SCCA-IgM determination may detect patients at risk for Barrett’s oesophagus, oesophageal cancer
Determination of the immunocomplexed form of squamous cell carcinoma antigen–immunoglobulin M (SCCA-IgM) helps identify patients at risk for Barrett’s oesophagus (BO) or oesophageal adenocarcinoma (OAC), and allows the stratification of BO patients in subgroups with different cancer risk, according to the results of a phase III study.
Patients with BO/OAC had significantly higher median SCCA-IgM compared with controls (p=0.0001). SCCA-IgM levels above the cutoff led to 33-times higher relative risk of harbouring BO or OAC (p=0.0001).
Patients “at risk,” with long or dysplastic BO, had SCCA-IgM levels significantly higher than those with short nondysplastic BO (p=0.035). SCCA-IgM levels above the cutoff were associated with eight times higher relative risk of having BO “at risk.”
SCCA was expressed in Barrett mucosa but not in cardiac metaplasia.
“Because of the still limited number of controls, large, prospective studies are required to confirm this evidence,” the authors said.
In this study, the authors determined SCCA-IgM levels (enzyme-linked immunosorbent assay) in 231 patients who were prospectively recruited (71 with BO, 53 with OAC and 107 controls), including 42 blood donors and 65 patients with gastro-oesophageal reflux.
Receiver operating characteristic curves were used to calculate SCCA-IgM cutoffs between BO/OAC and controls, as well as for BO “at risk” vs short nondysplastic BO. The authors obtained immunostaining for SCCA-IgM in a subgroup of patients.
“The cost-effectiveness of surveillance in BO is still debated and the use of biomarkers in screening and surveillance still not recommended,” the authors said. “No information is available regarding SCCA-IgM determination in BO.”