Prognostic value of pretreatment level of carcinoembryonic antigen on tumour downstaging and early occurring metastasis in locally advanced rectal cancer following neoadjuvant radiotherapy (30 Gy in 10 fractions)

Molecular mechanisms of radiation resistance in colorectal cancer: in silico identification of AURKA, BIRC5 and PLK1 proteins as potential biomarkers

PURPOSE

The development of radiation resistance by tumor cells severely affects the survival of colorectal cancer patients. The aim of this work is to study the molecular mechanisms involved in the resistance to radiotherapy treatment in colorectal cancer and the identification of key genes as possible biomarkers.

METHODS

Data mining was performed in PubMed with the keywords 'colorectal neoplasms', 'radiotherapy', and 'resistance', generating a total of 242 articles in which a series of inclusion and exclusion criteria were applied to select the articles of interest. Then, an in-silico analysis of the selected genes was performed with the bioinformatic tools: GeneCodis, Metascape, KEGG, REACTOME, STRING, STITCH, CHEA3, DGIdb, CTD, and GEPIA.

RESULTS

Different mechanisms and genes involved in radiation resistance were described. These are related to evasion of apoptosis, cell cycle dysregulation, epithelial-mesenchymal transition, and repair of DNA breaks, with the last one being the most relevant and influential. The In-silico study carried out with 21 genes involved in radiation resistance showed the implication of FoxO signaling and EGFR tyrosine kinase inhibitor resistance as the most enriched pathways. In addition, the study identified the key proteins AURKA, BIRC5, and PLK1, showing multiple interacting chemicals and drugs; such as tamoxifen, omacetaxine mepesuccinate, and hydroxyzine pamoate, among others.

CONCLUSION

The identification of multiple transcription factors that regulate the expression of these key genes as well as the validation in patient samples where higher expression is observed in tumor patients, conserved across tumor stages I-IV, suggests their potential as possible biomarkers.

Prognostic Value of Pretreatment Carcinoembryonic Antigen (CEA) in Rectal Cancer Treated with Preoperative Short-Course Radiotherapy with Delayed Surgery or Long-Course Radiotherapy

Purpose

To investigate the prognostic value of the pretreatment serum carcinoembryonic antigen (CEA) level in patients with rectal cancer treated by preoperative short-course radiotherapy (SCRT) followed by chemotherapy and delayed surgery.

Patients and Methods

Two hundred and sixty-six consecutive patients with locally advanced rectal adenocarcinoma without distant metastasis receiving preoperative radiotherapy were enrolled. Group 1 patients (n=144) received long-course radiotherapy (LCRT) with 50.4 Gy in 28 fractions using photon radiotherapy (XRT). Group 2 patients (n=122) received SCRT with 25 Gy in 5 fractions using XRT or proton beam therapy (PBT) followed by chemotherapy and delayed surgery. Pathological complete response (pCR), near pathological complete response (npCR), locoregional recurrence (LRR), distant metastasis (DM), disease-specific survival (DSS) and overall survival (OS) rates were estimated and compared to scrutinize the prognostic significance of factors including CEA level.

Results

In group 1, higher CEA level (≥ 7 ng/mL) was a significant negative prognostic factor of pCR (p = 0.003, OR: 0.133), OS (p = 0.011, HR: 2.999), DM (p = 0.008, HR: 2.569), LRR (p = 0.044, HR: 3.160), and DSS (p = 0.015, HR: 3.273). In group 2, higher CEA level (≥ 7 ng/mL) was a significant negative prognostic factor of pCR (p = 0.002, OR: 0.038), OS (p < 0.001, HR: 44.658), DM (p < 0.001, HR: 8.926), LRR (p = 0.028, HR: 8.570), and DSS (p = 0.001, HR: 43.918). The npCR rates for clinical T4 patients were 6.5% and 22.0% (p = 0.032), in group 1 and group 2, respectively.

Conclusion

This study elucidates the prognostic merit of the pretreatment serum CEA level in patients with rectal cancer treated by either preoperative LCRT or SCRT followed by chemotherapy and delayed surgery.

Risk Factors for Distant Metastasis in T3 T4 Rectal Cancer

Background

Distant metastasis is the leading cause of death in patients with rectal cancer. This study aims to comprehensively analyze the risk factors of distant metastasis in T3 T4 rectal cancer using magnetic resonance imaging (MRI), pathological features, and serum indicators.

Methods

The clinicopathological data of 146 cases of T3 T4 rectal cancer after radical resection from January 2015 to March 2023 were retrospectively analyzed. Pre- and postoperative follow-up data of all cases were collected to screen for distant metastatic lesions. Univariate and multivariate Logistic regression methods were used to analyze the relationship between MRI features, pathological results, serum test indexes, and distant metastasis.

Results

Of the 146 included patients, synchronous or metachronous distance metastasis was confirmed in 43 (29.4%) cases. The patients' baseline data and univariate analysis showed that mrEMVI, maximum tumor diameter, mr T Stage, pathological N stage, number of lymph node metastasis, cancer nodules, preoperative serum CEA, (Carcinoembryonic antigen) and CA199 were associated with distant metastasis. In the multiple logistic regression model, mrEMVI, pathological N stage, number of lymph node metastasis, maximum tumor diameter, and preoperative serum CEA were identified as independent risk factors for distant metastasis: mrEMVI [odds ratio (OR) = 3.06], pathological N stage (OR = 6.52 for N1 vs N0; OR = 63.47 for N2 vs N0), preoperative serum CEA (OR = 0.27), tumor maximum diameter (OR = 1.03), number of lymph nodes metastasis (OR = 0.62). And, the receiver operating characteristic (ROC) curve was plotted and the area under the curve was calculated (area under the curve [AUC) = 0.817, 95% CI = 0.744-0.890, P < .001].

Conclusions

mrEMVI, pathological N stage, number of lymph node metastasis, maximum tumor diameter and preoperative serum CEA are the independent risk factors for distant metastasis in T3 T4 rectal cancer. A comprehensive analysis of the risk factors for distant metastasis in rectal cancer can provide a reliable basis for formulating individualized treatment strategies, follow-up plans, and evaluating prognosis.

Predictors of Early Distant Relapse in Rectal Cancer Patients Submitted to Preoperative Chemoradiotherapy

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) is a standard treatment for locally advanced rectal cancer. CRT leads to a better local control; however, this does not translate into a survival benefit. Long-term survival is mostly affected by the development of distant metastases after surgery. This study aimed to evaluate predictive clinical factors for the development of early metastatic disease after CRT.

METHODS

Clinical data of patients with stage II/III rectal cancer submitted to CRT between January 2000 and October 2014 were collected from prospectively maintained electronic databases of three Italian institutes. Patients were divided into two groups: those who developed metastasis within 12 months from surgical resection (Group A) and patients without or with late distant relapse (Group B).

RESULTS

Among 635 patients, 86 (13.5%) had early distant relapse within 1 year from surgery (Group A), and 549 (86.5%) did not (Group B). A higher rate of early distant relapse was associated with CEA levels above 3 ng/dL (20% vs. 10%; p <0.001), tumor lying under 5 cm from anal verge (20% vs. 9%; p <0.001), and age under 63 years (17% vs. 11%; p = 0.036). Multivariate analysis confirmed these factors to be independently correlated with a higher risk of early metastasis.

CONCLUSIONS

Younger age, low tumors, and high serum CEA may be associated with unfavorable early oncological outcomes after CRT and surgery for rectal cancer. These clinical factors could be useful to select patients for more aggressive therapeutic strategies.

Pretreatment magnetic resonance imaging of regional lymph nodes with carcinoembryonic antigen in prediction of synchronous distant metastasis in patients with rectal cancer

Distant metastasis in patients with rectal cancer remains a problem influencing prognosis. Prediction of synchronous distant metastasis is important for the choice of personalized treatment strategies and postoperative follow-up protocol. So far, there are few studies about the predictive value of MRI features combined with clinical characteristics for synchronous distant metastasis in rectal cancer, especially for the lesions developed within 6 months after surgery. We retrospectively reviewed the pretreatment clinical characteristics and magnetic resonance imaging (MRI) features of 271 patients from January 2010 to December 2011with pathologically confirmed rectal adenocarcinoma and tried to identify independent risk factors for synchronous distant metastasis. Forty-nine patients (18.1%) were confirmed to have synchronous distant metastasis. Multivariate logistic regression model demonstrated that the elevated carcinoembryonic antigen (CEA), positive MRI-predicted lymph nodes staging (mrN), and MRI-predicted mesorectal fascia (mrMRF) involvement were independent risk factors. The odd ratios were 12.2 for elevated CEA, 5.4 for mrN1 and 7.6 for mrN2, and 3.8 for mrMRF involvement, respectively. The accuracy and specificity for predicting synchronous distant metastasis by evaluating the positive mrN combined with elevated CEA were improved to 87.8% and 94.6%, respectively. The accuracy, sensitivity and specificity of positive mrN assessment were 86.1%, 71.4% and 91.7%, respectively using the histopathologic results as the reference standard. Altogether, our findings suggest that pretreatment positive mrN and elevated CEA are independent risk factors for synchronous distant metastasis in rectal cancer and combination of both could help to recognize the patients with high risk for structuring personalized treatment protocol.

Predictive and Prognostic Molecular Biomarkers for Response to Neoadjuvant Chemoradiation in Rectal Cancer

The standard of care in locally advanced rectal cancer is neoadjuvant chemoradiation (nCRT) followed by radical surgery. Response to nCRT varies among patients and pathological complete response is associated with better outcome. However, there is a lack of effective methods to select rectal cancer patients who would or would not have a benefit from nCRT. The utility of clinicopathological and radiological features are limited due to lack of adequate sensitivity and specificity. Molecular biomarkers have the potential to predict response to nCRT at an early time point, but none have currently reached the clinic. Integration of diverse types of biomarkers including clinicopathological and imaging features, identification of mechanistic link to tumor biology, and rigorous validation using samples which represent disease heterogeneity, will allow to develop a sensitive and cost-effective molecular biomarker panel for precision medicine in rectal cancer. Here, we aim to review the recent advance in tissue- and blood-based molecular biomarker research and illustrate their potential in predicting nCRT response in rectal cancer.

Prognostic aspects of dynamic contrast-enhanced magnetic resonance imaging in synchronous distant metastatic rectal cancer

OBJECTIVES

To explore the correlations between DCE-MRI quantitative parameters and synchronous distant metastasis and the clinicopathological factors in rectal cancers.

METHODS

Sixty-three patients with rectal cancer (synchronous distant metastasis, n = 31; non-metastasis, n = 32) were enrolled in this study. Student's t test and ANOVA were used to compare DCE-MRI parameters (K ^trans , K _ep and V _e ). The receiver operating characteristic (ROC) analysis was used to find the reasonable threshold of DCE-MRI parameters to differentiate lesions with synchronous distant metastasis from those without metastasis.

RESULTS

The K ^trans , K _ep , and V _e value were significantly higher in the lesions with distant metastasis than in the lesions without distant metastasis (0.536 ± 0.242 vs. 0.299 ± 0.118 min^-1, p < 0.001; 1.598 ± 0.477 vs. 1.341 ± 0.390 min^-1, p = 0.022; and 0.324 ± 0.173 vs. 0.249 ± 0.091, p = 0.034; respectively). The K ^trans showed the highest AUCs of 0.788 (p < 0.001), with sensitivity of 61.29 % and specificity of 87.5 %, respectively.

CONCLUSIONS

DCE-MRI parameters may represent a prognostic indicator for synchronous distant metastases in patients with rectal cancer.

KEY POINTS

• The K ^trans , K _ep and V _e values correlated with synchronous distant metastasis. • Higher K ^trans , K _ep and V _e values were noted among patients with metastasis. • DCE-MRI parameters might represent a prognostic indicator for synchronous distant metastases.

Predicting pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer: a systematic review

AIM

Approximately 20% of patients treated with neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer achieve a pathological complete response (pCR) while the remainder derive the benefit of improved local control and downstaging and a small proportion show a minimal response. The ability to predict which patients will benefit would allow for improved patient stratification directing therapy to those who are likely to achieve a good response, thereby avoiding ineffective treatment in those unlikely to benefit.

METHOD

A systematic review of the English language literature was conducted to identify pathological factors, imaging modalities and molecular factors that predict pCR following chemoradiotherapy. PubMed, MEDLINE and Cochrane Database searches were conducted with the following keywords and MeSH search terms: 'rectal neoplasm', 'response', 'neoadjuvant', 'preoperative chemoradiation', 'tumor response'. After review of title and abstracts, 85 articles addressing the prediction of pCR were selected.

RESULTS

Clear methods to predict pCR before chemoradiotherapy have not been defined. Clinical and radiological features of the primary cancer have limited ability to predict response. Molecular profiling holds the greatest potential to predict pCR but adoption of this technology will require greater concordance between cohorts for the biomarkers currently under investigation.

CONCLUSION

At present no robust markers of the prediction of pCR have been identified and the topic remains an area for future research. This review critically evaluates existing literature providing an overview of the methods currently available to predict pCR to nCRT for locally advanced rectal cancer. The review also provides a comprehensive comparison of the accuracy of each modality.

Intermediate Neoadjuvant Radiotherapy Combined With Total Mesorectal Excision for Locally Advanced Rectal Cancer: Outcomes After a Median Follow-Up of 5 Years

BACKGROUND

We previously reported the oncologic results for intermediate neoadjuvant radiotherapy (nRT) plus total mesorectal excision (TME) for locally advanced rectal cancer in a retrospective study. The objective of the present study was to further investigate the efficacy and long-term outcomes after this nRT regimen.

PATIENTS AND METHODS

From 2002 to 2011, 382 patients with resectable locally advanced rectal cancer were treated at the Peking University Cancer Hospital with 30 Gy of intermediate nRT in 10 fractions (biologic equivalent dose, 36 Gy) plus TME. Surgery, RT, and pathologic examination were standardized. The primary endpoints were local recurrence-free survival (LRFS), cancer-specific survival (CSS), and overall survival (OS).

RESULTS

The median patient age at the initial treatment was 58 years (range, 22-85 years). The median patient follow-up time was 5.5 years. The estimated 5-year LRFS, CSS, and OS were 93.6%, 79.0%, and 73.6%, respectively. Of the 382 patients, 4 (1%), 4 (1%), 4 (1%), and 11 (2.9%) patients died of postoperative complications, secondary malignancies, cardiovascular and/or neurologic events, or other causes, respectively. Seven patients (1.8%) developed late-onset ileus and died after conservative treatment in peripheral hospitals.

CONCLUSION

The 10-fraction intermediate nRT regimen reported in the present study is efficient and safe. The long-term outcome is acceptable. This treatment schedule is useful as an alternative that provides efficiency, patient convenience, and low medical costs.

Prognostic Effect of Pretreatment Serum Carcinoembryonic Antigen Level: A Useful Tool for Prediction of Distant Metastasis in Locally Advanced Rectal Cancer Following Neoadjuvant Chemoradiotherapy and Total Mesorectal Excision

Many studies have reported the prognostic value of pretreatment serum carcinoembryonic antigen (pre-CEA) levels on colorectal cancer outcomes. However, controversy remains concerning the significance of pre-CEA levels in patients with rectal cancer treated with neoadjuvant chemoradiotherapy (CRT). Our aim in this study was to investigate the prognostic role of the pre-CEA level in patients with locally advanced rectal cancer undergoing neoadjuvant CRT followed by total mesorectal excision (TME).A total of 419 patients with stages II and III rectal cancer treated with neoadjuvant CRT followed by TME with available pre-CEA data were included. The outcomes studied were 5-year local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS). Optimal pre-CEA cutoff values to predict DMFS were determined based on current smoking history.The median pre-CEA level of smokers was 3.8 ng/mL, and that of nonsmokers was 2.8 ng/mL (P < 0.01). Pre-CEA levels of 6.6 ng/mL for nonsmokers and 11.4 ng/mL for smokers were determined to best separate patients on the basis of time to distant metastasis by using log-rank statistics. The pre-CEA level was associated with DMFS (hazard ratio = 1.743, 95% confidence interval = 1.129-2.690, P = 0.01). The pre-CEA level was not associated with LRFS or DFS.The pre-CEA level appears to be a significant preoperative prognostic factor. Moreover, it is as valuable as any known pathologic factor. Future studies evaluating oncologic outcomes should take into consideration the pre-CEA level.

Prognostic value of CD45RO(+) tumor-infiltrating lymphocytes for locally advanced rectal cancer following 30 Gy/10f neoadjuvant radiotherapy

AIM

This study aims to evaluate the prognostic value of CD45RO(+) tumor-infiltrating lymphocytes (TILs) in locally advanced rectal cancer treated with 30 Gy/10 fraction (10 f) neoadjuvant radiotherapy.

METHODS

This retrospective study involved 185 patients with locally advanced rectal cancer who underwent 30 Gy/10 f nRT (biologic equivalent dose, 30 Gy) followed by total mesorectal excision (TME) between August 2003 and October 2009. The density of CD45RO(+) TILs was assessed by immunohistochemistry using an image-analysis system and tissue microarray and was evaluated for its association with histopathologic features along with disease-free survival (DFS).

RESULTS

Following neoadjuvant radiotherapy, the median density of CD45RO(+) TILs is 654/mm(2). High density of CD45RO(+) TILs was significantly associated with increased T and N downstaging effect (p = 0.006; p = 0.014), lesser-advanced T stage (p = 0.003) and TNM stage (p = 0.022). Prolonged DFS (89.0 vs. 68.1%) was also observed in CD45RO(+Hi) cases. On multivariate regression model, CD45RO(+) TILs (p = 0.026; odds ratio (OR), 0.436 (95% confidence interval (CI), 0.209-0.907)), tumor differentiation (p = 0.057; OR, 1.878 (95% CI, 0.982-3.593)), ypT stage (p = 0.066; OR, 2.383 (95% CI, 0.943-6.025)), and ypN stage (p = 0.009; OR, 2.612 (95% CI, 1.266-5.388)) were independent factors for DFS.

CONCLUSION

The density of CD45RO(+) TILs cannot only predict tumor downstaging and ypTNM stage for rectal cancer following 30 Gy/10 f nRT but also promisingly predict long-term outcomes. These findings may be used to stratify patients and make alternative strategy of adjuvant treatment.

Feasibility of mesorectal vascular invasion in predicting early distant metastasis in patients with stage T3 rectal cancer based on rectal MRI

OBJECTIVES

To evaluate the feasibility of mesorectal vascular invasion (MVI) in predicting early distant metastasis developed within 1 year of diagnosis of T3 rectal cancer using magnetic resonance imaging (MRI) METHODS: Sixty-five patients with T3 rectal cancer (early metastasis, n = 28; non-metastasis, n = 37) were enrolled in this study. Early distant metastases developed in 28 patients (liver, n = 15; lung, n = 9; both, n = 4). Logistic regression was used to determine the independent predictors for early distant metastasis.

RESULTS

In univariate analysis, tumour location, carcinoembryonic antigen (CEA), lymphovascular invasion (LVI), MRI-detected MVI, and mesorectal fat infiltration (MFI) (odds ratio [OR], 4.533, 9.583, 5.539, 27.046, and 5.539, respectively) were associated with early distant metastasis. Multivariate analysis demonstrated that MVI (OR, 29.949; P < 0.002) and LVI (OR, 6.684; P = 0.033) were independent factors for early distant metastasis. Specificity and positive predictive value (PPV) of MVI (94.59%, and 89.47%, respectively) were significantly higher than those of LVI (64.86%, and 61.76%), but sensitivity and negative predictive value were not significantly different between MVI (60.71%, and 76.09%) and LVI (75.00%, and 77.42%).

CONCLUSIONS

While sensitivity of MRI-detected MVI was equal to that of CEA in predicting early distant metastasis from T3 rectal cancer, specificity and PPV may be improved by assessing MVI.

KEY POINTS

• Mesorectal vascular invasion (MVI) may be a radiologic prognostic factor for rectal cancer. • Specificity of MVI was higher than lymphovascular invasion in predicting early metastasis. • Mesorectal vascular invasion may be a better predictor for early distant metastasis.

Tumor regression grades: potential outcome predictor of locally advanced rectal adenocarcinoma after preoperative radiotherapy

AIM

To analyze tumor regression grade (TRG) for prognosis of locally advanced rectal adenocarcinoma (LARA) treated with preoperative radiotherapy.

METHODS

One hundred and ninety patients with clinical stage II/III LARA were studied. All patients underwent radical surgery (between 2004 and 2010) after 30-Gy/10-fraction preoperative radiotherapy (pre-RT). All 190 patients received a short course of pre-RT and were reassessed for disease recurrence and survival; the slides of surgical specimens were reviewed and classified according to Mandard TRG. We compared patients with good response (Mandard TRG1 or TRG2) vs patients with bad/poor response (Mandard TRG3-5). Outcomes evaluated were 5-year overall survival (OS), 5-year disease-free survival (DFS), and local, distant and mixed recurrence. Fisher's exact test or χ(2) test, log-rank test and proportional hazards regression analysis were used to calculate the probability that Mandard TRG was associated with patient outcomes.

RESULTS

One hundred and sixty-six of 190 patients (87.4%) were identified as Mandard bad responders (TRG3-5). High Mandard grade was correlated with tumor height (41.7% < 6 cm vs 58.3% ≥ 6 cm, P = 0.050), ypT stage (75% ypT0-2 vs 25% ypT3-4, P = 0.000), and ypN stage (75% ypN0 vs 25% ypN1, P = 0.031). In univariate survival analysis, Mandard grade bad responders had significantly worse OS and DFS than good responders (TRG1/2) (OS, 83.1% vs 96.4%, P = 0.000; DFS, 72.3% vs 92.0%, P = 0.002). In multivariate survival analysis, Mandard bad responders had significantly worse DFS than Mandard good responders (DFS 3.8 years (95%CI: 1.2-12.2 years, P = 0.026).

CONCLUSION

Mandard grade good responders had a favorable prognosis. TRG may be a potential predictor for DFS in LARA after pre-RT.

Phosphatidylinositol 3-kinase CB association with preoperative radiotherapy response in rectal adenocarcinoma

AIM

To examine the correlation of phosphatidylinositol 3-kinase (PIK3) CB expression with preoperative radiotherapy response in patients with stage II/III rectal adenocarcinoma.

METHODS

PIK3CB immunoexpression was retrospectively assessed in pretreatment biopsies from 208 patients with clinical stage II/III rectal adenocarcinoma, who underwent radical surgery after 30-Gy/10-fraction preoperative radiotherapy. The relation between PIK3CB expression and tumor regression grade, clinicopathological characteristics, and survival time was statistically analyzed. Western blotting and in vitro clonogenic formation assay were used to detect PIK3CB expression in four colorectal cancer cell lines (HCT116, HT29, LoVo, and LS174T) treated with 6-Gy ionizing radiation. Pharmacological assays were used to evaluate the therapeutic relevance of TGX-221 (a PIK3CB-specific inhibitor) in the four colorectal cancer cell lines.

RESULTS

Immunohistochemical staining indicated that PIK3CB was more abundant in rectal adenocarcinoma tissues with poor response to preoperative radiotherapy. High expression of PIK3CB was closely correlated with tumor height (P < 0.05), ypT stage (P < 0.05), and high-degree tumor regression grade (P < 0.001). High expression of PIK3CB was a potential prognostic factor for local recurrence-free survival (P < 0.05) and metastasis-free survival (P < 0.05). High expression of PIK3CB was also associated with poor therapeutic response and adverse outcomes in rectal adenocarcinoma patients treated with 30-Gy/10-fraction preoperative radiotherapy. In vitro, PIK3CB expression was upregulated in all four colorectal cancer cell lines concurrently treated with 6-Gy ionizing radiation, and the PIK3CB-specific inhibitor TGX-221 effectively inhibited the clonogenic formation of these four colorectal cancer cell lines.

CONCLUSION

PIK3CB is critically involved in response to preoperative radiotherapy and may serve as a novel target for therapeutic intervention.