Precision oncology in pancreatobiliary cancers: A longitudinal study.

Abstract

399 Background: Precision oncology – the use of next-generation sequencing (NGS) to identify therapeutic options for advanced cancer patients – is being used widely, but its utility in patients with pancreatobiliary (PB) cancers has not been studied systematically. We evaluated the prevalence of actionable alterations and their impact on therapeutic decision-making in patients with PB cancers. Methods: We conducted a retrospective cohort study of consecutive patients seen at the Cleveland Clinic between 2013 and 2016 with incurable solid tumor malignancies, in whom FoundationOne™ (Cambridge, MA) NGS was ordered. All results were reviewed at a multidisciplinary genomics tumor board (GTB), which determined actionability and made therapeutic recommendations. Treatment decisions (on label, off label, or clinical trials) based on said recommendations were reviewed. Results: The study population was 600 patients, of whom 53 had PB cancers. For these 53, median age was 59.6 years; 62.2% (33/53) were female; 86.8% (46/53) were Caucasian. Eight samples (15.1%) had inadequate tissue; of 45 resulted cases, 21 (46.7%) were recommended treatment, including clinical trials (n = 19) and off-label drugs (n = 2). The most common targets for therapy were FGFR (5/21) and CDKN2 (3/21). Of 21 patients with recommendations, only two (9.5%) received genomics-driven therapy, compared with 31.7% (86/271) of patients with other solid tumor malignancies (p = 0.03). One received an IDH1 inhibitor, and one received dabrafenib and trametinib for a BRAF alteration; both on clinical trials. At time of last follow-up, best responses were unknown and partial response, respectively. Unavailability of clinical trials in the vicinity (9.5%), and clinical trial ineligibility, mainly due to poor performance status (9.5%), were common reasons for lack of actionability. Conclusions: Benefit from precision oncology in the PB population is low, with only 4.4% (2/45) of patients with NGS results eventually receiving genomics-driven therapy. Benefit to patients will not improve until access to clinical trials is enhanced and patients are evaluated for these trials earlier in the course of their disease, when their performance status is likely to be higher.