The Role of Adjuvant Radiotherapy for the Treatment of Resected High-Risk Stage III Cutaneous Melanoma in the Era of Modern Systemic Therapies.

Modern adjuvant systemic therapies (STs) have revolutionized the management of stage III melanoma. Currently, the role of adjuvant radiotherapy (RT) remains unclear. In this single-center retrospective study, patients with clinically detectable stage III melanoma with high-risk features for lymph node basin (LNB) recurrence and whose tumors were fully resected with complete lymphadenectomy (CLD) between 2010 and 2019 were assessed. We determined the cumulative incidence (CIF) of LNB recurrence and any disease recurrence or progression using competing risk analysis. A total of 108 patients were identified; the median age was 59 years (24-92), and 74 (69%) were men. A total of 51 (42%) received adjuvant RT, 22 (20%) received adjuvant ST, and 35 (32%) received no adjuvant therapy. The advent of ST changed clinical practice, with a significant increase in the use of adjuvant ST and a decrease in the use of RT when comparing practice patterns before and after 2015 (p < 0.001). The 3-year CIF of LNB recurrence was similar in patients treated with adjuvant RT (6.3%) and adjuvant ST (9.8%). The 3-year CIF of any disease recurrence or progression was lower in patients receiving adjuvant ST (24%) compared to those receiving adjuvant RT (52%) or no adjuvant therapy (55%, p = 0.06). Three-year overall survival (OS) was not significantly different in patients treated with ST compared to those not treated with any ST (p = 0.118). Despite ST replacing RT as the dominant adjuvant treatment modality, this change in practice has not resulted in increased LNB recurrence for patients at high risk of LNB recurrence following CLD.

Immune Checkpoint Inhibitors in Advanced Cutaneous Squamous Cell Carcinoma: Real-World Experience from a Canadian Comprehensive Cancer Centre.

Immune checkpoint inhibitors (ICI) cemiplimab and pembrolizumab have revolutionized the treatment of advanced cutaneous squamous cell carcinoma (cSCC). We aimed to evaluate the effectiveness and safety of ICI in a real-world cSCC population, including patients with conditions that would exclude clinical trial participation. In this single-center, retrospective cohort study, we included all non-trial patients with advanced cSCC treated with ICI between 2017 and 2022. We evaluated investigator-assessed best overall response (BOR) and immune-related adverse events (irAEs). We correlated survival outcomes with age, performance status, immune status and irAEs. Of the 36 patients identified, the best overall response (BOR) to ICI was a partial response (PR) in 41.7%, a complete response (CR) in 27.8%, and stable disease in (SD) 13.9%. The progression-free survival (PFS) rate for 1 year was 58.1%; the median PFS was 21.3 months (95% CI 6.4-NE). The 1-year overall survival (OS) was 76.7%, and the median OS was 38.6 months (95% CI 25.4-NE). Immune-compromised patients, ECOG performance 2-3, and age ≥ 75 years were not significantly associated with PFS or OS. IrAE grades 3-4 were seen in 13.9% of patients. In our Canadian experience with real-world patients, ICI was an effective and safe treatment for advanced cSCC patients. Patients achieved great benefits with ICI regardless of age, immune status or ECOG performance status. We acknowledge the small sample size and retrospective methodology as the main limitations of our study.

BRAF Mutations in CNS Tumors-Prognostic Markers and Therapeutic Targets.

Gliomas are a heterogeneous group of brain tumors with limited therapeutic options. However, identification of BRAF V600E mutations in a subset of gliomas has provided a genomic-targeted approach for management of these diseases. In this review, we aimed to review the role of BRAF V600E in gliomagenesis, to characterize concurrent genomic alterations and their potential prognostic implications, and to review comprehensively the efficacy data of BRAF inhibitors (combined or not with MEK inhibitors) for the treatment of low- and high-grade gliomas. We also provide a summary of the toxicity of these agents and describe resistance mechanisms that may be circumvented by alternative genomic approaches. Although the efficacy of targeted therapy for management of BRAF V600E-mutant gliomas has mostly been assessed in small retrospective and phase 2 studies with heterogeneous populations, the data generated so far are a proof of concept that genomic-directed therapies improve outcomes of patients with refractory/relapsed glioma and underpin the need of comprehensive genomic assessments for these difficult-to-treat diseases. In the future, the role of targeted therapy in the first-line setting and of genomic-directed therapies to overcome resistance mechanisms should be assessed in well-designed clinical trials.

Turnaround Times in Melanoma BRAF Testing and the Impact on the Initiation of Systemic Therapy at a Single Tertiary Care Cancer Center.

PURPOSE: The identification of BRAF mutations in melanoma enables targeted therapy and improves patient outcomes. Barriers to BRAF molecular testing affect the quality of care and therapeutic options. METHODS: This retrospective study mapped BRAF testing timelines in adult patients with melanoma at the Princess Margaret Cancer Centre to identify obstacles to timely BRAF reporting and its impact on the initiation of therapy. RESULTS: Sixty-six cases were included. The median time between BRAF request and result was 12 days (95% CI, 8 to 15) when the BRAF test was ordered by pathology, compared with 20 days (95% CI, 16 to 23) if the test was requested by another specialist (P < .001). When the BRAF test and biopsy were performed within the same institution, the BRAF median turnaround time (TAT) was 13 days (95% CI, 6 to 19) compared with 19 days (95% CI, 16 to 21) if the sample was transferred from another institution (P = .02). Forty-seven patients received systemic therapy, and 20 had metastatic disease. In the metastatic subgroup, if the BRAF result was available at the first medical oncology visit, the initiation of treatment was 20 days (95% CI, 9.6 to 30.3), but was delayed to 31 days (95% CI, 10.8 to 51.1) if the BRAF result was not available (P = .03). CONCLUSION: This study showed variations in BRAF test results in TAT. One factor affecting this timeline is the transfer time, which can be streamlined by pathology reflex testing. Delays in TAT affect the timing and type of therapeutic intervention, especially in patients with stage IV disease.

Presumed complement-mediated, checkpoint inhibitor-induced, thrombotic microangiopathy in a patient with metastatic melanoma.

Immune checkpoint inhibitors (ICIs) are associated with a variety of immune-related adverse events (irAEs), but haematological irAEs are rare. We report a case of presumed complement-mediated thrombotic microangiopathy (CM-TMA) in a 78-year-old man with metastatic melanoma following treatment with ICIs. Following two doses of combination nivolumab and ipilimumab therapy, he developed microangiopathic haemolytic anaemia, thrombocytopenia and increased creatinine. ADAMTS13 activity was preserved, CH50 was high, haptoglobin was depleted and a blood film demonstrated fragments. Given this constellation of findings, a diagnosis of CM-TMA was made. Immunotherapy was held and the patient received steroids and supportive care. Six months after his last dose of immunotherapy, he has no evidence of melanoma or CM-TMA. CM-TMA should be suspected in patients on ICI with unexplained anaemia and thrombocytopenia with preserved ADAMTS13 activity. Suspicion of complement dysregulation may have therapeutic implications, such as the necessity of complement pathway inhibition.

Genomic Landscape of Malignant Peripheral Nerve Sheath Tumor‒Like Melanoma.

Malignant peripheral nerve sheath tumor (MPNST)-like melanoma is a rare malignancy with overlapping characteristics of both neural sarcoma and melanoma. Although the genomics of cutaneous melanoma has been extensively studied, those of MPNST-like melanoma have not. To characterize the genomic landscape of MPNST-like melanoma, we performed a single-center, retrospective cohort study at a tertiary academic cancer center. Consecutive patients with a confirmed histologic diagnosis of MPNST-like melanoma were screened, and those whose tissues were locally available were included in this analysis. Archival tissue from six patients (eight samples) was submitted for whole-exome and transcriptome sequencing analysis. We compared these data with available genomic studies of cutaneous melanoma and MPNST. NF1 was altered (mutated, deleted, or amplified) in 67% of patients. Genes related to cell cycle regulation were frequently altered, with frequent deletion of ZNF331, which, to the best of our knowledge, has not been previously described in cutaneous melanoma. The serine protease inhibitor SERPINB4 was deleted in 100% of the patients. We show that MPNST-like melanoma presents overlapping genomic features with cutaneous melanoma and MPNST, but it is unique by the frequency of loss of function of ZNF331 and SERPINB4.

CANDIED: A Pan-Canadian Cohort of Immune Checkpoint Inhibitor-Induced Insulin-Dependent Diabetes Mellitus.

Immune checkpoint inhibitor (ICI)-induced insulin-dependent diabetes mellitus (IDDM) is a rare but potentially fatal immune-related adverse event (irAE). In this multicentre retrospective cohort study, we describe the characteristics of ICI-induced IDDM in patients treated across five Canadian cancer centres, as well as their tumor response rates and survival. In 34 patients identified, 25 (74%) were male and 19 (56%) had melanoma. All patients received anti-programed death 1 (anti-PD1) or anti-programmed death ligand-1 (anti-PD-L1)-based therapy. From ICI initiation, median time to onset of IDDM was 2.4 months (95% CI 1.1-3.6). Patients treated with anti-PD1/PD-L1 in combination with an anti-cytotoxic T lymphocyte antigen 4 antibody developed IDDM earlier compared with patients on monotherapy (1.4 vs. 3.9 months, p = 0.05). Diabetic ketoacidosis occurred in 21 (62%) patients. Amongst 30 patients evaluable for response, 10 (33%) had a complete response and another 10 (33%) had a partial response. Median overall survival was not reached (95% CI NE; median follow-up 31.7 months). All patients remained insulin-dependent at the end of follow-up. We observed that ICI-induced IDDM is an irreversible irAE and may be associated with a high response rate and prolonged survival.