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Melanoma Study Underscores Need For Early Detection

Basocellular and spinocellular carcinoma, together called the epitheliomas, are the most frequent types of skin cancer, responsible for about 90% of all skin cancers.

They arise from the epithelial cells (keratinocytes) in the skin. Over 95% of these tumors are curable, but they can cause significant disfigurement if treated in later stages.

Melanoma is the third type of skin cancer, arising from the pigment cells (melanocytes) in the skin. It is the most aggressive type of skin cancer and it's responsible for over 75% of all skin cancer deaths.

In the second half of the 20th century, there has been a spectacular increase in melanoma: from the beginning of the sixties till the end of the eighties, the number of new cases increased annually from 3 to 7%, meaning a doubling of the number of new cases every 10 to 20 years.

In this respect, melanoma was the most rapidly increasing cancer among whites, with the exception of lung cancer in females. This "melanoma epidemic" is attributed to changed sun behavior since the second World War, with increased sun exposure during leisure time and changed modes of dress.

The highest melanoma incidence is reported in Australia and New Zealand, where predominantly white populations live near the equator and suffer intense sun exposure. In Australia, melanoma is the fourth most incident cancer.

The most spectacular increases seem to have ceased, and more recent international data suggest a moderation to stabilization in the number of deaths due to melanoma. But in Belgium, the number of melanoma deaths has been increasing since 1954. Analysis of more recent data (1983-1992) does not indicate any moderation in melanoma mortality.

A research group at the University of Ghent in Belgium studied melanoma in Belgium from several different angles. The group's findings are applicable to most countries of the world. Among those findings:

During the period 1987-1992, some 400 new cases of melanoma have been reported annually to the National Cancer Registry in Belgium (± 10 million inhabitants), of which 65% were in females. In this way, melanoma represented about 1.2% of all new cancer cases and it was the 16th-17th most commonly reported cancer. This is comparable to the situation in other European countries.

Based on these data, the lifetime risk of developing melanoma was estimated at 1 in 190 in females and 1 in 270 in males. These numbers underestimate the real situation, since the National Cancer Registry only registered hospitalized cases prior to 1996, whereas some melanomas (especially thin melanomas) can be treated on an outpatient basis.

In evaluating melanoma's burden on public health, the Ghent researchers say, it is also important to mention its predilection for the younger age groups when compared to other cancers. More than half of all new melanoma cases present before the age of 60.

In the age group 20-39, melanoma is the third most common cancer preceeded by brain tumors and leukemia in males and by breast and cervical cancer in females. A similar predilection for the younger age groups is noticed in the mortality statistics.

Early detection and appropriate management of melanoma are extremely important. Breslow thickness -- the thickness of the tumor microscopically measured and expressed in millimeters -- is the most important prognostic factor in local disease. The thinner the tumor, the better the chances for cure; the thicker the tumor, the higher the risk of metastatic spread of malignant cells to lymph nodes and other organs.

Melanoma, arising from the pigment cells of the skin, usually presents as a pigmented lesion on the skin, visible to the naked eye. In that way, it offers a unique opportunity for early detection.

"Melanoma writes its message in the skin with its own ink and is there for all of us to see. Unfortunately, some see but do not comprehend," cancer researcher Neville Davis has said.

The Ghent group studied the diagnostic pathway of melanoma within the specific context of Belgian health care. 130 patients residing in East Flanders and diagnosed with melanoma between 1995 and 1999 were interviewed about the way their melanoma had been detected.

In more than half of all patients, more than 3.5 months elapsed from the first notice of a new or changing lesion to its excision with diagnosis of melanoma.

The most important delay occurred between the moment of first attention to a lesion to the moment when medical advice was sought for this lesion (more than 2 months in more than half of the patients). This delay time was not influenced by gender, age, marital status, educational level or employment status of the patient, nor by the localization of the lesion or the reason for seeking medical advice.

The lesion was usually first noticed by the patient himself (63%). In 20% of the cases, a family member was the first to pay attention to the lesion. In 13% of the cases, the lesion was coincidentally detected by a doctor during a consultation for another reason (general practitioner 53%, dermatologist 18%, other specialties such as occupational physician, gynecologist, surgeon, internist 29%).

Some 57% of all patients remembered the presence of a mole or another pigmented skin lesion at the site of the melanoma. Increasing size, changing color and elevation were the changes most frequently reported.

In more than half of the patients, the lesion was removed within 2 weeks after the first medical advice. In some patients, the doctor who was asked advice about the lesion did not take any immediate action. This suggests mis-diagnosis of melanoma by the doctor. In these cases, the time to final excision of the lesions increased to more than 4 months in more than half of the cases (compared to 1 week if immediate action was undertaken).

In cases of immediate referral to a specialist doctor, the time from the first medical advice to the final excision of the lesion exceeded 2 weeks in more than half of the patients. This delay is unusual in a health care system with easy accessibility and no long medical waiting lists. A reason for this delay was not found.

The Ghent study demonstrates that the time elapsing from the first attention to a new/changing lesion to its final removal with microscopical confirmation of melanoma diagnosis exceeds 3.5 months in more than half of all patients.

A substantial part of this delay is attributed to a delay in seeking medical advice for such lesions. This suggests that people are often insufficiently alarmed in cases of a changing mole or a newly arisen pigmented skin lesion. This could indicate a lack of public awareness about the possible dangers of these signs. Cancer prevention campaigns should stress the importance of a changing mole, the researchers say.

Their study also demonstrates that health professionals, especially primary health care workers, should be aware of the possibility of melanoma during routine examinations.

References:

Bleyen L, De Bacquer D, Myny K, Brochez L, Naeyaert JM, De Backer G. Trends in mortality from cutaneous malignant melanoma in Belgium. Int. J. Epidemiol. 1999; 28:40-45.

L Brochez, K Myny, L Bleyen, G De Backer, JM Naeyaert The melanoma burden in Belgium; premature morbidity and mortality make melanoma a considerable health problem. Melanoma Res. 1999; 9: 614-618.

Brochez L, Verhaeghe E, Bleyen L, Myny K, De Backer G, Naeyaert JM Under-registration of melanoma in Belgium: an analysis. Melanoma Res. 1999; 9: 413-41

Brochez L, Verhaeghe E, Bleyen L, Naeyaert JM Time delays and related factors in the diagnosis of cutaneous melanoma. Eur. J. Cancer 2001; 37: 843-848.

22-Jun-2001

 

 

 

 

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