Surgical excision margins in primary cutaneous melanoma: A meta-analysis and Bayesian probability evaluation.

BACKGROUND: Surgery is the only curative treatment for primary cutaneous melanoma, therefore it is important to determine excision margins that minimise risk of local recurrence, distant recurrence and death. METHODS: MEDLINE, EMBASE and Cochrane CENTRAL were searched from 2009 to 2015. Inclusion criteria were: population/setting - patients with primary melanoma; comparison - narrow versus wide margins; outcomes - overall survival, melanoma-specific survival, recurrence-free survival, and loco-regional recurrence; design - randomized controlled trials (RCTs). Results were pooled using meta-analysis and data explored using likelihood Bayesian probability plots. RESULTS: Six RCTs with 4233 patients were included. Narrow margins were defined as 1 or 2 cm of clinically normal skin around the melanoma; wide margins as 3, 4 or 5 cm. Hazard ratios (HR) were as follows (HR>1 indicates wide margin better): overall survival 1.09 (95% CI 0.98-1.22; p=0.1); melanoma-specific survival 1.17 (CI 1.03-1.34; p=0.02); recurrence-free survival 1.08 (CI 0.97-1.20; p=0.2); loco-regional recurrence 1.10 (CI 0.96-1.26; p=0.2), with no evidence of heterogeneity between trials for any end point or within subgroup analyses. There was an 94% probability that overall survival was worse with a narrow margin and a 43% probability that it was more than 10% worse in proportional terms (i.e. HR>1.1). Probabilities that narrow margins were worse were 99%, 92% and 92% for melanoma-specific survival, recurrence-free survival and loco-regional recurrence respectively. CONCLUSIONS: Contrary to recommendations in several national guidelines that narrow margins are safe, this systematic review and meta-analysis provides evidence that a narrow margin may lead to a worse outcome than a wide margin.

Melanoma histopathology reporting: are we complying with the National Minimum Dataset?

BACKGROUND: The Royal College of Pathologists introduced the National Minimum Dataset (NMDS) for the histopathological reporting of cutaneous melanoma in February 2002. AIM: To determine if histological reporting of invasive primary cutaneous melanoma in the West Midlands region of the UK was compliant with the NMDS. METHODS: Reports were identified from March 2002 to March 2003 via the regional Cancer Intelligence Unit, and compared with the NMDS. If all items of the NMDS were adhered to, the report was considered compliant. If not compliant, the report was checked to see if it included selected clinical and staging parameters. RESULTS: 543 cases of invasive cutaneous melanoma were identified, but only 407 reports were analysed. 69/407 (17%) (95% CI 14% to 20%) reports were fully compliant with the NMDS. Of the non-complaint reports, 45/361 (12%) (95% CI 9% to 16%) reported all staging and clinically relevant parameters; 62/361 (17%) (95% CI 59% to 65%) reported all staging parameters. Breslow thickness was reported in all but one of the reports (99.7%), Clark's level was reported in 344/407 (85%), ulceration in 280/407 (69%), and microsatellites in 146/407 (36%). CONCLUSION: There was slow uptake of the NMDS in this region in the year following its introduction. Although major parameters required for staging were more consistently reported, ulceration and microsatellites were less frequently reported.