Sam Polesie

Adjunct Senior Lecturer

Department of Dermatology and Venereology
Visiting address
Gröna stråket 16 Pl 2 SU/Sahlgrensk
41345 Göteborg
Postal address
Sahlgrenska Universitetssjukhuset
41345 Göteborg

About Sam Polesie

Sam Polesie (S.P.) is a consultant and an associate professor in dermatology and venereology working at the Department of Dermatology and Venereology at Sahlgrenska University Hospital. He defended his dissertation in 2019, and his PhD project was based on his own formulated question that appeared during an outpatient clinic. The question was whether methotrexate (MTX) was associated with an enhanced risk of cutaneous melanoma. The first five papers of the dissertation consisted of epidemiological studies that used health care registries from the National Board of Health and Welfare and Statistics Sweden. Overall, use of MTX was only weakly associated with risk of melanoma. The studies have contributed to an increased understanding of the risk benefit assessment of MTX, especially for patients with a history of melanoma disease, where the results showed that the patients who had previously had a melanoma and then were exposed to MTX did not have a significantly increased risk of developing a new primary melanoma.

The PhD-project has also led to a collaboration with the pharmacoepidemiological unit at the University of Southern Denmark in Odense and which used the Danish population to see if use of MTX was associated with the risk of skin cancer including melanoma. The results was published in February 2023 in British Journal of Cancer. The interest in epidemiological studies is palpable and in a recently published study S.P. and colleagues analyzed whether patients with psoriasis have an increased risk of cutaneous melanoma. The study demonstrated a minimal increase in risk for melanoma compared to matched controls without psoriasis. The investigation contributes to an increased understanding of psoriasis and associated comorbidities.

Since 2018, S.P. has conducted research revolving machine learning (ML) and artificial intelligence (AI). The work began with examining the attitudes towards artificial intelligence (AI) among dermatologists and dermatopathologists. These studies were initiated by S.P. and were conducted with international collaborators from the USA, Italy, Greece and Austria. Overall, attitudes towards AI were positive and both dermatologists and dermatopathologists saw great potential with an increased use of ML.

The ML-related research has continued by developing applications in imaging that can prove valuable for healthcare. Although melanoma is usually easy to detect, it is often more difficult to discriminate in situ melanoma from invasive melanoma preoperatively. This classification problem is important since it may affect the selection of appropriate excision margin for the first operation. S.P. and co-workers have developed an algorithm that performs at the level of dermatologists. The work has received attention in press releases and media. The work of refining and developing the algorithm further is ongoing. The aim is to find applications that have practical importance for doctors in a real-life practice.

S.P. conducts research on dermatoscopic findings that may distinguish between in situ and invasive melanomas. This research is carried out partly in collaboration with a research group in Austria. S.P. has experience in clinical studies and is a co-investigator in a prospective clinical trial that evaluates different treatment models for basal cell carcinoma.

S.P. is involved as a co-author in several projects at the Department of Dermatology and Venereology and works closely with former co-supervisor Professor John Paoli and statistician Martin Gillstedt who is the statistician and data analyst employed at our department.

During dermatology residency, S.P. worked a year at the departments of clinical genetics and clinical pathology. S.P. is interested in genetic diseases that affect the skin (genodermatoses) and has also co-authored a publication describing phenotypic traits in individuals with 12q12 duplications. Since 2021, S.P. also is also a part of the research group led by Professor Sirkku Peltonen, which will, among other things, investigate epidemiological aspects of genodermatosis in Sweden.

Overall, S.P. has a profound interest in dermatology research and is an active supervisor. Since 2020 he has supervised eight medical students in their degree project and is currently co-supervisor for six doctoral students (main supervisors John Paoli and Sirkku Peltonen) and the principal supervisor for one doctoral student.

Another major interest is to be a reviewer for scientific publications. Since 2022 S.P. works as a deputy editor for Acta Dermato-Venereologica, where he is mainly involved with manuscripts revolving "Machine learning and artificial intelligence".

More research:

- Melanoma thickness equally hard for algorithms and dermatologists to judge (Pressrelease 2022-07-20)

- Use of methotrexate is associated with an increased risk of skin cancer (Pressrelease 2023-02-07)

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