Increase In Incidence Of Melanoma Research Articles

Predictors of sun exposure in adolescents in a southeastern U.S. population

With the increase in melanoma incidence, the sun exposure and protective behaviors of adolescents are of great concern. Limited data are available on the prevalence and predictors of risk behavior in adolescents in the southeastern United States. This study examined the levels of sun exposure and variables predictive of sun exposure among adolescents in two Alabama middle schools. A total of 509 sixth-graders completed a self-administered survey assessing: (a) their knowledge, attitudes, and beliefs about malignant melanoma; and (b) their sun exposure and sunburns for a specific weekend and for the summer. Levels of sun exposure and frequency of sunburn were high. Regression models determined the predictors of weekend and summer sun exposure, and weekend sunburn. Significant predictors varied by outcome and included gender, perceived importance of a suntan, parent and peer modeling, and sunscreen use. Reducing the risk of melanoma will require a three-pronged intervention strategy with efforts directed at adolescents, their parents, and the broader community.

Recent incidence trends imply a nonmetastasizing form of invasive melanoma

In the mid- to late-1980s white populations in Australia, New Zealand and Scotland showed a sharp increase in melanoma incidence above preceding long-term trends, in some cases as much as doubling in as little as 2 years. Most of this increase was in thin melanomas, (< 1.50 mm thick), and males were more affected than females. Thicker melanomas also generally increased in incidence, particularly in males aged 65 years or older. Examination of Australian Medicare and pathology laboratory data indicated that excision of skin lesions and laboratory diagnosis of pigmented lesions also rose sharply in this period, suggesting that advancement of the time of diagnosis was a likely factor in the increase in melanoma incidence. However the maintenance of new higher incidence levels and the increase in incidence of thicker lesions suggests that advancement of diagnosis cannot explain all of the increase. A real increase in incidence and increasing diagnosis of a preexisting, non-metastasizing form of thin melanoma may also have contributed.

Effect of Sunscreens on UV Radiation-Induced Enhancement of Melanoma Growth in Mice

Epidemiologic evidence suggests that exposure to UV radiation plays a significant role in the development of melanoma skin cancers. As early surgical removal of the melanoma is the only effective therapy, current strategies for reducing mortality from melanoma focus on prevention of the disease. Chemical sunscreens protect mice from development of skin cancers that resemble sunlight-induced human squamous cell cancers, but there appears to be a complex relationship between UV radiation exposure and development of melanoma. We asked whether common sunscreens would protect mice against UV radiation-induced enhancement of melanoma incidence. C3H mice were exposed to 4.8 kJ/m2 UVB from FS40 sunlamps twice a week for 3 weeks. Sunscreens containing 7.5% 2-ethylhexyl-p-methoxycinnamate, 8% octyl-N-dimethyl-p-aminobenzoate, 6% benzophenone-3, or the oil-in-water vehicle alone were applied to the ears and tails of the mice 20 minutes before irradiation. At various times during and after exposure, we determined UV radiation-induced inflammation by measuring ear swelling. We also examined the ears histologically for UV radiation-induced alterations. One day after the final irradiation, 2.5 x 10(4) syngeneic K1735 melanoma cells were injected into the external ears. Mice were examined weekly for tumor growth for 5-8 weeks after tumor cell injection. Control mice were treated in the identical way except for exposure to UV radiation. The incidence of melanomas was significantly higher in the UV-irradiated mice. All three sunscreens protected against UV radiation-induced ear swelling and clearly diminished histopathologic alterations, including sunburn cell formation, epidermal hyperplasia, and mononuclear cell infiltrate in the dermis. However, the sunscreens failed to protect against UV radiation-induced increase in melanoma incidence. The sunscreens or vehicle alone did not significantly alter tumor growth. Protection against sunburn does not necessarily imply protection against other possible UV radiation effects, such as enhanced melanoma growth. Sunscreen protection against UV radiation-induced inflammation may encourage prolonged exposure to UV radiation and thus may actually increase the risk of melanoma development. These findings suggest that further research on the ability of sunscreens to prevent melanoma is urgently needed.

Case-Control Study of Melanoma and Dietary Vitamin D: Implications for Advocacy of Sun Protection and Sunscreen Use

The rapid increase in melanoma incidence and mortality has given rise to nationwide and international campaigns that encourage the public to protect themselves from solar radiation with clothing, sunscreens, and other measures. The basis of these campaigns has been challenged by proponents of the theory that vitamin D, which is generated in the skin by ultraviolet B radiation, inhibits the development of melanoma. The present investigation tests this theory by examining the relation between dietary vitamin D and melanoma risk in a case-control study. Vitamin D intake was assessed by a food-frequency questionnaire in 165 melanoma patients and 209 controls. After controlling for age, hair color, and family history of melanoma, there was no association of melanoma risk with total vitamin D intake, calorie-adjusted vitamin D intake, vitamin D intake from foods, or consumption of milk or vitamin D supplements. We find no evidence to suggest that vitamin D protects against melanoma, and therefore continue to support the ongoing public health campaigns aimed at reducing sun exposure for the prevention of melanoma.

Epidemiology on malignant melanoma in Europe.

Mortality and incidence of malignant melanoma of the skin is increasing at a rate of between 3 and 7% per year in many European countries. All over Europe melanoma is the cancer showing the most rapid increase in incidence. Within Europe the variation in incidence and mortality rates is close to a factor of ten with the disease being more common in northern than in southern Europe. Higher rates are consistently reported on intermittently exposed body sites. Skin melanoma differ from non-melanoma skin cancer with regard to sex-, age-, and anatomic distribution. There is mounting evidence from analytical studies that the increase in melanoma incidence is a result of intermittent recreational sun exposure. Severe sunburns, in particular, is a strong risk factor, being especially harmful in childhood. Outdoor work with chronic sun exposure is not associated with increased melanoma risk and it may even be protective. The total number of pigmented naevi is an important risk factor in several studies. Freckling, fair complexion, and skin which burns rather than tans at sun exposure, are other well-established risk factors. Today no non-solar environmental risk factors have been identified. Information campaigns based on our knowledge of risk factors, warning against excessive sun exposure should significantly reduce the incidence in the future. Population-based education of risk groups may lead to earlier diagnosis and thereby reduced mortality.

Time trends in malignant melanoma of the upper limb in Connecticut

Time trends in the incidence of malignant melanoma of the anatomic subsites of the upper limb in Connecticut from 1935 to 1984 were examined. Among males, the incidence of melanoma of the hand was stable, in sharp contrast to the 15-fold to 16-fold increase in the upper arm and forearm. Among females, the 3-fold increase in melanoma of the hand was substantially less than the 12-fold to 14-fold increase in the upper arm and forearm. However, melanoma of the dorsal surface of the hand in females increased sevenfold. These results are in partial agreement with the hypothesis that the hand would be relatively resistant to increased melanoma incidence because it has continually been a sun-exposed site over the decades. The results contradict the hypothesis that the rise in incidence would be greater in the upper arm (a usually unexposed site that has received increasing exposure due to changes in recreation and dress habits) than in the forearm (a site of intermediate exposure).

Epidemiology of Cutaneous Melanoma: An Update

Dramatic increases in melanoma incidence and more moderate increases in the death rate have been observed. Although paradoxes exist, most, but not all, melanomas appear to be related in some way to solar exposure and genetic factors. No other exogenous factor has been strongly implicated.

Is chronic sunlight exposure important in accounting for increases in melanoma incidence?

Most attempts to relate changes in patterns of sunlight exposure to the rise in incidence of malignant melanoma have concentrated on the positive association between intermittent exposure to sunlight and risk of melanoma. The Western Canada Melanoma Study, however, also detected a significant inverse association between melanoma and chronic or long-term occupational sun exposure in men, with the lowest risk (OR = 0.5) in those with maximum occupational exposure, suggesting that chronic exposure may be protective. Data obtained from Canadian census figures indicated that since 1951 there has been a substantial reduction in the number of males engaged in outdoor occupations in Canadian society. These observations suggest that part of the increase in the incidence of melanoma in low-sunlight areas may be due to a reduction over the past 40 years of the size of this group of individuals "protected" by their exposure to UV light.

Cancer Incidence and Mortality Trends Among Whites in the United States, 1947–84

Cancer incidence trends from the late 1940s to 1983-84 were assessed among white residents of five geographic areas (Atlanta, Connecticut, Detroit, Iowa, San Francisco-Oakland) by means of data derived from several National Cancer Institute surveys, the Connecticut Tumor Registry, and the Surveillance, Epidemiology, and End Results Program. Incidence trends were compared with mortality trends for the entire United States and for the same five study areas. This study documented rising incidence and mortality rates for four cancers: lung cancer, melanoma of the skin, multiple myeloma, and non-Hodgkin's lymphomas. Increases in lung cancer continued through the early 1980s, but the rate of increase has been moderating during recent years, particularly among males and at younger ages for whom recent declines are evident. Overall, lung cancer incidence rates increased more than 220 and 400% among males and females, respectively. Although much rarer than lung cancer, melanoma of the skin and multiple myeloma increased greatly until the early 1980s among both males and females. The overall rate of increase in melanoma incidence among males was greater than that for lung cancer, and the rate of increase in multiple myeloma mortality among females was exceeded only by that for lung cancer. Increases of 70-120% were observed for non-Hodgkin's lymphomas. Increases in incidence and mortality rates for pancreatic cancer were apparent during the early years but less conspicuous in recent years. Laryngeal and kidney cancer rates generally increased substantially, although the changes were not remarkable for laryngeal cancer mortality among males and kidney cancer mortality among females. The rates for cancers of the mouth and pharynx increased among females but not males. Prostate, colon, and bladder cancer incidence rates increased more than 65% among males, whereas mortality rates changed only moderately. The incidence of thyroid cancer increased more than 75% among both sexes until the late 1970s, but mortality rates have declined during the period of study. Breast cancer incidence increased 30%, whereas mortality rates remained remarkably constant. The incidence of corpus uteri cancer increased dramatically during the mid-1970s and decreased substantially thereafter; these changes were not reflected in the mortality rates, which continually declined during the entire time period. The incidence of testicular cancer increased more than 90% and that of Hodgkin's disease did not change greatly; however, mortality rates for both cancers declined more than 50% since the late 1960s and early 1970s.(ABSTRACT TRUNCATED AT 400 WORDS)

A genetic analysis of melanoma--polygenic inheritance as a threshold trait.

A total of 214 melanoma patients and 193 age- and sex-matched controls, interviewed at the Roswell Park Memorial Institute during the years 1974--1978, provided information regarding 1134 and 1043 New York State first order relatives (parents, offspring and siblings). The vital information provided was checked against the records of the New York State Tumor Registry to find cases of melanoma among relatives. Five cases of melanoma were found among the 1027 New York State relatives of melanoma index cases alive during the period 1949--1978, inclusive. No cases of melanoma were found among New York State relatives of controls. The expected number of melanomas among a cohort of relatives of identical sex and age composition for the interval was 0.625 cases, giving a ratio of observed to expected of 8.0. A similar analysis, restricted to parent-offspring pairs, yielded a ratio of observed to expected of 12.7. A search for additional melanoma cases among second degree relatives of familial index cases yielded no further affected relatives. The incidence of melanoma among relatives of melanoma cases and in a comparable general population were used to estimate the heritability of liability to melanoma as a polygenic trait. A heritability estimate of 0.49 was obtained, using parent-offspring data, indicating that nearly half of the variability in liability to melanoma in this population may be attributed to the additive action of many genes, each with small effect. Pending the replication of these findings, the 12-fold increase in incidence of melanoma among parents and offspring of melanoma cases suggests the importance of counseling and surveillance of relatives of affected individuals by the clinician.

DO POLYUNSATURATED FATS PREDISPOSE TO MALIGNANT MELANOMA?

The consumption of polyunsaturated fats of patients with malignant melanoma and of a control group of patients with benign naevi has been compared in order to determine whether polyunsaturated fats predispose to the development of malignant melanoma. Patients with malignant melanoma had not consumed excessive quantities of polyunsaturated fats. Thus, there was no evidence to indicate that ingestion of polyunsaturated fats is associated with an increase in incidence of melanoma.