br Individualized treatment of left and right
Individualized treatment of left and right colon cancer is mainly reflected in chemotherapy. A CALGB / SWOG 80405 phase III clinical trial  showed that, in RAS wild-type mCRC, when tumors were located in the left colon, the overall survival time of cetuximab treatment was longer than that OSMI4 of bevacizumab, and when tumors were located in the right colon, the overall survival time of cetuximab treatment was shorter than that of bevacizumab treatment. With further studying the potential differences between left and right colon cancer, the treatment of colon cancer will be more precise and individualized in the future.
Although the correlation between the primary site of tumor and the prognosis of colorectal cancer is still controversial, most scholars believe that the primary site of tumor is an independent factor in the prognosis of CRC. Previous studies have shown
ACCEPTEDthatcomparedwithLCC,RCChasasignificantly lower mean survival time and 5-year survival rate. A research conducted by Benedix et al. showed that patients with RCC
had a worse prognosis than LCC. Besides, data from the Surveillance, Epidemiology, and End Results Program (SEER) database showed that the median survival of colon cancer was 83 months, and the median survival of right and left colon cancers were 78 and 89 months, respectively. The difference between the two groups was statistically significant (P<0.05). In our study, the median survival of patients with RCC, LC and RC were 72, 70 and 73 months, respectively. The median survival of the three groups was statistically significant (P=0.049). Therefore, the results of the study were inconsistent with previously published ones, which could be caused by inadequate sample size and loss of follow-up. In addition, surgical methods (laparoscopic or open surgery) and surgical types (radical or palliative resection) could
also have an impact on the results.
In conclusion, colorectal cancer at different anatomical subsites exhibits different epidemiological and clinicopathological features. The age of onset of right-sided colon cancer is the oldest on average and poorly differentiated tumors accounted for the highest proportion. Besides, average maximum tumor diameter is the largest in right-sided colon cancer. Comprehensive understanding of the clinicopathological features
and prognosis of colorectal cancer at differentMANUSCRIPTanatomicalsubsitesisofgreatguiding significance for clinical diagnosis and treatment of colorectal cancer, and is helpful for individualized treatment and precise treatment. According to our opinion, Corepressor is highly necessary to find and confirm the molecular biological differences of colorectal cancer at different anatomical subsites. Further studies are encouraged to investigate on this topic.
Z.F and X.M.S. drafted the manuscript. Y.F.Z and S.Y.R. supervised the whole project.
All authors read and approved the final manuscript.
This study was supported by the National Natural Science Foundation of China (81372669).
Conflicts of interests
The authors declare that there is no conflict of interests in this study.
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