Background/Objectives: Pancreatic cancer is the third leading cause of death related to cancer. The only possible cure presently is complete surgical resection; however, this is limited by difficulty in clearly defining tumor margins. Enhancement of the visualization of pancreatic ductal adenocarcinoma (PDAC) tumor margins using near-infrared dye-conjugated tumor-specific antibodies was pioneered by using anti-CEA, anti-CA19.9, and anti-MUC5AC in orthotopic mouse models of pancreatic cancer. Recently, an antibody to Mucin 4 (MUC4) conjugated to a fluorescent probe has shown promise in targeting colon tumors in orthotopic mouse models. Methods: In the present study, we targeted pancreatic cancer using an anti-MUC4 antibody conjugated to IRDye800 (anti-MUC4-IR800) in orthotopic mouse models. Two pancreatic cancer human cell lines were used, SW1990 and CD18/HPAF. Results: Anti-MUC4-IR800 targeted the two pancreatic cancer cell line tumors in orthotopic mouse models with high tumor-to-pancreas ratios and high tumor-to-liver ratios, with greater targeting seen in SW1990. Conclusions: The present results suggest anti-MUC4-IR800’s potential to be used in fluorescence-guided surgical resection of pancreatic cancer.

Background/Purpose: The only potentially curative procedure for pancreatic cancer is R0 resection, which is difficult to achieve due to poorly defined tumor margins. In the present study, we used an anti-CA19-9 antibody conjugated to a near-infrared fluorophore in orthotopic mouse models to target and visualize pancreatic cancer. Methods: Orthotopic models of the human pancreatic cancer cell lines SW1990 and BxPC3 were established by implanting tumor fragments into the pancreas of athymic nude mice. Anti-CA19-9 and control IgG were conjugated with IRDye800CW. Mice received 50 µg of CA19-9–IRDye800CW or IgG-IRDye800CW via tail-vein injection and were imaged after 72 h. MIA PaCa-2, a CA19-9-negative cell line, was used in subcutaneous models to assess targeting specificity. Results: Using the LI-COR Pearl imaging system in the SW1990 model, the tumor-to-pancreas ratio (TPR) was 4.51 (±0.74), and the tumor to the liver ratio (TLR) was 3.05 (±0.60) with CA19-9-IRDye800CW, while the TPR was 1.67 (±0.16) and the TLR was 0.95 (±0.05) for the non-specific control IgG–IRDye800CW. Using a clinically available fluorescence laparoscope, CA19-9-1RDye800CW demonstrated a TPR of 2.34 (±0.44) and a TLR of 2.23 (±0.49), compared to 1.11 (±0.13) and 0.69 (±0.07), respectively, for IgG-IRDye800CW in the SW1990 orthotopic model. In the BxPC3 models, the TPR was 3.82 (±0.55) and the TLR was 4.13 (±0.77) for CA19-9-IRDye800CW compared to 2.40 (±0.31) and 1.49 (±0.23), respectively, for IgG-IRDye800CW. Conclusions: CA19-9-IRDye800CW provided specific in vivo targeting of two human pancreatic cancer cell lines in orthotopic nude mouse models with superior TPRs and TLRs compared to IgG-IRDye800CW. This tumor-specific fluorescent CA19-9 antibody is a promising clinical tool for improved visualization of pancreatic cancer.