Precision oncology using organoids of a secretory carcinoma of the salivary gland treated with TRK-inhibitors.

The use of anticancer drugs targeting specific molecular tumor characteristics is rapidly increasing in clinical practice, but selecting patients to benefit from these remains a challenge. It has been suggested that organoid cultures would be ideally suited to test drug responses in vitro. Here we describe and characterize in depth a case of ETV6-NTRK3 gene fusion-positive secretory carcinoma of the salivary glands and corresponding organoid cultures that responded and subsequently acquired resistance to TRK targeting therapy with larotrectinib. This case-culture-characterization illustrates the advances made in precision oncology, but also exposes important caveats in using organoids to predict treatment response.

Development and characterization of patient-derived salivary gland cancer organoid cultures.

OBJECTIVE: Three-dimensional organoid cell cultures have been established for a variety of human cancers. For most rare cancers, including salivary gland cancer (SGC), these models are lacking, despite the great unmet need to study cancer biology in these diseases. Therefore, we aimed to develop patient-derived organoid (PDO) models for different subtypes of SGC. METHODS: Tumor samples of SGC patients were processed and embedded in Matrigel. Successful PDOs (expandable > 1*106 cells) were phenotypically characterized using immunohistochemistry (IHC) and genotypically by gene fusion analysis and by targeted and whole-exome sequencing. Successfully established PDOs were subjected to small-scale drug screening. RESULTS: Out of 37 attempts, 7 viable short-term PDOs were established (19 % success rate; 3 salivary duct carcinoma, 3 adenoid cystic carcinoma and 1 mucoepidermoid carcinoma). Each PDO showed close phenotypical mimicry to parental tissue. Genotypic characterization revealed that in each PDO > 97.6 % of all COSMIC annotated variants and all MYB, MYBL1 and NFIB gene rearrangements were retained. Drug screening was proven feasible in all PDOs. CONCLUSION: We present the first comprehensively characterized short-term SGC PDO models for three subtypes of SGC with close phenotypic and genotypic resemblance to parental tissue, which can be used for drug screening applications.

Identification of Fusion Genes and Targets for Genetically Matched Therapies in a Large Cohort of Salivary Gland Cancer Patients.

Introduction: Salivary gland cancer (SGC) is a rare cancer for which systemic treatment options are limited. Therefore, it is important to characterize its genetic landscape in search for actionable aberrations, such as NTRK gene fusions. This research aimed to identify these actionable aberrations by combining NGS-based analysis of RNA (gene fusions) and DNA (single and multiple nucleotide variants, copy number variants, microsatellite instability and tumor mutational burden) in a large cohort of SGC patients. Methods: RNA and DNA were extracted from archival tissue of 121 patients with various SGC subtypes. Gene fusion analysis was performed using a customized RNA-based targeted NGS panel. DNA was sequenced using a targeted NGS panel encompassing 523 cancer-related genes. Cross-validation of NGS-based NTRK fusion detection and pan-TRK immunohistochemistry (IHC) was performed. Results: Fusion transcripts were detected in 50% of the cases and included both known (MYB-NFIB, MYBL1-NFIB, CRTC1-MAML2) and previously unknown fusions (including transcripts involving RET, BRAF or RAD51B). Only one NTRK fusion transcript was detected, in a secretory carcinoma case. Pan-TRK IHC (clone EPR17341) was false positive in 74% of cases. The proportion of patients with targets for genetically matched therapies differed among subtypes (salivary duct carcinoma: 82%, adenoid cystic carcinoma 28%, mucoepidermoid carcinoma 50%, acinic cell carcinoma 33%). Actionable aberrations were most often located in PIK3CA (n = 18, 15%), ERBB2 (n = 15, 12%), HRAS and NOTCH1 (both n = 9, 7%). Conclusions: Actionable genetic aberrations were seen in 53.7% of all SGC cases on the RNA and DNA level, with varying percentages between subtypes.

Predictive and Prognostic Biomarker Identification in a Large Cohort of Androgen Receptor-Positive Salivary Duct Carcinoma Patients Scheduled for Combined Androgen Blockade.

Patients suffering from recurrent or metastatic (R/M) salivary duct carcinoma (SDC) are often treated with combined androgen blockade (CAB). However, CAB frequently fails, resulting in a worse prognosis. Therefore, biomarkers that can predict treatment failure are urgently needed. mRNA from 76 R/M androgen receptor (AR)-positive SDC patients treated with leuprorelin acetate combined with bicalutamide was extracted from pre-treatment tumor specimens. AR, Notch, MAPK, TGFß, estrogen receptor (ER), Hedgehog (HH), and PI3K signaling pathway activity scores (PAS) were determined based on the expression levels of target genes. Additionally, 5-alpha reductase type 1 (SRD5A1) expression was determined. These markers were related to clinical benefit (complete/partial response or stable disease ≥6 months) and progression-free and overall survival (PFS/OS). SRD5A1 expression had the highest general predictive value for clinical benefit and positive predictive value (PPV: 85.7%). AR PAS had the highest negative predictive value (NPV: 93.3%). The fitting of a multivariable model led to the identification of SRD5A1, TGFß, and Notch PAS as the most predictive combination. High AR, high Notch, high ER, low HH PAS, and high SRD5A1 expression were also of prognostic importance regarding PFS and SRD5A1 expression levels for OS. AR, Notch PAS, and SRD5A1 expression have the potential to predict the clinical benefit of CAB treatment in SDC patients. SRD5A1 expression can identify patients that will and AR PAS patients that will not experience clinical benefit (85.7% and 93.3% for PPV and NPV, respectively). The predictive potential of SRD5A1 expression forms a rational basis for including SRD5A1-inhibitors in SDC patients' treatment.

Thermal distribution, physiological effects and toxicities of extracorporeally induced whole-body hyperthermia in a pig model.

BACKGROUND: Extracorporeally induced whole-body hyperthermia (eWBH) might be a beneficial treatment in cancer patients. Objectives of this pig study were to assess thermal distribution, (patho-)physiological effects, and safety of eWBH with a new WBH device. METHODS: Fourteen healthy adult pigs were anesthetized, mechanically ventilated, and cannulated; 12 were included in the analysis. Blood was heated in 11 pigs (one pig served as control) using a WBH device (Vithèr Hyperthermia B.V.) containing two separate fluidic circuits and a heat exchanger. Temperature was monitored on nine different sites, including the brain. Core temperature (average of 4 deep probes) was elevated to 42°C for 2 hr. RESULTS: Elevation of core body temperature to 42°C took on average (± standard deviation) 38 ± 8 min. Initially observed temperature spikes diminished after lowering maximal blood temperature to 45°C. Hereafter, brain temperature spikes never exceeded 42.5°C, mean brain temperature was at highest 41.9°C during maintenance. WBH resulted in increased heart rates and decreased mean arterial pressures. The vast amounts of fluids required to counter hypotension tended to be smaller after corticosteroid administration. Hemodialysis was started in three animals (potassium increase prevention in two and hyperkalemia treatment in one). Severe rhabdomyolysis was observed in all pigs (including the control). All animals survived the procedure until planned euthanasia 1, 6, or 24 hr post procedure. CONCLUSION: Fast induction of eWBH with homogenous thermal distribution is feasible in pigs using the Vithèr WBH device. Severe hemodynamic disturbances, rhabdomyolysis, and hyperkalemia were observed.

Advances and challenges in precision medicine in salivary gland cancer.

Salivary gland cancer (SGC) is a rare malignancy consisting of 22 subtypes with different genetic, histological and clinical characteristics. This rarity and heterogeneity makes systemic treatment of recurrent or metastatic (R/M) disease challenging. Use of chemotherapy is scarcely studied and chemotherapy at best has moderate effects. New therapeutic strategies are therefore warranted, but advances made in SGC are lagging behind on advances made in more common cancers. By unraveling tumor characteristics of SGC, such as genetic alterations and protein expression profiles, therapeutic strategies tailored to the patient's tumor can be rationalized. This genomic profiling and mapping of immunohistochemical expression profiles is essential in the search for a suitable treatment approach. Thereby, it alleviates the paucity in systemic treatment options and can significantly alter the prognosis of patients with R/M SGC. This review aims to give a comprehensive overview of known genetic alterations and expression profiles amenable for targeted therapy in every histological subtype of SGC. We discuss the remaining knowledge gaps and the implications of these targets for future studies and personalized treatments, thereby aiding clinicians faced with this rare and heterogeneous type of cancer.

Dose recommendations for anticancer drugs in patients with renal or hepatic impairment.

Renal or hepatic impairment is a common comorbidity for patients with cancer either because of the disease itself, toxicity of previous anticancer treatments, or because of other factors affecting organ function, such as increased age. Because renal and hepatic function are among the main determinants of drug exposure, the pharmacokinetic profile might be altered for patients with cancer who have renal or hepatic impairment, necessitating dose adjustments. Most anticancer drugs are dosed near their maximum tolerated dose and are characterised by a narrow therapeutic index. Consequently, selecting an adequate dose for patients who have either hepatic or renal impairment, or both, is challenging and definitive recommendations on dose adjustments are scarce. In this Review, we discuss the effect of renal and hepatic impairment on the pharmacokinetics of anticancer drugs. To guide clinicians in selecting appropriate dose adjustments, information from available drug labels and from the published literature were combined to provide a practical set of recommendations for dose adjustments of 160 anticancer drugs for patients with hepatic and renal impairment.