title: Multicenter retrospective analysis of 581 patients with primary intestinal non-hodgkin lymphoma from the Consortium for Improving Survival of Lymphoma (CISL).
abstract: BACKGROUND
  Primary intestinal non-Hodgkin lymphoma (NHL) is a heterogeneous disease with regard to anatomic and histologic distribution. Thus, analyses focusing on primary intestinal NHL with large number of patients are warranted.
  
  
  METHODS
  We retrospectively analyzed 581 patients from 16 hospitals in Korea for primary intestinal NHL in this retrospective analysis. We compared clinical features and treatment outcomes according to the anatomic site of involvement and histologic subtypes.
  
  
  RESULTS
  B-cell lymphoma (n = 504, 86.7%) was more frequent than T-cell lymphoma (n = 77, 13.3%). Diffuse large B-cell lymphoma (DLBCL) was the most common subtype (n = 386, 66.4%), and extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) was the second most common subtype (n = 61, 10.5%). B-cell lymphoma mainly presented as localized disease (Lugano stage I/II) while T-cell lymphomas involved multiple intestinal sites. Thus, T-cell lymphoma had more unfavourable characteristics such as advanced stage at diagnosis, and the 5-year overall survival (OS) rate was significantly lower than B-cell lymphoma (28% versus 71%, P < 0.001). B symptoms were relatively uncommon (20.7%), and bone marrow invasion was a rare event (7.4%). The ileocecal region was the most commonly involved site (39.8%), followed by the small (27.9%) and large intestines (21.5%). Patients underwent surgery showed better OS than patients did not (5-year OS rate 77% versus 57%, P < 0.001). However, this beneficial effect of surgery was only statistically significant in patients with B-cell lymphomas (P < 0.001) not in T-cell lymphomas (P = 0.460). The comparison of survival based on the anatomic site of involvement showed that ileocecal regions had a better 5-year overall survival rate (72%) than other sites in consistent with that ileocecal region had higher proportion of patients with DLBCL who underwent surgery. Age > 60 years, performance status ≥ 2, elevated serum lactate dehydrogenase, Lugano stage IV, presence of B symptoms, and T-cell phenotype were independent prognostic factors for survival.
  
  
  CONCLUSIONS
  The survival of patients with ileocecal region involvement was better than that of patients with involvement at other sites, which might be related to histologic distribution, the proportion of tumor stage, and need for surgical resection.
authors.affiliation: Division of Hematology and Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seok Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Chul Won
authors.initials: CW
authors.lastname: Choi
authors.forename: Yeung-Chul
authors.initials: YC
authors.lastname: Mun
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Oh
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kang
authors.forename: Soon Il
authors.initials: SI
authors.lastname: Lee
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Won
authors.forename: Min Kyoung
authors.initials: MK
authors.lastname: Kim
authors.forename: Jung Hye
authors.initials: JH
authors.lastname: Kwon
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Kim
authors.forename: Jae-Yong
authors.initials: JY
authors.lastname: Kwak
authors.forename: Jung Mi
authors.initials: JM
authors.lastname: Kwon
authors.forename: In Gyu
authors.initials: IG
authors.lastname: Hwang
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Sukjoong
authors.initials: S
authors.lastname: Oh
authors.forename: Keon Woo
authors.initials: KW
authors.lastname: Park
authors.forename: Cheolwon
authors.initials: C
authors.lastname: Suh
authors.forename: Won Seog
authors.initials: WS
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007414:Intestinal Neoplasms / Q000145:classification / Q000473:pathology*; D053208:Kaplan-Meier Estimate; D016393:Lymphoma, B-Cell / Q000145:classification / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000145:classification / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000145:classification / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D055815:Young Adult