Uson Junior, Pedro Luiz Serrano

Fibroblast growth factor receptor 2 (FGFR2) inhibitors are now being included in the treatment guidelines of multiple countries for patients with advanced cholangiocarcinoma (CCA). Activation of the FGF–FGFR pathway is related to proliferation and tumor progression. Targeting the FGF–FGFR pathway is effective and can yield durable responses in patients with CCA harboring FGFR2 fusions or rearrangements. In this review article, we address molecules and clinical trials evaluating FGFR inhibitors in advanced CCA. We will further discuss identified mechanisms of resistance and the strategies to overcome it. The incorporation of next-generation sequencing in advanced CCA and circulating tumor DNA on disease progression will unveil mechanisms of resistance and improve the development of future clinical trials and more selective drugs and combinations.

PURPOSE This investigation sought to evaluate the prognostic value of pretreatment of circulating tumor DNA (ctDNA) in metastatic biliary tract cancers (BTCs) treated with platinum-based first-line chemotherapy treatment. MATERIALS AND METHODS We performed a retrospective analysis of 67 patients who underwent ctDNA testing before platinum-based chemotherapy for first-line treatment for metastatic BTC. For analysis, we considered the detected gene with highest variant allele frequency as the dominant clone allele frequency (DCAF). Results of ctDNA analysis were correlated with patients' demographics, progression-free survival (PFS), and overall survival (OS). RESULTS The median age of patients was 67 (27-90) years. Fifty-four (80.6%) of 67 patients evaluated had intrahepatic cholangiocarcinoma; seven had extrahepatic cholangiocarcinoma, and six gallbladder cancers. Forty-six (68.6%) of the patients were treated with cisplatin plus gemcitabine, and 16.4% of patients received gemcitabine and other platinum (carboplatin or oxaliplatin) combinations, whereas 15% of patients were treated on a clinical trial with gemcitabine and cisplatin plus additional agents (CX4945, PEGPH20, or nab-paclitaxel). TP53, KRAS, FGFR2, ARID1A, STK11, and IDH1 were the genes with highest frequency as DCAF. The median DCAF was 3% (0%-97%). DCAF > 3% was associated with worse OS (median OS: 10.8 v 18.8 months, P = .032). Stratifying DCAF in quartiles, DCAF > 10% was significantly related to worse PFS (median PFS: 3 months, P = .014) and worse OS (median OS: 7.0 months, P = .001). Each 1% increase in ctDNA was associated with a hazard ratio of 13.1 in OS when adjusting for subtypes, metastatic sites, size of largest tumor, age, sex, and CA19-9. CONCLUSION DCAF at diagnosis of advanced BTC can stratify patients who have worse outcomes when treated with upfront platinum-based chemotherapy. Each increase in %ctDNA decreases survival probabilities.

Abstract The past decade has seen a rise in the availability of breakthrough therapeutic strategies for treatment of hepatocellular carcinoma (HCC). A tumor microenvironment in HCC is regulated by various immunotolerance mechanisms; therefore, therapeutic strategies aiming at disrupting tumor immune tolerance are becoming attractive curative options in HCC. Immune checkpoint inhibitors have demonstrated impressive effectiveness in HCC, including in sorafenib-unresponsive patients. Synergistic approaches with checkpoint inhibitors (anti-PD-1/PD-L1 and CTLA-4) and antiangiogenic drugs are burgeoning as first-line treatment therapeutic modalities in HCC.

PURPOSE To present a summary of the recommendations for the treatment and follow-up for the biochemical recurrence of castration-resistant prostate cancer (PCa) as acquired through a questionnaire administered at the Prostate Cancer Consensus Conference for Developing Countries. METHODS A total of 27 questions were identified as relating to this topic. Responses from the clinician were tallied and are presented in percentage format. Topics included the use of imaging in staging, treatment recommendations across different patient scenarios of life expectancy and prostate-specific antigen (PSA) doubling time, and follow-up for nonmetastatic castration-resistant PCa. RESULTS A consensus agreed that in optimal conditions, positron emission tomography-computed tomography with prostate-specific membrane antigen would be used although in limited resource situations the combined use of CT of the abdomen and pelvic (or pelvic MRI), a bone scan, and a CT of the thorax or chest x-ray was recommended. In cases when PSA levels double in < 10 months, more than 90% of clinicians agreed on the use of apalutamide or enzalutamide, regardless of life expectancy. With a doubling time of more than 10 months, > 54% of experts recommended no treatment independent of life expectancy. More than half of the experts, regardless of resources, recommended follow-up with a physical examination and PSA levels every 3-6 months and imaging only in the case of symptoms. CONCLUSION The voting results and recommendations presented in this document can be used by physicians to support management for biochemical recurrence of castration-resistant PCa in areas of limited resources. Individual clinical decision making should be supported by available data.

Abstract Purpose Recent advances in molecular diagnostic technologies allow for the evaluation of solid tumor malignancies through noninvasive blood sampling, including circulating tumor DNA profiling (ctDNA). Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, often because of late presentation of disease. Diagnosis is often made using endoscopic ultrasound or endoscopic retrograde cholangiopancreatography, which often does not yield enough tissue for next-generation sequencing. With this study, we sought to characterize the ctDNA genomic alteration landscape in patients with advanced PDAC with a focus on actionable findings. Materials and Methods From December 2014 through October 2019, 357 samples collected from 282 patients with PDAC at Mayo Clinic underwent ctDNA testing using a clinically available assay. The majority of samples were tested using the 73-gene panel which includes somatic genomic targets, including complete or critical exon coverage in 30 and 40 genes, respectively, and in some, amplifications, fusions, and indels. Clinical data and outcome variables were available for 165 patients; with 104 patients at initial presentation. Results All patients included in this study had locally advanced or metastatic PDAC. Samples having at least one alteration, when variants of unknown significance (VUS) were excluded, numbered 266 (75%). After excluding VUS, therapeutically relevant alterations were observed in 170 (48%) of the total 357 cohort, including KRAS (G12C), EGFR, ATM, MYC, BRCA, PIK3CA, and BRAF mutations. KRAS, SMAD, CCND2, or TP53 alterations were seen in higher frequency in patients with advanced disease. Conclusion Our study is the largest cohort to date that demonstrates the feasibility of ctDNA testing in PDAC. We provide a benchmark landscape upon which the field can continue to grow. Future applications may include use of ctDNA to guide treatment and serial monitoring of ctDNA during disease course to identify novel therapeutic targets for improved prognosis. Implications for Practice Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis often due to late presentation of disease. Biopsy tissue sampling is invasive and samples are often inadequate, requiring repeated invasive procedures and delays in treatment. Noninvasive methods to identify PDAC early in its course may improve prognosis in PDAC. Using ctDNA, targetable genes can be identified and used for treatment.