Stereotactic body radiation therapy showed promising rates of local control and survival in patients diagnosed with early-stage hepatocellular carcinoma, according to a North American pooled analysis presented at Gastrointestinal Cancers Symposium.
“Stereotactic body radiation therapy is a noninvasive, ablative treatment for patients with hepatocellular carcinoma,” Ashwathy Susan Mathew, DNB, MBBS, MD, clinical fellow in the department of radiation oncology at Princess Margaret Cancer Centre, and colleagues wrote. “Outcomes similar to radiofrequency ablation have been observed post-stereotactic body radiation therapy for early-stage hepatocellular carcinoma, primarily from Asia. There are few North American series with long-term follow-up.”
Mathew and colleagues hypothesized that patients with HCC without vascular invasion who were ineligible for or experienced recurrence after standard local treatments would have improved OS after SBRT than historical controls treated with trans-arterial chemoembolization (TACE).
The collaborative analysis included 310 patients (median age, 69.6 years) with stage I to stage IIIa HCC treated with radical-intent SBRT at a minimum of 4.5 Gy/fraction between June 2003 and December 2016.
Overall, 23% of patients were Child-Pugh class B (21%) or C (2%), and 40% previously had unsuccessful liver-aimed therapies. Median tumor size was 2.4 cm (range, 0.5-18.1).
OS served as the study’s primary endpoint. Secondary endpoints included local progression, intrahepatic progression, distant progression and toxicity.
Median follow-up was 19.9 months.
The median prescribed dose of SBRT was 39 Gy in five fractions (range, 14-60 Gy in 2-6 fractions). The median biologically equivalent dose was 78.75 Gy (range, 23.8-180).
Researchers reported local control rates of 91.5% at 1 year, and 82.6% at 3 years and 5 years.
Only 4.2% of patients showed progression of the irradiated lesion as the initial site of recurrence.
Multivariable analysis found that the use of a breath-hold motion approach was significantly correlated with local control (P = .0098), but T stage, size and dose were not.
Overall, 37.9% of patients achieved 3-year OS and 23.5% achieved 5-year OS.
Researchers observed improved rates of 3-year OS among patients with Child Pugh A disease vs. Child Pugh B/C disease (43% vs. 22.6%) and among patients with alpha-fetoprotein levels less than 10 mg/L compared with 10 mg/L or greater (44.5% vs. 29.6%).
A total of 8.4% of patients received liver transplant after SBRT. These patients showed superior rates of 3-year OS (92% vs. 32.8%).
On multivariable analysis, improved OS appeared associated with baseline Child-Pugh A score (median OS, 30.3 months vs. 17.6 months; HR = 0.47; 95% CI, 0.33-0.66) and transplant after SBRT (median OS, not reached vs. 24 months; HR = .06; 95% CI, 0.01-0.23), whereas poorer OS was associated with higher pretreatment alpha-fetoprotein levels (21.1 months vs. 32.9 months; HR = 1.59; 95% CI, 1.17-2.16).
Grade 3 or higher luminal gastrointestinal organ toxicity occurred in 2.5% of patients, whereas a decrease in Child-Pugh score of two points or more occurred in 16.7% of patients 3 months following SBRT.
Grade 3 and higher liver enzyme elevations occurred in 12.6% of patients at baseline and in 8.1% at 3 months following SBRT. – by Jennifer Byrne
Mathew AS, et al. Abstract 350. Presented at: Gastrointestinal Cancers Symposium; Jan. 17-19, 2019; San Francisco.
Disclosures: Mathew reports an immediate family member is employed with Sanofi. Please see the abstract for all other authors’ relevant financial disclosures.