Miho Nakao

Slight Dilatation of the Main Pancreatic Duct and Presence of Pancreatic Cysts as Predictive Signs of Pancreatic Cancer: A Prospective Study

PURPOSE To prospectively determine whether slight dilatation of the main pancreatic duct and pancreatic cysts detected at ultrasonography (US) are predictive signs of pancreatic cancer. MATERIALS AND METHODS The research protocol was approved by the institutional review board, and written informed consent was obtained from all participants. One thousand fifty-eight subjects (age range, 36-80 years; mean, 61.8 years) with various kinds of abnormal US findings in the pancreas were enrolled from 1999 to 2002, after exclusion of pancreatic neoplasm and other malignant diseases. The endpoint was the subsequent development of pancreatic cancer, and the outcome was determined at the end of December 2007. To identify independent predictive variables for the subsequent development of pancreatic cancer, various baseline characteristics were examined by using a Cox regression model and a Cox proportional hazards model. The cumulative incidence of pancreatic cancer was estimated by using the Kaplan-Meyer method. RESULTS During the mean follow-up of 75.5 months (+/- 17.3[standard deviation]), pancreatic cancer subsequently developed in 12 of 1058 subjects. The risk of pancreatic cancer was significantly elevated in subjects with slight dilatation (> or = 2.5 mm) of the main pancreatic duct or presence of cyst (s) (> or = 5 mm). The respective hazard ratios were 6.38 (P = .018) and 6.23 (P = .003). For subjects with both findings, the 5-year cumulative risk of pancreatic cancer was 5.62% (95% confidence interval: .37%, 13.03%), and the age-and sex-adjusted hazard ratio compared with the risk in the absence of these findings was 27.50 (P = .002). CONCLUSION Main pancreatic duct dilatation (> or = 2.5 mm) and presence of a pancreatic cyst (> or = 5 mm) were both strong independent predictors of the subsequent development of pancreatic cancer. (c) RSNA, 2010.

Periodic ultrasonography checkup for the early detection of pancreatic cancer: preliminary report.

Objectives: To introduce our new ultrasonography (US) system for early detection of pancreatic cancer and report its preliminary results. Methods: The basis of the system is periodic checkups for high-risk patients. Abnormal US findings, such as main pancreatic duct dilatation or pancreatic cyst(s), were indicated as high risk. Special US focusing on the pancreas and a set of serum tests were performed every 3 or 6 months. When some development was detected, additional examinations, including ERP with pancreatic juice cytology, were performed. There were 1098 subjects admitted through the end of May 1998, and the outcomes of these subjects were followed through the end of March 2002. Results: Three hundred ninety-three patients were registered for the periodic checkups. Pancreatic ductal adenocarcinoma was detected in 44 patients: 41 by the initial examination and 3 by the periodic checkups. Surgical resection was performed in 40.9%, and 50% of the resected patients were in stages 0–III. The cumulative 3-year survival rates of the resected patients were 100% in stages 0 and III, 75% in stage I, and 33% in stage IVa. Conclusion: Periodic US checkups for patients with main pancreatic duct dilatation or cyst(s) are considered to be an effective method for the early detection of pancreatic cancer.

Evaluating the ability to detect pancreatic lesions using a special ultrasonography examination focusing on the pancreas

PURPOSE The ability to detect pancreatic cysts was compared between special ultrasonography (US) examination focusing on the pancreas (special pancreatic US) and routine upper abdominal ultrasonography to objectively assess the ability of the former to detect cysts. SUBJECTS AND METHODS Of 3704 patients who underwent special pancreatic US at our hospital, 186 underwent routine upper abdominal US within six months, had pancreatic cysts, and underwent magnetic resonance imaging (MRI). In these patients, 447 cysts measuring ≥5mm were detected via MRI, which was used as the gold standard. The ability and sensitivity of the US modalities to detect each cyst was determined. RESULTS The sensitivity of special pancreatic US was 92.2% (95% confidence interval [CI], 89.7%-94.7%) and that of routine upper abdominal US was 70.2% (95% CI, 66.0%-74.5%). McNemar test (Stata Version 13.1) revealed a significant difference in the cyst (≥5mm) detection sensitivity between the two modalities (p<0.001). An analysis stratified by patients similarly revealed a significant difference between the two modalities (p<0.001). The cyst detection sensitivity was also analyzed in various parts of the pancreas. The sensitivity of special pancreatic US was 88.7% for the uncinate process and inferior head, 97.5% for the head, 97.1% for the body, 89.0% for the body-tail, and 66.7% for the tail, whereas that of routine upper abdominal US was 74.2% for the uncinate process, 69.5% for the head, 81.0% for the body, 67.0% for the body-tail, and 26.7% for the tail. The McNemar test revealed significant differences in the sensitivity of the two modalities for all pancreatic parts (p<0.001-0.016). CONCLUSION Compared with routine upper abdominal US, special pancreatic US had higher sensitivity in detecting pancreatic cysts.