Pancreatic cysts are very frequent radiological findings. It is said that such changes may be found by MR examination in every fifth person. The most frequent type of cysts are postinflammatory ones. Their recognition is not difficult because patients report experienced acute or chronic pancreatitis. Diagnostic problem emerges when it is known that a cyst has no inflammatory basis. Serous cystadenomas, intraductal papillary mucinous neoplasms and cystic tumours may appear among cystic changes. However, only serous cystadenomas cause no immediate risk of malignant transformation. It is connected with the need of exact analysis of such changes regarding potential development of malignant tumour.
Until now, doctors based on radiological examination and identification of carcinoembryonic antigen (CEA) level. Scientists from Sahlgrenska Academy, University of Gothenburg in Sweden, report that there is a better way to predict change development – analysis of mucins in material taken from cysts.
Mucins are heavy glycoproteins which appear in a secretory form or are connected to cell membrane. They perform protective function by strengthening cell’s barrier. They also take part in neoplastic processes: they are produced de novo in numerous tumours including adenocarcinomas. This has been known for years since scientists searched for mucins in the material as a direct neoplastic marker. They used immunohistochemical methods which were burdened with a certain number of ambiguous results since they had different glycosilation of proteins depending on various pancreatic cancers. In order to eliminate errors, scientists from Sweden sought for protein ingredient with the use of proteomics – an analysis of proteome.
78 patients aged over 18 were involved into research. Everyone of them underwent endoscopic ultrasonography and had had his fluid from changes taken through stomach or duodenum access. Obtained material was initially subjected to cytologic analysis and content of carcinoembryonic antigen was marked. Then, scientists performed electrophoresis in polyacrylamide gel and analysis with the use of mass spectrometry.
Results obtained with the use of the new method were more than just satisfactory. It was possible to differentiate between benign and malignant changes with 97,5% accuracy. It is higher result in comparison with cytologic examination (71,4%) and predictive value of carcinoembryonic antigen (78%). Only in one person scientists obtained result which was falsely negative, meaning that it was not possible to predict neoplastic transformation. All detected changes of malignant progression potential (23) have shown an expression of at least one of mucines: MUC5AC, MUC2 and MUC1. MUC5AC was detected in 82,6% of the cases.
The scientists stress that this new method allows for faster and accurate differential diagnostics of cystic changes in pancreas. With over 97% accuracy it would be possible to avoid extensive surgery in patients with benign changes and in those with small probability of malignancy. On the other hand, acquisition of information about malign potential of a change will allow for its surgical removal in presymptomatic stage thus guaranteeing better prognosis.
Written by: Julia Rudnicka, Anna Kozioł
Source:
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3. Matthaei H, Schulick RD, Hruban RH, Maitra A. Cystic precursors to invasive pancreatic cancer. Nat Rev Gastroenterol Hepatol. 2011;8(3):141–150.
4. Strobel O, Rosow DE, Rakhlin EY, et al.Pancreatic duct glands are distinct ductal compartments that react to chronic injury and mediate Shh-induced metaplasia. Gastroenterology. 2010;138(3):1166–1177.
5. Canto MI, Hruban RH, Fishman EK, et al. Frequent detection of pancreatic lesions in asymptomatic high-risk individuals. Gastroenterology. 2012;142(4):796–804.
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7. http://www.sciencedaily.com/releases/2014/03/140321101603.htm
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