Background Antibiotic treatment (ABT) affects the outcome of cancer patients treated with immune
checkpoint inhibitors (ICIs) and chemotherapy, possibly by altering the gut microbiome.
We investigated the impact of ABT on overall survival (OS) and progression free survival
(PFS) in patients with advanced HCC treated with sorafenib.
Methods HCC patients treated with sorafenib between 05/2006 and 03/2020 at the Medical University
of Vienna were retrospectively analyzed. ABT was defined as antibiotic use within
30 days prior to or after sorafenib initiation.
Results Of 206 patients, the majority was male (n = 171, 83 %) with a mean age of 66±9.6
years. Half of patients (n = 94, 46 %) had impaired liver function (Child-Pugh stage
B). Median time of follow-up was 10.8 (95 %CI: 9.2-12.3) months. ABT was administered
in 23 (11 %) patients due to different types of proven or clinically suspected bacterial
infections (n = 16, 8 %) and hepatic encephalopathy (n = 7, 30 %). Median duration
of ABT was 14 (IQR: 12-30) days. The ABT group had a significantly shorter median
OS (4.7 (95 %CI: 3.2-6.1) months vs. 11.4 (95 %CI: 9.9-12.9) months, p = 0.012), which
was confirmed in multivariable analysis (HR: 1.91 (95 %CI: 1.1-3.2), p = 0.014). Similarly,
PFS trended to be shorter in the ABT group (3.5 (95 %CI: 1.6-5.4) months vs. 4.8 (95 %CI:
3.9-5.7) months, p = 0.099). None of the 10 patients with complete or partial response
was found in the ABT group.
Conclusions ABT was independently associated with worse outcome in sorafenib-treated HCC patients.
Prospective studies are needed to elucidate the underlying mechanism.
