Surgery or external beam radiation for solitary small hepatocellular carcinoma

Background

There is little evidence on the efficacy of external beam radiation (EBR) compared to liver resection (LR) for patients with solitary small (≤5 cm) hepatocellular carcinoma (HCC).

Objective

We aimed to investigate this clinical question based on the Surveillance, Epidemiology, and End Results (SEER) database.

Method

SEER database was used to identify 416 patients with solitary small HCC who underwent LR or EBR. Survival analysis and Cox proportional hazards model were performed to evaluate overall survival (OS) and identify prognostic factors for OS. Propensity score matching (PSM) method was used to adjust the baseline characteristics of the two groups.

Result

Before PSM, the 1- and 2-year OS rates were 92.0% and 85.2% in the LR cohort and 76.0% and 60.3% in the EBR cohort, respectively (P < 0.001). After PSM, LR (n = 62) demonstrated improved OS compared to EBR (n = 62) (1-year OS rate: 96.5% vs. 76.0%; 2-year OS rate: 89.3% vs. 60.3%, P < 0.001), despite stratification on tumor size. Multivariate Cox regression analysis indicated that treatment type was the only factor associated with OS (hazard ratio: 5.297; 95% confidence interval: 1.952-14.371, P = 0.001).

Conclusion

For patients with solitary small HCC, LR may offer better survival outcomes than EBR.

MiR-320b/RAD21 axis affects hepatocellular carcinoma radiosensitivity to ionizing radiation treatment through DNA damage repair signaling

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world and is associated with high mortality. Ionizing radiation (IR)-based therapy causes DNA damage, exerting a curative effect; however, DNA damage repair signaling pathways lead to HCC resistance to IR-based therapy. RAD21 is a component of the cohesion complex, crucial for chromosome segregation and DNA damage repair, while it is still unclear whether RAD21 is implicated in DNA damage and influences IR sensitivity in HCC. The current research explores the effect and upstream regulatory mechanism of RAD21 on IR sensitivity in HCC. In the present study, RAD21 mRNA and protein expression were increased within HCC tissue samples, particularly within IR-insensitive HCC tissues. The overexpression of RAD21 partially attenuated the roles of IR in HCC by promoting the viability and suppressing the apoptosis of HCC cells. RAD21 overexpression reduced the culture medium 8-hydroxy-2-deoxyguanosine concentration and decreased the protein levels of γH2AX and ATM, suggesting that RAD21 overexpression attenuated IR treatment-induced DNA damage to HCC cells. miR-320b targeted RAD21 3'-UTR to inhibit RAD21 expression. In HCC tissues, particularly in IR-insensitive HCC tissues, miR-320b expression was significantly downregulated. miR-320b inhibition also attenuated IR treatment-induced DNA damage to HCC cells; more importantly, RAD21 silencing significantly attenuated the effects of miR-320b inhibition on IR treatment-induced DNA damage, suggesting that miR-320b plays a role through targeting RAD21. In conclusion, an miR-320b/RAD21 axis modulating HCC sensitivity to IR treatment through acting on IR-induced DNA damage was demonstrated. The miR-320b/RAD21 axis could be a novel therapeutic target for further study of HCC sensitivity to IR treatment.

Clinical results of proton beam therapy for hepatocellular carcinoma over 5 cm

AIM

This study aimed to evaluate the safety and efficacy of proton beam therapy for large hepatocellular carcinoma (HCC).

METHODS

Twenty-four patients with a HCC larger than 5.0 cm were treated with proton beam therapy at our institution between 2008 and 2015.

RESULTS

The clinical stage was I in 2 patients, II in 9 patients, and IIIB in 13 patients. Ten of the 24 patients were not surgical candidates because of advanced HCC or old age. Median tumor size was 90 mm (range, 50-180 mm). Median total dose delivered was 72.6 Gray-equivalents (GyE) in 22 fractions (range, 60.8-85.8 GyE). Median follow-up period was 17.5 months (range, 3-70 months). Local control rate at 2 years was 87.0%. The 2-year overall survival rate was 52.4%. The predominant tumor progression pattern was new hepatic tumor development outside the irradiated field. No acute or late treatment-related toxicity of grade 3 or higher, other than dermatitis, was observed.

CONCLUSIONS

These results show that proton beam therapy offers an effective and safe method for treating patients with large HCC. Proton beam therapy represents a promising method for treatment of large-volume HCC.