Accuracy of partial biopsies in the management of cutaneous melanoma

Abstract

Background: The recommended method for histopathological diagnosis of cutaneous melanoma is excisional biopsy, although partial biopsies (shave and punch) are often used. Following a partial biopsy, treatment guidelines recommend a narrow excisional biopsy to plan definitive management. There is limited evidence on the benefits of direct wide local excision (WLE) following diagnostic partial biopsies.Methods: Retrospective cohort study of cutaneous melanoma cases, from two tertiary referral centres from January 2013 to December 2015. Demographic and histopathological data, including tumour thickness (T-stage) from initial biopsy and subsequent excisions, were collected. Logistic regression was used to examine histopathological T-staging between biopsy and subsequent excisions (upstaging).Results: 2304 melanomas (2157 patients) were identified; 455 shave, 308 punch, 14 incisional and 1527 excisional biopsies. Out of 1527, 5 (<1%) excisional biopsies were upstaged from original biopsy T-stage to final WLE; compared to 28/455 (6%) for shave, 45/308 (15%) for punch and 2/14 (14%) for incisional biopsies. Histopathology upstaging were increased with punch (OR, 52.1; 95% CI, 20.5-132.4. P < 0.001) and shave biopsy (OR, 20.0; 95% CI, 7.7-52.0. P < 0.001) compared to excisional biopsy. Upstaging rates of 9.4% for desmoplastic (OR, 6.9; 95% CI, 2.4-19.7. P < 0.001) and 21.9% for acral lentiginous (OR, 18.4; 95% CI, 6.9-49.2. P < 0.001) melanomas were elevated compared to 1.4% for superficial spreading melanoma. Conclusions:In most cases, partial biopsy (particularly shave biopsy) can provide sufficient information to plan for definitive surgical melanoma management. Punch and incisional biopsies have elevated upstaging rates, a consideration in planning therapy. Partial biopsies of desmoplastic or acral lentiginous melanomas have high rates of upstaging and should have a complete excision prior to definitive treatment.

Impact of Shave Biopsy on Diagnosis and Management of Cutaneous Melanoma: A Systematic Review and Meta-Analysis

“…It is also the strongest prognostic indicator for patients with localized cutaneous melanoma. 6,26 Many international and national guidelines recommend excision biopsy as the preferred mode for biopsy of suspicious pigmented skin lesions because it allows for examination of the entire lesion and therefore provides the most accurate measurement of true Breslow thickness. 3,[28][29][30] Additional treatments following a melanoma diagnosis include WLE and SLNB.…”

“…Regarding the impact of lesion thickness on deep margin status, Doolan et al, in a study of 455 patients, further reported that the rate of deep margin positivity increased from 48% for those with melanomas \1 mm in Breslow thickness, to 90% in those with Breslow thickness [2 mm. 26 High heterogeneity was observed across studies (I 2 = 98.9%).…”

“…9,12,19,21,22,27 The level of experience between practitioners was not reported; however, Doolan et al reported no statistically significant difference in the rate of T-stage change between different health providers following WLE. 26 Similarly, Kaiser et al reported no statistically significant difference in the rate of change in treatment recommendation following WLE between different health professionals. 21 Because practitioner experience is likely to significantly impact accurate sampling by shave biopsy, further study into this, as well as effective training strategies, is warranted.…”

“…The staging system utilized for determining T stage varied among the studies. The AJCC 6th edition was used by Hieken et al, 17 the 7th edition was used by Mills et al 18 and Saco and Thigpen, 20 and the 8th edition was used by Doolan et al 26 and De Menezes et al 27 In four studies, it was not specified which version of the AJCC was used. 9,12,22,25 T-stage upstaging following WLE was captured by eight studies (n = 1883).…”

“…Egnatios, 2011 [12] Zager, 2011 [9] Hieken, 2013 [17] Mills, 2013 [18] Saco, 2014 [20] Namin, 2018 [25] De Menezes, 2019 [27] Doolan, 2019 [26] Overall (I^2 = 89.66%, p = 0.00) area, and in under-resourced patient and clinical environments and/or time-sensitive environments. The drawbacks are particularly notable for first-line practitioners such as community doctors and general practitioners, as well as those working in high-volume or resource-restrained clinics where serial examination or immediate biopsy is not feasible.…”