title: Oncologic Impact of Fewer Than 12 Lymph Nodes in Patients Who Underwent Neoadjuvant Chemoradiation Followed by Total Mesorectal Excision for Locally Advanced Rectal Cancer.
abstract: A minimum of 12 harvested lymph nodes (hLNs) are recommended in colorectal cancer. However, a paucity of hLNs is frequently presented after preoperative chemoradiation (pCRT) in rectal cancer and the significance of this is still uncertain. The aim of this study is to analyze the impact of hLNs on long-term oncologic outcomes. A total of 302 patients with locally advanced rectal cancer who underwent pCRT and curative resection between 1989 and 2009 were reviewed. Patients were categorized into 2 groups according to the number of hLNs: <12 versus ≥12 LN. The 2 groups were compared with respect to 5-year disease-free and overall survival. The optimal number or ratio of hLNs was investigated in subgroup analysis according to LN status. The median follow-up was 57 months. Patient characteristics other than age did not differ between the 2 groups. The group with <12 LNs had more favorable ypTNM and ypN stage than those with ≥12 LNs. However, the long-term oncologic outcomes were not significantly different between the 2 groups. In subgroup analysis of ypN(-), the group with <5 hLNs had the most favorable oncologic outcomes. In ypN(+) cases, a higher LN ratio tended to be associated with poorer 5-year overall survival. The paucity of hLNs in locally advanced rectal cancer after chemoradiation did not imply poor oncologic outcomes in this study. In addition, <5 hLNs in ypN(-) patients could reflect a good tumor response rather than suboptimal radicality.
authors.affiliation: From the Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Woo Ram
authors.initials: WR
authors.lastname: Kim
authors.forename: Yoon Dae
authors.initials: YD
authors.lastname: Han
authors.forename: Min Soo
authors.initials: MS
authors.lastname: Cho
authors.forename: Hyuk
authors.initials: H
authors.lastname: Hur
authors.forename: Byung Soh
authors.initials: BS
authors.lastname: Min
authors.forename: Kang Young
authors.initials: KY
authors.lastname: Lee
authors.forename: Nam Kyu
authors.initials: NK
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy; D013505:Digestive System Surgical Procedures / Q000592:standards / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000592:standards / Q000706:statistics & numerical data*; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies