The risk of subsequent invasive melanoma after a primary in situ or invasive melanoma in a high incidence country (New Zealand)

Abstract

Background Patients with invasive melanoma are at increased risk of developing subsequent invasive melanoma, but the risks for those with primary in situ melanoma are unclear. Objectives To assess and compare the cumulative risk of subsequent invasive melanoma after primary invasive or in situ melanoma. To estimate the standardized incidence ratio (SIR) of subsequent invasive melanoma compared to population incidence in both cohorts. Methods Patients with a first diagnosis of melanoma (invasive or in situ) between 2001 and 2017 were identified from the New Zealand national cancer registry, and any subsequent invasive melanoma during follow‐up to the end of 2017 identified. Cumulative risk of subsequent invasive melanoma was estimated by Kaplan–Meier analysis separately for primary invasive and in situ cohorts. Risk of subsequent invasive melanoma was assessed using Cox proportional hazard models. SIR was assessed, allowing for age, sex, ethnicity, year of diagnosis and follow up time. Results Among 33 284 primary invasive and 27 978 primary in situ melanoma patients, median follow up time was 5.5 and 5.7 years, respectively. A subsequent invasive melanoma developed in 1777 (5%) of the invasive and 1469 (5%) of the in situ cohort, with the same median interval (2.5 years) from initial to first subsequent lesion in both cohorts. The cumulative incidence of subsequent invasive melanoma at 5 years was similar in the two cohorts (invasive 4.2%, in situ 3.8%); the cumulative incidence increased linearly over time in both cohorts. The risk of subsequent invasive melanoma was marginally higher for primary invasive compared to in situ melanoma after adjustment for age, sex, ethnicity and body site of the initial lesion (hazard ratio 1.11, 95% CI 1.02–1.21). Compared to population incidence, the SIR of invasive melanoma was 4.6 (95% CI 4.3–4.9) for the primary invasive and 4 (95% CI 3.7–4.2) for the primary in situ melanoma cohorts. Conclusions The risk of subsequent invasive melanoma is similar whether patients present with in situ or invasive melanoma. Thus follow‐up surveillance for new lesions should be similar, although patients with invasive melanoma require more surveillance for recurrence.

Skin cancer special issue in Skin Health and Disease

“…In this special issue of Skin Health and Disease we aimed to highlight the complexity of skin cancers by publishing a wide array of manuscripts covering different aspects related to skin cancers, ranging from primary prevention strategies related to sun education, 11 genetics, 12 and epidemiology 13 , 14 , 15 , 16 to surgical 17 , 18 and non‐surgical 19 , 20 , 21 treatments. From these papers, we would like to highlight some hot topics such as the paper from Borg et al 17 evaluating the impact of the COVID‐19 pandemic in the surgical management of skin cancers on the head and neck area in elderly patients.…”

Skin cancer special edition

“… 2 The incidence of melanoma has been increasing worldwide over the past 50 years, especially in white populations and people living nearer to the equator. 2 Australia and New Zealand have experienced the greatest incidence of melanoma, then North America, as well as the European countries, between 2013 and 2015. 2 The incidence rates of Merkel cell carcinoma (MCC), an aggressive cutaneous cancer, have tripled from 0.15 cases per 100,000 individuals in 1986 to 0.7 per 100,000 in 2013.…”

“… 2 Australia and New Zealand have experienced the greatest incidence of melanoma, then North America, as well as the European countries, between 2013 and 2015. 2 The incidence rates of Merkel cell carcinoma (MCC), an aggressive cutaneous cancer, have tripled from 0.15 cases per 100,000 individuals in 1986 to 0.7 per 100,000 in 2013. 3 MCC is three times more lethal than melanoma.…”

“…However, BCC and cSCC are both more common in females than males in England under the age of 50 1 . Melanoma is the 19th most common cancer internationally 2 . The incidence of melanoma has been increasing worldwide over the past 50 years, especially in white populations and people living nearer to the equator 2 .…”

“…Melanoma is the 19th most common cancer internationally 2 . The incidence of melanoma has been increasing worldwide over the past 50 years, especially in white populations and people living nearer to the equator 2 . Australia and New Zealand have experienced the greatest incidence of melanoma, then North America, as well as the European countries, between 2013 and 2015 2 .…”