Poor survival in pancreatic cancer is due not to early spread but to late diagnosis. Early diagnosis of this cancer is rare because symptoms develop gradually and cancer is often present for many months or even years before diagnosis. Physicians use a range of imaging techniques to confirm the diagnosis. Tumor markers do not yet enable early diagnosis of pancreatic cancer (Lowenfels 2006).
The use of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for fluid collection enables physicians to detect tumor markers and abnormal cells which supplement EUS imaging in pancreatic cancer diagnosis (Turner 2010), and with a minimal risk of tumor seeding (Paquin 2005). EUS-FNA can also reveal, in approximately 10% of patients, metastatic spread (Dumonceau 2011).
Future Methods of Diagnosis. Optical coherence tomography (OCT) imaging can reliably distinguish between low risk (benign) and high risk (potentially malignant) pancreatic cystic lesions with over 95% accuracy (specificity and sensitivity ex vivo). However, at the time of writing, this technique is not yet available to patients with pancreatic disease, as a minimally invasive probe for intra-cystic OCT imaging still needs to be developed (Iftimia 2011).
Prognostic biomarkers are indicators of the tumor’s aggressiveness (or growth potential) and the patients’ final outcome, regardless of the treatment used. A recent study showed that circulating tumor cells (CTCs) are an independent prognostic biomarker (De Albuquerque 2011). CTCs are cancer cells that detach from the primary tumor and travel in the blood, leading to cancer spread (Fidler 2003). CTCs were detected in 49.3% of blood samples from patients with advanced pancreatic adenocarcinoma and their detection correlated with poor prognosis. The median progression free survival was 60.7 days in patients with positive CTC detection vs. 163.6 days in those with negative CTC detection (X u 2011). As of the time of writing, CTC analysis is currently not commercially available for pancreatic cancer.
High platelet counts are associated with poor survival (Brown 2005; Suzuki 2004).
Patients with a neutrophil to lymphocyte ratio (NLR) value of < 5 have a significantly higher median survival duration compared to those with a NLR value of ≥ 5 (Aliustaoglu 2010).