Immediate Postoperative AbnobaVISCUM® F as an Adjuvant Treatment in Patients Receiving Standard Care after Pancreatic Cancer Resection

Abstract

Purpose: AbnobaVISCUM^® F is an anti-malignant tumor agent derived from Viscum album, a mistletoe species parasitic to ash trees. It is known to exert anticancer effects by activating the patient's immune system without directly inducing tumor toxicity. We retrospectively investigated the anticancer effect of AbnobaVISCUM^® F in patients with resected pancreatic cancer.

Materials and methods: We reviewed a total of 985 patients who underwent radical resection for pancreatic cancer between January 2005 and August 2022 at Severance Hospital, Seoul, Korea. Patients were divided into two groups based on whether Abnoba VISCUM^® F was administered (Viscum group) or not (Control group), and clinicopathologic characteristics, disease-free survival (DFS) and overall survival (OS) were compared after propensity score matching (PSM).

Results: Of the 985 patients, 310 received Viscum therapy at least 12 times (Viscum group), while 590 did not receive it at all (Control group). After PSM, both groups showed similar DFS (p=0.518), whereas the Viscum group showed superior OS (p<0.001). Subgroup analyses revealed better OS for the Viscum group in T1 (p=0.014), T2 (p=0.012), N0 (p=0.010), N1 (p=0.001), R0 resection patients (p<0.001), and in patients who underwent no adjuvant chemotherapy or chemotherapy regimens other than FOLFIRINOX (p<0.001). Multivariable analysis identified Viscum therapy as an independent factor for improved OS (hazard ratio 0.601, p< 0.001), although it did not significantly impact DFS.

Conclusion: Viscum treatment significantly improved OS in patients with completely resected stage I and II pancreatic cancer, particularly among those unable to tolerate adjuvant chemotherapy. This anticancer effect, based on immune enhancement, should be further investigated, and large-scale randomized controlled study is warranted.

Keywords: Viscum album; adjuvant treatment; pancreatic cancer.

Fig. 1. Survival analysis of Control and Viscum groups. (A) The Viscum group demonstrated superior outcomes in both DFS (2-year DFS: Control group, 29.8% vs. Viscum group, 37.3%, p=0.047). (B) OS (2-year OS: Control group, 53.5% vs. Viscum group, 74.7%, p<0.001) compared to the Control group. DFS, disease-free survival; OS, overall survival.

Fig. 2. Survival analysis of control and viscum groups after PSM. (A) The superior DFS of the Viscum group diminished after PSM (2-year DFS: Control group, 32.6% vs. Viscum group, 31.5%; p=0.518). (B) However, the OS in the Viscum group remained superior even after PSM (2-year OS: Control group, 54.6% vs. Viscum group, 70.1%; p<0.001). PSM, propensity score matching; DFS, disease-free survival; OS, overall survival.

Fig. 3. Subgroup survival analysis according to the chemotherapy regimen. (A) For patients who did not receive adjuvant chemotherapy or received chemotherapy with gemcitabine or other regimens (n=304), the Viscum group (n=151) exhibited superior OS compared to the Control group (n=153) (2-year OS: Control group, 51.6% vs. Viscum group, 67.9%; p<0.001), without a difference in DFS (2-year DFS: Control group, 32.0% vs. Viscum group, 28.8%; p=0.405). (B) However, among patients who received adjuvant FOLFIRINOX chemotherapy (n=75), there were no survival differences between the two groups: Control group (n=36; 2-year DFS, 35.1%) vs. Viscum group (n=39; 2-year DFS, 41.0%; p=0.884) and OS (Control group, 67.2% vs. Viscum group, 78.0%; p=0.175). DFS, disease-free survival; OS, overall survival.