Adjuvant systemic therapies for melanoma in Alberta: An early descriptive analysis of population characteristics and treatment outcomes.

Abstract

e22013 Background: Adjuvant immunotherapies and adjuvant targeted therapy for melanoma became available in clinical practice in 2018 in Alberta, Canada. We describe the delivery of adjuvant systemic therapy, local-regional treatment, recurrence patterns, and treatment toxicity, in tertiary academic centers. Methods: We conducted a retrospective chart review of patients who received adjuvant systemic therapy for melanoma in Alberta. Adjuvant systemic treatment options included Nivolumab, Pembrolizumab, and Dabrafenib/Trametinib. Results: From September 2017 to January 2020, 71 patients were identified. Forty-one (61%) were male with a median age of 60 years (15-88). Seven (9.8%), 26 (36.6%), 27 (38%), 4 (5.6%), and 3 (4.2%) patients were stage IIIA, IIIB, IIIC, III-unspecified, and IV, respectively. BRAF mutations were detected in 31 (50.8%) patients. The median time from last surgical procedure to start of treatment was 10.8 weeks (4-28), with a median follow up time of 12 months. Sixty-one patients (85.9%) received Nivolumab, four (5.6%) patients received Pembrolizumab, and four (5.6%) Dabrafenib/Tremetinib. Twenty-eight (87.5%) of 32 patients with a positive sentinel lymph node biopsy did not complete elective regional lymph node dissection. Only two patients received adjuvant radiation. Local-regional surveillance with regular nodal ultrasound was not consistently performed. Seven (9.8%) patients had clinical or radiographic finding of enlarged regional lymph node while on treatment. At time of analysis, thirteen (18.3%) patients have completed adjuvant therapy, 18 (25.3%) discontinued therapy, and 39 (54.9%) patients were still on treatment. Eleven (15.4%) patients discontinued treatment due to toxicity, 8 (13.1%) from Nivolumab, 3 (75%) from Dabrafenib/Trametinib. Nine (12.6%) patients relapsed on treatment, of those, five (55.5%) had incidental findings on baseline imaging. Hypothyroidism affected 11 (15.4%) patients, hypophysitis and other immune-related side effects were described in 14 (19.7%) cases. Conclusions: Our cohort reflects excellent patient selection and delivery of adjuvant therapy consistent with clinical trial data. Surgical and radiation oncology care has adapted, and differs from trial procedure. Adjuvant immunotherapy was used in most patients. There appears to be a higher rate of discontinuation due to toxicity with Dabrafenib/Trametinib. Toxicity and recurrence findings are preliminary and will be updated.