Occurrence of melanomas on the upper and lower limbs in eastern Australia

The anatomic distribution of cutaneous melanoma: A detailed study of 5141 lesions

BACKGROUND/OBJECTIVES

There is evidence that cutaneous melanomas at different anatomic sites present with distinctive clinicopathologic features. We examined the anatomic distribution of cutaneous melanoma and its variation by patient characteristics, subtype and Breslow thickness, using high-resolution anatomic site data.

METHODS

A cross-sectional study was performed of all primary cutaneous melanoma cases managed at a tertiary referral centre, analysing prospectively collected clinical data across 50 anatomic subsites.

RESULTS

The study included 5141 in situ or invasive melanomas; most were invasive (76.2%), and the median Breslow thickness of invasive lesions was 1.0 mm. Superficial spreading (57.2%), lentigo maligna (20.8%) and nodular (12.2%) were the most common histopathological subtypes. Sun-exposed sites such as the female nose and cheek, the male ear, as well as the upper back in both sexes had the highest incidence of melanoma per unit area. When compared to the posterior forearm, the scalp, ear, preauricular, perioral, subungual and plantar sites had thicker invasive melanomas (each P < 0.05). The peri-auricular, ear and cheek had the highest incidence of nodular melanoma per unit area. There were subtype-, age- and sex-specific differences in melanoma anatomic distribution.

CONCLUSION

Melanoma most commonly arises in sun-exposed facial areas, as well as the upper back. Increased thickness is found for melanoma in acral and many head and neck sites. Nodular melanoma is more likely to occur in head and neck sites including the peri-auricular area, ear and cheek. Clinicians should carefully assess these sites during skin examinations.

Missed opportunity to diagnose subungual melanoma: potential pitfalls!

Subungual melanoma, an uncommon form of acral melanoma that arises within the nail matrix, accounts for 1%-3% of all cutaneous melanoma in Caucasians. As subungual melanoma presents in a more disguised manner than cutaneous lesions, increased vigilance is required. It most commonly presents as a discolouration of the nail, nail splitting or nail-bed bleeding. Black pigmentation of the adjacent nail fold, termed Hutchinson's sign, may be a diagnostic clue. Treatment of subungual melanoma remains surgical with wide local excision and amputation primary modalities. We present the case of a 61-year-old man with an 18-month history of a left thumb nail-bed abnormality and a 6-week history of left axillary lymphadenopathy. One year earlier, he presented to the emergency department with a purulent discharge from his left thumb but declined nail-bed ablation. He was referred to the 'Hand and Plastic Injuries Clinic' by his general practitioner and diagnosed with a chronic traumatic-induced nail-bed injury. As his symptoms did not improve, he was referred to the 2-week wait Skin Cancer Clinic. The left thumb nail-bed was excised as a nail unit down to bone, and the diagnosis of melanoma was rendered. Left axillary lymphadenopathy was confirmed as metastatic melanoma. He underwent amputation of his left thumb at the interproximal phalangeal joint, and a left axillary node dissection was performed. No residual melanoma was identified in his thumb. Microscopically, his left axillary dissection confirmed 9 out of 36 positive nodes for metastatic melanoma with extracapsular spread. He was staged at IIIC disease. This case report demonstrates missed opportunities to diagnose subungual melanoma and acts as a cautionary tale in considering this pathology in the differential diagnosis of nail-bed lesions with prompt referral for further investigation.

Cumulative ultraviolet radiation flux in adulthood and risk of incident skin cancers in women

BACKGROUND

Solar ultraviolet (UV) exposure estimated based on residential history has been used as a sun exposure indicator in previous case-control and descriptive studies. However, the associations of cumulative UV exposure based on residential history with different skin cancers, including melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC), have not been evaluated simultaneously in prospective studies.

METHODS

We conducted a cohort study among 108,578 women in the Nurses' Health Study (1976-2006) to evaluate the relative risks of skin cancers with cumulative UV flux based on residential history in adulthood.

RESULTS

Risk of SCC and BCC was significantly lower for women in lower quintiles vs the highest quintile of cumulative UV flux (both P for trend <0.0001). The association between cumulative UV flux and risk of melanoma did not reach statistical significance. However, risk of melanoma appeared to be lower among women in lower quintiles vs the highest quintile of cumulative UV flux in lag analyses with 2-10 years between exposure and outcome. The multivariable-adjusted hazard ratios per 200 × 10(-4) Robertson-Berger units increase in cumulative UV flux were 0.979 (95% confidence interval (CI): 0.933, 1.028) for melanoma, 1.072 (95% CI: 1.041, 1.103) for SCC, and 1.043 (95% CI: 1.034, 1.052) for BCC.

CONCLUSIONS

Associations with cumulative UV exposure in adulthood among women differed for melanoma, SCC, and BCC, suggesting a potential variable role of UV radiation in adulthood in the carcinogenesis of the three major skin cancers.

Increases in invasive melanoma in England, 1979-2006, by anatomical site

BACKGROUND

National melanoma incidence trends with details of anatomical site have not been previously described for England.

OBJECTIVES

To describe site-specific trends in cutaneous melanoma for England as a whole during the last three decades.

METHODS

Anonymized data, 1979-2006, were obtained from national cancer registrations of all patients in England up to age 89years with incident primary invasive cutaneous melanomas (n=124055). Sex-specific age-standardized incidence rates and average annual percentage change in rates were calculated for each broad anatomical site.

RESULTS

Overall incidence rates of cutaneous melanoma in England, 1979-2006, were 81 and 100 per million, in males and females, respectively. Site-specific rates were consistently highest on the lower limbs in females followed by the trunk in males. Greatest annual increases occurred on the trunk in both sexes over 45years (males 9·9%, females 6·8%), then upper limbs (males 8·7%, females 6·8%). Incidence trends in males relative to females varied little across sites apart from a more rapid rise in head/neck melanomas in males than in females after the 1980s.

CONCLUSIONS

Invasive melanoma rates continue to rise in England, particularly on the trunk and arms, and in males on the head/neck. The steeper increases in melanoma rates among males are consistent with their greater sun exposure and poorer compliance with sun protection measures than females.

Clinical guidelines for the recognition of melanoma of the foot and nail unit

Malignant melanoma is a life threatening skin tumour which may arise on the foot. The prognosis for the condition is good when lesions are diagnosed and treated early. However, lesions arising on the soles and within the nail unit can be difficult to recognise leading to delays in diagnosis. These guidelines have been drafted to alert health care practitioners to the early signs of the disease so an early diagnosis can be sought.

A comparison of the anatomic distribution of cutaneous melanoma in two populations with different levels of sunlight: the west of Scotland and Queensland, Australia 1982-2001

To explore whether the anatomic distribution of melanoma differs with ambient sunlight levels, we compared age- and site-specific melanoma incidence in two genetically similar populations from different geographic regions. We ascertained all new cases of invasive cutaneous melanoma in the west of Scotland and Queensland 1982-2001. Melanoma incidence was calculated for four anatomic regions (head and neck, trunk, upper and lower limbs), standardized to the European population and adjusted for relative surface area of each site. Highest rates among males aged <40 years and 40-59 years were observed on the trunk, but on the upper limbs among Queensland females and lower limbs among Scottish females. After age 60, melanoma rates were highest on the head and neck in both sexes. In both sexes and at all ages, lower limb melanomas were more common in Scotland than expected from the Queensland population. These analyses indicate that while the overall distribution of melanoma is similar in populations with different levels of ambient sunlight, important differences remain. Identifying the causes of these differences is likely to provide better understanding of how sunlight causes melanoma.

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.

An analysis of risk factors for cutaneous melanoma by anatomical site (Australia)

OBJECTIVE

Emerging evidence suggests that melanomas arising on the head and neck that are not lentigo maligna melanomas have different associations with phenotypic and environmental risk factors than those on the trunk and other sites. We sought to test this hypothesis in a population-based study in Queensland, Australia.

METHODS

Risk factor data were collected from 2360 participants with incident cutaneous melanoma diagnosed 1982--1990, including 167 participants with lentigo maligna melanoma. For each risk factor, polytomous logistic regression analysis, using the trunk as a reference category, was used to estimate the odds ratio and 95% confidence interval for cutaneous melanomas by anatomical site.

RESULTS

Participants with melanomas of the head and neck were significantly older than those with melanomas of the trunk (males 52.7 versus 49.7 years; females 47.8 versus 40.5 years). Compared with patients with truncal melanomas, those of the head and neck were less likely to have many nevi (OR 0.41, 95% CI 0.13--1.31), although this did not reach statistical significance. Among females, melanomas of the lower limb were negatively associated with a past history of non-melanoma skin cancer (OR 0.41, 95% CI 0.23-0.74).

CONCLUSIONS

We have observed heterogeneity for melanoma risk by anatomical site, lending weight to the hypothesis that cutaneous melanomas may develop through multiple causal pathways.

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.

Body site distribution of cutaneous malignant melanoma in relationship to patterns of sun exposure

A study of all newly incident melanoma patients in British Columbia in 1991-1992 was undertaken to test the hypothesis raised by an earlier study, which showed that in younger patients the incidence rate of melanoma per unit area of skin was higher on intermittently exposed skin areas than on continuously exposed areas. Using 1,033 patients and a more detailed body site categorisation than was previously possible, our results confirmed that in both men and women under age 50 the highest melanoma density was on the back. At ages over 50, the greatest density occurred on fully exposed sites, such as the face, though the dorsum of the hand and forearm, likely also to have high exposure, show very low melanoma densities. Differences between males and females correlate well with differences in likely exposure patterns. These results were seen for all invasive cutaneous melanomas combined; the patterns were similar for subtypes and for both invasive and in situ melanoma, with the exception of lentigo maligna melanoma (LMM), which occurs almost exclusively on the face, even at younger ages. Comparison with the earlier study (1976-1979) shows that the age-standardised rates for melanoma excluding LMM have increased by 60%, with the greatest proportional increase being at younger ages; in the recent data, the age-standardised rate for intermittently exposed sites exceeds that for usually exposed sites. Our results confirm that intermittent sun exposure has a greater potential for producing melanoma than continuous exposure at ages below about 50, though at older ages melanoma is more common on body sites with continuous sun exposure.