A novel role of the tumor size in pancreatic cancer as an ancillary factor for predicting resectability

Background: Pancreatic adenocarcinoma (PCA) is a devastating disease. Only surgery can provide effective treatment. The resectability of pancreatic cancer is mainly determined by image studies. However, half of the patients deemed as operable, radiologically, are found to be inoperable during surgery. Previously, we have showed that both CA 19-9 and tumor size could predict PCA resectability, independently. Here, we aimed to determine the cut-off value for tumor size permitting PCA resectability by receiver operating characteristic (ROC) curve analysis. Materials and Methods: We retrospectively reviewed 372 patients undergoing surgery for histopathologically proven PCA. We compared tumor sizes of patients in resectable and unresectable groups and analyzed them by the ROC curve. Results: The tumor size in unresectable groups is significantly larger than that in the resectable group. The area under the ROC curve was 0.73 (95% confidence interval [CI], 0.665-0.789), which represented a good correlation between the tumor size and pancreatic cancer resectability. The PCA patients with a tumor diameter of > 4.8 cm had a 5.043-fold higher chance of unresectability than did those with a tumor diameter < 4.8 cm (odds ratio, 5.043; 95% CI, 3.221-7.894). Conclusions: A tumor diameter > 4.8 cm is a potential ancillary parameter for determining the resectability of PCA in addition to traditional image studies. Diagnosis laparoscopy may be indicated for radiologically resectable PCA patients with tumor size > 4.8 cm to prevent unnecessary laparotomy.