BARCELONA, Spain—The difference between a borderline resectable pancreatic cancer and true locally advanced disease is often difficult to determine, said a speaker here at the European Society for Medical Oncology World Congress on Gastrointestinal Cancer.
“Do not underestimate locally advanced pancreatic cancer,” warned Pascal Hammel, MD, PhD, Professor in the Department of Gastroenterology and Pancreatology at Hôpital Beaujon in France. “Many cases diagnosed as locally advanced are in fact metastatic.”
But don't overestimate it either, he said. Inflammatory perivascular infiltration (pancreatitis or intraductal papillary mucinous neoplasm [IPMN]) mimics tumor extension and does not always contraindicate surgery.
Hammel said some patients may appear eligible for resection, but that could be based on an old CT scan: “When you have a CT scan exceeding three weeks, you have a possibility of development of metastasis in the lung or liver.”
In the ancillary CirCe 07 study to the LAP07 trial (Bidard et al: Ann Oncol 2013;24:2057-2061), circulating tumor cells were found at baseline in nine percent of the 79 patients at diagnosis. Patients who had circulating tumor cells had a worse prognosis, Hammel said. “On the other hand, when you think the cancer is unresectable, you can miss the possibility of surgery in up to 20 percent of cases.”
There are intrinsic difficulties in evaluating locally advanced pancreatic cancer before and after treatment, he explained. He cited a 2007 study (Vullierme et al: Radiology 2007;245:483-490) whose authors concluded that “CT is helpful in the differentiation of in situ and invasive IPMN, but that classic vascular invasion criteria lead to the overestimation of surgical tumor unresectability in patients with malignant IPMN.”
Front-Line RT Controversial
Front-line radiotherapy is controversial, and Hammel noted studies with contradictory outcomes: one with chemotherapy alone shown as superior to use of chemoradiotherapy in overall survival (Chauffert et al: Ann Oncol 2008;19:1592-1599) and another showing chemoradiotherapy to be superior to chemotherapy alone (Loehrer et al: JCO 2011;29:4105-4112).
Hammel said that his opinion is that radiotherapy is not suitable in first-line treatment because conditions are not optimal, due to pain, jaundice, malnutrition, and anxiety, and also because of tumor aggressiveness and the possible presence of micrometastases.
“Systemic treatment is required on first intention and should be optimized, using more aggressive regimens,” he said.
He called FOLFIRINOX a promising regimen in locally advanced disease, but said it needs prospective assessment.
And secondary surgery, while infrequent, is possible, although he cautioned once again that evaluation is difficult after induction chemotherapy or chemoradiotherapy.