NRF2 Dysregulation in Hepatocellular Carcinoma and Ischemia: A Cohort Study and Laboratory Investigation

Background Intermediate stage hepatocellular carcinomas (HCCs) are treated by inducing ischemic cell death with transarterial embolization (TAE) or transarterial chemoembolization (TACE). A subset of HCCs harbor nuclear factor E2-related factor 2 (NRF2), a major regulator of the oxidative stress response implicated in cell survival after ischemia. NRF2-mutated HCC response to TAE and/or TACE is unknown. Purpose To test whether ischemia resistance is present in individuals with NRF2-mutated HCC and if this resistance can be overcome by means of NRF2 inhibition in HCC cell lines. Materials and Methods This was a combined retrospective review of an institutional database (from January 2011 to December 2018) and prospective study (from January 2014 to December 2018) of participants with HCC who underwent TAE and a laboratory investigation of HCC cell lines. Imaging follow-up included liver CT or MRI at 1 month after the procedure followed by 3-month interval scans. Tumor radiologic response was assessed on the basis of follow-up imaging. The time to local progression after TAE for individuals with and individuals without NRF2 pathway alterations was estimated by using competing risk analysis (Gray test). The in vitro response to ischemia in four HCC cell lines with and without NRF2 overexpression was evaluated, and the combination of ischemia with NRF2 knockdown by means of short hairpin RNA or an NRF2 inhibitor was tested. Doubling time estimates, dose response curve regression, and comparison analyses were performed. Results Sixty-five individuals (median age, 69 years [range, 19-84 years]; 53 men) were evaluated. HCCs with NRF2 pathway mutation had a shorter time to local progression after TAE compared to those without mutation (6-month cumulative incidence of local progression, 56% [range, 19%-91%] vs 22% [range, 12%-34%], respectively; P < .001) and confirmed ischemia resistance in NRF2-overexpressing HCC cell lines. However, ischemia and NRF2 knock-down worked synergistically to decrease proliferation of NRF2-overexpressing HCC cell lines. Dose response curves of ML385, an NRF2 inhibitor, showed that ischemia induces addiction to NRF2 in cells with NRF2 alterations. Conclusion Hepatocellular carcinoma with nuclear factor E2-related factor 2 (NRF2) alterations showed resistance to ischemia, but ischemia simultaneously induced sensitivity to NRF2 inhibition. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Weiss and Nezami in this issue.

Evaluation of the Effect of Operator Experience on Outcome of Hepatic Artery Embolization of Hepatocellular Carcinoma in a Tertiary Cancer Center

RATIONALE AND OBJECTIVES

There is lack of information on the learning curve and the effect of operator's experience on the quality outcomes of transarterial hepatic embolization (TAE). The aim of this study was to evaluate the effect of operator experience on outcomes of TAE of hepatocellular carcinoma.

MATERIALS AND METHODS

Demographic characteristics and outcomes including overall survival (OS), time to local tumor progression (TLP), and post-procedure complications in patients with hepatocellular carcinoma treated with TAE were collected. Operators' experience was measured in years based on the years after completion of fellowship and the date of first embolization, and was divided into five groups: G1, less than 5 years of operator's experience (YOE) at the time of first embolization; G2, 5-10 YOE; G3, 10-15 YOE; G4, 15-20 YOE; and G5, more than 20 YOE. The effects of operator's experience and outcomes were assessed using linear regression.

RESULTS

From January 2012 to January 2015, 93 patients (age range = 30-86 years) were treated. The number of patients treated by each group was as follows: G1 = 12; G2 = 8; G3 = 23; G4 = 5; and G5 = 45. All groups were similar in regard to degree of cirrhosis, Barcelona Clinic Liver Cancer staging, and Child-Pugh score (P > .05). Median TLP was 8.8 months. TLP was 7.0, 6.8, 19.2, 7.9, and 8.2 months in G1, G2, G3, G4, and G5, respectively (P = .56). OS for 1, 2, and 3 years was 75%, 56%, and 42% for G1; 87%, 54%, and 54% for G2; 91%, 71%, and 45% for G3, 100%, 50%, and 0 for G4; and 84%, 65%, and 40% for G5.

CONCLUSION

Among interventional radiology fellowship-trained operators in a tertiary cancer center, OS, TLP, and post-procedure complications of TAE were not affected by the years of post-fellowship experience.

Pneumothorax with prolonged chest tube requirement after CT-guided percutaneous lung biopsy: incidence and risk factors

PURPOSE

To evaluate the incidence and risk factors of pneumothoraces requiring prolonged maintenance of a chest tube following CT-guided percutaneous lung biopsy in a retrospective, single-centre case series.

MATERIALS AND METHODS

All patients undergoing CT-guided percutaneous lung biopsies between June 2012 and May 2014 who required chest tube insertion for symptomatic or enlarging pneumothoraces were identified. Based on chest tube dwell time, patients were divided into two groups: short term (0-2 days) or prolonged (3 or more days). The following risk factors were stratified between groups: patient demographics, target lesion characteristics, and procedural/periprocedural technique and outcomes.

RESULTS

A total of 2337 patients underwent lung biopsy; 543 developed pneumothorax (23.2 %), 187 required chest tube placement (8.0 %), and 55 required a chest tube for 3 days or more (2.9 % of all biopsies, 29.9 % of all chest tubes). The median chest tube dwell time for short-term and prolonged groups was 1.0 days and 4.7 days, respectively. The transfissural needle path predicted prolonged chest tube requirement (OR: 2.5; p = 0.023). Other factors were not significantly different between groups.

CONCLUSION

Of patients undergoing CT-guided lung biopsy, 2.9 % required a chest tube for 3 or more days. Transfissural needle path during biopsy was a risk factor for prolonged chest tube requirement.

KEY POINTS

• CT-guided percutaneous lung biopsy (CPLB) is an important method for diagnosing lung lesions • A total of 2.9 % of patients require a chest tube for ≥3 days following CPLB • Transfissural needle path is a risk factor for prolonged chest tube time.

Locoregional Therapy for Hepatocellular Carcinoma with and without Extrahepatic Spread

PURPOSE

To evaluate the use of locoregional therapy in patients with hepatocellular carcinoma (HCC) with and without extrahepatic disease (EHD).

MATERIALS AND METHODS

Patients who underwent locoregional therapy for HCC were identified from institutional databases. Clinicopathologic and treatment characteristics were compared between patients with and without EHD. Survival and progression were assessed using the Kaplan-Meier method, and multivariate analysis was completed.

RESULTS

Of 224 patients, 39 (17%) had radiologic evidence of EHD. Patients without EHD were older than patients with EHD (68.8 y ± 10.1 vs 65.0 y ± 11.7, P = .04); underlying liver disease/function and tumor characteristics were not different. Type of locoregional therapy (hepatic artery embolization vs drug-eluting bead transarterial chemoembolization, P = .12; radiofrequency ablation + embolization, P = .07) was similar. Progression occurred in 75% (169/224) of patients. Progression-free survival (PFS) did not differ between the 2 groups (13 [10.3-15.7] mo EHD vs18 [14.6-21.4] mo no EHD, P = .13). Overall survival (OS) was 13 (4.1-21.9) months and 25 (20.4-29.6) months in the EHD and no EHD groups, respectively (P = .02). On multivariate analysis, systemic therapy after locoregional treatment was the only variable independently associated with PFS (hazard ratio [HR] 0.70 [0.49-1.00], P = .04); EHD (HR 1.60 [1.02-2.50], P = .04) and tumor size (HR 1.77 [1.21-2.58], P = .003) were independently associated with worse OS.

CONCLUSIONS

Patients with HCC and limited EHD treated with locoregional therapy had worse OS than patients without EHD; PFS was not different. Use of systemic therapy after locoregional therapy was independently associated with improved PFS in this cohort. Further prospective studies of locoregional, systemic, and combination therapies are necessary to improve outcome in these high-risk patients.

A herpes oncolytic virus can be delivered via the vasculature to produce biologic changes in human colorectal cancer

Genetically engineered herpes simplex viruses (HSVs) can selectively infect and replicate in cancer cells, and are candidates for use as oncolytic therapy. This long-term report of a phase I trial examines vascular administration of HSV as therapy for cancer. Twelve subjects with metastatic colorectal cancer within the liver failing first-line chemotherapy were treated in four cohorts with a single dose (3 x 10(6) to 1 x 10(8) particles) of NV1020, a multimutated, replication-competent HSV. After hepatic arterial administration, subjects were observed for 4 weeks before starting intra-arterial chemotherapy. All patients exhibited progression of disease before HSV injection. During observation, levels of the tumor marker carcinoembryonic antigen (CEA) decreased (median % drop = 24%; range 13-74%; P < 0.02). One of three individuals at the 10(8) level showed a 39% radiologic decrease in tumor size by cross-section and 75% by volume. HSV infection was documented from liver tumor biopsies. After beginning regional chemotherapy, all patients demonstrated a further decrease in CEA (median 96%; range 50-98%; P < 0.008) and a radiologic partial response. Median survival for this group was 25 months. During follow-up, no signs of virus reactivation were found. Multimutated HSV can be delivered safely into the human bloodstream to produce selective infection of tumor tissues and biologic effects.

Prospective, blinded comparison of helical CT and CT arterial portography in the assessment of hepatic metastasis from colorectal carcinoma

OBJECTIVE

This prospective blinded comparison of helical CT and helical CT arterial portography aimed to detect liver metastasis from colorectal carcinoma.

METHODS AND MATERIALS

50 patients with colorectal carcinoma were evaluated comparing helical CT with helical CT arterial portography. Each imaging study was evaluated on a 5-point ROC scale by radiologists blinded to the other imaging findings, and the results were compared, with the surgical and pathologic findings as the gold standard.

RESULTS

Of the 127 lesions found at pathology identified as metastatic colorectal cancer, helical CT correctly identified 85 (69%) and CT portography 96 (76%). When subgroups with lesions <3 cm (48 patients) and patients with maximum tumor size <3 cm (18 patients) were considered, CT portography was always better than helical CT in terms of sensitivity, specificity, positive predictive value, and negative predictive value. ROC analysis adjusting for multiple lesions per patient revealed significantly greater area under the curve (AUC) for the subgroup of lesions <3 cm (CT-AUC of 77% and CT portography AUC of 81%; P = 0.002).

CONCLUSIONS

For identification of large metastases, helical CT and CT portography have similar yield. However, for detection of small liver metastases, CT portography remains superior for lesion detectability.

Phase I, Open-Label, Dose-Escalating Study of a Genetically Engineered Herpes Simplex Virus, NV1020, in Subjects with Metastatic Colorectal Carcinoma to the Liver

Current regimens of systemic chemotherapy result in only modest lengthening of survival in patients with advanced stage, liver-dominant, metastatic colorectal cancer who have failed first-line chemotherapy. The objective of this study was to investigate the safety and tolerability of NV1020, a replication-competent, attenuated, genetically engineered herpes simplex virus type 1 (HSV-1), in patients with hepatic colorectal metastases refractory to first-line chemotherapy. A phase I, open-label, dose-escalating study of a single 10-min hepatic arterial infusion of NV1020 in four cohorts. Three patients in each cohort received doses of 3 x 10(6), 1 x 10(7), 3 x 10(7), and 1 x 10(8) plaque-forming units. Adverse events were either mild or moderate in severity, and self-limiting. Only three serious adverse events (one transient rise in serum y-glutamyltransferase, one diarrhea, and one leukocytosis) experienced by three patients were considered to be possibly or probably related to NV1020. There were no deaths during the study, and there was no evidence of disseminated herpes infection. Viral presence was detected in only one saliva sample and two serum samples from one asymptomatic patient in the highest dose cohort. In the first week after viral administration only rare and minor increases were noted for tumor necrosis factor-alpha (six samples; three patients; peak, 40 pg/ml), interleukin (IL)-1 (two samples; two patients; peak, 28 pg/ml), and interferon-y (four samples; two subjects; peak, 54 pg/ml). No IL-2 was detected. Mild liver enzyme elevations were self-limiting and not associated with clinical symptoms. We conclude that NV1020, a genetically engineered but replication-competent HSV-1 oncolytic virus, can be safely administered into the hepatic artery without significant effects on normal liver function.

Factors associated with pneumothorax and pneumothorax requiring treatment after percutaneous lung biopsy in 443 consecutive patients

PURPOSE

To describe patient- and procedure-related factors associated with post-biopsy pneumothorax and those that require intervention.

MATERIALS AND METHODS

Patient and procedure data from all lung biopsies performed at a single center between January 2000 and July 2001 were recorded prospectively. Data included patient demographics, lesion size, lesion depth from skin, needle size, number of passes, patient position during biopsy, imaging method used (computed tomography/fluoroscopy), if sedation was used, occurrence of pneumothorax and whether the pneumothorax required treatment. Patient charts were retrospectively reviewed to determine smoking history, as well as previous ipsilateral chest surgery or radiation therapy. Univariate and multivariate analysis was performed, and P <.05 was considered significant.

RESULTS

Four-hundred fifty-three biopsies were performed on 443 patients. One-hundred six patients (23.4%) had post-biopsy pneumothorax and 31 patients (6.8% overall, 29.2% of pneumothorax group) required intervention. By univariate analysis, increased patient age, smaller lesion size, increased depth from skin, supine position, and no history of surgery were significant predictors of biopsy-related pneumothorax. However, only increased patient age, supine position, no history of ipsilateral surgery, and history of smoking were associated with pneumothorax that required intervention. By multivariate analysis, increased patient age, smaller lesion size, and no history of surgery predicted pneumothorax; supine position, history of smoking, and no history of ipsilateral surgery predicted which patients with pneumothorax would require treatment.

CONCLUSION

Independent risk factors for pneumothorax include increased patient age, smaller lesion size, and no history of surgery. Previous surgery and prone positioning during biopsy appear to provide a "protective effect" against clinically significant post-biopsy pneumothorax.

Percutaneous laser disc decompression: an update--Spring 1992

Percutaneous laser disc decompression (PLDD) is being performed in multiple centers in the United States, Germany, Austria, France, and Switzerland with the Nd:YAG having the longest follow up at more than 75 months. The experience with this procedure, in both humans and animals, carried out over the past decade is presented along with a detailed discussion of the surgical procedure. Conditions that favor such surgery and contraindications to the procedure are also presented. There are a number of important advantages to PLDD that make it a procedure that merits continued investigation. Because PLDD is relatively noninvasive, it can be repeated. Because there is no cutting, there is no perispinal scar formation, with possible future pain secondary to entrapment of nerves by scar. Because of its effectiveness for treatment, the laser, in this application, should prove to be an important addition to the spinal surgeon's armamentarium.