Yamashita Keishi, Sakuramoto Shinichi, Kikuchi Shiroh, Katada Natsuya, Kobayashi Nobuyuki, Watanabe Masahiko
Department of Surgery, Kitasato University Hospital, 1-15-1 Kitastato, Sagamihara, Kanagawa 228-8555, Japan.
Gastric Cancer. 2008;11(2):111-8. doi: 10.1007/s10120-008-0466-7. Epub 2008 Jul 2.
The two major staging systems for gastric cancer, the Japanese classification of gastric cancer (JCGC) and the International Union Against Cancer (UICC) TNM system, are periodically revised as a consequence of critical validation studies in light of newly accumulated clinical data. This study aimed to validate and improve upon the current versions for a better prognostic stratification of gastric cancer.
One thousand and ten gastric cancer patients who underwent tumor resection were enrolled at the Kitasato University Hospital for staging validation. According to the JCGC stage, the patients consisted of stage IA (n=453), IB (n=185), II (n = 119), IIIA (n=75), IIIB (n=51), and IV (n=127).
Regarding consistency between the JCGC and the UICC system, the results were: for patients in stage IA (100%), IB (98%), II (84%), IIIA (51%), IIIB (24%), and IV (64%). The JCGC system was superior to the UICC system for the prognostic stratification of stage IIIA, IIIB, and IV cancers; we therefore used the JCGC system for prognostic validation according to depth of invasion in cancers of the same stage. Stage II and IIIA cancers were heterogeneous for prognosis according to depth of invasion, and the outstanding difference was found between the muscularis propria (MP) and subserosa (SS), which are both classified as pT2 in the JCGC system. MP cancer represented an earlier property of gastric cancer rather than an advanced one. A proposed novel staging system adjusted for this heterogeneity provided a clearer stratification of prognosis with a homogeneous prognostic distribution within each stage.
Our findings revealed that invasion into the MP has an earlier propensity than expected, and a novel staging system taking this into account may provide a better stratification of prognosis than the current systems.
胃癌的两大分期系统，即日本胃癌分类法（JCGC）和国际抗癌联盟（UICC）的TNM系统，会根据新积累的临床数据进行关键验证研究，从而定期修订。本研究旨在验证并改进当前版本，以实现对胃癌更好的预后分层。
北里大学医院纳入了1010例行肿瘤切除术的胃癌患者进行分期验证。根据JCGC分期，患者包括IA期（n = 453）、IB期（n = 185）、II期（n = 119）、IIIA期（n = 75）、IIIB期（n = 51）和IV期（n = 127）。
关于JCGC和UICC系统之间的一致性，结果如下：IA期患者为100%，IB期为98%，II期为84%，IIIA期为51%，IIIB期为24%，IV期为64%。在IIIA期、IIIB期和IV期癌症的预后分层方面，JCGC系统优于UICC系统；因此，我们根据同一分期癌症的浸润深度，使用JCGC系统进行预后验证。II期和IIIA期癌症根据浸润深度的预后存在异质性，在JCGC系统中均归类为pT2的固有肌层（MP）和浆膜下（SS）之间存在显著差异。MP癌代表胃癌的早期特征而非晚期特征。针对这种异质性提出的新型分期系统提供了更清晰的预后分层，且每个分期内的预后分布均匀。
我们的研究结果表明，浸润至MP的倾向比预期更早，考虑到这一点的新型分期系统可能比当前系统提供更好的预后分层。
