Melanoma in the elderly -- a neglected public health challenge

Successful strategies for early detection in the young are not benefiting older people

MJA 1998; 169: 403-404

Melanoma has long been recognised in Australia for its relatively high incidence in young adults, compared with other cancers, and its significant contribution to premature mortality.1,2 Twenty-five years ago it was recognised that many melanomas begin with a flat, superficial growth pattern and the term "radial growth phase" was coined by the late Wallace Clark.3 Diagnostic criteria were adjusted to direct attention to flat lesions with what are known as "ABCD" features (Asymmetry, Border irregularity, Colour variation and large Diameter) and away from raised, nodular lesions. This promoted the early detection of radial growth phase melanomas (superficial spreading, lentigo maligna and acral lentiginous melanomas) and has been associated with a progressive decline in tumour thickness and a corresponding improvement in prognosis. Further, benchmark public education campaigns such as the Anti-Cancer Council of Victoria's Sunsmart program have contributed to significant changes in behaviour aimed at primary prevention.4 The new and recently demonstrated decline in melanoma incidence among people under 35 years of age5 may be a result of these behavioural changes. These, then, are among the success stories in the fight against melanoma. But where are we failing? In this issue of the Journal Hanrahan et al direct our attention to a group that appears to have been bypassed by the advances -- elderly men.6 The elderly comprise an important group among those affected with melanoma. The age-specific incidence of melanoma continues to rise throughout life, most steeply in men.1 While incidence rates have levelled off or are falling in younger age groups, they continue to rise steeply in the elderly.5 However, it is not incidence, but mortality, that most strongly conveys the predicament of the elderly in our population with respect to melanoma. Mortality from melanoma for Australian men aged between 80 and 84 years is 10 times that of those aged between 40 and 44 years (48.16 v. 4.92 per 100 000 person-years).7 As Hanrahan and colleagues point out, some 50% of deaths from melanoma in New South Wales occur in males over 50 years, even though this group accounts for only 12%-14% of the population. In light of this high mortality, and with tumour thickness being the most important prognostic indicator, as might be expected, tumours diagnosed in the elderly are thicker at the time of diagnosis.8 Why have the elderly so comprehensively failed to follow the trend toward early detection of melanoma that has been shown in younger members of the community? Obviously, they may be disadvantaged by age-related handicaps, such as failing eyesight, loss of a partner and the development of numerous seborrhoeic keratoses that may appear similar to melanoma. Surprisingly, however, the work of Hanrahan et al suggests that it is not primarily these difficulties, but the greater proportion of nodular melanoma compared with superficial spreading melanoma (particularly in men), that inhibits early detection of melanoma in the elderly. The direction of attention to flat lesions, while greatly improving the detection of those tumours that are easiest to detect early, has ignored the problem of early detection of nodular melanomas (which exhibit only vertical growth and have no radial growth phase). An additional difficulty for elderly men is that their melanomas occur predominantly on the back (48%). Hanrahan and colleagues found that once tumour type, site and thickness, and age were taken into account, men were no less likely than women to detect their melanomas. While people aged 50 years or over were somewhat less likely than younger people to identify the changes of melanoma (62% v. 72%), Hanrahan et al have demonstrated in a related study that older people are no less able to identify the changes of early melanoma in computer-altered images of pigmented lesions.9 These findings suggest that the elderly are not making use of their skills in detecting melanomas, and that public education campaigns might usefully encourage them to do this. Where have we gone wrong for the elderly with melanoma? By directing public education about primary prevention at the young we have also generated early detection behaviour primarily in this group. Marks et al10 and Del Mar et al11 have drawn attention to the mismatch between the age at which pigmented lesions are being excised, and the later age at which melanoma is more likely to occur. Among people aged 21-40 years the ratio of benign naevi to melanomas among excised lesions was 27.2, compared with 1.4 in those aged 60 and over.10 By focusing early detection efforts on flat lesions we have distracted attention from the clinical features of the nodular melanomas that more frequently affect the elderly. Nodular melanoma is, of course, more difficult to detect in its early stages because these lesions are invasive from the outset and grow in both depth and diameter, while the invasive, vertical growth phase of other melanomas is preceded by a flat, radial growth phase that may last many months or years. However, my own clinical experience suggests that it is generally possible to diagnose nodular melanoma lesions in patients undergoing regular surveillance when they are about 1.0 mm in thickness. We must make the elderly aware that melanoma is a significant and potentially curable health problem in later life. Further research is needed to define the most useful clinical features for early detection of nodular melanoma and to explore the best methods of promoting earlier detection. The article by Hanrahan et al in this issue provides some clues: changes in colour are found less frequently and changes in sensation more frequently in nodular melanomas; bleeding is associated with thick melanoma and is therefore not useful in early detection. Healthcare practitioners who work with the elderly need to be particularly aware of the clinical features of nodular melanoma, and the role of opportunistic screening by general practitioners is of special importance for elderly men in view of the greater impediments to self- diagnosis (nodular melanomas and location on the back). This role needs emphasis in the education of general practitioners. John W Kelly Head, Victorian Melanoma Service, Head, Dermatology Unit, and Clinical Associate Professor, Monash University Department of Medicine, Alfred Hospital, Melbourne, VIC Jelfs PL, Giles G, Shugg D, et. al. Cutaneous malignant melanoma in Australia, 1989. Med J Aust 1994; 161: 182-187. Gold J, Yuerning L, Kaldor JM. Premature mortality in Australia 1983-1992, the first decade of the AIDS epidemic. Med J Aust 1994; 161: 652-656. Clark WH, Ainsworth AM, Bernadino EA, et al. The developmental biology of primary human malignant melanomas. Semin-Oncol 1975; 2: 83-103. Hill D, Boulter J. Sun protection behaviour -- determinants and trends, Cancer Forum 1996; 20: 204-211. Giles G, Thursfield V. Trends in skin cancer in Australia. Cancer Forum 1996; 20: 188-191. Hanrahan PF, Hersey P, D'Este CA. Factors involved in presentation of older people with thick melanoma. Med J Aust 1998; 169: 410-414. Giles G, Armstrong BK, Burton RC, et al. Has mortality from melanoma stopped rising in Australia? Analysis of trends between 1931 and 1994. BMJ 1996; 312: 1121-1125. Hersey P, Sillar R, Howe CG, et.al., Factors related to the presentation of patients with thick primary melanomas. Med J Aust 1991; 154: 583-587. Hanrahan PF, Hersey P, Menzies SW, et al. Examination of the ability of people to identify early changes of melanoma in computer-altered pigmented skin lesions. Arch Dermatol 1997; 133: 301-311. Marks R, Jolley D, McCormack C, Dorevitch AP. Who removes pigmented skin lesions? A study of the ratio of melanoma to other benign pigmented tumors removed by different categories of physicians in Australia in 1989 and 1994. J Am Acad Dermatol 1997; 36: 721-726. Del Mar C, Green A, Cooney T, et al., Melanocytic lesions excised from the skin: what percentage are malignant? Aust J Public Health 1994; 18: 221-223.