1509P - Characteristics and prognosis of gastrointestinal stromal tumor in the pre-imatinib era: an analysis based on the Kinki GIST registry in Japan

Date 11 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics GIST
Sarcoma
Presenter Tadayoshi Hashimoto
Citation Annals of Oncology (2017) 28 (suppl_5): v521-v538. 10.1093/annonc/mdx387
Authors T. Hashimoto1, T. Takahashi2, Y. Kurokawa1, J. Fujita3, S. Hirota4, T. Nishida5, T. Tsujinaka6
  • 1Department Of Gastroenterological Surgery, Osaka University Graduate School of Medicine, 565-0871 - Suita/JP
  • 2Department Of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita/JP
  • 3Department Of Surgery, Sakai Medical Center, 593-8304 - Sakai/JP
  • 4Surgical Pathology, Hyogo College of Medicine, 663-8501 - Nishinomiya/JP
  • 5Director, National Cancer Center Hospital, 104-0045 - Tokyo/JP
  • 6Department Of Surgery, Kaizuka City Hospital, 597-0015 - Kaizuka/JP

Abstract

Background

Recent breakthroughs regarding the oncogenesis of gastrointestinal stromal tumor (GIST) have led to the wider use of imatinib (IM). In addition, since perioperative IM has been established, more accurate information regarding the clinical behavior of GIST is mandatory. However, there is no big data about the clinicopathological characteristics and prognosis of GIST in Japan. The aim of this study was to clarify them based on an analysis of the GIST registry conducted by the Kinki GIST Study Group in Japan.

Methods

The registry was designed to collect data on background characteristics, treatment methods, pathologic characteristics, and prognosis of primary GIST from 2003 through 2007 at 40 participating institutions.

Results

The study enrolled 346 male patients and 332 female patients. The median [range] age was 66 [18-93] years. The primary sites were stomach (74%), small intestine (19%), rectum (3%), esophagus (1%), colon (1%), and others (1%). Fifty-eight percent were asymptomatic and 42% were symptomatic e.g. bleeding (17%), pain (10%), and digestive symptoms (9%). None of the patients was received perioperative IM therapy. Pathological examination revealed that the tumor size was 4.0 [0.1-35]cm and the mitotic count was 3 [0-300] per 50 high-powered fields. There were 91.0% KIT positive GISTs and 82.9% CD34 positive GISTs. Ninety-seven (14.5%) patients showed recurrence and the common recurrent sites were liver (n = 58) and peritoneum (n = 33). According to the modified-Fletcher criteria, the recurrence rates were 0% (0/93, very low-risk group), 2.6% (6/230, low-risk,), 4.6% (4/87, intermediate-risk), and 38.9% (75/193, high-risk), respectively. The 5-years overall survival rate was 89.0%. The 5-years recurrent free survival rate (RFS) of gastric GISTs was significantly better than that of other sites’ GISTs (5-years RFS:82.7% vs. 63.9%, P 

Conclusions

We reported the clinicopathological characteristics of GIST in multi-center registry study in Japan. Currently applied GIST risk classification system is comparable to predict high- or low-risk patients with primary non-metastatic and completely resected GIST in pre-IM era.

Clinical trial identification

Legal entity responsible for the study

Kinki GIST registry

Funding

Kinki GIST registry

Disclosure

All authors have declared no conflicts of interest.