Cyst fluid SPINK1 may help to differentiate benign and potentially malignant cystic pancreatic lesions.
OBJECTIVE
Differential diagnosis between benign and potentially malignant cystic pancreatic lesions may be difficult. Previously we have compared cyst fluid serine protease inhibitor Kazal type I (SPINK1) with some traditionally used tumour markers (amylase, CEA, Ca19-9) and found that it may be a new promising maker in the differential diagnosis of cystic pancreatic lesions. In the present study, we focused on cyst fluid SPINK1 levels in benign and potentially malignant cystic pancreatic lesions.


METHODS
Sixty-one patients operated on for cystic pancreatic lesion in Tampere University Hospital, Finland and in Verona University Hospital, Italy, were included. Cyst fluid was aspirated during surgery, stored at -70 °C, and analysed with immunofluorometric assay for SPINK1. The final diagnosis was acute pancreatitis with fluid collection (Acute FC) in 4 patients, chronic pseudocyst (PS) in 17 patients, serous cystadenoma (SCA) in 7 patients, mucinous cystadenoma (MCA) in 21 patients and intraductal papillary-mucinous neoplasm (IPMN) in 12 patients (9 main/mixed duct type and 3 branch duct type).


RESULTS
The acute FC patients had high SPINK1 levels. Among chronic cysts, SPINK1 levels were significantly higher in patients with potentially malignant cysts (main/mixed duct IPMN and MCA) than with benign cysts (side branch IPMN and SCA), (median and range, [480 (13-3602) vs. 18 (0.1-278) μg/L]; p < 0.0001). In the subcohort of 24 patients with <3 cm chronic cyst, cyst fluid SPINK 1 levels were significantly lower in SCA or side branch IPMN (3 [2-116] μg/L) than in main duct IPMN or MCA (638 [66-3602] μg/L; p = 0.018). The best sensitivity and specificity to differentiate any size MCA or main/mixed type IPMN from SCA or side branch IPMN were 85% and 84% (AUC 0.94; cut-off value 118 μg/L). The best sensitivity and specificity to differentiate <3 cm MCA or main duct IPMN from SCA or side branch IPMN were 93% and 89% (AUC 0.98; cut-off value 146 μg/L).


CONCLUSIONS
Cyst fluid SPINK1 may be a possible marker in the differential diagnosis of benign and potentially malignant cystic pancreatic lesions.
Department of Gastroenterology and Alimentary Tract Surgery, Finland; ARC-NET Research Center, University and Hospital Trust of Verona, Italy. Electronic address: sari.raty@pshp.fi.
Sari
S
Räty
Juhani
J
Sand
Johanna
J
Laukkarinen
Kaija
K
Vasama
Claudio
C
Bassi
Roberto
R
Salvia
Isto
I
Nordback
D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D020420:Cyst Fluid / Q000737:chemistry*; D018293:Cystadenoma, Serous / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010181:Pancreatic Cyst / Q000175:diagnosis*; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D014359:Trypsin Inhibitor, Kazal Pancreatic / Q000032:analysis*
D014408:Biomarkers, Tumor; D014359:Trypsin Inhibitor, Kazal Pancreatic
Cystic pancreatic lesions; SPINK1; Tumour markers