EUS-FNA Biopsies to Guide Precision Medicine in Pancreatic Cancer: Results of a Pilot Study to Identify KRAS Wild-Type Tumours for Targeted Therapy

Background

Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer death and lacks effective treatment options. Diagnostic endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsies represent an appealing source of material for molecular analysis to inform targeted therapy, as they are often the only available tissue for patients presenting with PDAC irrespective of disease stage. However, EUS-FNA biopsies are typically not used to screen for precision medicine studies due to concerns about low tissue yield and quality. Epidermal growth factor receptor (EGFR) inhibition has shown promise in clinical trials of unselected patients with advanced pancreatic cancer, but has not been prospectively tested in KRAS wild-type patients. Here, we examine the clinical utility of EUS-FNA biopsies for molecular screening of KRAS wild-type PDAC patients for targeted anti-EGFR therapy to assess the feasibility of this approach.

Patients and Methods

Fresh frozen EUS-FNA or surgical biopsies from PDAC patient tumours were used to screen for KRAS mutations. Eligible patients with recurrent, locally advanced, or metastatic KRAS wild-type status who had received at least one prior line of chemotherapy were enrolled in a pilot study (ACTRN12617000540314) and treated with panitumumab at 6mg/kg intravenously every 2 weeks until progression or unacceptable toxicity. The primary endpoint was 4-month progression-free survival (PFS).

Results

275 patient biopsies were screened for KRAS mutations, which were detected in 88.3% of patient samples. 8 eligible KRAS wild-type patients were enrolled onto the interventional study between November 2017 and December 2020 and treated with panitumumab. 4-month PFS was 14.3% with no objective tumour responses observed. The only grade 3/4 treatment related toxicity observed was hypomagnesaemia.

Conclusions

This study demonstrates proof-of-principle feasibility to molecularly screen patients with pancreatic cancer for targeted therapies, and confirms diagnostic EUS-FNA biopsies as a reliable source of tumour material for molecular analysis. Single agent panitumumab was safe and tolerable but led to no objective tumour responses in this population.

Prognostic role of alpha-fetoprotein in patients with hepatocellular carcinoma treated with repeat transarterial chemoembolisation

BACKGROUND

Repeat transarterial chemoembolisation (rTACE) is often required for hepatocellular carcinoma (HCC) to achieve disease control, however, current practice guidelines regarding treatment allocation vary significantly. This study aims to identify key factors associated with patient survival following rTACE to facilitate treatment allocation and prognostic discussion.

METHOD

Patients with HCC undergoing rTACE at six Australian tertiary centers from 2009 to 2014 were included. Variables encompassing clinical, tumour, treatment type and response factors were analysed against the primary outcome of overall survival. Univariate analysis and multivariate Cox regression modelling were used to identify factors pre- and post-TACE therapy significantly associated with survival.

RESULTS

Total of 292 consecutive patients underwent rTACE with mainly Child Pugh A cirrhosis (61%) and BCLC stage A (57%) disease. Median overall survival (OS) was 30 months (IQR 15.2-50.2) from initial TACE. On multivariate analysis greater tumour number (p = 0.02), higher serum bilirubin (p = 0.007) post initial TACE, and hepatic decompensation (p = 0.001) post second TACE were associated with reduced survival. Patients with serum AFP ≥ 200 ng/ml following initial TACE had lower survival (p = 0.001), compared to patients with serum AFP level that remained < 200 ng/ml post-initial TACE, with an overall survival of 19.4 months versus 34.7 months (p = 0.0001) respectively.

CONCLUSION

Serum AFP level following initial treatment in patients undergoing repeat TACE for HCC is a simple and useful clinical prognostic marker. Moreover, it has the potential to facilitate appropriate patient selection for rTACE particularly when used in conjunction with baseline tumour burden and severity of hepatic dysfunction post-initial TACE.

The role of body composition in diverticular disease

BACKGROUND

Diverticular disease is a common, chronic inflammatory disease of the bowel. This study investigates the differences in body composition between patients with diverticular disease and those without.

METHODS

Appropriate patients were identified using a search of the radiology database. Demographic and disease information was gathered using scanned medical records. Body composition analysis was performed at level L3 using single-slice computed tomography techniques.

RESULTS

Two hundred seventy-one patients were included in this study: 83 controls, 93 with diverticulosis and 95 with diverticulitis. Diverticulitis and diverticulosis were associated with a significantly higher visceral fat area (VFA), than the control group (p < 0.001, p < 0.001). Diverticulitis and diverticulosis were associated with a significantly higher visceral fat area to subcutaneous fat area ratio (VFA:SCFA), than the control group (p = 0.005, p = 0.019). Only diverticulosis was associated with increased levels of extramyocellular fat, when compared to the control group (p = 0.001).

CONCLUSION

Diverticular disease is associated with a higher amount and a higher proportion of visceral fat than seen in controls without diverticular disease.