Clinical features and surgical indications and malignant risk factors analysis of intraductal papillary mucinous neoplasms of the pancreas

Abstract

Objective To investigate the clinical features and surgical indications of subtypes of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and analyze its malignant risk factors. Methods The retrospective case-control study was conducted. The clinicopathological data of 77 patients with IPMN of the pancreas who were admitted to the First Hospital of Peking University from January 2008 to December 2016 were collected. The subtypes of IPMN of the pancreas detected by preoperative imaging examination included main-duct type (MD-IPMN) in 46 patients, branch-duct type (BD-IPMN) in 12 patients, mixed type (MT-IPMN) in 19 patients. The surgical indications were consulted from the Guideline for the diagnosis and treatment of pancreatic cystic lesions composed by the Pancreatic Surgery Group of Surgery Branch of China Medical Association. Surgical procedure was selected according to the location and size of the IPMN. Four to 6 cycles of chemotherapy with S-1 and/or Gemcitabine were conducted for patients with malignant IPMN according to the tolerance and baseline characteristics. Observation indicators included: (1) comparison of the clinical features MD-IPMN, MT-IPMN and BD-IPMN; (2) surgical and postoperative conditions; (3) results of postoperative pathological examination and malignant risk factors analysis; (4) accuracy evaluation of Sendai and Fukuoka guidelines for the diagnosis of malignant IPMN of the pancreas; (5) follow-up results and survival. Patients were followed up by outpatient examination and telephone interview till December 2016. The postoperative adjuvant therapy, tumor recurrence and metastasis of malignant IPMN patients and postoperative survival condition of all the patients were collected. Measurement data with normal distribution were expressed as ±s or average (range), and pairwise comparison was analyzed by t test. Measurement data with skewed distribution were expressed by median (range). Comparison between count data and univariate analysis were done by chi-square test. Multiple factors analysis was done by Logistic regression model. The survival curve was drawn and the survival rate were calculated by Kaplan-Meier method. The comparison of survival was done by Log-rank test. Results (1) Comparison of clinical features between MD-IPMN, MT-IPMN and BD-IPMN: The numbers of patients with symptoms, jaundice, those complicated with diabetes and elevated CA19-9 were 55, 20, 43 and 28 in MD-IPMN and MT-IPMN, and 6 , 0, 3 and 1 in BD-IPMN, with statistically significant difference (χ2=5.421, 3.516, 5.525, 3.834, P 0.05), while significant difference in the specificity between the 2 guidelines were detected (χ2=12.500, P<0.05). (5) Follow-up and survival: Seventy of 77 patients were followed up, including 42 with benign IPMN and 28 with malignant IPMN. The median survival time was 35.0 months (range, 6.0-94.0 months). All the malignant IPMN patients received adjuvant therapy. The 1-, 3-, 5-year overall survival rates of 47 patient with benign IPMN were 100.0%, 96.2% and 96.2%, respectively, and 1 patient died of cardiac infarction. The 1-, 3-, 5-year overall survival rates of 30 patients with malignant IPMN were 96.6%, 81.8%, 38.6%, respectively, and 11 patients died of tumor recurrence or metastasis with median time of tumor recurrence or metastasis of 20.5 months (6.0-61.6 months). The 1-, 3-, 5-year overall survival rates of 17 patients with negative lymph node metastasis were 100.0%, 100.0% and 60.0%, respectively, and the 1-, 3-, 5-year overall survival rates of 13 patients with positive lymph node metastasis were 91.7%, 57.1% and 0, respectively. There was statistically significant difference between patients with benign and malignant IPMN (χ2=12.530, P<0.05). There was statistically significant difference between patients with negative lymph node metastasis and those with positive lymph node metastasis (χ2=16.977, P<0.05). Conclusions Patients with MD-IPMN or MT-IPMN are more vulnerable to be complicated with diabetes, jaundice, elevated CA19-9 and high malignancy, and thus surgery is recommended. Jaundice, elevated CEA and CA19-9, tumor diameter≥3.0 cm, MD-IPMN are the independent risk factors influencing the malignancy of IPMN. Key words: Intraductal papillary mucinous neoplasms of the pancreas; Classification; Surgical procedures, operative; Prognosis