Oral Presentation Australasian Melanoma Conference 2026

Clinical and pathological characteristics of thin cutaneous melanomas with rapid recurrence. (#51)

Prachi Bhave 1 2 , Terence Wong 3 , Kim Margolin 4 , Lotte Hoeijmakers 5 , Johanna Mangana 6 , Maria G Vitale 7 , Paolo A Ascierto 7 8 , Andrea Maurichi 9 , Mario Santinami 9 , Georgina Heddle 10 , Clara Allayous 11 , Celeste Lebbe 11 , Adnan Khattak 12 , Stephan Forchhammer 13 , Jolien Kessels 14 , Peter Lau 15 , Serigne N Lo 3 , Tony Papenfuss 2 , Grant McArthur 1 16
  1. Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria, Australia
  2. Department of Computational Biology, Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
  3. Melanoma Institute Australia, Sydney, NSW, Australia
  4. St John’s Cancer Institute, Los Angeles, California, United States of America
  5. Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
  6. University Hospital Zürich, Zurich, Switzerland
  7. Melanoma, Cancer Immunotherapy and Development Therapeutics, Istituto Nazionale Tumori IRCCS Fondazione "G.Pascale", Napoli, Italy
  8. Università di Napoli "Federico II", Napoli, Italy
  9. Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori di Milano, Milan, Italy
  10. Department of Dermatology, Queen Elizabeth Hospital, Adelaide, South Australia, Australia
  11. AP-HP Dermatology, Saint-Louis Hospital, Paris, France
  12. Medical Oncology, Fiona Stanley Hospital, Perth, Western Australia, Australia
  13. Department of Dermatology, Eberhard Karls University, Tuebingen, Germany
  14. Universitair Ziekenhuis Brussel, Brussels, Belgium
  15. Sir Charles Gairdener Hospital, Perth, Western Australia, Australia
  16. Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia

Background: Although thin, T1 (≤1mm) melanomas have an excellent cure rate with surgery alone, >25% of melanoma deaths originate from thin melanomas. There is, therefore, an urgent need to improve the identification and management of patients with thin melanomas at high risk of recurrence.

 

Methods: Consecutive patients meeting one of the following two criteria were identified retrospectively: i) T1 melanoma with recurrence within 2 years of diagnosis (T1 rapid group) ii) T1 melanoma with recurrence ≥10 years after diagnosis (T1 late group). Univariable and multivariable logistic regression analyses were conducted to investigate factors associated with first recurrence in the two patient subgroups.

 

Results: A total of 442 patients from 14 sites in Australia, Europe and the USA were included: 310 and 132 patients in the T1 rapid and late groups, respectively. Median age at primary melanoma diagnosis was 51 years [15-85], 272 (62%) male, 254 (58%) superficial spreading and 101 (23%) head/neck primary. Median follow-up from primary melanoma diagnosis was 4.3 and 17.1 years for the rapid and late groups, respectively. The majority (73%) of recurrences in the T1 rapid group were locoregional. Univariable regression analysis revealed that age >65 years (p<0.0001), lentigo maligna (LM) melanoma histopathological subtype (p=0.025), head/neck primary melanoma site (p=0.0065), mitoses ≥1/mm2 (p=0.0181) and ulceration (p=0.0087) were significantly associated with T1 rapid recurrence compared to T1 late recurrence. On multivariable analysis, age >65 years (HR 3.0, p=0.0009) and ulceration (HR 1.12. p=0.042) remained significantly associated with rapid recurrence, with a trend towards significance for mitoses ≥1/mm2 (HR 1.88, p=0.059). When the multivariable analysis was adjusted to only include variables that were statistically significant (p<0.05) on the univariable analysis, age >65 years (p=0.0010), mitoses ≥1/mm2 (p=0.0492) and ulceration (p=0.0372) remained significant.

 

Conclusions: This is one of the largest studies to explore the characteristics of thin, T1 melanoma with recurrence ≤2 years of diagnosis. Such recurrence is strongly associated with age >65 years, LM melanoma histopathological subtype, head/neck primary melanoma site, mitoses ≥1/mm2 and ulceration. Patients harbouring these characteristics at melanoma diagnosis may benefit from more aggressive management and closer surveillance to enable timely detection of recurrence.