Human-AI interaction in skin cancer diagnosis: a systematic review and meta-analysis.

The development of diagnostic tools for skin cancer based on artificial intelligence (AI) is increasing rapidly and will likely soon be widely implemented in clinical use. Even though the performance of these algorithms is promising in theory, there is limited evidence on the impact of AI assistance on human diagnostic decisions. Therefore, the aim of this systematic review and meta-analysis was to study the effect of AI assistance on the accuracy of skin cancer diagnosis. We searched PubMed, Embase, IEE Xplore, Scopus and conference proceedings for articles from 1/1/2017 to 11/8/2022. We included studies comparing the performance of clinicians diagnosing at least one skin cancer with and without deep learning-based AI assistance. Summary estimates of sensitivity and specificity of diagnostic accuracy with versus without AI assistance were computed using a bivariate random effects model. We identified 2983 studies, of which ten were eligible for meta-analysis. For clinicians without AI assistance, pooled sensitivity was 74.8% (95% CI 68.6-80.1) and specificity was 81.5% (95% CI 73.9-87.3). For AI-assisted clinicians, the overall sensitivity was 81.1% (95% CI 74.4-86.5) and specificity was 86.1% (95% CI 79.2-90.9). AI benefitted medical professionals of all experience levels in subgroup analyses, with the largest improvement among non-dermatologists. No publication bias was detected, and sensitivity analysis revealed that the findings were robust. AI in the hands of clinicians has the potential to improve diagnostic accuracy in skin cancer diagnosis. Given that most studies were conducted in experimental settings, we encourage future studies to further investigate these potential benefits in real-life settings.

Long noncoding RNA plasmacytoma variant translocation 1 is overexpressed in cutaneous squamous cell carcinoma and exon 2 is critical for its oncogenicity.

BACKGROUND: Cutaneous squamous cell carcinoma (cSCC) is one of the most common and fastest increasing forms of cancer worldwide with metastatic potential. Long noncoding RNAs (lncRNAs) are a group of RNA molecules with essential regulatory functions in both physiological and pathological processes. OBJECTIVES: To investigate the function and mode of action of lncRNA plasmacytoma variant translocation 1 (PVT1) in cSCC. METHODS: Quantitative reverse transcriptase polymerase chain reaction and single-molecule in situ hybridization were used to quantify the expression level of PVT1 in normal skin, premalignant skin lesions, actinic keratosis (AK) and primary and metastatic cSCCs. The function of PVT1 in cSCC was investigated both in vivo (tumour xenografts) and in vitro (competitive cell growth assay, 5-ethynyl-2'-deoxyuridine incorporation assay, colony formation assay and tumour spheroid formation assay) upon CRISPR-Cas9-mediated knockout of the entire PVT1 locus, the knockout of exon 2 of PVT1, and locked nucleic acid (LNA) gapmer-mediated PVT1 knockdown. RNA sequencing analysis was conducted to identify genes and processes regulated by PVT1. RESULTS: We identified PVT1 as a lncRNA upregulated in cSCC in situ and cSCC, associated with the malignant phenotype of cSCC. We showed that the expression of PVT1 in cSCC was regulated by MYC. Both CRISPR-Cas9 deletion of the entire PVT1 locus and LNA gapmer-mediated knockdown of PVT1 transcript impaired the malignant behaviour of cSCC cells, suggesting that PVT1 is an oncogenic transcript in cSCC. Furthermore, knockout of PVT1 exon 2 inhibited cSCC tumour growth both in vivo and in vitro, demonstrating that exon 2 is a critical element for the oncogenic role of PVT1. Mechanistically, we showed that PVT1 was localized in the cell nucleus and its deletion resulted in cellular senescence, increased cyclin-dependent kinase inhibitor 1 (p21/CDKN1A) expression and cell cycle arrest. CONCLUSIONS: Our study revealed a previously unrecognized role for exon 2 of PVT1 in its oncogenic role and that PVT1 suppresses cellular senescence in cSCC. PVT1 may be a potential biomarker and therapeutic target in cSCC.

A Novel Method Using Fine Needle Aspiration from Tumor-Draining Lymph Nodes Could Enable the Discovery of New Prognostic Markers in Patients with Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell cancer (cSCC) is the second most common form of skin cancer, characterized by abnormal, accelerated growth of squamous cells. When caught early, most cSCCs are curable. About 5 percent of the cSCC cases have advanced to such an extent, generally metastatic, that they are far more dangerous, with very poor prognosis and challenging to treat. All efforts to find biomarkers, in blood or in the tumor itself, for early identification of patients with a risk for metastasis have so far failed. The present study describes a novel method that enables the identification of lymphocyte markers in tumor-draining lymph nodes. Six patients with advanced cSCC were analyzed using a combination of a sentinel lymph node biopsy (SLNB) protocol, fine needle aspiration (FNA), and flow cytometry. Immunological results from the sentinel nodes were combined with corresponding data from peripheral blood and unfixed tumor tissues. The result demonstrates a striking difference between the subsets of T-cells from the three compartments. Our interpretation of this first pilot study is that the ability to follow specific immunological markers on lymphocytes in tumor-draining lymph nodes will enable the identification of novel prognostic biomarkers not detectable in material from blood and tumor tissues.

Increasing melanoma incidence and survival trend shifts with improved melanoma-specific survival between 1990 and 2020 in Sweden.

BACKGROUND: Melanoma-specific survival (MSS) is heterogenous between stages and is highly dependent on the T stage for primary localized disease. New systemic therapies for metastatic cutaneous melanoma (CM) have been introduced since 2012 in Sweden. OBJECTIVES: To analyse the incidence and MSS time trends between 1990 and 2020 in Sweden. METHODS: Nationwide, population-based and prospectively collected clinico-pathological data on invasive CM from the Swedish Melanoma Registry (SweMR) were analysed for survival trends between 1990 and 2020 using Kaplan-Meier curves and Cox proportional hazard ratios (HRs). RESULTS: In total, 77 036 primary invasive CMs were diagnosed in 70 511 patients in Sweden between 1990 and 2020. The 5-year MSS [95% confidence interval (CI)] was 88.9% (88.3-89.4) for 1990-2000, 89.2% (88.7-89.6) for 2001-2010 and 93.0% (92.7-93.9) for 2011-2020. The odds ratios for being diagnosed with nodular melanoma (vs. superficial spreading melanoma) was significantly reduced by 20% (2001-2010) and by 46% (2011-2020) vs. the reference period 1990-2000. Overall, the MSS improved over both diagnostic periods (2001-2010 and 2011-2020) vs. the reference period 1990-2000 among men and women, respectively [HRmen: 2001-2010: 0.89 (95% CI 0.82-0.96) and 2011-2020: 0.62 (95% CI 0.56-0.67); HRwomen: 2001-2010: 0.82 (95% CI 0.74-0.91) and 2011-2020: 0.62 (95% CI 0.56-0.70)]. The risk of death from CM was significantly lower in all age groups for both men and women in the most recent diagnostic period (2011-2020 vs.1990-2000). CONCLUSIONS: The results emphasize the improved MSS among men and women in Sweden. The MSS improvements, specifically for the period 2011-2020, may be correlated to the introduction of new systemic therapies and are here shown for the first time in detail for Sweden.

MicroRNA-23b Plays a Tumor-Suppressive Role in Cutaneous Squamous Cell Carcinoma and Targets Ras-Related Protein RRAS2.

Cutaneous squamous cell carcinoma (cSCC) is one of the most common types of cancer with metastatic potential. MicroRNAs regulate gene expression at the post-transcriptional level. In this study, we report that miR-23b is downregulated in cSCCs and in actinic keratosis and that its expression is regulated by the MAPK signaling pathway. We show that miR-23b suppresses the expression of a gene network associated with key oncogenic pathways and that the miR-23b-gene signature is enriched in human cSCCs. miR-23b decreased the expression of FGF2 both at mRNA and protein levels and impaired the angiogenesis-inducing ability of cSCC cells. miR23b overexpression suppressed the capacity of cSCC cells to form colonies and spheroids, whereas the CRISPR/Cas9-mediated deletion of MIR23B resulted in increased colony and tumor sphere formation in vitro. In accordance with this, miR-23b-overexpressing cSCC cells formed significantly smaller tumors upon injection into immunocompromised mice with decreased cell proliferation and angiogenesis. Mechanistically, we verify RRAS2 as a direct target of miR-23b in cSCC. We show that RRAS2 is overexpressed in cSCC and that interference with its expression impairs angiogenesis and colony and tumorsphere formation. Taken together, our results suggest that miR-23b acts in a tumor-suppressive manner in cSCC, and its expression is decreased during squamous carcinogenesis.

Lead Time from First Suspicion of Malignant Melanoma in Primary Care to Diagnostic Excision: a Cohort Study Comparing Teledermatoscopy and Traditional Referral to a Dermatology Clinic at a Tertiary Hospital.

INTRODUCTION: The increasing use of teledermatoscopy in clinical practice has led to demands to evaluate the effects of this new technology on traditional healthcare systems. OBJECTIVES: To study lead times from first consultation in primary care to diagnostic excision of suspected malignant melanoma lesions in traditional referrals to a tertiary hospital-based dermatology clinic compared with mobile teledermatoscopy referrals. METHODS: A retrospective cohort study design was used. Data on sex, age, pathology, caregivers, clinical diagnosis, date for first visit to primary care unit, and date for diagnostic excision were collected from medical records. Patients managed through traditional referral (n=53) were compared with patients managed at primary care units using teledermatoscopy (n=128) regarding lead time from first visit to diagnostic excision. RESULTS: Mean time from date of first visit at primary care unit to diagnostic excision did not differ between the traditional referral and teledermatoscopy groups (16.2 vs. 15.7 days, median 10 vs. 13 days, p=0.657). Lead times from date of referral to diagnostic excision did not significantly differ (15.7 vs. 12.8 days, median 10 vs. 9 days, p=0.464). CONCLUSIONS: Our study indicates that lead time to diagnostic excision for patients with suspected malignant melanoma managed by teledermatoscopy was comparable and not inferior to that of the traditional referral pathway. If teledermatoscopy is used at first consultation in primary care, it could potentially be more efficient than traditional referral.

Melanoma-specific survival before and after inclusion in a familial melanoma dermatologic surveillance program in CDKN2A mutation carriers and non-carriers.

BACKGROUND: Inherited mutations in the CDKN2A gene are among the strongest known risk factors for cutaneous melanoma. Further, previous studies have reported inferior melanoma-specific survival in CDKN2A mutation carriers. OBJECTIVES: Here, the melanoma-specific survival was studied, depending on CDKN2A carrier status and if the melanomas had been diagnosed before or after families were included in a surveillance program. METHODS: Melanoma-prone families participating in this study were identified through a nationwide preventive program starting in 1987. Information on melanoma tumours and deaths was obtained through the Swedish Cancer Registry and Cause of Death Registry. Kaplan-Meier and Cox proportional hazards regression models were used to assess melanoma-specific survival in four defined cohorts, CDKN2A mutation (MUT) carriers with first invasive melanoma before or after inclusion [MUT-pre (n = 53) and MUT-post (n = 43)] and likewise in CDKN2A wild type (WT) cases [WT-pre (n = 255) and WT-post (n = 122)]. RESULTS: The MUT-pre and MUT-post cases were diagnosed with their first invasive melanoma at a significantly younger ages (38 and 42 years, respectively) than the WT-pre and WT-post cases (48 and 57 years, respectively). The melanomas in the MUT-pre had significantly higher T stage compared with MUT-post (p = 0.006), whereas no such difference was seen comparing WT-pre with WT-post (p = 0.849). MUT-pre had compared with WT-pre, significantly worse melanoma-specific survival, unadjusted (HR 2.33, 95% CI 1.33-4.08, p = 0.003) adjusted (HR 2.70, 95% CI 1.46-5.00, p = 0.001). However, the MUT-post cases had compared with the WT-post cases, no significant survival differences. CONCLUSION: This study is the first to address the impact on survival from introducing a dermatologic surveillance program to familial melanoma cases with or without CDKN2A mutations. The CDKN2A-mut carriers appeared to have a clear benefit with less advanced melanomas diagnosed and better melanoma-specific survival after inclusion. Among the CDKN2A-wt cases, the effect of the inclusion on the studied outcomes was less evident.

Mohs micrographic surgery revisited: A multidisciplinary, collaborative approach for the treatment of aggressive and recurrent basal cell carcinoma on the head and neck.

Mohs micrographic surgery is the preferred surgical option for high-risk basal cell carcinomas. In our institution, the method is exclusively used for the treatment of aggressive and recurrent facial tumours selected via multidisciplinary team meetings and consistently managed using a multidisciplinary approach. The aim of this retrospective patient-record study was to examine the outcomes for basal cell carcinomas managed with Mohs micrographic surgery and to present our experience from multidisciplinary team meetings and interdisciplinary collaborations. All patients treated between September 2009 and March 2019 at Karolinska University hospital were included. In a total of 143 facial basal cell carcinomas in 138 patients, 86 primary and 57 recurrent, the recurrence rate was 4.9% after a median follow-up of 24 months. In regions, where highly specialised Mohs surgeons performing all the steps of the procedure are limited, interdisciplinary collaboration can be an effective strategy for appropriate patient selection and for performing all steps of Mohs surgery with dermatosurgeons eradicating the tumour, pathologists evaluating the histopathology, followed by reconstructive surgery by plastic surgeons. The approach we present here provides a robust and functioning Mohs surgical service during the build-up of the organisation, while providing the opportunity to train new surgeons. Once the clinic has been set up, the multidisciplinary approach should always be considered and applied when dealing with complex cases.

Trend Shifts in Age-Specific Incidence for In Situ and Invasive Cutaneous Melanoma in Sweden.

BACKGROUND: The incidence of invasive cutaneous melanoma (CM) is increasing in Sweden. The aim was to present age- and sex-specific trends of the age-standardised incidence and the average annual percentage change (AAPC) for in situ and invasive CM. METHODS: Joinpoint regression models were used to analyse data from the Swedish Cancer Register and the Swedish Melanoma Registry 1997-2018 (N = 35,350 in situ CM; 59,932 CM). RESULTS: The AAPC of CM for women was 4.5 (4.1-5.0; p < 0.001) for the period 1997-2018. For men, the APCC was 4.2 (3.0-5.4; p < 0.001), with a significantly higher annual percentage change (APC) for the period 2000-2018 (5.0; 4.6-5.4; p < 0.001) compared to 1997-1999. An increasing annual incidence of CM ≤ 0.6 mm and 0.7 mm Breslow tumour thickness was found for men with a significant incidence shift for the period 2006-2015, respectively. Similarly for women, with a significantly higher APC for CM ≤ 0.6 mm from 2005. The incidence of intermediate thick CM (2.1-4.0 mm) has not increased since 2011. The incidence of CM > 4.0 mm has been increasing among both sexes, with a significantly lower APC among women from 2005. CONCLUSIONS: The incidence of in situ and low-risk CM ≤ 1.0 mm in tumour thickness has been rising among both sexes since the 2000s.

The Proportion Cured of Patients with Resected Stage II-III Cutaneous Melanoma in Sweden.

BACKGROUND: Cure proportion represents the proportion of patients who experience the same mortality rate as the general population and can be estimated together with the survival of the proportion experiencing excess mortality (the uncured). The aim was to estimate the cure proportions and survival among uncured stage II-III cutaneous melanoma (CM) patients. METHODS: 1- and 5-year relative survival ratios, cure proportions and the median survival times of uncured stage II-III CM patients in Sweden (n = 6466) were calculated based on data from the nationwide population-based Swedish Melanoma Register 2005-2013 with a follow-up through 2018. RESULTS: Stages IIB and IIC showed significant differences in standardized cure proportions vs. stage IIA CM (0.80 (95% CI 0.77-0.83) stage IIA; 0.62 (95% CI 0.59-0.66) stage IIB; 0.42 (95% CI 0.37-0.46) for stage IIC). Significant differences in standardized cure proportions were found for stages IIIB and IIIC-D CM vs. stage IIIA (0.76 (95% CI 0.68-0.84) stage IIIA; 0.52 (95% CI 0.45-0.59) stage IIIB; 0.35 (95% CI 0.30-0.39) for stage IIIC-D). CONCLUSIONS: The results are emphasizing the poor prognosis with low proportions cured by surgery only for sub-groups of stage II-III CM, specifically within stages IIB-C CM.

CDKN2A genetic testing in melanoma-prone families in Sweden in the years 2015-2020: implications for novel national recommendations.

Background: Inherited pathogenic variants (PVs) in the CDKN2A gene are among the strongest known risk factors for cutaneous melanoma. Carriers are at high risks to develop multiple primary melanomas and other cancers, in particular pancreatic cancer. In this study, the CDKN2A testing, carried out in Sweden in the years 2015-2020, was evaluated.Materials and methods: Included families had (1) three or more cases of melanoma and/or pancreatic cancer, (2) two melanomas in first-degree relatives, the youngest case <55 years or (3) individuals with three or more multiple primary melanomas, the first before the age of 55 years, and no other affected family members. The included families had at least one affected member that had been tested for CDKN2A PVs.Results: In total, 403 families were included, whereof 913 family members had been diagnosed with cutaneous melanoma and 129 with pancreatic cancer, 33 (8.2%) were found to have PVs in CDKN2A. Frequencies ranged from 0.9% in families with only two melanomas to 43.2% in families with three or more melanoma cases and pancreatic cancer (p < 0.001). The frequency of PVs ranged from 2.1% to 16.5% in families where the youngest case was ≥55 years or <35 years (p = 0.040). In families with or without CDKN2A PVs, 37.6% and 10.0% had melanoma cases that had died from melanoma, respectively (p < 0.001).Discussion: Significant differences were seen in the frequencies of CDKN2A PVs, dependent on numbers or age at diagnosis of melanomas and diagnoses of pancreatic cancers in the family. Further, melanoma cases belonging to families that tested positive for CDKN2A PVs had a significantly higher mortality. To summarize, the current evaluation shows that, with adequately selected criteria to guide genetic testing, CDKN2A PVs are identified at significant frequencies. Identification of carrier families is of importance to ensure that members are enrolled in a preventive surveillance program.

MiR-130a Acts as a Tumor Suppressor MicroRNA in Cutaneous Squamous Cell Carcinoma and Regulates the Activity of the BMP/SMAD Pathway by Suppressing ACVR1.

Cutaneous squamous cell carcinoma (cSCC) is a malignant neoplasm of the skin resulting from the accumulation of somatic mutations due to solar radiation. cSCC is one of the fastest increasing malignancies, and it represents a particular problem among immunosuppressed individuals. MicroRNAs are short noncoding RNAs that regulate the expression of protein-coding genes at the post-transcriptional level. In this study, we identify miR-130a to be downregulated in cSCC compared to healthy skin and precancerous lesions (actinic keratosis). Moreoever, we show that its expression is regulated at the transcriptional level by HRAS and MAPK signaling pathway. We demonstrate that overexpession of miR-130a suppresses long-term capacity of growth, cell motility and invasion ability of human cSCC cell lines. We report that miR-130a suppresses the growth of cSCC xenografts in mice. Mechanistically, miR-130a directly targets ACVR1 (ALK2), and changes in miR-130a levels result in the decreased activity of the BMP/SMAD pathway through ACVR1. These data reveal a link between activated MAPK signaling and decreased expression of miR-130a, which acts as a tumor-suppressor microRNA in cSCC and contribute to a better understanding of the molecular processes during malignant transformation of epidermal keratinocytes.

Multiple Primary Melanoma Incidence Trends Over Five Decades: A Nationwide Population-Based Study.

BACKGROUND: Over the past decades, many regions have experienced a steady increase in the incidence of cutaneous melanoma. Here, we report on incidence trends for subsequent primary melanoma. METHODS: In this nationwide population-based study, patients diagnosed with a first primary cutaneous melanoma reported to the Swedish Cancer Registry were followed for up to 10 years for a diagnosis of subsequent primary melanoma. Patients were grouped with patients diagnosed with first melanoma in the same decade (1960s, 1970s, 1980s, 1990s, and 2000s, respectively). Frequencies, incidence rates (IRs), standardized incidence ratios (SIRs), and 95% confidence intervals (CIs) for second melanomas were calculated. All tests of statistical significance were 2-sided. RESULTS: Of patients with melanoma, 54 884 were included and 2469 were diagnosed, within 10 years, with subsequent melanomas. Over the 5 decades, there was a statistically significant steady increase in the frequency, IR, and SIR for second primary melanoma. For example, in the 1960s cohort, less than 1% (IR = 1.0, 95% CI = 0.5 to 1.7, and IR = 1.1, 95% CI = 0.5 to 1.9 per 1000 person-years in women and men, respectively) had second primary melanoma, and this rose to 6.4% (IR = 7.5, 95% CI = 6.8 to 8.3, per 1000 person-years) in the women and 7.9% (IR = 10.3, 95% CI = 9.3 to 11.2, per 1000 person-years) in the men in the 2000s cohort. This rise was seen independent of age, sex, invasiveness, or site of the melanoma. Further, in patients diagnosed with a second melanoma, the frequency of those having more than 2 melanomas increased statistically significantly and was 0.0% in the 1960s and rose to 18.0% in the 2000s (P < .001). CONCLUSIONS: This is the first study to evaluate and report on a rising trend for subsequent primary melanoma. Additional primary melanomas worsen the patients' survival, and precautions are needed to turn this steep upgoing trend.

Clinical characteristics of pediatric hidradenitis suppurativa: a cross-sectional multicenter study of 140 patients.

Hidradenitis suppurativa (HS) rarely affects pediatric patients. The literature on pediatric HS patients is scarce. This is a cross-sectional study based on case note review or interviews and clinical examination of 140 pediatric patients undergoing secondary or tertiary level care. Patients were predominantly female (75.5%, n = 105) with a median age of 16. 39% reported 1st-degree relative with HS. Median BMI percentile was 88, and 11% were smokers (n = 15). Median modified Sartorius score was 8.5. Notable comorbidities found were acne (32.8%, n = 45), hirsutism (19.3%, n = 27), and pilonidal cysts (16.4%, n = 23). Resorcinol (n = 27) and clindamycin (n = 25) were the most frequently used topical treatments. Patients were treated with tetracycline (n = 32), or oral clindamycin and rifampicin in combination (n = 29). Surgical excision was performed in 18 patients, deroofing in five and incision in seven patients. Obesity seemed to be prominent in the pediatric population and correlated to parent BMI, suggesting a potential for preventive measures for the family. Disease management appeared to be similar to that of adult HS, bearing in mind that the younger the patient, the milder the disease in majority of cases.

A comprehensive analysis of coding and non-coding transcriptomic changes in cutaneous squamous cell carcinoma.

Cutaneous Squamous Cell Carcinoma (cSCC) is the most common and fastest-increasing cancer with metastatic potential. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) are novel regulators of gene expression. To identify mRNAs, lncRNAs and circRNAs, which can be involved in cSCC, RNA-seq was performed on nine cSCCs and seven healthy skin samples. Representative transcripts were validated by NanoString nCounter assays using an extended cohort, which also included samples from pre-cancerous skin lesions (actinic keratosis). 5,352 protein-coding genes, 908 lncRNAs and 55 circular RNAs were identified to be differentially expressed in cSCC. Targets of 519 transcription factors were enriched among differentially expressed genes, 105 of which displayed altered level in cSCCs, including fundamental regulators of skin development (MYC, RELA, ETS1, TP63). Pathways related to cell cycle, apoptosis, inflammation and epidermal differentiation were enriched. In addition to known oncogenic lncRNAs (PVT1, LUCAT1, CASC9), a set of skin-specific lncRNAs were were identified to be dysregulated. A global downregulation of circRNAs was observed in cSCC, and novel skin-enriched circRNAs, circ_IFFO2 and circ_POF1B, were identified and validated. In conclusion, a reference set of coding and non-coding transcripts were identified in cSCC, which may become potential therapeutic targets or biomarkers.