Clinico-pathological predictors of clinical complete response in rectal cancer

Gross morphologic features of surgical specimen in rectal cancer patients with pathological complete response following neoadjuvant chemoradiotherapy: A cross-sectional study

BACKGROUND

pathological complete response (pCR) is achieved in 10%-30% of rectal cancer patients following neoadjuvant chemoradiotherapy and surgery. Residual mucosal abnormalities, which make patients ineligible for nonoperative management, may not be an accurate indicator of the pCR. The purpose of this study was to report the gross findings of rectal cancer patients with pathological complete responses.

METHODS

This study was conducted at Tehran University of Medical Sciences, Tehran, Iran. A total of 130 patients with rectal adenocarcinoma, treated by neoadjuvant chemoradiotherapy, followed by surgical resection between March 2007, and March 2017, with a surgical pathology report of pCR, were included. Patients' demographics and pretreatment tumor characteristics were collected from the medical records. Data regarding residual mucosal abnormalities were extracted from postoperative surgical pathology reports. Abnormal findings were reported as "ulcer" or " non-ulcerative lesion".

RESULTS

One hundred and fifteen patients (88.5%; 95% CI: 81.7%-93.4%) had at least one abnormal finding in the gross examination, including ulcer or non-ulcerative lesion (any mucosal abnormalities other than ulcers, including polyps, telangiectasia, etc.). Patients with higher-stage tumors had a higher chance of having an ulcerative lesion (p = 0.05). Younger patients tended to have deeper layers of involvement (p = 0.013). Patients with different gross findings were not significantly different regarding baseline characteristics, except for the pretreatment stage, where patients with a higher stage had higher odds of having ulcerative lesions.

CONCLUSIONS

Most rectal cancer patients achieving a pCR exhibit abnormalities on gross examination. The higher pretreatment stages were significantly associated with gross abnormalities especially ulcers.

Association Between RAS/BRAF Mutations and Complete Response Following Total Neoadjuvant Therapy in Patients with Rectal Cancer: A Prospective Multicentered Study

BACKGROUND

The impact of RAS/BRAF mutation on primary response rates after total neoadjuvant therapy (TNT) in patients with advanced rectal cancer is unclear. The aim of this study was to assess complete response rates after TNT according to RAS/BRAF mutation status.

METHODS

A prospective observational study was performed in patients with rectal cancer who underwent TNT with curative intent at three South Australian hospitals between 2019 and 2023. Patients were classified according to their mutation status: mutant RAS/BRAF (mutRAS) or wild-type RAS/BRAF (wtRAS). The primary endpoint was overall complete response (oCR) rate, defined as the proportion of patients who achieved clinical complete response (cCR) and/or pathological complete response (pCR).

RESULTS

Of the 150 patients eligible for inclusion, 80 patients with RAS/BRAF status available were identified. Of these, 43 (53.8%) patients were classified as mutRAS and 37 (46.3%) patients as wtRAS. Patients with mutRAS had significantly lower cCR and oCR rates after TNT than patients with wtRAS (14% vs. 37.8%, p = 0.014; 11.6% vs. 43.2%, p = 0.001, respectively). There was no significant difference in pCR rate between the groups. Of the 80 rectal cancer patients tested, 35 (43.8%) had metastatic disease (M1). There was no significant difference in complete M1 response rates between the groups (17.6% vs. 38.9%, p = 0.254).

CONCLUSION

RAS/BRAF mutations negatively impact primary tumor response rates after TNT in patients with advanced rectal cancer. Large-scale national studies are needed to determine whether RAS/BRAF status could be used to select optimal oncologic therapy in rectal cancer patients.

Neutrophil-to-lymphocyte ratio predict survival of patients with rectal cancer receiving neo-adjuvant chemoradiation followed by radical resection: a meta-analysis

BACKGROUND

Neutrophil-to-lymphocyte ratio is suggested as a prognostic and predictive factor for patients with rectal cancer. The purpose of the current meta-analysis is to evaluate the relationship between neutrophil-lymphocyte ratio (NLR) and the outcome of patients, with rectal cancer receiving chemoradiation and surgery.

METHODS

A systematic review on two databases and a selection of studies were done. Thereafter, two meta-analyses were performed, evaluating the relationship of baseline NLR with overall survival (OS) and disease-free survival (DFS).

RESULTS

Thirty-one retrospective studies were selected. Twenty-six studies have documented a significant relationship of NLR to OS (HR 2.05, CI 1.66-2.53), whereas 23 studies have reported a weaker but significant relationship of NLR to DFS (HR 1.78, CI 1.49-2.12). Among the moderator variables, a possible effect for age and sex on the relationship of NLR with DFS is suggested.

CONCLUSIONS

Baseline NLR >3 is a simple and reproducible prognostic factor, with a more consistent effect in the elderly. It could be a reliable variable to support clinicians in defining personalized treatment strategies, even though a standardization of the cutoff and a better characterization among microsatellite unstable rectal tumors are necessary.

Radiomics Approaches for the Prediction of Pathological Complete Response after Neoadjuvant Treatment in Locally Advanced Rectal Cancer: Ready for Prime Time?

In recent years, neoadjuvant therapy of locally advanced rectal cancer has seen tremendous modifications. Adding neoadjuvant chemotherapy before or after chemoradiotherapy significantly increases loco-regional disease-free survival, negative surgical margin rates, and complete response rates. The higher complete rate is particularly clinically meaningful given the possibility of organ preservation in this specific sub-population, without compromising overall survival. However, all locally advanced rectal cancer most likely does not benefit from total neoadjuvant therapy (TNT), but experiences higher toxicity rates. Diagnosis of complete response after neoadjuvant therapy is a real challenge, with a risk of false negatives and possible under-treatment. These new therapeutic approaches thus raise the need for better selection tools, enabling a personalized therapeutic approach for each patient. These tools mostly focus on the prediction of the pathological complete response given the clinical impact. In this article, we review the place of different biomarkers (clinical, biological, genomics, transcriptomics, proteomics, and radiomics) as well as their clinical implementation and discuss the most recent trends for future steps in prediction modeling in patients with locally advanced rectal cancer.

A novel prediction model for pathological complete response based on clinical and blood parameters in locally advanced rectal cancer

Background

The aim of this study was to investigate whether clinical and blood parameters can be used for predicting pathological complete response (pCR) to neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC).

Methods

We retrospectively enrolled 226 patients with LARC [allocated in a 7:3 ratio to a training (n = 158) or validation (n = 68) cohort] who received nCRT before radical surgery. Backward stepwise logistic regression was performed to identify clinical and blood parameters associated with achieving pCR. Models based on clinical parameters (CP), blood parameters (BP), and clinical-blood parameters (CBP) were constructed for comparison with previously reported Tan's model. The performance of the four models was evaluated by receiver operating characteristic (ROC) curve analysis, calibration, and decision curve analysis (DCA) in both cohorts. A dynamic nomogram was constructed for the presentation of the best model.

Results

The CP and BP models based on multivariate logistic regression analysis showed that interval, Grade, CEA and fibrinogen-albumin ratio index (FARI), sodium-to-globulin ratio (SGR) were the independent clinical and blood predictors for achieving pCR, respectively. The area under the ROC curve of the CBP model achieved a score of 0.818 and 0.752 in both cohorts, better than CP (0.762 and 0.589), BP (0.695 and 0.718), Tan (0.738 and 0.552). CBP also showed better calibration and DCA than other models in both cohorts. Moreover, CBP revealed significant improvement compared with other models in training cohort (P < 0.05), and CBP showed significant improvement compared with CP and Tan's model in validation cohort (P < 0.05).

Conclusion

We demonstrated that CBP predicting model have potential in predicting pCR to nCRT in patient with LARC.

Clinical and Basic Evaluation of the Effects of Upregulated TNFAIP3 Expression on Colorectal Cancer

Objective

To assess the TNFAIP3 and nuclear factor κB (NFκB) protein expressions in colorectal cancer (CRC) tissue and to analyze the association of these proteins with the clinical pathological characteristics of CRC.

Methods

The following methods should be used in clinical trials: information collection and immunohistochemical methods. The following methods are used for cell experiment: cell transfection, CCK8 detection method, transwell experiment, and western blot experiment. Explore the TNFAIP3 expression in CRC cells, and assess the effect of upregulated TNFAIP3 expression on CRC cell proliferation, invasion, and migration. In clinical experiment, we selected the tumor tissues of 39 CRC patients as our experimental samples. We also collected corresponding patient demographics, such as sex, age, cell differentiation, tumor type, and lymph node metastasis. We also analyzed the TNFAIP3 and NFκB protein expressions in 20 experimental and 20 control samples and evaluated potential correlations between these two proteins and clinical pathological characteristics of CRC. For basic experiment, we established CRC cell lines with elevated TNFAIP3 expression and then randomly divided the cells into three groups, namely, TNFAIP3, NS, and Con groups. Using the transwell and CCK8 methods, we detected the CRC migration abilities and cell proliferation, respectively. We also employed western blot analysis to assess protein expression in the three groups.

Results

NFκB was highly expressed, and TNFAIP3 was scarcely expressed in the experimental group versus control. The expression of both these proteins were strongly related to the degree of tumor differentiation (P < 0.05). The TNFAIP3 and NFκB protein expressions were significantly associated with lymph node metastasis and tumor differentiation (P < 0.05). For basic experiment, compared to the Con and NS groups, TNFAIP3 protein expression levels, cell proliferation, invasion, and migration were significantly increased in the TNFAIP3 group (P < 0.05).

Conclusion

TNFAIP3 overexpression strongly inhibited CRC proliferation, invasion, and migration. Enhanced NFκB protein expression in CRC tissues was associated with elevated malignant degree, metastasis, and TNFAIP3 protein expression in patients who demonstrated high malignant degree and metastasis. Our evidences suggest the promising potential of utilizing TNFAIP3 and NFκB as important reference indices for determining the prognostic outcome of CRC. Furthermore, we revealed that TNFAIP3 overexpression inhibited CRC cell proliferation, invasion, and migration.