Development of pancreatic cancers during long-term follow-up of side-branch intraductal papillary mucinous neoplasms.
OBJECTIVE
Side-branch intraductal papillary mucinous neoplasms (SB-IPMNs), and associated synchronous and metachronous pancreatic cancers are increasingly detected as imaging modalities become more sensitive. We investigated the natural history of SB-IPMN, and the incidence and characteristics of pancreatic cancers among patients undergoing long-term follow-up.


METHODS
We reviewed the clinical, imaging, and pathological features in 103 patients, diagnosed at the Aichi Cancer Center between September 1988 and September 2006 as having SB-IPMN, and conservatively followed up for ≥ 2 years (median 59 months) based on an endoscopic ultrasonography (EUS) database.


RESULTS
74 (71.8 %) patients had nonprogressive lesions. Overall, six patients (5.8 %) developed pancreatic cancers during follow-up, with intraductal papillary mucinous (IPM) carcinoma in four, and ductal carcinoma of pancreas that was not IPMN in two patients. Of the six pancreatic cancers, five were diagnosed at a resectable stage. The 5-year and 10-year actuarial rates of development of pancreatic cancer were 2.4 % and 20.0 %, respectively. Although, at the last follow-up, cyst size, main pancreatic duct (MPD) diameter, mural nodule size, and frequency of metachronous and/or synchronous cancers of other organs were significantly higher in patients who developed IPM carcinoma, resected SB-IPMNs without mural nodules and dilated MPDs had no IPM carcinomas.


CONCLUSIONS
The frequency of pancreatic cancers is high on long-term follow-up of SB-IPMN. Although conservative management is appropriate for selected patients, regular and long-term imaging, especially by EUS is essential, even if SB-IPMN remains unchanged for 2 years. Presence of mural nodule and dilated MPD seem to be more appropriate indicators for resection than cyst size alone for SB-IPMNs.
Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Y
Y
Sawai
K
K
Yamao
V
V
Bhatia
T
T
Chiba
N
N
Mizuno
A
A
Sawaki
K
K
Takahashi
M
M
Tajika
Y
Y
Shimizu
Y
Y
Yatabe
A
A
Yanagisawa
D002288:Adenocarcinoma, Mucinous / Q000000981:diagnostic imaging / Q000473:pathology*; D000231:Adenocarcinoma, Papillary / Q000000981:diagnostic imaging / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology*; D018450:Disease Progression; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology*; D010183:Pancreatic Ducts / Q000000981:diagnostic imaging / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology*; D011379:Prognosis; D018709:Statistics, Nonparametric; D013997:Time Factors