J Mark Elwood1, Stella J-H Kim1, Ken H-K Ip2, Amanda Oakley3, Marius Rademaker3. 1. School of Population Health, University of Auckland, Auckland, New Zealand. 2. Department of Medicine, Middlemore Hospital, Auckland, New Zealand. 3. Waikato Clinical Campus, University of Auckland, Hamilton, New Zealand.
Abstract
BACKGROUND: Few population-based studies assess both invasive and in situ melanoma. We document all patients with a first biopsied melanoma in a general population in New Zealand (NZ). METHODS: All residents in a defined area of New Zealand with a biopsy showing a new primary invasive or in situ melanoma from 2010 to 2012 were identified, 974 patients; analysis used multivariate methods. RESULTS: Age-standardised incidence rates were 34.3 in females (F) and 41.4 in males (M) for invasive, 20.9 F and 27.6 M for in situ, and 55.2 F and 69.0 M for total melanoma. More in situ melanoma occurred in older patients and on the head and neck. Geometric mean Breslow thickness for invasive was 0.78 mm F and 0.85 mm M, with thicker lesions at ages over 60 and on the lower limb; there was no significant relationship with sex, distance from care or social deprivation assessed from residential address. Nodular melanomas (15%) were more frequent in older and male patients, and on the limbs, and were thicker. The estimated cumulative risk for melanoma is 4.4% F and 4.6% M by age 70. The body site distribution and sex differences were consistent with sun exposure patterns. Estimated incidence of melanoma in New Zealand in 2018 is 2500 invasive and 1700 in situ cases. CONCLUSIONS: Assessing both in situ and invasive melanoma expands the clinical picture, better estimating health care demand and costs. Results suggest that in situ disease is a more slowly growing lesion than the early phase of invasive disease. The features of thicker or nodular melanoma show priorities for prevention and early detection.
BACKGROUND: Few population-based studies assess both invasive and in situ melanoma. We document all patients with a first biopsied melanoma in a general population in New Zealand (NZ). METHODS: All residents in a defined area of New Zealand with a biopsy showing a new primary invasive or in situ melanoma from 2010 to 2012 were identified, 974 patients; analysis used multivariate methods. RESULTS: Age-standardised incidence rates were 34.3 in females (F) and 41.4 in males (M) for invasive, 20.9 F and 27.6 M for in situ, and 55.2 F and 69.0 M for total melanoma. More in situ melanoma occurred in older patients and on the head and neck. Geometric mean Breslow thickness for invasive was 0.78 mm F and 0.85 mm M, with thicker lesions at ages over 60 and on the lower limb; there was no significant relationship with sex, distance from care or social deprivation assessed from residential address. Nodular melanomas (15%) were more frequent in older and male patients, and on the limbs, and were thicker. The estimated cumulative risk for melanoma is 4.4% F and 4.6% M by age 70. The body site distribution and sex differences were consistent with sun exposure patterns. Estimated incidence of melanoma in New Zealand in 2018 is 2500 invasive and 1700 in situ cases. CONCLUSIONS: Assessing both in situ and invasive melanoma expands the clinical picture, better estimating health care demand and costs. Results suggest that in situ disease is a more slowly growing lesion than the early phase of invasive disease. The features of thicker or nodular melanoma show priorities for prevention and early detection.
Authors: Jeremy Hay; Jeff Keir; Clara Jimenez Balcells; Nikita Rosendahl; Martelle Coetzer-Botha; Tobias Wilson; Simon Clark; Astrid Baade; Cath Becker; Luke Bookallil; Chris Clifopoulos; Tony Dicker; Martin Paul Denby; Douglas Duthie; Charles Elliott; Paul Fishburn; Mark Foley; Mark Franck; Irene Giam; Patricio Gordillo; Alister Lilleyman; Roger Macauley; James Maher; Ewen McPhee; Michael Reid; Bob Shirlaw; Graeme Siggs; Robert Spark; John Stretch; Keith van Den Heever; Thinus van Rensburg; Chris Watson; Harald Kittler; Cliff Rosendahl Journal: Australas J Dermatol Date: 2022-04-19 Impact factor: 2.481