Northeast Cancer Centre

5060 Background: Rucaparib significantly improved radiographic progression-free survival (rPFS) in men with BRCA-mutated chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC) vs a control arm of physician’s choice of therapy (docetaxel or androgen-receptor pathway inhibitor [ARPI] therapy: abiraterone acetate or enzalutamide) in the randomized, multicenter, open-label, phase 3 TRITON3 (NCT02975934) study. Herein, we conducted an analysis to determine the impact of germline vs somatic mutation status on the efficacy of rucaparib. Methods: Patients were randomized 2:1 to receive rucaparib 600 mg BID or physician’s choice of docetaxel or ARPI following progression while on 1 prior second-generation ARPI in any setting. The primary endpoint was rPFS. Color Health did genetic testing. Treatment-emergent adverse events (TEAEs) were reported for the BRCA subgroup. Results: In the rucaparib arm, 201/270 patients had BRCA mutations, and in the physician’s choice arm, 101/135 patients had BRCA mutations. Of patients with BRCA mutations: in the rucaparib arm, 80/201 (40%) were germline and 116/201 (58%) were somatic with 5/201 (2%) BRCA mutation status unknown, while in the physician’s choice arm, 39/101 (39%) were germline and 48/101 (48%) were somatic with 14/101 (14%) BRCA mutation status unknown. rPFS was significantly improved with rucaparib treatment vs physician’s choice in both the germline and somatic mutation groups (germline: HR, 0.52 [95% CI, 0.32–0.84]; somatic: HR, 0.38 [95% CI, 0.25–0.59]). Incidence rates of TEAEs were similar overall between patients with germline and somatic BRCA mutations in both arms. Conclusions: Rucaparib improves progression-free survival for patients with mCRPC with either germline or somatic BRCA mutations with a manageable safety profile. These data support the use of rucaparib as a beneficial treatment option for patients with BRCA-mutated mCRPC with germline or somatic mutations. Clinical trial information: NCT02975934 .

BackgroundAdjuvant radiotherapy is prescribed after breast-conserving surgery to reduce the risk of local recurrence. However, radiotherapy is inconvenient, costly, and associated with both short-term and long-term side effects. Clinicopathologic factors alone are of limited use in the identification of women at low risk for local recurrence in whom radiotherapy can be omitted. Molecularly defined intrinsic subtypes of breast cancer can provide additional prognostic information.MethodsWe performed a prospective cohort study involving women who were at least 55 years of age, had undergone breast-conserving surgery for T1N0 (tumor size <2 cm and node negative), grade 1 or 2, luminal A–subtype breast cancer (defined as estrogen receptor positivity of ≥1%, progesterone receptor positivity of >20%, negative human epidermal growth factor receptor 2, and Ki67 index of ≤13.25%), and had received adjuvant endocrine therapy. Patients who met the clinical eligibility criteria were registered, and Ki67 immunohistochemical analysis was performed centrally. Patients with a Ki67 index of 13.25% or less were enrolled and did not receive radiotherapy. The primary outcome was local recurrence in the ipsilateral breast. In consultation with radiation oncologists and patients with breast cancer, we determined that if the upper boundary of the two-sided 90% confidence interval for the cumulative incidence at 5 years was less than 5%, this would represent an acceptable risk of local recurrence at 5 years.ResultsOf 740 registered patients, 500 eligible patients were enrolled. At 5 years after enrollment, recurrence was reported in 2.3% of the patients (90% confidence interval [CI], 1.3 to 3.8; 95% CI, 1.2 to 4.1), a result that met the prespecified boundary. Breast cancer occurred in the contralateral breast in 1.9% of the patients (90% CI, 1.1 to 3.2), and recurrence of any type was observed in 2.7% (90% CI, 1.6 to 4.1).ConclusionsAmong women who were at least 55 years of age and had T1N0, grade 1 or 2, luminal A breast cancer that were treated with breast-conserving surgery and endocrine therapy alone, the incidence of local recurrence at 5 years was low with the omission of radiotherapy. (Funded by the Canadian Cancer Society and the Canadian Breast Cancer Foundation; LUMINA ClinicalTrials.gov number, NCT01791829.)

40 Background: Continued smoking after a diagnosis of cancer negatively impacts cancer outcomes but the impact of tobacco on many innovative treatments has not yet been well established. Collecting and evaluating tobacco use in cancer clinical trials may advance understanding of the consequences of tobacco use on specific treatment modalities. We performed a systematic scoping review of the frequency of reporting and analysis of tobacco use in clinical trials run by cancer cooperative clinical trial groups. Methods: A comprehensive literature search was conducted to identify cancer cooperative group clinical trials published from January 2017 to October 2019 using Medline, Epub Ahead of Print and In-Process &amp; Other Non-Indexed Citations, Embase, Cochrane Central Register of Controlled Trials using OvidSP. Eligible studies evaluated either systemic and/or radiation therapies, involved at least one cancer cooperative group, included &gt; 100 adult patients and reported on at least one primary or secondary endpoint, which included overall survival (OS), disease/progression-free survival (DFS/PFS), response rates, toxicities/adverse events, or quality of life (QoL). Secondary analyses of previously published trials were excluded. Results: Among 14843 identified studies, 91 studies representing 90 trials met inclusion criteria. 24% were phase II trials, 2% phase II/III and 74% phase III. Trial start dates ranged from 1995-2015 with most (29%) between 2007-2008; median trial sample size was 406 (range: 100-4994); 86% involved systematic therapy, 35% involved radiation; 14% were lung and 5% were head and neck trials. 51% of trials had a curative intent, 33% were palliative and 16% involved hematologic cancers. 74 studies reported on OS, 73 DFS/PFS, and 88 toxicity/QoL. 19 studies reported baseline tobacco use information, while two reported collecting follow-up tobacco use. Of those collecting baseline tobacco use, only 7 reported any analysis of the impact of tobacco on clinical outcomes. There was significant heterogeneity in the reporting of baseline tobacco use: 5 reported never/ever status, 10 reported never/ex-smoker/current smoker status; 4 reported some measure of smoking intensity; none reported on verifying smoking status or second hand smoke exposure. Trials of tobacco related (lung and head and neck) cancers were more likely to report baseline tobacco use compared to non-tobacco related cancers (83% vs 6% p &lt; 0.001). Conclusions: Few cancer cooperative group clinical trials report and analyze trial participants’ baseline tobacco use, and even fewer collect follow up information. Significant heterogeneity exists in reporting tobacco use. Routine standardized collection and reporting of tobacco use, both at baseline and follow up in clinical trials, should be implemented to enable investigators to evaluate the clinical impact of tobacco use on new cancer therapies.