Non-L-cell immunophenotype and large tumor size in rectal neuroendocrine tumors are associated with aggressive clinical behavior and worse prognosis.
According to the 2010 World Health Organization classification, all gastrointestinal neuroendocrine tumors (NETs) are classified as malignant except for L-cell-type (glucagon-like peptide [GLP] and peptide YY [PYY]-producing) NETs. However, L-cell immunophenotype in rectal NETs has not been widely studied previously. Immunohistochemical labeling of L-cell markers with GLP1 and PYY was performed in 208 surgically or endoscopically resected rectal NET cases with tissue microarrays and was compared with clinicopathologic features and patient survival. Rectal NETs with non-L-cell immunophenotype and large tumor size (>1 cm) were associated with increased tumor grading, advanced T category, lymphovascular and perineural invasions, and lymph node and distant metastases (P<0.001, each). Rectal NET patients with non-L-cell phenotype and measuring >1 cm had significantly worse survival outcome than other groups by univariate (P<0.001) and multivariate (P<0.001) analyses. In summary, non-L-cell immunophenotype and large tumor size are associated with increased tumor grading and staging, concurrently indicating that they are independently poor prognostic indicators in rectal NET patients. Therefore, combining L-cell phenotype and tumor size can demonstrate the clinical behavior of rectal NETs more precisely than use of L-cell immunophenotype alone.
Departments of *Pathology §Gastroenterology ∥Surgery, Asan Medical Center, University of Ulsan College of Medicine †Department of Pathology, Korea University Anam Hospital, Korea University College of Medicine ‡Department of Biochemistry, College of Korean Medicine, Institute of Korean Medicine, Kyung Hee University, Seoul, Korea.
Joo Young
JY
Kim
Ki-Suk
KS
Kim
Kyung-Jo
KJ
Kim
In Ja
IJ
Park
Jong Lyul
JL
Lee
Seung-Jae
SJ
Myung
Yangsoon
Y
Park
Young Soo
YS
Park
Chang Sik
CS
Yu
Jin Cheon
JC
Kim
Eunsil
E
Yu
Hyeung-Jin
HJ
Jang
Seung-Mo
SM
Hong
D000328:Adult; D000368:Aged; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D019894:Peptide YY / Q000378:metabolism*; D011379:Prognosis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D046888:Tissue Array Analysis; D055815:Young Adult
D019894:Peptide YY; D052216:Glucagon-Like Peptide 1