Localization of CEACAM5-Positive Metastatic Nodules
tumor, uncinate tumors
DISEASE, TUMOR, COLORECTAL ADENOCARCINOMA, PANCREATIC ADENOCARCINOMA
A total of 5 patients were recruited for the control group. One patient (patient 5) did not undergo surgical resection because of abnormal preoperative cardiac clearance findings that were not deemed related to SGM-101 infusion. The mean (SD) lesion size in the control cohort was 1.33 (0.48) cm. Patients 1 and 2 had elevated serum CEA markers, whereas patients 3 and 4 had normal serum CEA levels. Of the 4 patients who underwent surgical intervention, those with 2+ and 3+ tissue CEACAM5 expression had excellent tumor fluorescence, with a mean (SD) tumor to background ratio (TBR) of 3.11 (0.45) (Patient 1 had 2 concerning nodules on preoperative workup (Patient 3 had known stage 3 (T2N3M0) pancreatic adenocarcinoma that was operated on 6 months earlier. This patient had no serum CEA elevation. The nodule was not visualized in vivo but demonstrated mild CEACAM5 (1+) staining with fluorescence that was detected on ex vivo assessment. Retrospective analysis of the index operation revealed a normal serum CEA level at the time of pancreaticoduodenectomy with mild CEACAM5 staining on uncinate tumors. Conversely, in patient 4 with colorectal adenocarcinoma, who never had serum CEA elevation but had strong CEACAM5 staining at the time of index operation, nodules suggestive of disease were visualized in vivo and ex vivo and were associated with CEACAM5 staining (2+). Compared with patients 1 and 2, the nodule was significantly smaller (0.51 cm) and produced visible but statistically significantly lower fluorescence emission (mean [SD] TBR, 1.89 [0.33]; 