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Objective:To investigate the influencing factors of recurrence after radical resection of middle and low rectal cancer, and to establish a prediction model based on magnetic resonance imaging (MRI) measurement of perirectal fat content and investigate its application value.Methods:The retrospective cohort study was constructed. The clinicopathological data of 254 patients with middle and low rectal cancer who were admitted to Tianjin Union Medical Center from December 2016 to December 2021 were collected. There were 188 males and 66 females, aged (61±9)years. All patients underwent radical resection of rectal cancer and routine pelvic MRI examina-tion. Observation indicators: (1) follow-up and quantitative measurement of perirectal fat content; (2) factors influencing tumor recurrence after radical resection of middle and low rectal cancer; (3) construction and evaluation of the nomogram prediction model of tumor recurrence after radical resection of middle and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(rang) and M( Q1, Q2). Count data were described as absolute numbers. Univariate and multivariate analyses were conducted using the COX regression model. The rms software package (4.1.3 version) was used to construct the nomogram and calibration curve. The survival software package (4.1.3 version) was used to calculate the C-index. The ggDCA software package (4.1.3 version) was used for decision curve analysis. Results:(1) Follow-up and quantitative measurement of perirectal fat content. All 254 patients were followed up for 41.0(range, 1.0?59.0)months after surgery. During the follow-up period, there were 81 patients undergoing tumor recurrence with the time to tumor recurrence as 15.0(range, 1.0?43.0)months, and there were 173 patients without tumor recurrence. The preoperative rectal mesangial fascia envelope volume, preoperative rectal mesangial fat area, preoperative rectal posterior mesangial thickness were 159.1(68.6,266.5)cm3, 17.0(5.1,34.4)cm2, 1.2(0.4,3.2)cm in the 81 patients with tumor recurrence, and 178.5(100.1,310.1)cm3, 19.8(5.3,40.2)cm2 and 1.6(0.3,3.7)cm in the 173 patients without tumor recurrence. (2) Factors influencing tumor recurrence after radical resection of middle and low rectal cancer. Results of multivariate analysis showed that poorly differentiated tumor, tumor pathological N staging as N1?N2 stage, rectal posterior mesangial thickness ≤1.43 cm, magnetic resonance extra mural vascular invasion, tumor invasion surrounding structures were independent risk factors of tumor recurrence after radical resection of middle and low rectal cancer ( hazard ratio=1.64, 2.20, 3.19, 1.69, 4.20, 95% confidence interval as 1.03?2.61, 1.29?3.74, 1.78?5.71, 1.02?2.81, 2.05?8.63, P<0.05). (3) Construction and evaluation of the nomogram prediction model of tumor recurrence after radical resection of middle and low rectal cancer. Based on the results of multivariate analysis, the tumor differentiation, tumor pathological N staging, rectal posterior mesangial thickness, magnetic resonance extra mural vascular invasion, tumor invasion surrounding structures were included to construct the nomogram predic-tion model of tumor recurrence after radical resection of middle and low rectal cancer. The total score of these index in the nomogram prediction model corresponded to the probability of post-operative tumor recurrence. The C-index of the nomogram was 0.80, indicating that the prediction model with good prediction accuracy. Results of calibration curve showed that the nomogram prediction model with good prediction ability. Results of decision curve showed that the prediction probability threshold range was wide when the nomogram prediction model had obvious net benefit rate, and the model had good clinical practicability. Conclusions:Poorly differentiated tumor, tumor pathological N staging as N1?N2 stage, rectal posterior mesangial thickness ≤1.43 cm, magnetic resonance extra mural vascular invasion, tumor invasion surrounding structures are independent risk factors of tumor recurrence after radical resection of middle and low rectal cancer. Nomogram prediction model based on MRI measurement of perirectal fat content can effectively predict the probability of postoperative tumor recurrence.
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Total mesorectal excision (TME) has become the basic principle of surgical treat-ment for middle and low rectal cancer. Some of patients with ultra-low rectal cancer require under-going intersphincteric resection (ISR). Due to the limitation of the narrow pelvis, TME and ISR put forward higher requirements for the precise separation of the anatomical level and the protection of neurological function during the operation. At present, evaluation of the difficulty of surgery for middle and low rectal cancer is mainly based on the subjective judgment of chief surgeon, and there is no unified and objective scoring system or prediction model that can classify the difficulty of surgery for middle and low rectal cancer before surgery. The authors review relevant literatures and summarize the existing studies related to pelvic measurement for predicting the difficulty of surgery for middle and low rectal cancer, in order to provide significant guidance for the selection of surgical approach for patients with middle and low rectal cancer.
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Lateral lymph node metastasis (LLNM) is one of the major causes for post-operative local recurrence of middle and low rectal cancer. At present, there are still controversies on the diagnosis and treatment of LLNM. The radiological assessment of LLNM generally relies on morphological criteria such as the size or shape of the node or the response to therapy, in which the diagnostic accuracy of MRI is superior to that of other imaging techniques. Neoadjuvant chemoradiotherapy could not achieve good local control for suspicious LLNM. Lateral lymph node dissection (LLND) can reduce tumor local recurrence significantly, but the clinical value of LLND in survival and quality of life of patients has been questioned. 4K laparoscope can decrease the incidence of perioperative complications and urinary and sexual dysfunction to a certain extent. Thus, selective LLND should be undertaken to patients with suspicious LLNM after neoadjuvant chemoradiotherapy, in order to reduce tumor local recurrence and improve the prognosis of patients. The authors elaborate on diagnosis and treatment including surgery or chemoradiotherapy of LLNM in 4K laparoscopic surgery for middle and low rectal cancer combined with their own experiences.
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Objective To explore the clinical value of neutrophil/lymphocyte ratio (NLR) in staging of stage Ⅱ/Ⅲ middle and low rectal cancer. Methods The clinical and pathological data of 111 patients with middle and low rectal cancer who underwent surgical treatment were retrospectively analyzed. The NLR values along with various clinical factors and pathological parameters were also statistically analyzed, and then the relationship between preoperative NLR and various clinical factors was determined. All patients were divided into high and low groups based on NLR, with the cut-off value of 1.99. Then, the clinical, pathological parameters and disease-free survival of the two groups were analyzed. Results The maximum diameter of the tumor and the NLR value were positively correlated (P ＜ 0.05). The patients with high and low NLR had significant differences in age, stage Ⅱ and Ⅲ, N stage, pathological type, maximum diameter of the tumor, and disease-free survival (P ＜ 0.05). Conclusion Preoperative NLR values may be used as predictive values for the pathological parameters of stage Ⅱ and Ⅲ middle and low rectal cancer, and NLR may be an indicator of its prognostic assessment.
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Objective To study the clinical value of neoadjuvant radiotherapy (NRT),neoadjuvant chemoradiotherapy (NCRT) or surgery alone (S) in treatment of middle and low rectal cancer.Methods 139 cases were divided into 3 groups:47 cases were given NRT (50 Gy/25 f/5 w) as group NRT,46 cases were given NCRT (Capox+ radiotherapy) as group NCRT,and the remaining 46 cases were treated with surgery alone as group S.Patients in 3 groups were followed-up for 3 years for the observation of the rates of anuspreserving and 3-year survival rates.Results Compared with the patients in group S,the rates of anuspreserving in group NRT and NCRT were significant improvement [74.47 ％ (35/47) and 73.91％ (34/46) vs 54.35 ％ (25/46)],(x2 =4.111,3.827; P=0.043,0.050).The 1,2,3-year survival rates of the 3 groups had no significantly different (P ＞0.05).However,the 1-year survival rates might be lower in group NRT and group NCRT than that in group S [87.23 ％ (41/47) and 88.89 ％ (40/45) vs 97.83 ％ (45/46)] (x2 =4.611,P =0.100).Conclusion NRT and NCRT can improve the rate of anus-preserving,but might not improve the 1,2,3-year survival rate,instead,the death rate may increase in the first year.