A Retrospective Study of Diameter and Breslow Thickness in Invasive Melanomas.

INTRODUCTION: A diameter larger than 6 mm is included in the criteria used in public health messages to detect a cutaneous melanoma. We aimed to investigate the independent association of Breslow thickness with the melanoma diameter. METHODS: A retrospective study was performed in patients with invasive melanomas of the nodular melanoma (NM) or superficial spreading melanoma (SSM) subtype. The quartiles of the diameter (lower, median, upper) were studied in non-parametric quantile regression model. RESULTS: In total, 537 cases of invasive melanomas were included and 60% had Breslow thickness ≤1.0 mm. There were 429 SSM (79.9%) and 108 NM (20.1%). Although NMs were significantly thicker (median Breslow thickness: 2.7 mm vs. 0.7 mm, respectively, p < 0.0001), they were not associated with larger diameter compared to SSMs (p = 0.71). After adjustment for age and sex, melanoma location and subtype, having Breslow thickness ≤1.0 mm was not significantly associated with the lower quartile, median and upper quartile of the diameter (p values: 0.063, 0.083, and 0.791, respectively). CONCLUSION: In our study including melanomas of the NM or SSM subtype, Breslow thickness was not associated with the diameter, adding evidence to support the limitations of using diameter larger than 6 mm for the detection of invasive melanomas and indicating the potential of smaller melanomas to be thicker tumors.

Breslow density ability to predict melanoma survival: should it be used in clinical practice?

BACKGROUND: Breslow density (BD) is an estimation of melanoma volume, which has emerged as a novel histopathological prognostic biomarker. OBJECTIVES: Our aim was to evaluate the role of BD as predictor of patients´ survival and assess its prognostic value in relation to overall survival (OS), disease-free survival (DFS), melanoma-specific survival (MSS) and metastasis-free survival (MFS). METHODS: A retrospective observational study in a cohort of 107 patients with invasive melanoma was conducted. Kaplan-Meier and Log-rank tests were used for 10-year survival analysis. The ability of BD and Breslow thickness (BT) to predict survival was assessed using receiver operating characteristic curves. RESULTS: The average follow-up was 115 months excluding deaths. BD ≥65% showed lower survival rates compared with the BD<65% group (log-rank test p<0.001). Area under the curve (AUC) of BD ≥65% was higher than BT's for all studied survival rates except for melanoma-specific survival, in which absolute BD showed the highest value. CONCLUSIONS: BD is proposed as a simple, valuable and inexpensive histopathological feature that could provide with valuable information to current melanoma staging, since it has proved a statistically significant prognostic value in relation to survival in melanoma patients, and comparable 10-year survival prediction ability to BT.

Thin Amelanotic and Hypomelanotic Melanoma: Clinicopathological and Dermoscopic Features.

Background and Objectives: Amelanotic/hypomelanotic melanomas (AHMs) account for 2-8% of all cutaneous melanomas. Due to their clinical appearance and the lack of specific dermoscopic indicators, AHMs are challenging to diagnose, particularly in thinner cutaneous lesions. The aim of our study was to evaluate the clinicopathological and dermoscopic features of thin AHMs. Identifying the baseline clinical-pathological features and dermoscopic aspects of thin AHMs is crucial to better understand this entity. Materials and Methods: We divided the AHM cohort into two groups based on Breslow thickness: thin (≤1.00 mm) and thick (>1.00 mm). This stratification helped identify any significant clinicopathological differences between the groups. For dermoscopic analysis, we employed the "pattern analysis" approach, which involves a simultaneous and subjective assessment of different criteria. Results: Out of the 2.800 melanomas analyzed for Breslow thickness, 153 were identified as AHMs. Among these, 65 patients presented with thin AHMs and 88 with thick AHMs. Red hair color and phototype II were more prevalent in patients with thin AHMs. The trunk was the most common anatomic site for thin AHMs. Patients with thin AHMs showed a higher number of multiple melanomas. Dermoscopic analysis revealed no significant difference between thin AHMs and thick AHMs, except for a more frequent occurrence of residual reticulum in thin AHMs. Conclusions: Thin AHMs typically affect individuals with lower phototypes and red hair color. These aspects can be related to the higher presence of pheomelanin, which provides limited protection against sun damage. This also correlates with the fact that the trunk, a site commonly exposed to intermittent sun exposure, is the primary anatomical location for thin AHMs. Multiple primary melanomas are more common in patients with thin AHMs, likely due to an intrinsic predisposition as well as greater periodic dermatologic follow-ups in this class of patients. Apart from the presence of residual reticulum, no other significant dermoscopic differences were observed, complicating the differential diagnosis between thin and thick AHMs based on dermoscopy alone.

Risk of recurrence of nail unit melanoma after functional surgery versus amputation.

BACKGROUND: Minimally invasive nail unit melanoma (NUM) can be treated with functional surgery (FS) instead of amputation. OBJECTIVE: To determine risk factors associated with recurrence in NUM. METHODS: We retrospectively reviewed patients with NUM between 2008 and 2022 at a tertiary referral center. Multivariable Cox regression models adjusted for male sex and Breslow thickness (BT) were generated. Receiver operating characteristic analysis was performed to determine optimal cut-off points of the BT for stratifying recurrence risk. RESULTS: We evaluated 140 NUM cases (33 amputation and 107 FS). The mean BT values were 3.14 ± 2.62 mm (amputation) and 0.70 ± 1.36 mm (FS). Recurrence occurred in 10 (30.30%) patients with amputation and 23 (21.5%) with FS. Distant disease occurred in 10 (30.30%) patients with amputation and 8 (7.48%) with FS. Male sex, greater BT, amelanotic color, ulcers, and nodules were associated with greater risk for recurrence or distant disease. A BT of 0.8 mm was deemed the optimal cut-off for stratifying recurrence risk after surgery (odds ratio, 5.32; 95% CI, 2.04-13.85). LIMITATIONS: Small sample. CONCLUSION: FS can be considered for NUM with a BT < 0.8 mm, providing an amputation-sparing benefit. However, NUM with risk factors for recurrence requires patient counselling and close follow-ups.

Ultra-High Frequency Ultrasound in Melanoma Management: A New Combined Ultrasonographic-Histopathological Approach.

OBJECTIVES: The main aim of this study is to evaluate the correspondence between the ultrasonographic thickness and the Breslow thickness in melanoma using ultra-high frequency ultrasound and the intra- and inter-operator repeatability in the ultrasonographic measurements of melanoma depth. Moreover, we propose a new protocol based on a combined ultrasonographic-histopathological approach. METHODS: We analyzed 27 melanomas in a population consisted of 27 patients (mean age 57.6 years, 51.8% males), who came at the Department of Dermatology (University of Pisa, Pisa, Italy) from April 2016 to March 2018 and had an ultrasonographic examination of a suspected lesion before the surgical removal using ultra-high frequency ultrasound (Vevo®MD, Fujifilm, Visualsonics, Toronto, Canada; 70 MHz probe). B-mode images were analyzed by two skilled and blinded operators, and the maximum depth of the lesions was measured using a dedicated graphical user interface developed in Matlab R2016b (MathWorks Inc., Natick, MA), to obtain repetitive measurements. RESULTS: All melanomas appeared as band-like or oval/fusiform shaped hypoechoic inhomogeneous lesions. We observed an excellent agreement between the Breslow thickness of melanomas and the ultrasonographic thickness, as well as a reduced intra- and inter-operator variability in the ultrasonographic measurements of melanoma depth. CONCLUSIONS: We propose a ultrasonographic-histopathological protocol which may help clinicians to reduce the diagnostic delay, improve prognosis and survival rates, perform a surgical excision with negative margins, and reduce the variability in the assessment of Breslow thickness.

Invasive Cutaneous Melanoma: Evaluating the Prognostic Significance of Some Parameters Associated with Lymph Node Metastases.

Background and Objectives: This study aimed to assess the clinical-pathological profile of patients with invasive cutaneous melanomas and to identify the parameters with a prognostic role in the lymph nodal spread of this malignant tumor. Materials and Methods: We performed a retrospective study on patients with invasive cutaneous melanomas who underwent surgery in the "Pius Brînzeu" County Clinical Emergency Hospital from Timișoara, Romania, and were evaluated for the status of loco-regional lymph nodes. We selected and analyzed some parameters searching for their relationship with lymph node metastases. Results: We identified 79 patients with invasive cutaneous melanomas (29 men and 50 women, mean age 59.36 years). A percentage of 58.3% of melanomas had Breslow tumor thickness >2 mm; 69.6% of melanomas showed a Clark level IV-V. Tumor ulceration was present in 59.5% of melanomas. A mitotic rate of ≥5 mitoses/mm2 was observed in 48.1% of melanomas. Tumor-infiltrating lymphocytes (TILs), non-brisk, were present in 59.5% of cases and 22.8% of patients had satellite/in-transit metastasis (SINTM). Tumor regression was identified in 44.3% of cases. Lymph nodes metastases were found in 43.1% of patients. Statistical analysis showed that lymph node metastases were more frequent in melanomas with Breslow thickness >2 mm (p = 0.0002), high Clark level (p = 0.0026), mitotic rate >5 mitoses/mm2 (p = 0.0044), ulceration (p = 0.0107), lymphovascular invasion (p = 0.0182), SINTM (p = 0.0302), and non-brisk TILs (p = 0.0302). Conclusions: The Breslow thickness >2 mm, high Clark level, high mitotic rate and ulceration are the most important prognostic factors for lymph nodal spread in cutaneous melanomas. However, some melanomas without these clinical-pathological features can have an unexpected, aggressive evolution, which entails the necessity of close and prolonged clinical follow-up of patients, including those with lesions considered without risk.

The progressive relationship between increasing Breslow thickness and decreasing survival is lost in patients with ultrathick melanomas (≥15 mm in thickness).

BACKGROUND: Survival tends to decrease as the Breslow thickness of a primary melanoma increases. However, little is known about the prognostic value of Breslow thickness in patients with very thick melanomas. OBJECTIVE: We sought to assess survival in patients with melanomas ≥4.0 mm in Breslow thickness. METHODS: A pooled cohort of 5595 patients (4107 Dutch and 1488 Australian) with melanomas ≥4.0 mm in thickness diagnosed from 2000 to 2014 was analyzed. Standard and spline Cox regressions were generated for overall survival (OS) and recurrence-free survival (RFS). RESULTS: The median follow-up was 3.4 years. The continuous hazard ratios (HRs) for OS and RFS increased steadily as the Breslow thickness increased to 15 mm, stabilized up to 20 mm, and decreased thereafter. Using patients with melanomas 4 to <10 mm thick as a reference group, the categoric HR for OS increased up to the 15- to -<20-mm thickness category and then decreased (HR, 1.46 [95% CI, 1.29-1.66], P < .0001 for 10-<15 mm; HR, 1.97 [95% CI, 1.55-2.51], P < .0001 for 15-<20 mm; and HR, 1.36 [95% CI, 1.07-1.84], P = .045 for ≥20 mm). For the RFS, similar trends were observed. LIMITATIONS: Retrospective study. Small cohorts of patients with melanomas 15-<20mm and ≥20mm. CONCLUSION: The progressive relationship between increasing Breslow thickness and decreasing survival is lost in patients with melanomas ≥15 mm in thickness.

Preoperative Ultrasound-Guided Incisional Biopsy Enhances the Pathological Accuracy of Incisional Biopsy of Cutaneous Melanoma: A Prospective Clinical Trial in Chinese Patients.

OBJECTIVES: To assess the feasibility of preoperative ultrasound (US)-guided incisional biopsy through a prospective controlled clinical trial. METHODS: This was a prospective, double-arm, single-center study of Chinese patients. Thirty patients were enrolled in the study. Fourteen patients received incisional biopsies for which the choice of biopsy area relied on a clinical evaluation, and 16 patients received incisional biopsies for which the choice of biopsy area relied on a US-guided evaluation. The following procedure was used in the US-guided incisional biopsy group: 1) clinical and dermoscopic evaluation of skin lesions; 2) US examination; 3) incisional biopsy; 4) surgical excision; and 5) histopathological examination. The same procedure was used in the non-US-guided group except without US examination. RESULTS: In the non-US-guided group, the mean tumor thicknesses obtained from incisional biopsy and postoperative histopathological examination were 2.1 and 4.1 mm, respectively. Seven melanomas were underestimated by incisional biopsy, resulting in margins narrower than currently recommended. In the US-guided group, the mean tumor thicknesses obtained from US, incisional biopsy, and postoperative histopathological examination were 3.4, 2.9, and 2.7 mm, respectively. In only 3 melanomas was the tumor thickness of the incisional biopsy less than that of the postoperative histopathological examination, demonstrating that US-guided biopsy obtains the maximum thickness area. CONCLUSIONS: Preoperative US-guided incisional biopsy can enhance the pathological accuracy of incisional biopsy, which may allow us to better perform surgical excision with safe peripheral surgical margins.

Malignant Melanoma in Lagos, Nigeria: Elucidating Histopathologic Prognostic Factors.

BACKGROUND: Malignant melanoma (MM) is the most lethal of all cutaneous malignancies, accounting for about 79% of skin cancer related deaths. In blacks, it is associated with greater morbidity and mortality compared to Caucasians. Breslow thickness and ulceration status are two of the most important histopathologic prognostic factors in MM. No study on MM in Nigeria has however examined these factors. METHODS: Formalin-fixed paraffin-embedded (FFPE) tissue blocks and corresponding Haematoxylin and Eosin (H&E) stained slides of all confirmed cases of MM from January 2005 to December 2014 in the AMP Department of Lagos University Teaching Hospital (LUTH) were retrieved. RESULTS: Fifty-two MM cases were histologically diagnosed in LUTH during the study period which represented 1.0% of total solid malignancies. Forty-three of these occurred in the skin accounting for 19.7% of all skin malignancies and making MM the 3rd commonest skin malignancy after squamous cell carcinoma (SCC) and kaposi sarcoma (KS). Eighty eight percent (88%) of the tumour were in Clark's stage IV and V while 84% had Breslow thickness >4mm. Ulceration was present in 67%. The Clark's level and Breslow thickness were correlated with the ulceration status of the tumour. There is significant correlation between the Breslow thickness and ulceration with p-value < 0.05 while there is no significant association between the Clark's level and ulceration. CONCLUSION: MM constituted a significant proportion of skin malignancy in LUTH and majority of the cases present at an advanced stage. Breslow thickness and ulceration statuses of the tumour are important histopathologic parameters that should be reported in all MM biopsies.

CONTEXTE: Le mélanome malin (MM) est la plus meurtrière de toutes les affections malignes cutanées, représentant environ 79 % des décès liés au cancer de la peau. Chez les Noirs, il est associé à une plus grande morbidité et de mortalité plus élevées que chez les Caucasiens. L'épaisseur de Breslow et le statut d'ulcération sont deux des facteurs pronostiques histopathologiques les plus importants du MM. Aucune étude sur le MM au Nigeria n'a cependant examiné ces facteurs. MÉTHODES: Nous avons récupéré des blocs de tissus fixés au formol et incorporés en paraffine (FFPE) ainsi que les lames correspondantes colorées à l'hématoxyline et à l'éosine (H&E) de tous les cas confirmés de MM entre janvier 2005 et décembre 2014 dans le département AMP du Lagos University Teaching Hospital (LUTH). RÉSULTATS: Cinquante-deux cas de MM ont été diagnostiqués histologiquement au LUTH pendant la période d'étude, ce qui représente 1,0 % du total des tumeurs malignes solides. Quarantetrois de ces cas sont survenus dans la peau, ce qui représente 19,7% de toutes les tumeurs cutanées et fait du MM la troisième tumeur cutanée la plus fréquente après le carcinome épidermoïde (SCC) et le sarcome de Kaposi (KS). Quatre-vingt huit pour cent (88%) de la tumeur étaient au stade IV et V de Clark tandis que 84% avaient une épaisseur de Breslow e"4mm. Une ulcération était présente dans 67% des cas. Le niveau de Clark et l'épaisseur de Breslow étaient corrélés avec le statut d'ulcération de la tumeur. Il existe une corrélation significative entre l'épaisseur de Breslow et l'ulcération avec une valeur p < 0,05 alors qu'il n'y a pas d'association significative entre le niveau de Clark et l'ulcération. CONCLUSION: Le MM constitue une proportion significative des tumeurs cutanées malignes à l'hôpital LUTH et la majorité des cas sont à un stade avancé. L'épaisseur de Breslow et les statuts d'ulcération de la tumeur sont des paramètres histopathologiques importants qui devraient être rapportés dans toutes les biopsies de MM. Mots clés: Mélanome malin, épaisseur de Breslow, niveau de Clark, ulcération, facteurs pronostiques.

ROR2 has a protective role in melanoma by inhibiting Akt activity, cell-cycle progression, and proliferation.

BACKGROUND: Receptor tyrosine kinase-like orphan receptor 2 (ROR2) is a Wnt5a receptor aberrantly expressed in cancer that was shown to either suppress or promote carcinogenesis in different tumor types. Our goal was to study the role of ROR2 in melanoma. METHODS: Gain and loss-of-function strategies were applied to study the biological function of ROR2 in melanoma. Proliferation assays, flow cytometry, and western blotting were used to evaluate cell proliferation and changes in expression levels of cell-cycle and proliferation markers. The role of ROR2 in tumor growth was assessed in xenotransplantation experiments followed by immunohistochemistry analysis of the tumors. The role of ROR2 in melanoma patients was assessed by analysis of clinical data from the Leeds Melanoma Cohort. RESULTS: Unlike previous findings describing ROR2 as an oncogene in melanoma, we describe that ROR2 prevents tumor growth by inhibiting cell-cycle progression and the proliferation of melanoma cells. The effect of ROR2 is mediated by inhibition of Akt phosphorylation and activity which, in turn, regulates the expression, phosphorylation, and localization of major cell-cycle regulators including cyclins (A, B, D, and E), CDK1, CDK4, RB, p21, and p27. Xenotransplantation experiments demonstrated that ROR2 also reduces proliferation in vivo, resulting in inhibition of tumor growth. In agreement with these findings, a higher ROR2 level favors thin and non-ulcerated primary melanomas with reduced mitotic rate and better prognosis. CONCLUSION: We conclude that the expression of ROR2 slows down the growth of primary tumors and contributes to prolonging melanoma survival. Our results demonstrate that ROR2 has a far more complex role than originally described.

Characteristics of 637 melanomas documented by 27 general practitioners on the Skin Cancer Audit Research Database.

BACKGROUND AND OBJECTIVE: Most melanomas (including melanomas in situ), in Australasia, are treated by general practitioners (GPs). Previously undescribed, the characteristics of a series of melanomas treated by multiple GPs are examined. PATIENTS AND METHODS: Six hundred and thirty-seven melanomas treated by 27 Australasian GPs during 2013 and documented on the Skin Cancer Audit Research Database (SCARD) were analysed by anatomical site, subtype, Breslow thickness, diameter, associated naevi and linked adverse outcomes. RESULTS: Most melanomas (59.7%) were on males, mean age at diagnosis being 62.7 years (range 18-96). Most (65.0%) were in situ, with a high incidence of lentiginous melanoma (LM) (38.8%) and 32% were naevus associated. Most LM (86.4%) were in situ, compared to 55% of superficial spreading melanoma (SSM) (P < 0.0001). There was male predominance on the head, neck and trunk and female predominance on extremities. There was no significant association between Breslow thickness and diameter, with small melanomas as likely to be thick as large melanomas, and melanomas ≤3 mm diameter, on average, more likely to be invasive than larger melanomas. There was a positive correlation between age and both melanoma diameter and Breslow thickness. Seven cases progressed to melanoma-specific death: Five nodular melanoma (NM) and two SSM, one of which was thin (Breslow thickness 0.5 mm). CONCLUSIONS: A large series of melanomas treated by Australasian GPs were predominantly in situ, with a high proportion of LM subtype. With implications for GP training, NM linked to death was over-represented and there was a novel finding that older patients had larger diameter melanomas.

A brief synopsis on scalp melanoma.

Melanoma constitutes one of the most sinister and troublesome malignancies encountered by humanity. Generally, the diagnosis of advanced melanoma connotes a grave prognosis, prompting a sense of looming threat of death, however, the early-stage detected disease responds well to robust treatment resulting in reasonable survivorship. Scalp melanomas are even more troublesome, because they typically exhibit more aggressive biologic behavior and are often diagnosed at a late stage. This review tries to comprehensively highlight the various diagnostic, therapeutic, and outcome aspects of scalp melanomas. The literature research includes peer-reviewed articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) till May 2020 and reference lists of respective articles. Only articles published in English language were included.

The anatomic distribution of cutaneous melanoma: A detailed study of 5141 lesions.

BACKGROUND/OBJECTIVES: There is evidence that cutaneous melanomas at different anatomic sites present with distinctive clinicopathologic features. We examined the anatomic distribution of cutaneous melanoma and its variation by patient characteristics, subtype and Breslow thickness, using high-resolution anatomic site data. METHODS: A cross-sectional study was performed of all primary cutaneous melanoma cases managed at a tertiary referral centre, analysing prospectively collected clinical data across 50 anatomic subsites. RESULTS: The study included 5141 in situ or invasive melanomas; most were invasive (76.2%), and the median Breslow thickness of invasive lesions was 1.0 mm. Superficial spreading (57.2%), lentigo maligna (20.8%) and nodular (12.2%) were the most common histopathological subtypes. Sun-exposed sites such as the female nose and cheek, the male ear, as well as the upper back in both sexes had the highest incidence of melanoma per unit area. When compared to the posterior forearm, the scalp, ear, preauricular, perioral, subungual and plantar sites had thicker invasive melanomas (each P < 0.05). The peri-auricular, ear and cheek had the highest incidence of nodular melanoma per unit area. There were subtype-, age- and sex-specific differences in melanoma anatomic distribution. CONCLUSION: Melanoma most commonly arises in sun-exposed facial areas, as well as the upper back. Increased thickness is found for melanoma in acral and many head and neck sites. Nodular melanoma is more likely to occur in head and neck sites including the peri-auricular area, ear and cheek. Clinicians should carefully assess these sites during skin examinations.

Cutaneous nevi and risk of melanoma death in women and men: A prospective study.

BACKGROUND: It was unclear whether an increased number of common nevi (moles) predicts melanoma death. OBJECTIVE: We prospectively examined the association between number of common nevi and risk of melanoma death. METHODS: Our study used data from the Nurses' Health Study (n = 77,288 women) and Health Professionals Follow-up Study (n = 32,455 men). In 1986, participants were asked about the number of moles they had with a ≥3-mm diameter on the upper extremity, and we stratified their answers into 3 categories (none, 1-2, or ≥3) on the basis of data distribution. RESULTS: During follow-up (1986-2012), 2452 melanoma cases were pathologically confirmed; among these, we identified 196 deaths due to melanoma. Increased number of nevi was associated with melanoma death; the hazard ratio (HR) for ≥3 nevi compared with no nevi was 2.49 (95% confidence interval [CI] 1.50-4.12) for women and 3.97 (95% CI 2.54-6.22) for men. Among melanoma cases, increased number of nevi was associated with melanoma death in men (≥3 nevi, HR 1.89, 95% CI 1.17-3.05) but not in women. Similarly, the number of nevi was positively associated with Breslow thickness in men only (Ptrend = .01). LIMITATIONS: This is an epidemiologic study without examination into mechanisms. CONCLUSION: Increased number of cutaneous nevi was significantly associated with melanoma death. High nevus count might serve as an independent prognostic factor to predict the risk of melanoma death particularly among male melanoma patients.

Time to reconsider the role of sentinel lymph node biopsy in melanoma.

The Multicenter Selective Lymphadenectomy Trials indicate that there are no overall or melanoma-specific survival advantages to performing sentinel lymph node biopsy (SLNB) followed by immediate completion lymph node dissection compared with wide excision and observation for patients with positive sentinel nodes. These results make SLNB solely a staging procedure. The role of SLNB in the management of patients with melanoma deserves reappraisal. The potential marginal benefit of SLNB beyond the clinical and pathologic features of the melanoma has not been well studied. The use of sentinel lymph node status alone to accept and stratify patients into trials or to receive adjuvant treatment is not rational.

Association between Breslow thickness and dermoscopic findings in acral melanoma.

BACKGROUND: Dermoscopy is a useful tool for the diagnosis of acral melanomas (AMs). However, little is known about the influence of tumor thickness on the dermoscopic findings of AM. OBJECTIVE: To investigate the affect Breslow thickness (BT) has on the dermoscopic patterns of AM. METHODS: Data on cases of AM on the glabrous skin were collected from 4 university hospitals. We investigated the frequency of each dermoscopic feature of AM according to the BT. Statistical analysis was performed to investigate the association between the specific dermoscopic patterns and BT. RESULTS: Multivariable analysis revealed that the colors red (odds ratio [OR] 16.482, 95% confidence interval [CI] 3.605-99.016); blue (OR 7.092; 95% CI 1.707-37.435); and white (OR 5.048, 95% CI 1.152-22.897) were more common in AM with BT >2 mm than those with BT ≤2 mm. Regarding patterns, atypical vascular (OR 34.589, 95% CI 6.458-305.852); blue-white veils (OR 9.605, 95% CI 1.971-72.062); and ulcers (OR 5.084, 95% CI 1.145-24.152) were more frequently detected in cases with BT >2 mm than those with BT ≤2 mm. LIMITATIONS: A retrospective study design and small sample size. CONCLUSION: This study showed an association between dermoscopic patterns and tumor thickness among patients with AM. Dermoscopy can be a useful adjuvant tool for predicting BT in AM.

Prognostic value of sentinel lymph node biopsy according to Breslow thickness for cutaneous melanoma.

BACKGROUND: Sentinel lymph node (SLN) biopsy is widely performed for melanoma with certain histologic parameters and offers important prognostic and staging information. Breslow thickness (BT) by itself also provides meaningful prognostic information. OBJECTIVE: To evaluate whether SLN status provides prognostic information independent from that which is already provided by BT. METHODS: We conducted a retrospective cohort study of 896 patients who underwent SLN biopsy for primary cutaneous melanoma. Stratified analysis of the impact of SLN status within BT groups (0.01-1 mm, 1.01-2.00 mm, 2.01-4.00 mm, and >4.00 mm) was performed. In addition, a Cox proportional hazard model was fit to evaluate the interaction between BT unadjusted and then adjusted for SLN status to determine whether predictive ability is improved. RESULTS: Having a negative SLN did not confer a statistically significant survival advantage for any BT subgroup (P = .54, .075, .17, and .95 for subgroups 0.01-1 mm, 1.01-2.00 mm, 2.01-4.00 mm, and >4.00 mm, respectively). In multivariate analysis, SLN status did not demonstrate independent prognostic ability over that of BT alone (P = .067). LIMITATIONS: Retrospective study, single institution. CONCLUSION: Our data suggest that SLN status does not offer better prognostic information for patients than BT alone.

Melanoma staging: Varying precision and terminal digit clustering in Breslow thickness data is evident in a population-based study.

BACKGROUND: Errors in Breslow thickness reporting can give misclassification of T category, an important classifier in melanoma staging. OBJECTIVE: We sought to investigate precision (number of digits) and terminal digit clustering in Breslow thickness and potential consequences for T category. METHODS: All first primary and morphologically verified invasive melanomas in Norway between 2008 and 2015 were included. A smoothing model was fitted to estimate the underlying Breslow thickness distribution without digit clustering. RESULTS: Thickness was reported for 13,057 (97.5%) patients; the median was 1.0 mm (range, 0.09-85). It was reported as whole numbers (15.6%), to 1 decimal (78.2%) and 2 decimal places (6.2%)-thin tumors with more precision than thick tumors. Terminal digit clustering was found with marked peaks in the observed frequency distribution for terminal digits 0 and 5, and with drops around these peaks. Terminal digit clustering increased proportions of patients classified with T1 and T4 tumors and decreased proportions classified with T2 and T3. LIMITATIONS: Breslow thickness was not reported in 2.5% of cases. CONCLUSIONS: The Norwegian recommendation of measurement to the nearest 0.1 mm was not followed. Terminal digit clustering was marked, with consequences for T category. Pathologists, clinicians, and epidemiologists should know that clustering of thickness data around T category cut points can impact melanoma staging with consequent effect on patient management and prognosis.