0·24/100, 000 person-years for BCC and 14·98/100, 000 person-years for SCC). The incidence rates in the U.K. appear to be increasing at a greater rate when compared with the rest of Europe.

CONCLUSIONS

NMSC is an increasing problem for health care services worldwide. This review highlights a requirement for prevention studies in this area and the issues surrounding incomplete NMSC registration. Registration standards of NMSC should be improved to the level of other invasive disease.

A numeric model to simulate solar individual ultraviolet exposure

Exposure to solar ultraviolet (UV) light is the main causative factor for skin cancer. UV exposure depends on environmental and individual factors. Individual exposure data remain scarce and development of alternative assessment methods is greatly needed. We developed a model simulating human exposure to solar UV. The model predicts the dose and distribution of UV exposure received on the basis of ground irradiation and morphological data. Standard 3D computer graphics techniques were adapted to develop a rendering engine that estimates the solar exposure of a virtual manikin depicted as a triangle mesh surface. The amount of solar energy received by each triangle was calculated, taking into account reflected, direct and diffuse radiation, and shading from other body parts. Dosimetric measurements (n = 54) were conducted in field conditions using a foam manikin as surrogate for an exposed individual. Dosimetric results were compared to the model predictions. The model predicted exposure to solar UV adequately. The symmetric mean absolute percentage error was 13%. Half of the predictions were within 17% range of the measurements. This model provides a tool to assess outdoor occupational and recreational UV exposures, without necessitating time-consuming individual dosimetry, with numerous potential uses in skin cancer prevention and research.

Detailed site distribution of melanoma and sunlight exposure: aetiological patterns from a Swiss series

BACKGROUND

The relation between detailed cutaneous distribution of melanoma and indicators of sun exposure patterns has scantily been explored in moderately sun-sensitive populations.

PATIENTS AND METHODS

The precise site of 1658 primary malignant melanoma, registered from 1995 to 2002, in Switzerland were retrieved and clinically validated. Relative melanoma density (RMD) was computed by the ratio of observed to expected number of melanoma allowing for body site surface areas, and further adjusted for site-specific melanocyte density.

RESULTS

Sites of highest risks were the face, shoulder and upper arm for both sexes, the back for men, and leg for women. Major features of this series were: (i) an unexpectedly high RMD for the face in women (5.6 versus 3.7 in men), (ii) the absence of a male predominance for melanoma on the ears and (iii) for the upper limbs, a steady gradient of increasing melanoma density with increasing proximity to the trunk, regardless of sex. Age and sex patterns of RMD parallelled general indicators of sun exposure and behaviour, except for the hand (RMD = 0.2).

CONCLUSION

RMD increased with (cumulative) site sun exposure, but a few notable exceptions support the impact of intermittent exposure in melanoma risk.

Effective exposure to solar UV in building workers: influence of local and individual factors

Excessive exposure to solar UV light is the main cause of skin cancers in humans. UV exposure depends on environmental as well as individual factors related to activity. Although outdoor occupational activities contribute significantly to the individual dose received, data on effective exposure are scarce and limited to a few occupations. A study was undertaken in order to assess effective short-term exposure among building workers and characterize the influence of individual and local factors on exposure. The effective exposure of construction workers in a mountainous area in the southern part of Switzerland was investigated through short-term dosimetry (97 dosimeters). Three altitudes, of about 500, 1500 and 2500 m were considered. Individual measurements over 20 working periods were performed using Spore film dosimeters on five body locations. The postural activity of workers was concomitantly recorded and static UV measurements were also performed. Effective exposure among building workers was high and exceeded occupational recommendations, for all individuals for at least one body location. The mean daily UV dose in plain was 11.9 SED (0.0-31.3 SED), in middle mountain 21.4 SED (6.6-46.8 SED) and in high mountain 28.6 SED (0.0-91.1 SED). Measured doses between workers and anatomical locations exhibited a high variability, stressing the role of local exposure conditions and individual factors. Short-term effective exposure ranged between 0 and 200% of ambient irradiation, indicating the occurrence of intense, subacute exposures. A predictive irradiation model was developed to investigate the role of individual factors. Posture and orientation were found to account for at least 38% of the total variance of relative individual exposure, and were also found to account more than altitude on the total variance of effective daily exposures. Targeted sensitization actions through professional information channels and specific prevention messages are recommended. Altitude outdoor workers should also benefit from preventive medical examination.

High incidence of second basal cell skin cancers

We considered the risk of second basal cell cancers (BCC) of the skin using a population-based series of 1,868 BCC collected between 1976 and 1985 in the Swiss Cantons of Vaud and Neuchâtel, and followed-up to the end of 2003. Overall, 507 second BCC were observed versus 59.98 expected, corresponding to a standardized incidence ratio (SIR) of 8.45 (95% CI: 7.73-9.22). The SIRs were similar in men and women in subsequent calendar periods, but tended to decline with advancing age at diagnosis of first BCC, from 13.98 below age 50 to 7.13 at age 70 or over. Consequently, the rate of first BCC increased to approximately 30-fold between 7/100,000 at age 30-39 and 200/100,000 at age 70-79, but the rate of second BCC increased only about 3-fold between 31/1,000 at age 30-39 and 110/1,000 at age 70-79. The cumulative risk of second BCC was 11% at 5 years, 21% at 10 years and 40% at 20 years. This study indicates that the relative (but not the absolute) risk of second BCC is greater at younger age and declines with advancing age, and is therefore compatible with an excess baseline risk in a population of susceptible individuals.

Sun Exposure, Phenotypic Characteristics, and Cutaneous Malignant Melanoma. An Analysis According to Different Clinico-Pathological Variants and Anatomic Locations (Italy)

OBJECTIVE

The aim of the study was to examine the relation between sun exposure and other selected risk factors and the development of different clinico-pathological variants of cutaneous malignant melanoma (CMM) at different body locations.

METHODS

We analysed data from a case-control study conducted in Italy between 1992 and 1994 on 542 cases of CMM and 538 hospital controls. Clinico-pathological variants included 391 superficial spreading (SSM), 72 nodular (NM) and 39 lentigo maligna (LMM) melanomas.

RESULTS

The risk of SSM increased for a high education level (odds ratio, OR = 1.5, 95% confidence interval, CI, 1.0-2.2), sunburn episodes before age 15 (OR = 1.8, 95% CI, 1.1-2.8), light eye colour (OR = 1.6, 95% CI, 1.1-2.4) and solar lentigines (OR = 1.4, 95% CI, 1.0-1.8). The ORs for total number of nevi >30 were 4.4 (95% CI, 2.9-6.7) for SSM, 5.7 (95% CI, 2.6-12.5) for NM and 2.2 (95% CI, 0.5-9.4) for LMM. The risk of CMM located on the trunk seemed to be higher for a high education level (OR = 1.6, 95% CI, 1.0-2.6) and propensity to sunburn (OR = 1.6, 95% CI, 0.8-3.2). The ORs for sunburn episodes, eye and skin colour, and solar lentigines tended to be higher for CMM located on the face/neck and on the upper limbs than the trunk. Total number of nevi was strongly associated with all anatomic locations.

CONCLUSIONS

Total number of nevi was the major risk factor associated with all melanoma variants and locations. A higher level of education and sunburn episodes in early childhood appeared to be more strongly related to SSM than to other variants.

Cutaneous malignant melanoma in Europe

Cutaneous malignant melanoma is on the rise in fair skinned societies. Both its incidence and mortality rates have been increasing in Europe over the past decades, the latter seem to stabilise in Scandinavia. The main cause of melanoma is intermittent exposure to ultraviolet radiation, especially in combination with endogenous factors like skin type and genetic predisposition. Evidence on an association between sunbed use and melanoma is inconclusive, but seems to point to a slightly increased risk associated with sunbed use. Within Europe, considerably variation in patterns of melanoma incidence and mortality existed. In this paper, we discuss the possible explanations for the observed trends and options for primary and secondary prevention. Early detection seems the most promising way to combat the relatively poor survival rates in Southern and Eastern Europe.

Ultraviolet carcinogenesis in nonmelanoma skin cancer. Part I: incidence rates in relation to geographic locations and in migrant populations

Over the past two decades a worldwide increase in the incidence of skin cancer to near epidemic proportions has led to increased morbidity and appreciating cost. Well known risk factors include UV radiation, x or gamma irradiation, chemical carcinogens, genetic aberrations, and immunosuppression. This article reviews and analyzes the evidence for UV radiations role in the pathogenesis of nonmelanoma skin cancer (NMSC). Observations on the incidence of NMSC among migrants to temperate regions show an increase in both basal cell carcinoma and squamous cell carcinoma. There is also an increase in NMSC in areas with lower latitudes. Irradiation of human skin grafted to animals and animal models that develop NMSC lend further support to the role of UV radiation in the pathogenesis of NMSC. In the forthcoming Part II of this review, epidemiologic evidence will be presented attesting to the relationship between UV radiation and NMSC.

Nonmelanoma skin cancer in the Federal State of Saarland, Germany, 1995-1999

We analysed incidence data of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin from the Cancer Registry Saarland, Germany. During 1995–1999, the age-standardised incidence rates (world standard population) of BCC and SCC were 43.7 and 11.2 per 100 000 among men and 31.7 and 4.4 per 100 000 among women.