Clinical and pathologic factors associated with subclinical spread of invasive melanoma.

BACKGROUND: Indications to treat invasive melanoma with Mohs micrographic surgery (MMS) or analogous techniques with exhaustive microscopic margin assessment have not been defined. OBJECTIVE: Identify clinical and histologic factors associated with subclinical spread of invasive melanoma. METHODS: This retrospective, cross-sectional study evaluated 216 invasive melanomas treated with MMS and melanoma antigen recognized by T cells 1 immunostaining. Logistic regression models were used to correlate clinicopathologic risk factors with subclinical spread and construct a count prediction model. RESULTS: Risk factors associated with subclinical spread by multivariate analysis included tumor localization on the head and neck (OR 3.28, 95% confidence interval [CI] 1.16-9.32), history of previous treatment (OR 4.18, 95% CI 1.42-12.32), age ≥65 (OR 4.45, 95% CI 1.29-15.39), and ≥1 mitoses/mm2 (OR 2.63, 95% CI 1.01-6.83). Tumor thickness and histologic subtype were not associated with subclinical spread. The probability of subclinical spread increased per number of risk factors, ranging from 9.22% (95% CI 2.57%-15.86%) with 1 factor to 80.32% (95% CI 68.13%-92.51%) with 5 factors. LIMITATIONS: This study was conducted at a single academic institution with a small study population using a retrospective study design that was subject to potential referral bias. CONCLUSION: Clinical and histologic factors identify invasive melanomas that are at increased risk for subclinical spread and might benefit from MMS or analogous techniques prior to reconstruction.

Clinical factors associated with subclinical spread of in situ melanoma.

BACKGROUND: Subclinical spread of in situ melanoma occurs at a wide frequency, ranging from 12% to 71%. OBJECTIVE: To identify clinical factors associated with subclinical spread of in situ melanoma. METHODS: We used a retrospective, cross-sectional study of 674 consecutive in situ melanomas to examine 627 patients treated with Mohs surgery and melanoma antigen recognized by T cells 1 immunostaining. The presence of subclinical spread was correlated with clinical characteristics. Univariate and multivariate logistic regression analyses were performed to generate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Both univariate and multivariate analyses demonstrated significantly increased odds for subclinical spread of in situ melanomas when they were located on the head or neck, at acral sites, or on the pretibial leg (OR 1.97, 95% CI 1.41-3.40); in persons with a history of prior treatment (OR 2.77, 95% CI 1.74-4.420); melanomas of preoperative size >1 cm (OR 1.74, 95% CI 1.23-2.46, P = .002); or in persons ≥60 years old (OR 1.47, 95% CI 1.01-2.13, P = .042). A count prediction model demonstrated that the risk for subclinical spread increased with the number of clinical risk factors. LIMITATION: We used a single-site, retrospective study design. CONCLUSION: Clarifying the risk factors for subclinical spread might help to refine triage of in situ melanomas to the appropriate surgical techniques for margin assessment prior to reconstruction.

Melanoma Thickness and Survival Trends in the United States, 1989 to 2009.

BACKGROUND: With melanoma incidence rising and mortality stable, some question whether the melanoma epidemic is real. Melanoma thickness and survival trends may provide insights, but previous studies have been limited because of missing data on thickness. METHODS: With a validated imputation method for missing thickness data, we characterized melanoma thickness and survival trends among men and women in the Surveillance, Epidemiology, and End Results (SEER)-9 registries between 1989 and 2009. A total of 98,498 cases of invasive melanoma were identified. All statistical tests were two-sided. RESULTS: Incidence per 100 000 person-years increased (13.94, 95% confidence interval [CI] = 13.65 to 14.23, to 21.87, 95% CI = 21.56 to 22.19, P < .001) between 1989 to 1991 and 2007 to 2009, fatal incidence remained stable (2.32, 95% CI = 2.2 to 2.4, to 2.08, 95% CI = 2.0 to 2.2, P = .20) between 1989 to 1991 and 1998 to 2000, and five-year survival increased (88.29%, 95% CI = 87.60% to 88.95%, to 91.68%, 95% CI = 91.22% to 92.12%, P < .001) between 1989 to 1991 and 2001 to 2003. Increase in incidence occurred across all thickness groups. Median thickness decreased (0.73 to 0.58mm). Geometric mean thickness decreased (0.77 to 0.65mm) 4.6% (95% CI = 4.2% to 5.0%) every three years in multivariable analysis. Thickness decreased among T1/T2 tumors (0.01-1.00 and 1.01-2.00mm) and among all age and sex groups, whites, non-Hispanics, and all body sites. However, thickness increased among T3/T4 tumors (2.01-4.00 and > 4.00mm) and nodular melanomas; acral lentiginous melanomas approached statistical significance. Thickness remained unchanged among some racial minorities. Melanoma-specific survival improved (hazard ratio [HR] = 0.89, 95% CI = 0.88 to 0.91) every three years in multivariable analysis. Improvements in survival occurred across all subgroups except nonblack minorities, and nodular and acral lentiginous subtypes. CONCLUSIONS: Increasing incidence across all thickness groups coupled with T3/T4 lesions becoming thicker suggests that the melanoma epidemic is real and not simply an artifact of increased detection pressure of earlier-stage T1/T2 lesions. Survival is generally improving independent of thickness, but improvements in survival have not been experienced by certain minorities, and nodular and acral lentiginous subtypes.

Effects on skills and practice from a web-based skin cancer course for primary care providers.

BACKGROUND: Melanoma incidence and mortality is a growing concern. Better recognition and management of skin cancer by primary care providers (PCPs) could help, but studies suggest they would benefit from additional education. Effective educational programs are needed. METHODS: We developed and conducted a voluntary before-and-after evaluation of a 1- to 2-hour interactive, web-based course in skin cancer detection for practicing, board-certified PCPs (http://www.skinsight.com/info/for_professionals/dermatology-education-resources). Voluntary participants' ability to diagnose and manage skin cancer was assessed using pretests, immediate tests, and 6-month posttests. The effect on actual practice patterns was assessed using participants' patient panels: referrals or visits to dermatology and skin biopsies during the 6 months after the course were compared with those during the same period before the course. RESULTS: The mean age of the 54 participants was 50.5 years (standard deviation, 11.1); 54% were women and 52% were Asian. The mean score for appropriate diagnosis and management increased from 36.1% to 46.7% (odds ratio, 1.6; 95% confidence interval, 1.4-1.9), with greatest improvement in benign lesions, from 32.1% to 46.3% (odds ratio, 1.9; 95% confidence interval, 1.6-2.4). Dermatology referrals for suspicious lesions or new visits by participants' patients decreased at both sites after the course (from 630 to 607 and from 726 to 266, respectively). CONCLUSIONS: This course improved skills in practicing PCPs. Improvement was greatest in the diagnosis and appropriate management of benign lesions and dermatology utilization decreased.

The characterization and potential impact of melanoma cases with unknown thickness in the United States' Surveillance, Epidemiology, and End Results Program, 1989-2008.

BACKGROUND: In the United States, the Surveillance, Epidemiology, and End Results (SEER) Program is the authoritative source for population-based data on melanoma incidence and mortality. However, missing data on tumor thickness may lead to biased analyses in this frequently used database. We sought to characterize invasive melanomas with unknown thickness with emphasis on their association with melanoma survival, and to employ techniques to overcome the limitations of missing data on tumor thickness. METHODS: We conducted a retrospective cohort analysis of non-occult invasive melanomas in the SEER database from 1989 to 2008. RESULTS: Of 182184 cases, 24329 (13%) had unknown thickness. From 1989-1993 to 2004-2008, the proportion of unknown thickness cases decreased from 22% to 9% (P(trend) < 0.001). Unknown thickness cases had a significantly increased risk of death due to melanoma (hazard ratio [HR] 3.09, 95% confidence interval [CI]: 2.99, 3.19) than known thickness cases with an increasing trend over time (P(trend) < 0.001). In multivariate analysis, unknown thickness was found to be independently associated with poorer prognostic factors and lack of cancer-directed surgical treatment. Melanoma survival of cases with unknown thickness appeared most similar to 2.01-4.00 mm thickness cases. Multiple imputation demonstrated that imputed tumor thickness was significantly associated with melanoma survival (HR 1.31, 95% CI: 1.30, 1.32) and Clark level (odds ratio [OR] 1.85, 95% CI: 1.82, 1.89) though the strength of associations were not as strong as the associations of original SEER-coded known tumor thickness with melanoma survival (HR 1.46, 95% CI: 1.45, 1.47) and Clark level (OR 2.92, 95% CI 2.89, 2.95), respectively. CONCLUSIONS: Exclusion of missing data on melanoma thickness from SEER introduces a selection bias that leads to an underestimation in the prevalence of fatal and likely thicker melanomas. Multiple imputation appears to be an effective tool to predict missing tumor thickness data.

Developing an interactive web-based learning program on skin cancer: the learning experiences of clinical educators.

Web-based learning in medical education is rapidly growing. However, there are few firsthand accounts on the rationale for and development of web-based learning programs. We present the experience of clinical educators who developed an interactive online skin cancer detection and management course in a time-efficient and cost-efficient manner without any prior skills in computer programming or technical construction of web-based learning programs. We review the current state of web-based learning including its general advantages and disadvantages as well as its specific utility in dermatology. We then detail our experience in developing an interactive online skin cancer curriculum for primary care clinicians. Finally, we describe the main challenges faced and lessons learned during the process. This report may serve medical educators who possess minimal computer programming and web design skills but want to employ the many strengths of web-based learning without the huge costs associated with hiring a professional development team.

The contribution of nodular subtype to melanoma mortality in the United States, 1978 to 2007.

OBJECTIVE: To gain insight into reducing melanoma mortality by examining epidemiologic trends by subtype with emphasis on the contribution of each subtype to melanoma-related death. DESIGN: Retrospective population-based cohort study. SETTING: Original 9 registries of the Surveillance, Epidemiology, and End Results Program from 1978 to 2007. PARTICIPANTS: A total of 111,478 patients with histologically confirmed invasive melanoma. MAIN OUTCOME MEASURE: Proportion of ultimately fatal melanomas by subtype. RESULTS: Among melanomas of known subtype, superficial spreading melanoma comprised 66% of incident melanomas and 46% of ultimately fatal melanomas; nodular melanoma comprised 14% of incident melanomas and 37% of ultimately fatal melanomas. For superficial spreading melanoma, overall incidence per 100,000 per year increased (from 4.28 to 6.63), ultimately fatal incidence remained stable (at 0.56 to 0.51), and 10-year relative survival increased (from 90.6% to 96.5%) when comparing successive 5-year intervals. In contrast, for nodular melanoma, the overall incidence (1.30-1.32), ultimately fatal incidence (0.46-0.44), and 10-year relative survival rate (61.8%-61.5%) remained stable. Epidemiologic trends of melanoma, not otherwise specified, were similar to superficial spreading melanoma. There was a strong negative correlation between the proportion of melanoma, not otherwise specified, among all melanomas, and the proportion of superficial spreading melanoma, among melanomas of known subtype (r = -0.80; P = .01), across the registries. CONCLUSIONS: Superficial spreading and nodular melanoma constitute similar proportions of ultimately fatal melanomas. Although incidence of and survival from superficial spreading melanoma have increased from 1978 to 2007, neither the incidence of nor survival from nodular melanoma has changed. Public health efforts should include a focus on nodular melanoma for maximum reduction of melanoma mortality.