Pancreatic ductal carcinoma makes up the vast majority (90% 5) of all pancreatic neoplasms, and remains a disease with very poor prognosis and high morbidity.
Demographics and clinical presentation
Pancreatic cancer accounts for 22% of all deaths due to gastrointestinal malignancy, and 5% of all cancer deaths 1. In general it is a malignancy of the elderly with over 80% of cases occurring after the age of 60 1.
Risk factors include :
- cigarette smoking : strongest environmental risk factor
- diet rich in animal fats and protein
- hereditary syndromes 6
Perhaps surprisingly there is only a weak if at all present association with heavy alcohol consumption 1.
Cancerous cells arise from pancreatic ductal epithelium. As the majority of tumours (90%) 1 are not-resectable, this is mostly achieved with imaging (typically CT scan) although laparoscopy is often required to confirm resectability 1-2. The key to accurate staging is assessment of the SMA and coeliac axis, which if involved exclude the patient from any attempted resection 1-2
Histological types include
- adenocarcinoma : majority
- acinar cell carcinoma of pancreas
- adenosquamous carcinoma of pancreas
- undifferentied with osteoclasts giant cells
Location and classification
- head and uncinate process: 2/3 cases
- body and tai : 1/3 1
Findings are non-specific and include :
- generally hypoechoic mass
CT is the work-horse of pancreatic imaging. Typically ductal adenocarcinomas appear as poorly defined masses with extensive surrounding desmoplastic reaction. They enhance poorly compared to adjacent normal pancreatic tissue and thus appear hypodense on arterial phase scans in 75 - 90 % of cases, but may become isodense on delayed scans 1 (thus the need for multiple phase scanning when pancreatic cancer is the clinical question)
CT correlates well with surgical findings in predicting unresectablitly (positive predictive value of 89 - 100% 3). The most important feature to assess locally is the relationship of the tumour to surrounding vessels (SMA and coeliac axis). If the tumour surrounds a vessel by more than 180 degrees then it is deemed T4 disease and is unresectable 3.
Signal characteristics include
- T1 - hypo intense c.f. normal pancreas 5
- T1 FS (fat suppressed) - hypo intense c.f. normal pancreas 5
- T1 + C (Gd) - slower enhancement than normal pancreas, therefore dynamic injection with arterial phase imaging with fat saturation is ideal
- T2 / FLAIR - variable (therefore not very useful) depending on the amount of reactive desmoplastic reaction 1,5
Barium meal / small bowel follow through
If large enough may demonstrate a reverse impression on the duodenum : Frostburg's inverted 3 sign, or a wide duodenal sweep
Treatment and prognosis
Most tumours are non resectable at diagnosis.
Surgery for Stage I and II (see staging of pancreatic cancer) does offer the chance of cure, with however high morbidity ( 20 - 30 %) and mortality (5%) 3. Resection is performed with a Whipple's operation.
Even when resection is possible, the majority of patients succumb to recurrence, with only a doubling of survival in operated patients 1 from 5 to 10% at 5 years 4. Almost a quarter of patients are dead 12 months following diagnosis 4.
General imaging differential considerations include
- 1. Evans DB, Pisters PW, Abbruzzese JL. Pancreatic cancer. Springer Verlag. (2002) ISBN:0387951857. Read it at Google Books - Find it at Amazon
- 2. Greene FL, Cancer AJ, Society AC. AJCC cancer staging handbook, from the AJCC cancer staging manual. Springer Verlag. (2002) ISBN:0387952705. Read it at Google Books - Find it at Amazon
- 3. Lu DS, Reber HA, Krasny RM et-al. Local staging of pancreatic cancer: criteria for unresectability of major vessels as revealed by pancreatic-phase, thin-section helical CT. AJR Am J Roentgenol. 1997;168 (6): 1439-43. AJR Am J Roentgenol (abstract) - Pubmed citation
- 4. DeVita VT, Lawrence TS, Rosenberg SA et-al. DeVita, Hellman, and Rosenberg's cancer, principles & practice of oncology. Lippincott Williams & Wilkins. (2008) ISBN:0781772079. Read it at Google Books - Find it at Amazon
- 5. Mergo PJ, Helmberger TK, Buetow PC et-al. Pancreatic neoplasms: MR imaging and pathologic correlation. Radiographics. 17 (2): 281-301. Radiographics (abstract) - Pubmed citation
- 6. Schenk M, Schwartz AG, O'neal E et-al. Familial risk of pancreatic cancer. J. Natl. Cancer Inst. 2001;93 (8): 640-4. J. Natl. Cancer Inst. (link) - Pubmed citation
- 7. Morgan DE, Waggoner CN, Canon CL et-al. Resectability of pancreatic adenocarcinoma in patients with locally advanced disease downstaged by preoperative therapy: a challenge for MDCT. AJR Am J Roentgenol. 2010;194 (3): 615-22. doi:10.2214/AJR.08.1022 - Pubmed citation
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|Pancreatic ductal cancer||✗|
|Ductal carcinoma of pancreas||✗|
|Carcinoma of pancreas||✗|