Trends and patterns of care of sentinel node biopsy in cutaneous melanoma: a population-based study in Queensland

Sentinel node biopsy (SNB) has evolved from offering staging and prognostication to a procedure that guides therapeutic management. The aim was to evaluate the rate of SNB for patients with high-risk melanoma and assess factors that may have impacted on the procedure being performed.

Data of patients with primary invasive cutaneous melanoma from 01 January 2009 to 31 December 2019 were obtained from the Queensland Oncology Repository. High-risk melanoma was defined as ≥0.8 mm thick or < 0.8 mm with ulceration present (AJCC eighth edition pT1_b -pT₄ ).

14 006 (33.8%) of 41 412 patients diagnosed with cutaneous invasive melanoma were in the high-risk group. 2923(20.9%) patients had SNB, with the rate increasing from 14.2% (2009) to 36.8% (2019) (P = 0.002), and an increasing proportion being performed in public hospitals over the 11 year period (P = 0.02). Older age (OR0.96 (0.959-0.964) (P < 0.001)), female (OR0.91 (0.830-0.998) (P = 0.03)), head and neck primary (OR0.38 (0.33-0.45) (P < 0.001)), and pT_1b (OR0.22 (0.19-0.25) (P < 0.001)) were factors associated with SNB not being performed. Travel out of the Hospital and Health Services of residence for SNB occurred in 26.2%. Although the travel rate decreased from 24.7% (2009) to 23.0% (2019) (P = 0.04), the absolute number increased due to the increase in SNB rate. Those most likely to travel were younger, from remote areas, or from affluent backgrounds.

In this first Australian population-based study, there was an increased adherence to SNB guideline, although overall SLNB rates remain low, with nearly 2/3 of eligible cases not having the procedure in 2019. Although travel rates decreased marginally, the overall number increased. This study highlights the crucial need to further improve access to SNB for melanoma surgery for the Queensland population.