Impaired immunogenicity after vaccination for SARS-CoV-2 in patients with gastrointestinal cancer: does tumor entity matter?

BACKGROUND: SARS-CoV-2 immunogenicity in patients with gastrointestinal cancer (GI cancer) following second and third vaccination was analyzed.

METHODS: A total of 125 patients under active anticancer therapy or in follow-up care were included in this prospective study. Seroprevalence of SARS-CoV-2 anti-spike and surrogate neutralization antibodies (NABs) was measured.

RESULTS: Four weeks after second vaccination, adequate titers of SARS-CoV-2 anti-spike immunoglobulin G (IgG) [≥282.0 binding antibody units (BAU)/mL] were found in 62.2% of patients under treatment versus 96.3% of patients in follow-up care (P<0.01). Sufficient titers of SARS-CoV-2 surrogate NAB (≥85.0%) were found in 32.7% of patients under treatment versus 70.6% in follow-up care (P<0.01). Titers of SARS-CoV-2 anti-spike IgG were especially low in patients with colorectal cancer (CRC). For SARS-CoV-2 surrogate NAB, patients with hepatocellular carcinoma (HCC) and with pancreaticobiliary cancer showed the lowest titers (P<0.01). SARS-CoV-2 anti-spike IgG and SARS-CoV-2 surrogate NAB were associated with a correlation coefficient of 0.93. Reaching a titer of SARS-CoV-2 anti-spike IgG ≥482.0 BAU/mL, protective levels of SARS-CoV-2 surrogate NAB (≥85.0%) could be assumed. Following booster vaccination, all patients reached effective antibody titers.

CONCLUSIONS: Patients with active GI cancer showed impaired immunogenicity after second SARS-CoV-2 vaccination which was overcome by booster vaccination. Our findings were tumor-related and pronounced in patients with CRC and HCC. Waning immunity over time and antibody escape phenomena by variant of concern Omicron must be considered in these especially vulnerable patients.

2023 Journal of Gastrointestinal Oncology. All rights reserved.

PMID: 37435197