FORT LAUDERDALE, Fla--Clinicians now have at their disposal more accurate staging technologies for pancreatic cancer than were available in the past.
The appropriate roles of these technologies, particularly endoscopic ultrasound (EUS) and laparoscopy, engendered the most controversy among the panel members charged with creating preliminary practice guidelines on pancreatic cancer for the National Comprehensive Cancer Network (NCCN), panel chair Margaret Tempero, MD, said in an interview.
The various staging modalities provide different types of information and also differ with regard to cost and invas-iveness, said Dr. Tempero, of the University of Nebraska Medical Center. She presented the pancreatic cancer guidelines at the NCCN's second annual conference.
Consequently, she anticipates that the panel's recommendations about the use of staging technologies in various situations will change as the guidelines undergo review by the NCCN institutions.
The pancreatic cancer practice guidelines, developed by a nine-member multidisciplinary panel , consist of seven distinct paths for the workup and treatment of patients with ductal adenocarcinoma. The decision of which path should be followed for a particular patient rests primarily on the resectability status of the cancer and whether there is evidence of metastatic disease. Both of these determinations hinge on accurate staging.
NCCN Pancreatic Cancer Practice Guidelines PanelMargaret Tempero, MD Al Benson, MD John L. Cameron, MD Ephraim S. Casper, MD John Hoffman, MD Ted Lawrence, MD Ted Martin, MD Cornelius McGinn, MD Christopher Willett, MD |
Since definitions of resectability and unresectability are not clear in the literature, the panel developed its own criteria, and although these are fairly noncon-troversial, the yardsticks for borderline resectability may provoke some debate, Dr. Tempero said.
The panel deems lesions in either the head or body of the pancreas borderline resectable when there is bilateral or severe unilateral superior mesenteric vein or portal impingement, tumor abutment on the superior mesenteric artery, gastroduodenal artery encasement up to the origin at the hepatic artery, or direct invasion into the transverse colon.
For lesions in the tail of the pancreas, extension into the adrenal gland, kidney, or colon is characterized as borderline resectable.
Which Staging Tests to Use When?
The crux of the controversy over staging technologies is which test or tests to use when, Dr. Tempero said.
To determine resectability in the patient who presents with a mass in the head of the pancreas and who is not jaundiced, the panel recommends spiral (helical) CT. If the scan indicates that the mass is potentially resectable, the patient should undergo a laparotomy, and, if that confirms the CT findings, the resection should be completed.
The guidelines do not require a preop-erative biopsy prior to laparotomy. "Because of one of the histologic hallmarks of pancreatic cancer, ie, associated desmo-plasia, preoperative biopsies can often be misleading," Dr. Tempero noted. Thus, if a biopsy is taken in a desmoplastic area of the pancreas in a patient who actually has an adenocarcinoma, the cancer may go undetected.
If findings on spiral CT indicate that a mass is borderline resectable, the panel recommends the use of endoscopic ultrasound (EUS) (coupled with a transgas-tric biopsy) to ascertain whether that mass is truly resectable.
A number of studies have suggested that EUS is a far better staging tool than conventional ultrasound or CT, Dr. Tempero said. "However, we recognize that EUS is an operator-dependent modality. And even within our own NCCN institutions, we have not yet determined that all institutions have dedicated personnel who are skilled in this procedure."
If EUS findings indicate that the borderline lesion is, indeed, resectable, the committee advocates the use of laparos-copy rather than laparotomy to determine whether metastases are present.
"The reason for this is that many of these patients with borderline lesions will have peritoneal studding or other evidence of metastatic disease that would not have been apparent on the CT scan," Dr. Tempero said. "And so, it was the panel's feeling that, by doing a preop-erative laparoscopy, you would be able to spare some of these patients from undergoing laparotomy."
