Nomogram for prediction of pathologic complete remission using biomarker expression and endoscopic finding after preoperative chemoradiotherapy in rectal cancer

Correlation study of functional magnetic resonance index and clinicopathological features of rectal cancer

PURPOSE

To investigate the correlation between DCE-MRI, R2*, IVIM, and clinicopathological features of rectal cancer.

METHODS

This was a prospective study, enrolling 42 patients with rectal cancer, 20 of whom underwent rectal mesorectal excision. Dynamic contrast-enhanced magnetic resonance imaging scanning was performed preoperatively in all patients, and additional preoperative scanning of R2* imaging and intravoxel incoherent motion was performed in those who underwent surgery. Artificially delineate the ROI around the tumor. Functional magnetic resonance index parameters Ktrans, Ve, R2*, D, D*, and f were estimated by computer software to analyze postoperative pathological reports of patients undergoing total mesenteric resection. Correlation and significance analyses of imaging metrics and pathologic features were performed by GraphPad Prism 9 to assess statistical significance.

RESULTS

DEC-MRI, R2*, and IVIM have certain application values in the distance from the lower margin of the tumor to the anorectal ring, imaging T stage and N stage, tumor markers CEA and CA199, immunohistochemical indexes Ki-76 and P53, lymph node cancer metastasis, and rectal fascia status (P < 0.05).

CONCLUSION

DEC-MRI, R2*, and IVIM provide reliable quantitative parameters for preoperative clinicopathological evaluation of patients with rectal cancer.

A novel radiomics based on multi-parametric magnetic resonance imaging for predicting Ki-67 expression in rectal cancer: a multicenter study

BACKGROUND

To explore the value of multiparametric MRI markers for preoperative prediction of Ki-67 expression among patients with rectal cancer.

METHODS

Data from 259 patients with postoperative pathological confirmation of rectal adenocarcinoma who had received enhanced MRI and Ki-67 detection was divided into 4 cohorts: training (139 cases), internal validation (in-valid, 60 cases), and external validation (ex-valid, 60 cases) cohorts. The patients were divided into low and high Ki-67 expression groups. In the training cohort, DWI, T2WI, and contrast enhancement T1WI (CE-T1) sequence radiomics features were extracted from MRI images. Radiomics marker scores and regression coefficient were then calculated for data fitting to construct a radscore model. Subsequently, clinical features with statistical significance were selected to construct a combined model for preoperative individualized prediction of rectal cancer Ki-67 expression. The models were internally and externally validated, and the AUC of each model was calculated. Calibration and decision curves were used to evaluate the clinical practicality of nomograms.

RESULTS

Three models for predicting rectal cancer Ki-67 expression were constructed. The AUC and Delong test results revealed that the combined model had better prediction performance than other models in three chohrts. A decision curve analysis revealed that the nomogram based on the combined model had relatively good clinical performance, which can be an intuitive prediction tool for clinicians.

CONCLUSION

The multiparametric MRI radiomics model can provide a noninvasive and accurate auxiliary tool for preoperative evaluation of Ki-67 expression in patients with rectal cancer and can support clinical decision-making.

A nomogram and risk classification system forecasting the cancer-specific survival of lymph- node- positive rectal cancer patient after radical proctectomy

Background

The aim of the study was to develop and validate a nomogram for predicting cancer-specific survival (CSS) in lymph- node- positive rectal cancer patients after radical proctectomy.

Methods

In this study, we analyzed data collected from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. In addition, in a 7:3 randomized design, all patients were split into two groups (development and validation cohorts). CSS predictors were selected via univariate and multivariate Cox regressions. The nomogram was constructed by analyzing univariate and multivariate predictors. The effectiveness of this nomogram was evaluated by concordance index (C-index), calibration plots, and receiver operating characteristic (ROC) curve. Based on the total score of each patient in the development cohort in the nomogram, a risk stratification system was developed. In order to analyze the survival outcomes among different risk groups, Kaplan-Meier method was used.

Results

We selected 4,310 lymph- node- positive rectal cancer patients after radical proctectomy, including a development cohort (70%, 3,017) and a validation cohort (30%, 1,293). The nomogram correlation C-index for the development cohort and the validation cohort was 0.702 (95% CI, 0.687-0.717) and 0.690 (95% CI, 0.665-0.715), respectively. The calibration curves for 3- and 5-year CSS showed great concordance. The 3- and 5-year areas under the curve (AUC) of ROC curves in the development cohort were 0.758 and 0.740, respectively, and 0.735 and 0.730 in the validation cohort, respectively. Following the establishment of the nomogram, we also established a risk stratification system. According to their nomogram total points, patients were divided into three risk groups. There were significant differences between the low-, intermediate-, and high-risk groups (p< 0.05).

Conclusions

As a result of our research, we developed a highly discriminatory and accurate nomogram and associated risk classification system to predict CSS in lymph-node- positive rectal cancer patients after radical proctectomy. This model can help predict the prognosis of patients with lymph- node- positive rectal cancer.

Kif4A mediates resistance to neoadjuvant chemoradiotherapy in patients with advanced colorectal cancer via regulating DNA damage response

More and more patients with advanced colorectal cancer (CRC) have benefited from surgical resection or ablation following neoadjuvant chemoradiotherapy (nCRT), but nCRT may be ineffective and have potential risks to some patients. Therefore, it is necessary to discover effective biomarkers for predicting the nCRT efficacy in CRC patients. Chromokinesin Kif4A plays a critical role in mitosis, DNA damage repair and tumorigenesis, but its relationship with nCRT efficacy in advanced CRC remains unclear. Here, we find that Kif4A expression in pretreated tumor tissue is positively correlated with poorer tumor regression after receiving nCRT ( P=0.005). Knockdown of endogenous Kif4A causes an increased sensitivity of CRC cells to chemotherapeutic drugs 5-fluorouracil (5-FU) and Cisplatin (DDP), while overexpression of Kif4A enhances resistance of CRC cells to the chemotherapeutic drugs. Furthermore, depending on its motor domain and tail domain, Kif4A regulates DNA damage response (DDR) induced by 5-FU or DDP treatment in CRC cells. In conclusion, we demonstrate that Kif4A may be a potential independent biomarker for predicting the nCRT efficacy in advanced CRC patients, and Kif4A regulates chemosensitivity of CRC cells through controlling DDR.

Pre-Treatment Computed Tomography Radiomics for Predicting the Response to Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer: A Retrospective Study

Background and Purpose

Computerized tomography (CT) scans are commonly performed to assist in diagnosis and treatment of locally advanced rectal cancer (LARC). This study assessed the usefulness of pretreatment CT-based radiomics for predicting pathological complete response (pCR) of LARC to neoadjuvant chemoradiotherapy (nCRT).

Materials and Methods

Patients with LARC who underwent nCRT followed by total mesorectal excision surgery from July 2010 to December 2018 were enrolled in this retrospective study. A total of 340 radiomic features were extracted from pretreatment contrast-enhanced CT images. The most relevant features to pCR were selected using the least absolute shrinkage and selection operator (LASSO) method and a radiomic signature was generated. Predictive models were built with radiomic features and clinico-pathological variables. Model performance was assessed with decision curve analysis and was validated in an independent cohort.

Results

The pCR was achieved in 44 of the 216 consecutive patients (20.4%) in this study. The model with the best performance used both radiomics and clinical variables including radiomic signatures, distance to anal verge, lymphocyte-to-monocyte ratio, and carcinoembryonic antigen. This combined model discriminated between patients with and without pCR with an area under the curve of 0.926 and 0.872 in the training and the validation cohorts, respectively. The combined model also showed better performance than models built with radiomic or clinical variables alone.

Conclusion

Our combined predictive model was robust in differentiating patients with and without response to nCRT.

A Diagnostic Nomogram for Predicting the Risk of Anastomotic Leakage in Elderly Patients With Rectal Cancer: A Single-center Retrospective Cohort Study

BACKGROUND

Laparoscopic resection for rectal cancer has been gaining popularity over the past 2 decades. Whether elderly patients had more benefits from laparoscopy-assisted anterior resection (LAR) need further investigation when comparing with open anterior resection (OAR).

OBJECTIVES

This study aimed to evaluate the clinical outcomes and prognosis of LAR in elderly patients (65 y and above) with rectal cancer and investigate the factors associated with the anastomotic leakage (AL). Besides, the study sought to create a nomogram for precise prediction of AL after anterior resection for rectal cancer.

MATERIALS AND METHODS

A total of 343 rectal cancer patients over 65 years old who underwent LAR or OAR at a single center between January 2013 to January 2021 were retrospectively reviewed. Univariate analysis was conducted to explore potential risk factors for AL, and a nomogram for AL was created based on the multivariate logistic regression model.

RESULTS

A total of 343 patients were included in this study, 271 patients in LAR group and 72 patients in OAR group. Most of the variables were comparable between the 2 groups. The mean operative time was longer in the LAR group than that in the OAR group (191.66±58.33 vs. 156.85±53.88 min, P<0.0001). The LAR group exhibited a significantly lower intraoperative blood loss than the OAR group (85.17±50.03 vs. 131.67±79.10 mL; P<0.0001). Moreover, laparoscopic surgery resulted in shorter postoperative hospital stay, lower rates of diverting stoma and receiving sphincter sparing surgery in comparison with open surgery. The overall rates of complications were 25.1% and 40.3% in the LAR and OAR groups (P=0.011), respectively. And the reoperation rates in the OAR group (0%) was lower than in the LAR group (1.5%), but the difference did not reach statistical significance (P=0.300). Sex, location of tumor, diverting stoma and combined organ resection were identified as independent risk factors for AL based on multivariate analysis. Such factors were selected to develop a nomogram. After a median follow-up of 37.0 months, our study showed no significant difference in overall survival or disease free survival between the 2 groups for treatment of rectal cancer.

CONCLUSIONS

This study suggests that LAR is an alternative minimally invasive surgical procedure in patients above 65 years with better short-term outcomes and acceptable long-term outcomes compared with OAR. In addition, our nomogram has satisfactory accuracy and clinical utility may benefit for clinical decision-making.

Complete Pathologic Response of Multiple Liver Metastases and Clinical Complete Response of Rectal Cancer in a Patient with Ataxia-Telangiectasia Mutated Gene Mutations After XELOXIRI Plus Bevacizumab: A Case Report

Background

Doublet or triplet chemotherapy plus or minus targeted drugs can achieve a high objective response rate (ORR) and are currently considered to be the backbone of conventional therapy for liver metastatic colorectal cancer (mCRC). However, current biomarkers (such as UGT1A1 and DPYD) are limited to the prediction of toxicity and there are no effective biomarkers to predict chemotherapy response. Therefore, personalized cancer chemotherapy underpinned by genomic alterations in mCRC has received increasing attention.

Case Presentation

We present a case of a 28-year-old female rectal cancer patient with multiple liver metastases (clinical risk score, CRS = 5 points). The patient underwent XELOXIRI plus bevacizumab regimen that consisted of irinotecan (150 mg/m2), oxaliplatin (100 mg/m2) on day 1, capecitabine (1700 mg/m2 per day from day 2 to 15), bevacizumab (7.5 mg/kg) on day 1 (on the second cycle), given every three weeks for eight cycles. After multi-disciplinary team (MDT) discussion, the patient underwent right hemihepatectomy, partial liver resection of segment IV and cholecystectomy. Surprisingly, the patient achieved a complete pathologic response (pCR) of the hepatic metastasis and clinical complete response (cCR) of the primary rectal lesion. A paired tumor molecular profile revealed somatic mutations in ataxia-telangiectasia mutated (ATM) genes that may explain why the patient achieved such a dramatic tumor response. Treatment was discontinued after eight cycles of a single oral dose of capecitabine and the patient started a follow-up program of physical and radiological examinations. To monitor the signs of recurrence, we also obtained blood samples to analyze circulating tumor DNA (ctDNA). To date, the patient has remained disease-free.

Conclusion

The XELOXIRI-bevacizumab regimen is a feasible and effective regimen for patients with mCRC. Mutations in the ATM genes may characterize a subset of patients with a better prognosis who are more sensitive to chemotherapy plus biological agents.