OBJECTIVETo elucidate the historic and current diagnosis and treatment status of gastrointestinal stromal tumor (GIST) in the Chinese population based on four high volume databases.

METHODSClinicopathological data of GIST patients with follow-up information between January 1998 and December 2015 from Sun Yat-sen University Cancer Center, Union Hospital of Huazhong University of Science and Technology, Southern Medical University Nanfang Hospital and Guangdong General Hospital were retrospectively analyzed. Kaplan-Meire method was used to draw survival curve. The accumulative survival rate was calculated by life table method. Comparison of survival rate among groups was examined by Log-rank test.

RESULTSA total of 2 610 cases were enrolled into the study, including 667(25.6%) cases from Sun Yat-sen University Cancer Center, 754(28.9%) cases from Union Hospital of Huazhong University of Science and Technology, 692(26.5%) cases from Southern Medical University Nanfang Hospital and 497 (19.0%) cases from Guangdong General Hospital. There were 1 394 male and 1 216 female cases with the ratio of 1.15 to 1.00. The age of patients was from 18 to 95 (median 58.0) years old. Three-year was used as a time stage, then 18 years were divided into 6 stages. New GIST patients increased gradually year by year. There were 13(0.5%) cases during 1998 to 2000, 68(2.6%) cases during 2001 to 2003, 256(9.8%) cases during 2004 to 2006, 517 (19.8%) cases during 2007 to 2009, 814(31.2%) cases during 2010 to 2012, and 942 (36.1%) cases during 2013 to 2015. Primary GIST sites were esophagus in 50(1.9%) cases, stomach in 1 686(64.6%) cases, duodenum in 206 (7.9%) cases, jejunum and ileum in 446 (17.1%) cases, colon and rectum in 133 (5.1%) cases, and non-gastrointestinal tract in 89 (3.4%) cases. GIST lesions of 2 404(92.1%) cases located in the primary sites and relapse/metastasis occurred in 206 cases when consulting. Among 206 relapse/metastasis cases, liver metastasis was found in 126 (61.2%) cases, abdominal cavity/pelvic cavity metastasis in 64 (31.1%) cases, liver plus abdominal cavity/pelvic cavity metastasis in 12 (5.8%) cases, and other site metastasis in 4 (1.9%) cases. Among all the patients, 352 received gene detection, including 1 (0.4%) during 2004 to 2006, 7 (1.4%) during 2007 to 2009, 150 (18.4%) during 2010 to 2012, and 194 (20.6%) during 2013 to 2015. Most of the primary oncogenic mutational site occurred in c-Kit, including 30 (8.5%) cases in exon 9, 242 (68.8%) cases in exon 11, 4 (1.1%) cases in exon 13, 2 (0.6%) cases in exon 17, while 3 (0.9%) cases in PDGFRA exon 12 and 20 (5.7%) cases in PDGFRA 18, besides, no mutations of KIT and PDGFRA were detected in 51 (14.5%) cases. A total of 2 202 cases underwent operation, including 2 038 (92.6%) of radical resection and 164 (7.4%) of palliative resection. Among 2 038 patients undergoing radical resection, 450 (22.1%) cases were very low risk, 593 (29.1%) cases were low risk, 283 (13.9%) cases were moderate risk and 712 (34.9%) cases were high risk according to NIH risk classification. Of 995 patients with moderate and high risk, 550(55.3%) cases received postoperative imatinib adjuvant therapy, whose ratio in above 6 time stages was as follows: 0, 42.8%(12/28), 19.8%(20/101), 9.8% (21/215), 65.7% (176/268) and 85.6% (321/375). Of 206 relapse/metastasis patients, 200 (97.1%) cases received imatinib as the first-line therapy, and 22 (10.7%) received sunitinib as the second-line therapy. A total of 1 743 patients had complete follow-up data and median follow-up time was 35.9 (0.1 to 173.8) months. The 5-year overall survival rates in very low, low, moderate and high risk patients were 100%, 97%, 95% and 78% respectively.

CONCLUSIONThis retrospective study provides the largest data of GIST and indicates the historic changes of clinicopathological characteristics, diagnosis and treatment of GIST for further domestic GIST research.