[Analysis of clinical features and prognostic factors on reoperation patients with postoperative recurrence or metastasis of gastrointestinal stromal tumor].

OBJECTIVE

To investigate the clinical characteristics and prognostic factors of reoperation patients with postoperative recurrence or metastasis of gastrointestinal stromal tumor (GIST).

METHODS

A retrospective case-control study was performed on the clinical data of 31 patients with GIST who had recurrence or metastasis after the first surgery and underwent one or more operations again from February 2003 to January 2016 at Ruijin Hospital, Shanghai Jiaotong University School of Medicine. The clinical characteristics of these patients were analyzed. Kaplan-Meier survival curve was used to calculate the survival rate, Cox univariate and multivariate regression model was applied to prognosis analysis.

RESULTS

Age of these 31 patients at the first operation was 35-78 (median 49) years, including 17 males (54.8%) and 14 females (45.2%). The tumors of 21 cases located in small intestines (67.7%), 2 cases in stomach (6.5%), 4 cases (12.9%) in colorectum and of 4 cases (12.9%) in other sites. According to NIH criteria, risk assessment indicated 26 cases were(83.8%) with high risk, 3 cases (9.7%) with moderate risk, and 2 cases (6.5%) with low risk. After the first operation, 15 cases received the IM (imatinib) therapy regularly based on NCCN guideline,10 cases received the therapy irregularly, and the other 6 cases did not receive the therapy. R0 resection was performed in 29 cases (93.5%) and R1/R2 resection was performed in 2 cases (6.5%). The median interval between the first operation to the recurrence was 32.3 (5.2-117.6) months and the median age of recurrence was 56 years old. Refer to the recurrent location, 28 cases (90.3%) were found in the same location or liver, 1 case in greater omentum, and 2 cases in pelvic cavity. The median diameter of the tumor in reoperation was 6.5 cm. Twenty-three cases(74.2%) received R0 excision and the other 8 cases(25.8%) received R1/R2 excision. At diagnosis of tumor recurrence, 20 cases (64.5%) received the second surgery immediately and the other 11 cases received surgery after imatinib or sunitinib treatment. Twenty-nine (93.5%) patients were followed up for 7.3 to 160.3 (median 49.5) months. After the second surgery, the relapse-free survival (RFS) of the whole group was 3.2 to 148.6(median: 29.7) months. Till the end of follow-up, 9 cases died of recurrence. Among 20 alive cases, 8 cases were living with the tumor, 1 case received the third surgery. The median overall survival (OS) time was 38.4(6.2-160.3) months. The 5-year RFS and the 5-year OS of 15 cases who received regular targeted therapy after the first operation were 73.4% and 81.7% respectively, significantly higher than those of the other 16 cases who received irregular or no targeted therapy(37.6%, P=0.015 and 38.9%,P=0.023,respectively). The 5-year RFS rate and the 5-year OS rate of the 11 patients who were diagnosed or complicated with liver metastasis were 29.8% and 32.2% respectively, which were significantly lower than those of the 20 patients without liver metastasis (79.1% and 88.1% respectively, both P<0.001). Cox model for OS, the results showed that regular targeted therapy after first surgery(HR=0.362, 95%CI:0.210-1.074, P=0.089) and the liver metastasis (HR=5.342, 95%CI: 0.902-12.580, P=0.057) were not the independent risk factors.

CONCLUSIONS

Regular targeted therapy according to the guideline after the first operation for GIST patients with recurrence or metastasis may improve the prognosis. Prognosis of GIST patients with postoperative liver metastasis is poor.