[Endoscopy in the diagnosis and staging of pancreatic cancer]

Pancreatic carcinoma is the fourth cause of death for cancer in the USA, carrying a dismal prognosis and poor overall survival. Unfortunately, resection for cure is feasible in a limited number of patients, thus confirming the need for an early diagnosis and accurate preoperative staging to select patients potentially resectable from those candidates to palliative treatment. Among imaging modalities, endoscopic procedures (endoscopic retrograde cholangiopancreatography, laparoscopy and endoscopic ultrasonography) play a key role in the diagnosis and staging of pancreatic tumors. Endoscopic retrograde cholangiopancreatography (ERCP) allows direct visualization of the main pancreatic duct and its side branches with their morphologic alterations, which are present in most cases of pancreatic cancer. The method is very sensitive in experienced hands, with diagnostic accuracy over 95%. The most common finding in pancreatic cancer is the stricture of the pancreatic duct, the bile duct, or both. Moreover, ductal brush cytology and K-ras mutation analysis can be performed during ERCP, possibly improving the diagnostic accuracy of the technique. Diagnostic laparoscopy provides detection of small (< 1 cm) liver metastases and peritoneal implants of tumor which cannot be visualized by any other imaging modality, with the possibility to biopsy under direct vision suspicious areas or to perform peritoneal lavage. The adjunct of laparoscopic ultrasound improves the staging capabilities of the technique for pancreatic cancer (retroperitoneal spread, vascular invasion). Endoscopic ultrasonography (EUS) is able to produce great detail of the pancreatic parenchyma and regional lymph nodes. It is especially sensitive in the detection of small pancreatic masses which cannot be imaged with other modalities. EUS has the additional advantage of directing transduodenal fine-needle aspiration biopsies. Presently it is the most sensitive technique for the diagnosis and locoregional staging of pancreatic cancer, but limits have been identified in the lack of specificity (differentiation between malignant tumor and focal pancreatitis) and its operator-dependency. Reported is our experience with EUS in the diagnosis and staging of pancreatic cancer. Over a seven-year period 43 patients with pancreatic tumors were staged with EUS preoperatively. Twenty-two patients were submitted to surgery at our Institution and EUS findings were compared with results of pathology or surgical exploration. EUS provided sensitivity of 100% for the diagnosis of pancreatic cancer, while its accuracy for staging tumor infiltration, lymph node involvement and vascular invasion was 86.4%, 69.2% and 77.8%, respectively. Despite improvements in the noninvasive imaging modalities, endoscopic techniques are likely to remain established methods for the diagnosis and staging of pancreatic cancer. EUS with fine-needle aspiration biopsy is probably the most promising, followed by laparoscopy (and laparoscopic ultrasound) which is essential to rule out small peritoneal implants and liver metastasis.