Systematic review of optical coherence tomography usage in the diagnosis and management of basal cell carcinoma

Optical coherence tomography (OCT) is a noninvasive imaging tool used in vivo in real time for diagnosis, treatment delineation and monitoring of basal cell carcinoma (BCC). Features of BCC on OCT have been widely described and reviewed. However, the diagnostic accuracy of OCT in these various applications is unclear. We systematically reviewed the literature to assess the accuracy of OCT in diagnosis and management of BCC using the Embase and Medline databases. In total 179 unique references were identified in the initial search, of which 22 studies with 556 histologically proven BCCs were eligible. Assessment of the quality of eligible studies was undertaken using the STROBE criteria. Data extraction and quality assessment were performed independently by the two authors. This systematic review provides an overview of the clinical applications of OCT in the diagnosis and management of BCC. OCT has been suggested to be useful in the diagnosis, treatment planning and treatment monitoring of BCC. As the technology improves and its utility increases, further studies with good methodological quality will be needed to implement OCT into daily practice.     

Imaging of basal cell carcinoma by high‐definition optical coherence tomography: histomorphological correlation. A pilot study

Summary Background With the continued development of noninvasive therapies for basal cell carcinoma (BCC) such as photodynamic therapy and immune therapies, noninvasive diagnosis and monitoring become increasingly relevant. High‐definition optical coherence tomography (HD‐OCT) is a high‐resolution imaging tool, with micrometre resolution in both transversal and axial directions, enabling visualization of individual cells up to a depth of around 570 μm, and filling the imaging gap between conventional optical coherence tomography (OCT) and reflectance confocal microscopy (RCM). Objectives We sought to determine the feasibility of detecting BCC by this technique using criteria defined for RCM and conventional OCT and compared with histology. Methods In this pilot study skin lesions of 21 patients with a histologically proven BCC were imaged by HD‐OCT just before excision and images analysed qualitatively. Results Features for four different BCC subtypes were described in both transverse and axial directions. In general, these features were subepidermal or intradermal aggregations of cells. These islands or trabeculae were surrounded by a less refractile border corresponding with palisading and peritumoral mucin production. There was a pronounced architectural disarray of the epidermis. A variably refractile stroma together with abundant dilated peritumoral blood vessels was present. These features were comparable with histological features for each patient. Conclusions Using features already suggested by RCM and conventional OCT, the study implies that HD‐OCT facilitates in vivo diagnosis of BCC and allows the distinction between different BCC subtypes for increased clinical utility.     

In vivo differentiation of common basal cell carcinoma subtypes by microvascular and structural imaging using dynamic optical coherence tomography

The subtype of basal cell carcinoma (BCC) influences the choice of treatment. Optical coherence tomography (OCT) is a non‐invasive imaging tool, and a recent development of an angiographic version of OCT has extended the application of OCT to image the cutaneous microvasculature (so‐called dynamic OCT, D‐OCT). This study explores D‐OCT's ability to differentiate the common BCC subtypes by microvascular and structural imaging. Eighty‐one patients with 98 BCC lesions, consisting of three subtypes: 27 superficial BCC (sBCC), 55 nodular BCC (nBCC) and 16 infiltrative BCC (iBCC) were D‐OCT scanned at three European dermatology centres. Blinded evaluations of microvascular and structural features were performed, followed by extensive statistical analysis of risk ratio (RR) and multiple correspondence analysis. nBCC lesions displayed most characteristic structural and vascular features. Serpiginous vessels, branching vessels, vessels creating a circumscribed figure and sharply demarcated hyporeflective ovoid structures in the dermis were all associated with a higher risk of the subtype being nBCC. The presence of highly present lines and dark peripheral borders at the margin of ovoid structures was negatively associated with iBCC. Lastly, the finding of hyporeflective ovoid structures protruding from epidermis correlated with sBCC. We identified various microvascular and structural D‐OCT features that may aid non‐invasive identification of BCC subtypes. This would allow clinicians to individualize and optimize BCC treatment as well as aid follow‐up of non‐surgical treatment.     

Machine-learning classification of non-melanoma skin cancers from image features obtained by optical coherence tomography

Background/purpose: A number of publications have suggested that optical coherence tomography (OCT) has the potential for non-invasive diagnosis of skin cancer. Currently, individual diagnostic features do not appear sufficiently discriminatory. The combined use of several features may however be useful.
Methods: OCT is based on infrared light, photonics and fibre optics. The system used has an axial resolution of 10 μm, lateral 20 μm. We investigated the combined use of several OCT features from basal cell carcinomas (BCC) and actinic keratosis (AK). We studied BCC (41) and AK (37) lesions in 34 consecutive patients. The diagnostic accuracy of the combined features was assessed using a machine-learning tool.
Results: OCT images of normal skin typically exhibit a layered structure, not present in the lesions imaged. BCCs showed dark globules corresponding to basaloid islands and AKs showed white dots and streaks corresponding to hyperkeratosis. Differences in OCT morphology were not sufficient to differentiate BCC from AK by the naked eye. Machine-learning analysis suggests that when a multiplicity of features is used, correct classification accuracies of 73% (AK) and 81% (BCC) are achieved.
Conclusion: The data extracted from individual OCT scans included both quantitative and qualitative measures, and at the current level of resolution, these single factors appear insufficient for diagnosis. Our approach suggests that it may be possible to extract diagnostic data from the overall architecture of the OCT images with a reasonable diagnostic accuracy when used in combination.     

The utility of optical coherence tomography for diagnosis of basal cell carcinoma: a quantitative review

Basal cell carcinoma (BCC) is the most common form of skin cancer in the world. Its incidence in Europe has increased at an alarming rate of 5.5% per year over the past four decades. In the U.K., the incidence of BCC has risen at a rate six times higher than in the rest of Europe. The diagnosis of BCC typically requires a biopsy of the skin and careful analysis under a microscope. Optical coherence tomography (OCT) is an imaging tool that uses light to visualize the layers underneath the skin surface in real-time without the need to perform a skin biopsy. It has been proposed as a non-invasive, alternative tool to diagnose BCC. This study, from the U.S., investigated current medical literature to comprehensively assess the accuracy of OCT technology in evaluating BCCs. The authors reviewed 901 BCCs collected from 31 studies that utilized OCT for diagnosing BCC. The authors found that OCT was able to diagnose BCC with a sensitivity of 89.3%, meaning that it correctly identified 9 out of 10 BCCs. Of the different types of OCT, the most advanced, Fourier-Domain OCT, obtained the highest accuracy. OCT was able to detect features of BCC that are normally seen under the microscope in up to 80% of tumours. In addition, the authors noted that OCT was best at predicting the depth of shallow BCC tumors less than 1mm deep. Based on these results, the authors envision OCT to be a valuable, non-invasive tool for diagnosing BCC.     

In vivo optical coherence tomography of basal cell carcinoma

BACKGROUND: Optical coherence tomography (OCT) is a promising non-invasive imaging technique that has not systematically been studied in skin cancer such as basal cell carcinoma (BCC). OBJECTIVE: We aimed, first, to describe the in vivo histologic features of BCC by using OCT, and second, to find out whether it is possible to differentiate BCC subtypes by means of OCT. METHODS: Prior to the excision, the BCCs (n=43) as well as adjacent non-lesional skin sites were assessed by OCT in vivo. The lesional area of interest was marked prior to OCT and tattooed after excision, respectively, in order to enable topographical concordance between the cross-sectional OCT images and the histologic sections. RESULTS: Compared to non-lesional skin, a loss of normal skin architecture and disarrangement of the epidermis and upper dermis was observed in the OCT images of BCCs. Features that were frequently identified by OCT and correlated with histology included large plug-like signal-intense structures, honeycomb-like signal-free structures, and prominent signal free cavities in the upper dermis. With regard to the aforementioned OCT features, no statistically significant (P<0.05) difference was found between nodular, multifocal superficial, and infiltrative BCCs, respectively. CONCLUSIONS: OCT is capable to visualize altered skin architecture and histopathological correlates of BCC. However, there is not at this time sufficient data supporting the clinical use of OCT for the differentiation of BCC subtypes.     

Optical coherence tomography of basal cell carcinoma: influence of location,subtype, observer variability and image quality on diagnostic performance

Nonmelanoma skin cancer (NMSC) is the most common cancer affecting white‐skinned people worldwide, outnumbering all other cancers combined. Basal cell carcinoma (BCC) is the most common NMSC, with at least 100 000 new cases diagnosed in the UK each year, rising 4–10% every year, placing an ever‐increasing burden on healthcare services. At least 50% of skin biopsies for BCC are negative (no cancer tumour present) and so dermatologists wish for a non‐invasive imaging tool (i.e. using an image rather than biopsy surgery) that could provide more information to make a diagnosis to avoid unnecessary biopsies. This study of 256 BCC patients was performed at 6 centres based in Germany. The study examined the accuracy of diagnosis of BCC using a novel imaging device, the VivoSight Optical Coherence Tomography (OCT) scanner. A 2015 publication from this study (Ulrich et al., Brit. J. Dermatology, (15), 173, pp 428–435) reported that the accuracy of diagnosis using OCT was much improved over clinical/dermoscopic examination, in which a doctor examines the skin just by sight or using a handheld magnifier called a dermatoscope. In the present paper, the authors report on further analysis of the data: diagnostic performance – meaning the accuracy of the diagnosis – did not depend on where the lesion (affected patch of skin) was located on the body; that diagnostic performance was reduced when the lesion had scales/crusting (but was still superior to clinical/dermoscopic examination); that diagnostic performance was consistent between different medics (meaning their diagnoses were largely the same) and that they were more likely to be correct when they had high confidence in their diagnosis; and that BCC subtype can be diagnosed from OCT with moderate accuracy (62–72%). These conclusions support the targeted use of OCT to aid the diagnosis of BCC, potentially improving the standard of care by enabling more early‐stage BCCs to be detected and by supporting the use of non‐invasive treatment options.     

Dendritic cells in pigmented basal cell carcinoma: a relevant finding by reflectance-mode confocal microscopy

BACKGROUND: Reflectance-mode confocal microscopy (RCM) is a new approach for the in vivo diagnosis of skin tumors. A few studies of RCM on basal cell carcinoma (BCC) have provided specific diagnostic criteria, but large studies on pigmented basal cell carcinoma are lacking. Proliferation of large dendritic-shaped cells within a melanocytic tumor has been associated with the diagnosis of melanoma by RCM. Benign melanocytes and Langerhans cells may populate BCC according to previous histological studies. We studied 3 consecutive pigmented BCC by means of RCM and performed a histological and immunohistochemical correlation focusing on the presence of dendritic structures. OBSERVATIONS: Reflectance-mode confocal microscopy revealed highly refractive dendritic structures within tumor nests that correlated with the presence of melanocytes within the tumor by immunochemical analysis. In 1 case, dendritic structures on the overlying epidermis corresponding to Langerhans cells were also noted. Leaf-like areas observed on dermoscopy correlated with low-refractive cordlike structures and nodules by RCM and corresponded to nests of basaloid cells, whereas blue-gray globules presented as bright oval structures with ill-defined borders corresponding to melanophages. CONCLUSIONS: Reflectance-mode confocal microscopy allows the study of pigmented BCC and the identification of specific criteria described previously. In these tumors, dendritic melanocytes can be easily identified with this technique.     

Comparison of ex vivo optical coherence tomography with conventional frozen-section histology for visualizing basal cell carcinoma during Mohs micrographic surgery

Background Mohs micrographic surgery offers high cure rates of nonmelanoma skin cancers with optimal sparing of normal tissue. However, it is generally more time‐consuming and labour‐intensive than traditional surgery. Optical coherence tomography (OCT) is an emergent technology that has the potential to diagnose basal cell carcinoma (BCC) in vivo. Objective To compare the efficiency and accuracy of ex vivo OCT with frozen‐section histology for identifying BCC in Mohs surgery. Methods Thirty‐eight patients were enrolled. After the stages were taken, images were captured with an OCT microscope and subsequently processed for standard frozen sections. Results In total, 75 sections were scanned and the mean time to produce one OCT image was 7 min. In four of 26 positive haematoxylin–eosin sections and 23 of 49 negative sections, there was a good correlation with OCT images. The sensitivity and specificity were 19% and 56%, respectively. Conclusions It is possible to identify BCC with ex vivo OCT and this is more rapidly obtained than with haematoxylin–eosin frozen sections. However, tumour visualization in OCT was disappointing. Practical benefit may be obtained by optimizing this technology and combining it with other new diagnostic tools.     

Linear basal cell carcinoma: a distinct condition?

Linear basal cell carcinoma (BCC) was first reported as a distinct condition in 1985. Having managed two cases recently, we reviewed the published literature on this condition. The aim of the study was to review all reported cases in the literature and summarize the demographic data, histological and clinical features, and treatment methods used. We conducted a literature search from 1985 to 2008 for all published articles on linear BCC [PubMed (National Library of Medicine, Bethesda, MD, USA)] using the keywords ‘linear’ and ‘basal cell carcinoma’. In total, 37 cases of linear BCC in 15 papers were reviewed. There was an equal male : female ratio in the cases. The periocular skin and the neck were the sites most frequently involved. Although the nodular pattern was the commonest histological feature reported, there was a relatively high percentage of infiltrative and morphoeic subtypes. Mohs micrographic surgery was the most frequently used method of treatment. A history of preceding trauma, surgery or radiotherapy was described in only 18% of the reported cases. Linear BCC is a rare variant of BCC with distinct morphological and histological features, which have led some authors to regard it as a separate condition.     

The −1154 G/A VEGF gene polymorphism is associated with the incidence of basal cell carcinoma in patients from northern Poland

Vascular endothelial growth factor (VEGF) is believed to play a crucial role in neoplastic angiogenesis. Although the genetic background of basal cell carcinoma (BCC) has been analyzed in some papers, the mechanism of BCC pathogenesis is not fully understood. To the best of our knowledge, VEGF gene polymorphisms have not yet been explored. The aim of the study was to asses the frequency of three polymorphisms in the VEGF gene (?1154 G/A, ?460 T/C and +405 G/C) in patients of Polish origin with BCC and control group. In addition, VEGF serum levels of patients with BCC and controls were measured. The study involved 180 patients (96 women, 84 men) with BCC and a mean age of 68.9 ± 11.8, and 215 healthy age- and sex-matched volunteers. The VEGF polymorphisms at positions ?1154 and +405 were analyzed using the amplification refractory mutation system polymerase chain reaction method. To assess the VEGF gene polymorphism at position ?460, we used the polymerase chain reaction restriction fragment length polymorphism method. Serum levels of VEGF protein were measured using the ELISA test. The presence of the G allele (GA or GG) in the ?1154 VEGF polymorphism was associated with an increased risk of BCC development (OR = 7.28, p < 0.0001). Furthermore, the carriers of the AA genotype in ?1154 VEGF polymorphism showed significantly reduced risks of BCC (OR = 0.14, p < 0.0001). It was also shown that the GTC haplotype of VEGF predisposes to BCC development (OR = 1.69, p = 0.013), while the presence of the ATG haplotype significantly reduces this risk (OR = 0.17, p = 0.00001). We have found significantly increased VEGF serum levels among BCC patients, in comparison with the healthy controls (mean 596.7 ± 393.5 pg/ml; range 60.1–931.4 vs. 255.9 ± 174.6 pg/ml; range 42.2–553.0 pg/ml; p < 0.0004). The serum levels of VEGF significantly correlated with tumor size: r = 0.41, p < 0.0001. Our results testify to the importance of ?1154 G/A VEGF gene polymorphisms in altering the risk of BCC among the population from northern Poland.     

Utility of radiotherapy for treatment of basal cell carcinoma: a review

Radiotherapy is an available treatment for management of basal cell carcinoma (BCC). This study aims to analyse the published literature about radiotherapy in treatment of BCC. A focus of this study will be to compare the dosing regimens adopted in these studies. A search of the Medline database was conducted from 1984 to August 2013. Search terms used were ‘basal cell carcinoma’, ‘radiotherapy’, ‘epithelial skin cancer’ and ‘external irradiation’. Fourteen studies on the use of radiotherapy for BCC were included. Seven studies included only cases of BCC, while six studies also included patients treated for squamous cell carcinoma. The overall cure rates ranged from 79·2% to 100%. More than 90% of the patients reported good or excellent aesthetic outcome from radiotherapy (three studies). There was a wide variation in the total dose and dose per fraction of radiotherapy used. Nine studies utilized dosing regimens within the recommended guidelines of the National Comprehensive Cancer Network. There are a limited number of high‐quality prospective studies of radiotherapy for BCC. Based on the available evidence, radiotherapy provides a high rate of local control with low rates of complications that are comparable with surgery.     

Morphology of basal cell carcinoma in high definition optical coherence tomography: en‐face and slice imaging mode,and comparison with histology

Background Optical coherence tomography (OCT) allows real‐time, in vivo examination of basal cell carcinoma (BCC). A new high definition OCT with high lateral and axial resolution in a horizontal (en‐face) and vertical (slice) imaging mode offers additional information in the diagnosis of BCC and may potentially replace invasive diagnostic biopsies. Objectives To define the characteristic morphologic features of BCC by using high definition optical coherence tomography (HD‐OCT) compared to conventional histology. Methods A total of 22 BCCs were examined preoperatively by HD‐OCT in the en‐face and slice imaging mode and characteristic features were evaluated in comparison to the histopathological findings. Results The following features were found in the en‐face mode of HD‐OCT: lobulated nodules (20/22), peripheral rimming (17/22), epidermal disarray (21/22), dilated vessels (11/22) and variably refractile stroma (19/22). In the slice imaging mode the following characteristics were found: grey/dark oval structures (18/22), peripheral rimming (13/22), destruction of layering (22/22), dilated vessels (7/22) and peritumoural bright stroma (11/22). In the en‐face mode the lobulated structure of the BCC was more distinct than in the slice mode compared to histology. Conclusion HD‐OCT with a horizontal and vertical imaging mode offers additional information in the diagnosis of BCC compared to conventional OCT imaging and enhances the feasibility of non‐invasive diagnostics of BCC.     

Alcohol intake and risk of nonmelanoma skin cancer: a systematic review and dose–response meta‐analysis

Nonmelanoma skin cancer (NMSC) comprises mainly basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). The association between alcohol intake and NMSC has been inconclusive; therefore the objective of this study is to quantify the relationship between alcohol intake and NMSC using meta‐analyses. A systematic literature search of PubMed and Embase was performed on 30 October 2016. Eligible articles were case–control or cohort studies that examined alcohol intake and risk of BCC or cSCC and reported relative risks (RRs) with 95% confidence intervals (CIs). Of the 307 articles identified, 13 case–control and cohort studies were included in the systematic review, including 95 241 NMSC cases (91 942 BCC and 3299 cSCC cases). A random‐effects model was used to obtain summary RRs and 95% CIs for dose–response meta‐analyses. For every 10‐gram increase in ethanol intake per day, a positive association was found for both BCC (summary RR of 1·07; 95% CI 1·04–1·09) and cSCC (summary RR of 1·11; 95% CI 1·06–1·16). While there was evidence suggesting a nonlinear association for BCC, it may be due to the sparse data at higher alcohol intake levels. This meta‐analysis found evidence that alcohol drinking is positively associated with both BCC and cSCC risk in a dose‐dependent manner. These results should be interpreted with caution due to potential residual confounding. Nonetheless, because alcohol drinking is a prevalent and modifiable behaviour, it could serve as an important public health target to reduce the global health burden of NMSC.     

Exfoliative cytology as a diagnostic test for basal cell carcinoma: a meta-analysis

BACKGROUND: Exfoliative cytology is only occasionally used in clinical practice to diagnose basal cell carcinoma (BCC). OBJECTIVES: To systematically review the literature examining exfoliative cytology as a diagnostic tool for BCC and to meta-analytically summarize the accuracy of this test. METHODS: Diagnostic test meta-analysis. A computerized database search was made of MEDLINE (1966-2000) and EMBASE (1950-2000) using appropriately indexed terms. Hand searches of relevant journals were made. Bibliographies of relevant articles were further explored. Histopathology was used as the reference standard. A summary receiver-operating characteristic curve analysis was performed using the statistical package Meta-Test version 0.6 (J. Lau, New England Medical Center, Boston, MA, U.S.A., 1997). RESULTS: Eight primary studies (seven English language and one Italian language) fulfilled the inclusion criteria. The pooled sample included 1261 BCCs. These studies varied greatly in methodological quality and were, in general, poor. A meta-analysis showed the pooled sensitivity to be high at 97%[95% confidence interval (CI) 94-99]. Consequently, only 3% of BCCs included were misdiagnosed as non-BCC by cytology. The corresponding pooled specificity was 86% (95% CI 80-91). CONCLUSIONS: Exfoliative cytology probably has a high diagnostic accuracy for BCC. However, large, better designed and better reported studies are needed to ascertain the true accuracy of this technique. In the interim, this test should be considered in specific subgroups of patients in whom even a 2-mm punch biopsy may be considered inappropriate, e.g. a cosmetically sensitive site in a young person. Similarly, it should be considered when a BCC is to be treated without a diagnostic biopsy being taken, e.g. with cryotherapy.     

In vivo thickness measurement of basal cell carcinoma and actinic keratosis with optical coherence tomography and 20-MHz ultrasound

Background  Accurate assessment of tumour size is important when planning treatment of nonmelanoma skin cancer (NMSC). Imaging with optical coherence tomography (OCT) has the potential to diagnose and measure depth of NMSC.
Objectives  To compare accuracy of mean tumour thickness measurement in NMSC tumours < 2 mm of depth using OCT and 20-MHz high-frequency ultrasound (HFUS). In addition, OCT morphology of NMSC was studied in OCT images and the influence of histological and colorimetric values on the quality and penetration depth in OCT images was estimated.
Methods  In total, 93 patients were scanned and 34 lesions [23 basal cell carcinoma (BCC) and 11 actinic keratosis (AK) lesions] < 2 mm thick and easily identified in OCT images were studied. OCT and HFUS were compared with biopsies. The influence of skin pigmentation and infiltration analgesia on OCT image quality was studied. Skin colour was measured with a colorimeter.
Results  OCT presented narrower limits of agreement than HFUS. Both methods overestimated thickness but OCT was significantly less biased (0·392 mm vs. 0·713 mm). No relation between OCT penetration depth and skin colour was found.
Conclusions  OCT appears more precise and less biased than HFUS for thickness measurement in AK and BCC lesions < 2 mm, but both OCT and especially HFUS tended to overestimate tumour thickness.     

A systematic review of worldwide incidence of nonmelanoma skin cancer

Background Nonmelanoma skin cancer (NMSC) is the most common cancer affecting white‐skinned individuals and the incidence is increasing worldwide. Objectives This systematic review brings together 75 studies conducted over the past half century to look at geographical variations and trends worldwide in NMSC, and specifically incidence data are compared with recent U.K. cancer registry data. Methods Following the development of a comprehensive search strategy, an assessment tool was adapted to look at the methodological quality of the eligible studies. Results Most of the studies focused on white populations in Europe, the U.S.A. and Australia; however, limited data were available for other skin types in regions such as Africa. Worldwide the incidence for NMSC varies widely with the highest rates in Australia [> 1000/100 000 person‐years for basal cell carcinoma (BCC)] and the lowest rates in parts of Africa (< 1/100 000 person‐years for BCC). The average incidence rates in England were 76·21/100 000 person‐years and 22·65/100 000 person‐years for BCC and squamous cell carcinoma (SCC), respectively, with highest rates in the South‐West of England (121·29/100 000 person‐years for BCC and 33·02/100 000 person‐years for SCC) and lowest rates by far in London (0·24/100 000 person‐years for BCC and 14·98/100 000 person‐years for SCC). The incidence rates in the U.K. appear to be increasing at a greater rate when compared with the rest of Europe. Conclusions NMSC is an increasing problem for health care services worldwide. This review highlights a requirement for prevention studies in this area and the issues surrounding incomplete NMSC registration. Registration standards of NMSC should be improved to the level of other invasive disease.     

"High single-dose'' European PUVA regimen also causes an excess of non-melanoma skin cancer

We report the results of a long-term (12.8 years) follow-up study of the detection of malignant and benign skin tumours in patients with psoriasis, who were treated with PUVA according to the European, 'high single-dose' regimen. A total of 13 squamous cell carcinomas (SCC) and 24 basal cell carcinomas (BCC) were diagnosed in 11 of 260 patients. The incidence of both SCC and BCC was increased in comparison with the general Dutch population. The ratio of SCC to BCC in the general population was 1:8 but was 1:2.5 in our study group. A positive correlation was observed between the development of SCC and the total UVA dosage, the age of the patient at the start of the PUVA treatment and a history of arsenic use. This dose-related increase in the incidence of SCC, reported in studies from the U.S.A., has not been found in earlier European studies. The average time period between the start of PUVA therapy and the diagnosis of the first malignant skin tumour was 6.0 years for SCC and 4.7 years for BCC. Among the 49 benign skin tumours were actinic keratoses, a keratoacanthoma and 'PUVA keratoses', a newly described hyperkeratotic lesion, especially found in PUVA-treated patients.     

Occupational exposure to non‐artificial UV‐light and non‐melanocytic skin cancer – a systematic review concerning a new occupational disease

Background: Although UV exposure is the most important risk factor for cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), a systematic review analyzing the risk of occupational UV exposure is missing. Methods: Based on a systematic literature search in PubMed (until 05/2009) supplemented by hand search, the association between occupational UV exposure and SCC and BCC was analyzed. Literature search and data abstraction was done independently by 2 reviewers. The association between occupational UV exposure and cancer risk is presented as odds ratios (OR). Results: We identified 25 relevant epidemiologic studies (5 cohort studies, 17 case‐control studies, 3 cross‐sectional studies). 12 studies described a positive association between occupational UV exposure and risk of SCC with OR > 3 in 6 studies and OR 1.5–2.0 in another 6 studies. 3 studies did not find a relevant association (OR: 1.0–1.4). A significant positive association between occupational UV exposure and BCC was reported in 5 studies; 11 studies did not find a significant association. Conclusions: The association between occupational UV exposure and SCC is well and consistently documented epidemiologically (approximately 2‐fold increased risk), so that the criteria for a new occupational disease are fulfilled. The association with BCC is unclear due to significant methodological limitations in the published studies.     

Improving mandibular contour: A pilot study for indication of PPLA traction thread use

Background: The request for less-aggressive procedures to improve mandibular contour is increasing. Several kinds of threads have been used for this purpose. Nevertheless, PLLA (poly-L-Lactic acid) traction thread procedure has not been previously described. Aim: To investigate the role of PLLA traction threads in improving mandibular contour. Methods: Twenty women were enrolled in the study. They were differentially classified for skin laxity. Patients were treated in a single session with two PLLA traction threads per side. Specific post-procedure instructions were given to patients, and complications occurred after the procedures were estimated. A Fisher’s t-test was performed to identify criteria related to longevity of results. Results: We found longevity of results to be associated with younger age (p = 0.001), absence of severe skin laxity of jawline and neck (p = 0.001), and aesthetic satisfaction (p = 0.024). Edema, swelling, and temporary skin contour irregularities were found in most cases (N = 16; 80%), whereas paresthesia resolving without sequelae in 2–4 weeks was found in two cases (10%). Conclusions: Our results show that selected patients, younger than 51 and showing a mild-moderate degree of skin laxity of jawline and neck angle represent ideal candidates for PLLA traction thread treatment. Further studies will be performed to confirm our results.