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.

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.

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.

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.

Comparison of the accuracy of human readers versus machine-learning algorithms for pigmented skin lesion classification: an open, web-based, international, diagnostic study.

BACKGROUND: Whether machine-learning algorithms can diagnose all pigmented skin lesions as accurately as human experts is unclear. The aim of this study was to compare the diagnostic accuracy of state-of-the-art machine-learning algorithms with human readers for all clinically relevant types of benign and malignant pigmented skin lesions. METHODS: For this open, web-based, international, diagnostic study, human readers were asked to diagnose dermatoscopic images selected randomly in 30-image batches from a test set of 1511 images. The diagnoses from human readers were compared with those of 139 algorithms created by 77 machine-learning labs, who participated in the International Skin Imaging Collaboration 2018 challenge and received a training set of 10 015 images in advance. The ground truth of each lesion fell into one of seven predefined disease categories: intraepithelial carcinoma including actinic keratoses and Bowen's disease; basal cell carcinoma; benign keratinocytic lesions including solar lentigo, seborrheic keratosis and lichen planus-like keratosis; dermatofibroma; melanoma; melanocytic nevus; and vascular lesions. The two main outcomes were the differences in the number of correct specific diagnoses per batch between all human readers and the top three algorithms, and between human experts and the top three algorithms. FINDINGS: Between Aug 4, 2018, and Sept 30, 2018, 511 human readers from 63 countries had at least one attempt in the reader study. 283 (55·4%) of 511 human readers were board-certified dermatologists, 118 (23·1%) were dermatology residents, and 83 (16·2%) were general practitioners. When comparing all human readers with all machine-learning algorithms, the algorithms achieved a mean of 2·01 (95% CI 1·97 to 2·04; p<0·0001) more correct diagnoses (17·91 [SD 3·42] vs 19·92 [4·27]). 27 human experts with more than 10 years of experience achieved a mean of 18·78 (SD 3·15) correct answers, compared with 25·43 (1·95) correct answers for the top three machine algorithms (mean difference 6·65, 95% CI 6·06-7·25; p<0·0001). The difference between human experts and the top three algorithms was significantly lower for images in the test set that were collected from sources not included in the training set (human underperformance of 11·4%, 95% CI 9·9-12·9 vs 3·6%, 0·8-6·3; p<0·0001). INTERPRETATION: State-of-the-art machine-learning classifiers outperformed human experts in the diagnosis of pigmented skin lesions and should have a more important role in clinical practice. However, a possible limitation of these algorithms is their decreased performance for out-of-distribution images, which should be addressed in future research. FUNDING: None.

Reduced disease-specific survival following a diagnosis of multiple primary cutaneous malignant melanomas-a nationwide, population-based study.

Outcome data comparing patients with multiple primary invasive cutaneous malignant melanomas (MPMs) to single primary invasive cutaneous malignant melanomas (SPMs) show conflicting results. We have analyzed differences in disease-specific survival between these patients in a nationwide population-based setting. From the Swedish Melanoma Register, 27,235 patients were identified with a first invasive cutaneous malignant melanoma (CMM) between 1990 and 2007, followed-up through 2013. Of these, 700 patients developed MPMs. Cox proportional hazard regression was used for adjusted cause-specific hazard ratios (HRs). An interval of ≤5 years between CMM diagnoses was significantly correlated to a decreased CMM-specific survival in Stage I-II MPM- vs. SPM-patients (HR 1.32; 95% CI 1.04-1.67; p = 0.02). MPM-patients with longer time interval between diagnoses experienced similar risk of CMM-death as SPM-patients. The risk of CMM-death increased by almost 50% above the expected outcome according to stage of the index CMM by the diagnosis of a second CMM (HR 1.48; 95% CI 1.19-1.85; p < 0.001). MPM vs. SPM-patients had a worse outcome (HR 1.38; 95% CI 1.05-1.83; p = 0.001). This emphasizes the importance of prevention efforts in SPM-patients to decrease the risk of subsequent CMMs and has implications for more vigilant follow-up in MPM-patients.

Accuracy of dermatoscopy for the diagnosis of nonpigmented cancers of the skin.

BACKGROUND: Nonpigmented skin cancer is common, and diagnosis with the unaided eye is error prone. OBJECTIVE: To investigate whether dermatoscopy improves the diagnostic accuracy for nonpigmented (amelanotic) cutaneous neoplasms. METHODS: We collected a sample of 2072 benign and malignant neoplastic lesions and inflammatory conditions and presented close-up images taken with and without dermatoscopy to 95 examiners with different levels of experience. RESULTS: The area under the curve was significantly higher with than without dermatoscopy (0.68 vs 0.64, P < .001). Among 51 possible diagnoses, the correct diagnosis was selected in 33.1% of cases with and 26.4% of cases without dermatoscopy (P < .001). For experts, the frequencies of correct specific diagnoses of a malignant lesion improved from 40.2% without to 51.3% with dermatoscopy. For all malignant neoplasms combined, the frequencies of appropriate management strategies increased from 78.1% without to 82.5% with dermatoscopy. LIMITATIONS: The study deviated from a real-life clinical setting and was potentially affected by verification and selection bias. CONCLUSIONS: Dermatoscopy improves the diagnosis and management of nonpigmented skin cancer and should be used as an adjunct to examination with the unaided eye.

Shift in Occupational Risk for Basal Cell Carcinoma from Outdoor to Indoor Workers: A Large Population-based Case-control Register Study from Sweden.

Basal cell carcinoma (BCC) is the most common form of cancer worldwide. Exposure of the skin to ultraviolet (UV) radiation, from sunlight and other sources, is the most important risk factor. The aim of this large-scale case-control study was to determine which occupations are associated with increased risk of BCC in Sweden. The case cohort comprised 74,247 patients with BCC and the control cohort comprised 574,055 subjects linked to population-based registers. Compared with the occupational category of farmers, foresters and gardeners we observed elevated risks of BCC for almost all occupational categories studied. Legal workers with odds ratio (OR) 2.69 (95% confidence interval (CI) 2.36-3.06), dentists OR 2.69 (95% CI 2.35-3.08) and physicians OR 2.47 (95% CI 2.24-2.74) had the highest risk for both sexes taken together. In conclusion, there appears to have been a change in the risk of BCC from outdoor to indoor occupations in Sweden, possibly related to exposure to UV radiation during leisure activities exceeding occupational sun exposure as the main cause of BCC in Sweden.

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.

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.

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.

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.

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.

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.

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.