Abstract: Objective:To investigate the clinicopathological features and risk factors of lymph node metastasis of gastrointestinal neuroendocrine neoplasms (GINENs).
Methods:The retrospective casecontrol study was conducted. The clinicopathological data of 467 patients with GINENs who were admitted to the Fourth Hospital of Hebei Medical University from January 2006 to December 2015 were collected. Observation indicators:(1) occurrence sites and pathological classification of GINENs; (2) pathological characteristics of surgical specimens of GINENs; (3) univariate analysis and multivariate analysis affecting lymph node metastasis of GINENs: sex, age, tumor location, tumor diameter, pathological classification, pathological stage and tumor invasive depth. The univariate analysis and multivariate analysis were respectively done using the chisquare test and Logistic regression model.
Results:(1) Occurrence sites and pathological classification of GINENs: of 467 patients with GINENs, tumors of 304, 15, 7, 14 and 127 patients were located at stomach, duodenum, small intestine, colon and rectum, respectively. Tumor diameter was 0.3-12.0 cm, with an average diameter of 2.2 cm. Of 467 patients with GINENs, G1 and G2 of neuroendocrine tumors (NETs), G3 of neumendocfine carcinomas (NECs) and mixed adenoneuroendocfine carcinomas (MANECs) were respectively detected in 209, 64, 146 and 48 patients. Lymph node metastasis rate of GINENs was 31.48%(147/467). (2) Pathological characteristics of surgical specimens of GINENs: NETs were highdifferentiated NENs. Cells of NETs were solid and nest, trabeculum and tubularshaped, and consisted of small or medium cells, with moderate amount or massive cytoplasms, round or oval nucleus, particleshaped chromatin, unobvious nucleolus and positive endocrine markers. There were abundant of small blood vessels and surrounding fibrous stroma in peripheral tumor cell nests. NECs were lowdifferentiated NENs and included small cell carcinoma and large cell NEC. Cells of small cell carcinoma were small round or oval and looked similar to lymphocytes, with few amount cytoplasms, fine granularshaped or hyperchromatic nucleus and common mitosis figures. Cells of large cell NEC were large and greater than 3 lymphocytes, arrayed in organoid or chrysanthemumshape, with massive cytoplasms, coarse particleshaped chromatin, obvious nucleus, clear mitosis figures and large laminarshaped necrosis. There were different positive expressions of endocrine markers between small cell carcinoma and large cell NEC. MANECs had the characteristics of glandular cavity formation of traditional adenocarcinoma and NENs. Results of immunohistochemical staining in 467 patients showed that Ki67 of 467 patients was positive; CD56 in 379 of 428 with CD56 test was positive; synaptophysin (Syn) in 416 of 422 with Syn test was positive; cytokeratin (CK) in 354 of 396 with CK test was positive; chromogranin (CgA)in 264 of 388 with CgA test was positive; neuron specific enolase (NSE) in 287 of 346 with NSE test was positive. (3) Univariate analysis and multivariate analysis affecting lymph node metastasis of GINENs: results of univariate analysis showed that sex, tumor location, tumor diameter, pathological classification, pathological satge and tumor invasive depth were related factors affecting lymph node metastasis of patients with GINENs (χ2=20.654, 18.182, 26.788, 184.709, 163.738, 195.391, P<0.05). Results of multivariate analysis showed that pathological classification and pathological stage were independent influenced factors affecting lymph node metastasis of patients with GINENs (HR=2.129, 7.171, 95% confidence interval: 1.273-3.561, -2.327-22.098, P<0.05).
Conclusions:GINENs are mostly located on the stomach and rectum. Results of immunohistochemical staining could help diagnosis of GINENs. Pathological classification and pathological stage are independent influenced factors affecting lymph node metastasis of patients with GINENs.