Hoshino Nobuaki, Hasegawa Suguru, Hida Koya, Kawada Kenji, Sugihara Kenichi, Sakai Yoshiharu
Department of Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
Koujinkai Daiichi Hospital, Tokyo, Japan.
Int J Colorectal Dis. 2016 Jul;31(7):1307-13. doi: 10.1007/s00384-016-2602-x. Epub 2016 May 27.
A small number of lymph nodes retrieved (NLNR) is a known risk factor in stage II colorectal cancer. NLNR is influenced by age, but little is known about whether the impact of small NLNR on survival differs with age. This retrospective study sought to determine such impact in elderly patients with stage II colorectal cancer.
We reviewed data for 2100 patients with stage II colorectal cancer who underwent surgery without adjuvant chemotherapy between January 1997 and December 2003. The optimal cutoff value of NLNR for survival was determined, and the impact of small NLNR on survival was analyzed. The association between age and NLNR was evaluated. The relation between age and risk of small NLNR with respect to survival was then assessed to determine the impact of small NLNR on elderly patients' survival.
The optimal cutoff value of NLNR was determined as 6. The small NLNR group (SNG) showed significantly worse prognosis than the large NLNR group (LNG) (p < 0.001). Age, surgical method, and scope of lymph node dissection were significantly associated with NLNR. A potential interaction was noted between age and risk of small NLNR in relation to relapse-free survival (RFS). Five-year RFS was significantly worse in SNG than in LNG for elderly patients (41.7 and 76.4 %, respectively; p < 0.001) but not for non-elderly patients (75.9 and 84.6 %, respectively; p = 0.083).
NLNR <6 was identified to be an important prognostic factor for elderly patients with stage II colorectal cancer.
送检淋巴结数量少（NLNR）是II期结直肠癌的一个已知风险因素。NLNR受年龄影响，但对于小NLNR对生存的影响是否因年龄而异知之甚少。这项回顾性研究旨在确定小NLNR对老年II期结直肠癌患者生存的影响。
我们回顾了1997年1月至2003年12月期间2100例接受手术且未进行辅助化疗的II期结直肠癌患者的数据。确定了NLNR对生存的最佳临界值，并分析了小NLNR对生存的影响。评估了年龄与NLNR之间的关联。然后评估年龄与小NLNR生存风险之间的关系，以确定小NLNR对老年患者生存的影响。
NLNR的最佳临界值确定为6。小NLNR组（SNG）的预后明显比大NLNR组（LNG）差（p < 0.001）。年龄、手术方式和淋巴结清扫范围与NLNR显著相关。在无复发生存期（RFS）方面，年龄与小NLNR风险之间存在潜在的相互作用。老年患者中，SNG的5年RFS明显比LNG差（分别为41.7%和76.4%；p < 0.001），而非老年患者则无此差异（分别为75.9%和84.6%；p = 0.083）。
NLNR < 6被确定为老年II期结直肠癌患者的一个重要预后因素。
