Despite the adequacy of nodal evaluation was gradually improved for colon cancer (CC), rare attention has been paid for the effect of patient and tumor heterogeneity on nodal evaluation. We identified 109902 CC patients in stage I-III from Surveillance, Epidemiology, and End-Results (SEER) database during 2004-2013. The lymph nodes evaluations were separately assessed in different patient- and tumor-related features, including gender, age, T stage, histology, tumor differentiation, tumor size and tumor location. The 5-year cancer specific survival (CSS) was calculated with Kaplan-Meier method, log-rank tests were used to compare the differences of CSS in patients with ≥12 and <12 lymph nodes examined. Here, we identified features including gender, age, T stage, tumor differentiation, tumor size and location were independently associated with the median number of lymph node, the rate of ≥12 lymph nodes and the rate of node positivity of CC patients. We then divided CC patients into 29 subgroups according to different patient- and tumor-related features. The median number of lymph node presented a large variance from 12 to 24, the rate of ≥12 lymph nodes increased from 53.2% to 91.2% under the combined effect of patient and tumor heterogeneity. Furthermore, the positive association between increased lymph nodes count and improved survival couldn't be observed in 8261 CC patients with the effect of this heterogeneity. In conclusion, the tumor and patient heterogeneity lead to large alterations of nodal evaluation; we should pay more attention to this effect in clinical practice.

The precise role and potential underlying mechanisms of anoctamin 9 (ANO9) remain largely unknown. This study aims to characterize the role and oncogenic mechanisms of ANO9 in stage II and III colorectal cancer (CRC).

Radiotherapy is widely applied for locally advanced rectal cancer (RC) to improve both local control and long-term outcomes. However, the efficacy of radiotherapy for rectosigmoid junction cancer (RSC) is still undetermined. Here, we identified 10074 patients who were diagnosed with locally advanced RSC from Surveillance, Epidemiology, and End-Results (SEER) cancer registry. These patients were divided into three subgroups according to different therapy strategies, including surgery alone, surgery plus preoperative radiotherapy and surgery plus postoperative radiotherapy. 5-year cancer-specific survival (CSS) and 5-year overall survival (OS) were obtained. Kaplan-Meier methods and Cox regression models were used to estimate the correlations between prognostic factors and survival outcomes.The 5-year CSSs for RSC patients treated with pre- and postoperative radiotherapy were 72.3% and 72.2%, which were significantly higher than surgery alone (64.8%). The 5-year OSs for RSC patients treated with pre- and postoperative radiotherapy were 71.6% and 71.2%, which were higher than surgery alone (64.0%). In the separate analyses of stage II and III RSC patients, the similar trends were also obtained. In addition, pre- and postoperative radiotherapy were equally identified as valuable prognostic factors for better survival outcomes in RSC patients. Furthermore, the results following propensity score matching also confirmed that the long-term survivals of RSC patients were improved following radiotherapy. In conclusion, locally advanced RSCpatients could obtain potential long-term survival benefits from radiotherapy. A prospective randomized control trial should be performed to further validate the strength of evidence in current study.

Despite the adequacy of nodal evaluation was gradually improved for colon cancer, the disparity in nodal examination for right colon cancer (RCC) and left colon cancer (LCC) still begs the question of whether 12 nodes is an appropriate threshold for both RCC and LCC. From Surveillance, Epidemiology, and End-Results (SEER) database, we identified 53897 RCC patients and 11822 LCC patients. Compared with LCC patients, RCC patients examined more lymph nodes (18.7 vs 16.3), and more likely to examine ≥12 nodes (P<0.001), whereas RCC patients showed lower rates of node positivity (P<0.001). To balance the nodal disparity between RCC and LCC, we revised the 12-node measure based on different tumor locations. With the X-tile, we determined 15 as the optimal node number for RCC and 11 for LCC. To validate the availability of this revised nodal evaluation, the 5-year cancer specific survival (CSS) was calculated according to the optimal node number in RCC and LCC patients, Cox's regression model were used to further assess the prognostic value of this revised nodal evaluation. The results showed that 5-year CSSs were significantly improved for RCC patients with ≥15 lymph nodes, and also for LCC patients with ≥11 lymph nodes (P<0.001). This revised nodal evaluation could also improve the rate of nodal positivity and long-term survival in both RCC and LCC patients compared with 12-node measure. Therefore, the lymph node examination should be discriminately evaluated for RCC and LCC, instead of using 12-node measure to colon cancer as a whole.

Due to special tumor location and technical difficulty of transverse colon cancer (TCC), partial colectomy (PC) is being widely applied in selected TCC patients, instead of extended hemicolectomy (HC). However, the oncological safety of this less aggressive surgical approach is not well studied. Here, we identified 10344 TCC patients from Surveillance, Epidemiology, and End-Results (SEER) database. The surgical treatment for those patients included PC and HC. Firstly, we compared lymph nodes evaluations between patients treated with HC and PC, including median number of nodes, the rate of nodes ≥ 12 and the rate of node positivity. Then, 5-year cancer specific survival (CSS) was obtained. Kaplan-Meier methods and Cox regression models were performed to assess the correlations between prognostic factors and long-term survival. Despite of less node examined by PC, the rate of node positivity was equal between PC and HC, suggesting node retrieval under PC was adequate to tumor stage. In addition, the 5-year CSS for patients who underwent PC were 67.5%, which was similar to patients who received HC (66.5%). The result after propensity score matching also confirmed the equivalent survival outcome between HC and PC. However, subgroup analyses showed that patients with tumor size ≥ 5 cm could not obtain survival benefit from PC. Furthermore, surgical approach was not considered as independent prognostic factor for TCC patients. Therefore, although PC is a less aggressive surgical approach, it should be a safe and feasible option for selected TCC patients.

Due to large progress has been achieved in surgical techniques, anesthesia and perioperative care, it is accepted that the very elderly colon cancer (CC) patient is not contraindication for surgery. However, it is a controversy that an extended or a less aggressive surgical approach should be performed for this population. Here, we identified 28110 CC patients aged ≥80 from Surveillance, Epidemiology, and End-Results (SEER) database. The surgical approaches included extended hemicolectomy (HC) and partial colectomy (PC). 5-year cancer specific survival (CSS) was obtained. Kaplan-Meier methods and Cox regression models were used to assess the correlations between prognostic factors and long-term survival. The 5-year CSS for patients treated with HC were 45.6%, which were similar to patients who received PC (44.8%), the survival difference has no statistical significance (P=0.087). The result following propensity score matching further confirmed long-term survival were equal between HC and PC. However, patients in AJCC T3/T4 stage and with tumor size ≥5cm could obtain survival benefit from the extended surgery. In conclusion, most of elderly CC patients could not obtain survival benefit from extended resection. Partial colectomy should also be considered as an alternative approach for this group of patients.