Mainstream Model of Genetic Testing for Prostate Cancer at a Large Tertiary Cancer Centre.

BACKGROUND: An estimated 20% to 30% of men with advanced prostate cancer carry a mutation in DNA damage repair genes, of which half are estimated to be germline. Eligibility criteria for germline genetic testing expanded significantly for Ontario patients in May 2021 and many centers adopted a "mainstream" model, defined as oncologist-initiated genetic testing. METHODS: We conducted a retrospective chart review to report on the first-year mainstream experience of a large tertiary oncologic center, the Sunnybrook Odette Cancer Centre. All patients who underwent mainstream at the discretion of their treating physician were included. A subset underwent somatic profiling as part of clinical trial screening. Descriptive statistics were used to report baseline clinicopathologic characteristics and treatments received. RESULTS: Between May 1, 2021, and May 30, 2022, 174 patients with prostate cancer underwent mainstream germline genetic testing with a 19-gene panel. Median age was 75 (IQR 68-80), and 82% of patients were diagnosed with either de novo metastatic or high-risk localized prostate adenocarcinoma. Fourteen patients (8%; 95% CI 4%-12%) were found to have a deleterious germline mutation, including pathogenic or likely pathogenic variants in BRCA1/2, ATM, CHEK2, PMS2, RAD51C, HOXB13, and BRIP1. Forty-nine patients (28%; 95% CI 21%-35%) were found to have a variant of uncertain significance. Thirty-four patients also had next-generation sequencing (NGS) of their somatic tissue. Among this subset, 8 of 34 (23%) had an alteration in homologous recombination repair (HRR) genes. Of the 14 patients with a germline mutation, none had a prior personal history of malignancy and 6 (43%) did not have any first- or second-degree relatives with history of prostate, pancreatic, breast, or ovarian cancer. CONCLUSION: We report on the real-world characteristics of prostate cancer patients who underwent mainstream germline genetic testing. Personal history and family history of cancer cannot reliably stratify patients for the presence of pathogenic germline variants.

An assessment of extended pembrolizumab dosing in advanced non-small-cell lung cancer in the COVID-19 pandemic.

Background: There are limited clinical data comparing extended dosing (ED) versus standard dosing (SD) of pembrolizumab for metastatic non-small-cell lung cancer. Methods: This retrospective study included patients with metastatic non-small-cell lung cancer and PD-L1 tumor proportion score ≥50% treated with one or more cycles of single-agent pembrolizumab with SD or ED from January 2018 to December 2020. Results: A higher proportion of patients were alive in the ED group (vs SD) at 6 months (94 vs 51%), 12 months (94 vs 33%) and data cutoff (94 vs 26%) (p < 0.001 for all). The rate (44 vs 32%; p = 0.407) and severity of grade ≥3 immune-related adverse events were similar (50 vs 52%); however, ED patients more frequently discontinued treatment due to toxicity (45 vs 15%; p < 0.001). Conclusion: A greater proportion of ED patients were alive at data cutoff, and the rate and severity of immune-related adverse events were similar between groups.

Cancer in the lungs can be treated with drugs that use your immune system to kill cancer. This study showed that patients lived longer when the drugs were given further apart, and that the extended treatment was equally safe as the standard dosing schedule.

A study of the efficacy and toxicity outcomes of extended durvalumab dosing in patients with stage III unresectable non-small cell lung cancer (NSCLC) during the COVID-19 pandemic.

BACKGROUND: Durvalumab following chemoradiation in unresectable stage III non-small cell lung cancer (NSCLC) has led to improved outcomes. The schedule of administration has been determined by pharmacokinetic studies. This study evaluates real-world efficacy and safety outcomes of extended dosing (ED) vs. standard dosing (SD) of durvalumab. METHODS: Stage III NSCLC patients treated at the Cancer center of Southeastern Ontario with consolidative durvalumab from March 2017-December 2020 were included. Patient characteristics and outcomes were evaluated through retrospective review. Comparisons were made using chi-square and t-tests. Kaplan-Meier curves were used to analyze overall survival (OS). RESULTS: A total of 35 patients were included; 15 (43%) switched to ED. Distant recurrence rates were higher in the ED group (53% vs. 20%, p = 0.07), with no differences in the sites of disease recurrence. A similar proportion of patients were alive in the ED vs. SD group (93% vs. 80%, p = 0.3), with no significant difference in OS. There were less grade 3 or greater immune-related adverse events in the ED group (0% vs. 20%). Treatment discontinuation occurred in 47% vs. 50% in the ED vs. SD groups, respectively, owing to toxicity in 20% of patients in the ED group vs. 40% in the SD group. CONCLUSIONS: Extended dosing has similar efficacy and toxicity to standard dosing; however, there was a higher rate of toxicity necessitating discontinuation in the SD group, which may have impacted the clinical decision-making to switch to ED. Our data is limited by a small sample size and should be further validated in larger cohorts.

No association between BMI and immunotoxicity or clinical outcomes for immune checkpoint inhibitors.

Background: The impact of BMI on immune checkpoint inhibitor toxicity and efficacy has not been clearly characterized. Methods: The authors conducted a retrospective single-center study of patients with advanced unresectable/metastatic cancer initiated on immune checkpoint inhibitors. Results: Of the 409 patients included in the study, 115 (28%) had a BMI ≥30. There was no difference in the development of immune-related adverse events, treatment response or overall survival with respect to BMI <30 versus ≥30 for the whole study population or the melanoma subgroup. Conclusion: Patients with BMI in the obese range (≥30) were not at increased risk of immunotoxicity. Furthermore, BMI was not correlated with treatment response or overall survival in patients receiving immune checkpoint inhibitors.

Several previous studies have suggested that obesity may be correlated with improved efficacy of immunotherapy and raised the concern that obesity may be associated with increased immunotoxicity; however, other studies have not replicated these findings. The authors evaluated the records from one center of 409 patients with advanced cancer on immune checkpoint inhibitors. There was no difference with respect to adverse events, treatment response or survival between obese and nonobese patients.

Venous thromboembolism events in patients with advanced cancer on immune checkpoint inhibitors.

Aim: To evaluate the correlation between venous thromboembolism events (VTEs) and immune checkpoint inhibitor (ICI)-based regimens. Methods: This is a retrospective study of 403 patients with advanced cancer on ICI-based regimens. Results: We report 8% VTE incidence post-ICI initiation over a median of 11.1 months of follow-up. Compared with single-agent ICI, dual-ICI was significantly correlated with higher incidence of VTE (odds ratio [OR]: 4.196, 95% CI: 1.527-11.529, p = 0.005), but chemotherapy-immuno-oncology combination was not (OR: 1.374, 95% CI: 0.285-6.632, p = 0.693). Subsequent systemic therapy post-ICI was also independently associated with higher VTE incidence (OR: 2.599, 95% CI: 1.169-5.777, p = 0.019). Conclusion: Our findings suggest potential underreporting of VTE incidence in ICI clinical trials. As dual-ICI is becoming more prevalent in cancer management, clinicians should maintain vigilance regarding VTE in patients with advanced cancer on ICI-based regimens.

Safety and Clinical Outcomes of Immune Checkpoint Inhibitors in Patients With Cancer and Preexisting Autoimmune Diseases.

Immunotherapy has revolutionized treatment outcomes in numerous cancers. However, clinical trials have largely excluded patients with autoimmune diseases (ADs) due to the risk of AD flares or predilection for developing organ-specific inflammation. The objective of this study was to evaluate the safety and efficacy of immunotherapy in patients with cancer and preexisting ADs. A retrospective, single-center study of patients with cancer initiated on immune checkpoint inhibitors between 2012 and 2019 was conducted. The primary outcome was the development of immune-related adverse events (irAEs) with respect to the presence of AD at baseline. Associations were assessed using Kaplan-Meier curves, bivariate and multivariable analyses. Of the 417 patients included in this study, 63 patients (15%) had preexisting ADs. A total of 218 patients (53%) developed at least 1 irAE. There was no association between the presence of baseline AD on the development, grade, or number of irAEs; time to irAE or irAE recovery; systemic corticosteroid or additional immunosuppressant treatment for irAEs; permanent treatment discontinuation; or overall response rate. Two smaller cohorts were studied, melanoma and non-small cell lung cancer, and there was no effect of baseline AD on overall survival on either cohort. However, a greater proportion of patients with baseline ADs had full recovery from their irAE (P=0.037). Furthermore, age below 65, baseline steroid use, and single-agent immunotherapy regimens were protective in terms of the development of irAEs. Our study suggests that immune checkpoint inhibitors have similar safety and efficacy profiles in patients with preexisting ADs.