More sentinel lymph node biopsies for thin melanomas after transition to AJCC 8th edition do not increase positivity rate: A Danish population-based study of 7148 patients

BACKGROUND

We evaluated the outcome of sentinel lymph node biopsies (SLNB) in patients with thin melanoma before and after the implementation of AJCC 8th edition (AJCC8) and identified predictors of positive sentinel lymph nodes (+SLN).

METHODS

Patients diagnosed with T1 melanomas (Breslow thickness ≤1 mm) during 2016-2017 as per AJCC 7th edition (AJCC7) (n = 3414) and 2018-2019 as per AJCC8 (n = 3734) were identified in the Danish Melanoma Database.

RESULTS

More SLNBs were performed in the AJCC8 cohort compared to the AJCC7 (22.2% vs. 16.2%, p < 0.001), with no significant difference in +SLN rates (4.7% vs. 6.7%, p = 0.118). In the AJCC7 + SLN subgroup, no melanomas were ulcerated, 94.6% had mitotic rate (MR) ≥ 1, 67.6% were ≥0.8 mm and 32.4% would be T1a according to AJCC8. In the AJCC8 + SLN subgroup, 10.3% were ulcerated, 74.4% had MR≥ 1, 97.4% were ≥0.8 mm and 23.1% would be T1a according to AJCC7. On multivariable analysis younger age and MR ≥ 1 were significant predictors of +SLN.

CONCLUSION

More SLNBs were performed in T1 melanomas after transition to AJCC8 without an increase in +SLN rate. None of the AJCC8 T1b criteria were significant predictors of +SLN. We suggest that mitosis and younger age should be considered as indications for SLNB in thin melanoma.

Patient-and observer-reported long-term scar quality of wide local excision scars in melanoma patients

Wide local excision of the primary tumour is the mainstay of treatment for melanoma patients. The aims of this study were to assess the patient- and observer-reported long-term scar quality after surgery using the patient and observer scar assessment scale (POSAS) in melanoma patients, to assess the reliability and validity of POSAS, and to identify factors influencing the scar assessment. This cross-sectional clinical study included 320 melanoma patients with primary tumours on the trunk and limbs. Data regarding patients, treatment, scar characteristics and functional outcomes was analysed. Internal consistency, inter-rater reliability, and convergent validity were examined. Factors influencing the patient- and observer-reported scar quality were tested using regression analyses. Results of the POSAS showed an overall good scar quality. The internal consistency of POSAS was good, and the convergent validity was strong. The inter-rater reliability was only moderate. The patients were influenced by the POSAS sub-items: colour, irregularity, thickness and pain. The observer was influenced by the POSAS sub-items: vascularity, surface area, thickness, relief and pliability. Both patient- and observer-reported scar qualities were influenced by age, location, type of superficial suture, keloids and widened scars. Moreover, the patients were influenced by the scar tightness while the observer was influenced by postoperative complications, hypertrophic scars, suture marks and dog ears. In conclusion POSAS is a reliable and valid scar assessment tool. The factors influencing patient- and observer-reported scar quality differed, and better understanding of this may improve treatment and hence patient-reported scar quality.