Cancer of the pancreas
EPIDEMIOLOGY, ANATOMY AND TYPES
Pancreatic ductal adenocarcinoma is the commonest pancreatic malignancy and is highly aggressive. Most arise in the head, with body and tail tumours often presenting later. The pancreas is retroperitoneal; the head lies within the duodenal curve, the common bile duct traverses/abuts it, and the superior mesenteric vessels, portal vein and coeliac axis are crucial to resectability. Other tumours include neuroendocrine neoplasms and cystic neoplasms.
RISK FACTORS AND PATHOGENESIS
Risk factors include increasing age, cigarette smoking, chronic pancreatitis, obesity, diabetes (especially new-onset in older adults), family history and inherited syndromes (e.g. BRCA2, PALB2, CDKN2A, Lynch). Pancreatic intraepithelial neoplasia and mucinous cystic lesions may progress through molecular alterations including KRAS, CDKN2A, TP53 and SMAD4. Perineural and lymphovascular invasion contribute to early spread.
CLINICAL FEATURES
Head tumours commonly cause painless progressive obstructive jaundice, dark urine, pale stools, pruritus and weight loss. Courvoisier sign is a palpable non-tender gallbladder with jaundice, suggesting malignant distal biliary obstruction (not diagnostic). Other features include epigastric pain radiating to the back, anorexia, steatorrhoea, new diabetes, pancreatitis and migratory thrombophlebitis (Trousseau syndrome). Body/tail tumours often present with pain, weight loss or metastatic disease. Liver metastases, ascites and Virchow node may occur.
INVESTIGATIONS AND STAGING
Initial tests include FBC, renal function, liver profile, glucose/HbA1c and coagulation. Pancreas-protocol multiphasic contrast CT is the principal staging and resectability study. MRI/MRCP helps characterise lesions and biliary/pancreatic ducts. EUS-guided FNA/FNB provides tissue when neoadjuvant or systemic therapy is planned or diagnosis is uncertain; tissue confirmation is not always required before upfront surgery for a clearly resectable lesion. ERCP is mainly therapeutic for biliary drainage and allows brushings in selected cases. CA 19-9 is not a screening test; it may support prognosis and monitor response, but can be falsely elevated in cholestasis and absent in Lewis-antigen-negative individuals. Stage includes local vascular involvement, nodes and distant metastases; multidisciplinary review determines resectability.