Updates and Controversies in the Adjuvant Treatment of Pancreas Cancer
Updates and Controversies in the Adjuvant Treatment of Pancreas Cancer
US Oncological Disease 2006
Published: October 2008
Published: October 2008
There were approximately 31,860 new cases of pancreatic carcinoma diagnosed in 2004.With 31,270 deaths from pancreas cancer this same year, it remains the fourth leading cause of cancer death in the US. Reasons for the high rate of mortality with adenocarcinomas of the pancreas include the advanced stage of disease at the time of diagnosis for more than 90% of all patients, the lack of effective screening tests and the lack of effective treatment options. All this is reflected in a five–year overall survival of 15.2% in localized disease and less than 5% across stages. As such, pancreas cancer remains a formidable challenge.
Over 95% of pancreatic malignancies are adenocarcinoma, and will be the focus of this paper, hereafter referred to as pancreas cancer. Risk factors for pancreatic cancer are poorly understood.
Smoking appears to be consistently identified as a modifiable risk factor, with about 30% of all pancreas cancer diagnosis linked it. Chronic pancreatitis is associated with 10–15 fold increase in the risk of developing pancreas cancer. Hereditary pancreatitis and other familial syndromes involving the pancreas lend themselves to a 50–70 fold increase in pancreatic cancer. Other risk factors in the development of pancreatic cancer remain controversial. Thus, the role of cancer prevention is currently limited to education regarding tobacco use.
Diagnosis and Staging
In the last decade, significant advances have been achieved in the imaging and staging of pancreas cancer. The principal staging modalities include a helical computed tomography (CT) scan and endoscopic ultrasound. Standard magnetic resonance imaging (MRI) is less accurate for identifying vessel disease compared to CT, although magnetic resonance cholangiopancreatography (MRCP) has proven to be superior to CT, endoscopic retrograde cholangiopancreatograph (ERCP) or US in determining extrahepatic spread, lymph node and vascular invasion. Laparoscopy may reveal small (<1cm) peritoneal or liver metastases that cannot be seen by standard imaging modalities, and upstage approximately 10–40% of all patients depending on the location of their mass.
Staging of pancreatic cancer is based on tumour-nodemetastasis (TNM) criteria that apply to both pathologic and clinical staging at the same time, given the very small percentage of patients undergoing surgical resection. Stage I cancers are confined to the pancreas itself. Stage II disease may extend beyond the pancreas but involves neither the celiac axis nor the superior mesenteric artery. Stage I and II represent localized resectable cancer.When the mass involves the celiac axis or the superior mesenteric artery, the patient has stage III cancer or locally advanced disease. Finally, stage IV represents patients with metastatic disease.
CA19–9 is the best available tumor marker for pancreas cancer, and is approximately elevated in 80% of patients with pancreas cancer. Serum levels above 750U/ml are associated with a high probability of locally advanced or metastatic disease. Ca 19–9 should only be used to support the diagnosis and staging of pancreas cancer and to help monitor for recurrence or response to treatment.
