Qiongyan Zhang1,2,3, Junjie Peng2,4, Min Ye1,2, Weiwei Weng1,2, Cong Tan1,2, Shujuan Ni1,2, Dan Huang1,2, Weiqi Sheng5,6, Lei Wang7,8. 1. Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China. 2. Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China. 3. Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai, China. 4. Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, China. 5. Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China. shengweiqi2006@163.com. 6. Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China. shengweiqi2006@163.com. 7. Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China. wanglei056713@163.com. 8. Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China. wanglei056713@163.com.
Abstract
BACKGROUND: The presence of micrometastases is a source of recurrence after surgical resection of colorectal liver metastases (CRLM). The KRAS mutation is common in colorectal cancer, however the correlation between KRAS status and micrometastases has not been thoroughly clarified. METHODS: We enrolled a cohort of 251 consecutive CRLM patients who received complete liver surgery with known KRAS mutation status, and collected clinicopathological information, including micrometastases, margin status, preoperative chemotherapy, and liver recurrence-free survival (LRFS) and overall survival (OS) rates. RESULTS: KRAS-mutant (mutKRAS) patients had a higher incidence (60.3 vs. 40.8%; p = 0.002) and higher number of micrometastases [2.0 (range 0-38.0) vs. 0 (range 0-15.0); p < 0.001] than KRAS wild-type (wtKRAS) patients. The micrometastases in the mutKRAS group were more distant than those in the wtKRAS group [0.7 (range 0.1-9.0) vs. 0.6 (range 0.2-5.0) mm; p = 0.018). The mutKRAS group had more involved margin resections (21.5 vs. 9.2%; p = 0.07) and narrower margin widths [2.0 (range 0-40.0) vs. 4.3 (0-50.0) mm; p = 0.002] than the wtKRAS group. In addition, preoperative chemotherapy was associated with a lower rate of micrometastases in mutKRAS CRLM tumors (p < 0.05). mutKRAS status, positive margins, and micrometastases were all related to worse LRFS and OS (p < 0.05); however, micrometastases were not significantly correlated with OS in the multivariate analysis (p = 0.106). CONCLUSIONS: mutKRAS patients had more micrometastases, increased R1 resections, and narrower margins. The presence of micrometastases may have led to the narrow margin width observed in these cases.
BACKGROUND: The presence of micrometastases is a source of recurrence after surgical resection of colorectal liver metastases (CRLM). The KRAS mutation is common in colorectal cancer, however the correlation between KRAS status and micrometastases has not been thoroughly clarified. METHODS: We enrolled a cohort of 251 consecutive CRLMpatients who received complete liver surgery with known KRAS mutation status, and collected clinicopathological information, including micrometastases, margin status, preoperative chemotherapy, and liver recurrence-free survival (LRFS) and overall survival (OS) rates. RESULTS:KRAS-mutant (mutKRAS) patients had a higher incidence (60.3 vs. 40.8%; p = 0.002) and higher number of micrometastases [2.0 (range 0-38.0) vs. 0 (range 0-15.0); p < 0.001] than KRAS wild-type (wtKRAS) patients. The micrometastases in the mutKRAS group were more distant than those in the wtKRAS group [0.7 (range 0.1-9.0) vs. 0.6 (range 0.2-5.0) mm; p = 0.018). The mutKRAS group had more involved margin resections (21.5 vs. 9.2%; p = 0.07) and narrower margin widths [2.0 (range 0-40.0) vs. 4.3 (0-50.0) mm; p = 0.002] than the wtKRAS group. In addition, preoperative chemotherapy was associated with a lower rate of micrometastases in mutKRAS CRLMtumors (p < 0.05). mutKRAS status, positive margins, and micrometastases were all related to worse LRFS and OS (p < 0.05); however, micrometastases were not significantly correlated with OS in the multivariate analysis (p = 0.106). CONCLUSIONS: mutKRAS patients had more micrometastases, increased R1 resections, and narrower margins. The presence of micrometastases may have led to the narrow margin width observed in these cases.