Surgical Management of Pancreatic Cancer

Drs. Ahrendt and Pitt should be congratulated on a comprehensive and well-presented review of the surgical management of pancreatic cancer. Unfortunately, pancreatic cancer continues to be a major cause of cancer-related death. The majority (80%) of patients still present with unresectable locally advanced or metastatic disease. Preoperative Imaging Modalities and Laparoscopy In the 1980s, several surgical series reported dismal resectability rates of 25%. Due to poor imaging techniques, most patients were being staged intraoperatively by manual palpation of the plane between the tumor and the mesenteric vessels. Patients found to be unresectable had then undergone a major laparotomy with little benefit, and postoperative recovery delayed their treatment options. Dual-phase contrast-enhanced spiral computed tomography (CT) has revolutionized both the detection and staging of pancreatic cancer. The accuracy with which spiral CT predicts resectability ranges from 75% to 90%.[1] CT criteria for surgical resectability include (1) the absence of extrapancreatic disease, (2) a patent superior mesenteric vein-portal vein confluence, and (3) no direct tumor extension into the celiac axis or superior mesenteric artery. Investigators at the Massachusetts General Hospital reported that 24% of patients thought to have resectable pancreatic cancers on CT scan had occult metastatic disease found on diagnostic laparoscopy.[2] Patients found to have occult disease were spared an unnecessary laparotomy. However, with improved state-of-the-art spiral CT, routine use of staging laparoscopy may not be easily justified.[1] Ultrasound and PET More recently, endoscopic ultrasound has been shown to be helpful in detecting small pancreatic cancers. In our practice, the technique is used in patients with a clinical suspicion of pancreatic cancer and an equivocal or negative CT scan. Although the procedure is very user-dependent, it offers the additional benefit of image-guided tissue diagnosis. More experience with whole-body positron-emission tomography may help stage patients more accurately and also may be able to differentiate benign from malignant pancreatic tumors. Surgical Results and Pathologic Analysis Despite improved resectability rates and decreased perioperative mortality at high-volume surgical centers, long-term survival following pancreaticoduodenectomy remains poor. Median survival in most series ranges from 18 to 20 months, and 5-year actuarial survival rates range from 7% to 25%. Patterns of failure after curative resection for pancreatic carcinoma involve both local recurrence (60%) and distant hepatic metastases (60%).[3] Even among patients thought to be resectable for cure by preoperative CT and intraoperative exploration, 50% will have either gross or microscopic involvement of the surgical margins.[4] The most commonly involved is the retroperitoneal margin, which corresponds to the tissue along the proximal 3 to 4 cm of the superior mesenteric artery wall. Several studies have demonstrated that patients with grossly or microscopically positive surgical margins have a median survival of only 8 to 10 months, similar to the survival of patients with unresectable locally advanced tumors. From a technical aspect, failure to mobilize the superior mesenteric-portal vein may result in a positive margin due to incomplete removal of the uncinate process and the mesenteric soft tissue adjacent to the superior mesenteric artery. New treatment strategies to maximize margin-negative resections in patients with pancreatic cancer will hopefully be one component of improved locoregional tumor control. Both the evaluation of future innovative treatment strategies and the development of reproducible