Insights into Scalp Melanoma Survival: A Retrospective Inquiry

Original Article: Impact of scalp location on survival in head and neck melanoma: A retrospective cohort study

What are the key takeaways of this article?

Previous research indicates that survival rates for scalp melanoma are generally poorer than for other forms of cutaneous head and neck melanoma (CHNM). One study in particular highlighted that scalp melanoma frequently exhibits more high-risk clinical and histologic features in comparison to other CHNM. Despite these findings, it remains uncertain whether the location of the melanoma on the scalp independently impacts survival or if the lower survival rate is attributable to other adverse prognostic features. As such, this study aimed to assess and compare the survival rates of patients with scalp melanoma to those with other CHNM, while also investigating whether scalp location is an independent factor influencing melanoma survival.

To achieve this goal, the authors conducted a retrospective analysis of invasive primary cutaneous head and neck melanoma cases treated at the Victorian Melanoma Service (VMS) from October 1994 to February 2014. The VMS, located at the Alfred Hospital in Melbourne, serves as a major referral center for a substantial number of new melanoma cases in Victoria, Australia. Demographic data, including age, sex, date of diagnosis, and location of the tumor, was collected and tumor sites were classified by location, including scalp, face, neck, and ear. Furthermore, each melanoma's histology underwent a secondary evaluation by dermatopathologists. The study analyzed melanoma-specific survival (MSS) by comparing scalp melanoma to other CHNM, and across different head and neck site groups, using Kaplan-Meier survival estimates. Breslow thickness was considered a continuous variable in the analysis. Exclusion criteria included cases of mucosal and ocular melanoma as well as cases not reviewed by dermatopathologists or without available Breslow thickness measurements.

Out of 900 patients diagnosed with invasive CHNM, 237 individuals (26.3%) had melanoma on the scalp, 386 (42.9%) on the face, 174 (19.3%) on the neck, and 103 (11.4%) on the ear. In the analysis, patients with scalp melanoma demonstrated poorer MSS compared to other CHNM. However, when considering multivariable analysis for all tumors combined, scalp location did not show a significant association with MSS. However, in the thickness range of 0.76 to 1.50 mm, head and neck melanoma did have an independent association with MSS.

Overall, individuals diagnosed with scalp melanoma exhibited a 5-year MSS rate of 70%, contrasting with the 88% rate observed in other CHNM. Furthermore, they faced more than double the risk of melanoma-related mortality compared to those with other CHNM. Based on these results, the authors concluded that the poorer rate of survival in scalp melanoma can mainly be attributed to Breslow thickness and is found in a higher proportion in males.

In summary, the authors concluded that scalp melanoma demonstrates inferior survival compared to other types of cutaneous head and neck melanoma (CHNM), primarily due to higher Breslow thickness and a predominance of male patients. Given its distinct clinical presentations, high-risk histologic features, and notably poorer survival, particularly for tumors in the 0.76 to 1.50 mm thickness range, scalp melanoma warrants special attention when found in clinic.

Publication Date: February 26th, 2024

Reference: Xie C, Pan Y, McLean C, Mar V, Wolfe R, Kelly J. Impact of scalp location on survival in head and neck melanoma: a retrospective cohort study. Journal of the American Academy of Dermatology. 2017 Mar 1;76(3):494-8.

Summary By: McKenzie Van Eaton