Predicting neoadjuvant chemoradiotherapy response with functional imaging and liquid biomarkers in locally advanced rectal cancer

INTRODUCTION

Non-invasive predictive quantitative biomarkers are required to guide treatment individualization in patients with locally advanced rectal cancer (LARC) in order to maximise therapeutic outcomes and minimise treatment toxicity. Magnetic resonance imaging (MRI), positron emission tomography (PET) and blood biomarkers have the potential to predict chemoradiotherapy (CRT) response in LARC.

AREAS COVERED

This review examines the value of functional imaging (MRI and PET) and liquid biomarkers (circulating tumor cells (CTCs) and circulating tumor nucleic acid (ctNA)) in the prediction of CRT response in LARC. Selected imaging and liquid biomarker studies are presented and the current status of the most promising imaging (apparent diffusion co-efficient (ADC), K^trans, SUV_max, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) and liquid biomarkers (circulating tumor cells (CTCs), circulating tumor nucleic acid (ctNA)) is discussed. The potential applications of imaging and liquid biomarkers for treatment stratification and a pathway to clinical translation are presented.

EXPERT OPINION

Functional imaging and liquid biomarkers provide novel ways of predicting CRT response. The clinical and technical validation of the most promising imaging and liquid biopsy biomarkers in multi-centre studies with harmonised acquisition techniques is required. This will enable clinical trials to investigate treatment escalation or de-escalation pathways in rectal cancer.

Biomarkers in Locally Advanced Rectal Cancer: A Review

Locally advanced rectal cancers (LARC) are the subject of a rapidly evolving treatment paradigm. The critical timepoints where management decisions are required during the care of the LARC patient are: prior to the institution of any treatment, post neoadjuvant therapy and post-surgery. This article reviews the clinical, imaging, blood-based, tissue-based, and molecular biomarkers that can assist clinicians at these timepoints in the patient's management, in prognosticating for their LARC patients or in predicting responses to therapy in the multi-modality neoadjuvant treatment era.

Predicting pathological response to chemoradiotherapy for rectal cancer: a systematic review

Introduction: Pathological complete response (pCR) rates of approximately 20% following neoadjuvant long-course chemoradiotherapy for rectal cancer have given rise to non-operative or watch-and-wait (W&W) management. To improve outcomes there has been significant research into predictors of response. The goal is to optimize selection for W&W, avoid chemoradiotherapy in those who won't benefit and improve treatment to maximize the clinical complete response (cCR) rate and the number of patients who can be considered for W&W.Areas covered: A systematic review of articles published 2008-2018 and indexed in PubMed, Embase or Medline was performed to identify predictors of pathological response (including pCR and recognized tumor regression grades) to fluoropyrimidine-based chemoradiotherapy in patients who underwent total mesorectal excision for rectal cancer. Evidence for clinical, biomarker and radiological predictors is discussed as well as potential future directions.Expert opinion: Our current ability to predict the response to chemoradiotherapy for rectal cancer is very limited. cCR of 40% has been achieved with total neoadjuvant therapy. If neoadjuvant treatment for rectal cancer continues to improve it is possible that the treatment for rectal cancer may eventually parallel that of anal squamous cell carcinoma, with surgery reserved for the minority of patients who don't respond to chemoradiotherapy.

Nomogram for predicting pathological complete response and tumor downstaging in patients with locally advanced rectal cancer on the basis of a randomized clinical trial

Background

Preoperative fluoropyrimidine with radiotherapy was regarded as the standard of care for locally advanced rectal cancer (LARC). The model for predicting pCR in LARC patients was based on standard treatment only. This study aimed to establish a nomogram with pretherapeutic parameters and different neoadjuvant regimens for predicting pathologic complete response (pCR) and tumor downstaging or good response (ypT0-2N0M0) after receiving neoadjuvant treatment in patients with LARC based on a randomized clinical trial.

Methods

Between January 2011 and February 2015, 309 patients with rectal cancer were enrolled from a prospective randomized study (NCT01211210). All pretreatment clinical parameters were collected to build a nomogram for predicting pCR and tumor downstaging. The model was subjected to bootstrap internal validation. The predictive performance of the model was assessed with concordance index (C-index) and calibration plots.

Results

Of the 309 patients, 53 (17.2%) achieved pCR and 132 (42.7%) patients were classified as tumor downstaging with ypT0-2N0M0. Based on the logistic-regression analysis and clinical consideration, tumor length (P = 0.005), tumor circumferential extent (P = 0.036), distance from the anal verge (P = 0.019), and neoadjuvant treatment regimen (P < 0.001) showed independent association with pCR following neoadjuvant treatment. The tumor length (P = 0.015), tumor circumferential extent (P = 0.001), distance from the anal verge (P = 0.032), clinical T category (P = 0.012), and neoadjuvant treatment regimen (P = 0.001) were significantly associated with good tumor downstaging (ypT0-2N0M0). Nomograms were developed to predict the probability of pCR and tumor downstaging with a C-index of 0.802 (95% confidential interval [CI], 0.736–0.867) and 0.730 (95% CI, 0.672–0.784). Internal validation revealed good performance of the calibration plots.

Conclusions

The nomogram provided individual prediction responses to different preoperative treatment for patients with rectal cancer. This model might help physicians in selecting an optimized treatment, but warrants further external validation.

Sarcopenia is poor prognostic factor in older patients with locally advanced rectal cancer who received preoperative or postoperative chemoradiotherapy

Sarcopenia is associated with low muscle mass and low physical performance. Here, we performed to evaluate the sarcopenia as prognostic factor and treatment outcomes in older patients with locally advanced rectal cancer (LARC) who received preoperative or postoperative chemoradiotherapy (CRT).LARC patients aged ≥65 years who received either preoperative or postoperative CRT were analyzed retrospectively. Preoperative or postoperative CRT consisted of 50.4 Gy and fluoropyrimidine. Surgery was performed at 6 weeks after CRT completion. Postoperative CRT was performed at 4 weeks after surgery. One month after surgery or CRT, adjuvant chemotherapy was given. Overall survival (OS) and disease free survival (DFS), local recurrence (LR), and prognostic factor were evaluated.Thirty patients received preoperative CRT and 35 patients received postoperative CRT. Five-year OS rate, 5-year DFS rate, or 5-year LR rate was not significantly different between preoperative and postoperative CRT groups (69.0%, 58.5%, and 3.4% vs 73.6%, 67.9%, and 6.9%, P = .56, P = .37, and P = .77, respectively). Age, sex, stage, CEA level, or timing of CRT did not affect OS. However, 5-year OS rate of patients with sarcopenia was significantly lower than those without sarcopenia (38.0% vs 92.5%, P < .001). Multivariate analysis showed that sarcopenia was the only independent prognostic factor for overall survival (OS) (hazard ratio [HR]: 6.08, P = .001).There was no difference in survival between preoperative CRT and postoperative CRT in older patients with LARC. Sarcopenia is a poor prognostic factor in older patients with LARC who received preoperative or postoperative CRT.

Prospective evaluation of the performance and interobserver variation in endoscopic ultrasound staging of rectal cancer

BACKGROUND

Treatment and prognosis of patients with rectal adenocarcinoma (RAC) are dependent on accurate locoregional staging.

OBJECTIVES

The aim of this study was to measure the performance characteristics of rectal endoscopic ultrasound (EUS) compared with surgical pathology, and to assess the interobserver variation of rectal EUS in the staging of RAC.

PATIENTS AND METHODS

Patients referred for rectal EUS staging of a recently diagnosed RAC were prospectively enrolled between 2012 and 2016. Tandem EUS exams were performed by two independent endosonographers (ES1 and ES2) blinded to each other's findings.

RESULTS

Ninety-five patients were enrolled. Seventy-five (79%) underwent curative intent tumor resection, including 30 without neoadjuvant therapy. In this latter group, the sensitivity, specificity, and accuracy of transrectal ultrasonography staging were 75, 83, and 82% for uT1; 50, 65, and 58% for uT2; 56, 81, and 73% for T3; 72, 44, and 63% for N0, and 38, 75, and 63% for N1, respectively. Experienced operators rendered a more accurate N stage and were less likely to overstage compared with less experienced ones (P=0.01 and 0.02, respectively). Overall, T staging agreement between endosonographers was substantial (κ=0.61) and N stage agreement was moderate (κ=0.45).

CONCLUSION

Rectal EUS is more accurate in staging T1 and T3 tumors compared with T2 tumors. Interobserver agreement of rectal EUS in rectal cancer staging is generally good.

Phase II trial of capecitabine plus oxaliplatin (CAPOX) as perioperative therapy for locally advanced rectal cancer

PURPOSE

The standard strategy for locally advanced lower rectal cancer is chemoradiotherapy followed by total mesorectal excision (TME) in Western countries and TME followed by adjuvant chemotherapy without preoperative treatment in Japan.

METHODS

This phase II trial evaluated the efficacy of a preoperative CAPOX chemotherapy regimen without radiation therapy for patients with locally advanced rectal cancer. The primary endpoint was 2-year disease-free survival.

RESULTS

The trial enrolled 45 patients from 9 institutions between 2012 and 2014. The mean age was 63.5 (29-74) years; 31 patients were male. Most patients (n = 41) received preoperative chemotherapy (CTx), and the preoperative CTx completion rate was 95.2%. R0 resection after CTx was performed in 41 patients. The pathological complete response rate was 7.3% (3/41). After surgery, 35 patients (85.3%) received adjuvant CTx, and 22 of 35 completed the protocol treatment. The follow-up period ranged from 0.71 to 4.68 years (median 2.86 years). There was recurrence in 13 of 40 patients who underwent R0 resection, and the 2-year disease-free survival rate and overall survival rate were 71.6 and 92.7%, respectively.

CONCLUSIONS

Here we report the completion rates for neoadjuvant CTx and adjuvant CTx, the pathological complete response rate, and the mid-term prognosis. The results indicate that CAPOX followed by TME may be a safe treatment strategy for locally advanced rectal cancer.

GOLPH3 overexpression correlates with poor response to neoadjuvant therapy and prognosis in locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) combined with surgery is a standard therapy for locally advanced rectal cancer (LARC). The aim of this study was to assess the expression of GOLPH3 (Golgi phosphoprotein 3), a newly found oncogene, in LARC as well as its relationship with nCRT sensitivity and prognosis. We retrospectively analyzed 148 LARC cases receiving nCRT and total mesorectal excision (TME). Immunohistochemistry was used to assess GOLPH3 and mTOR (mammalian target of rapamycin) in tumor tissues. Then, the associations of GOLPH3 with pathological characteristics and prognosis of rectal cancer were assessed. The 148 cases included 77 with high GOLPH3 expression (52.03%), which was associated with tumor invasive depth and lymphatic metastasis. Cases with high GOLPH3 expression had 2.58 and 2.71 fold higher local relapse and distant metastasis rates compared with the low expression group. Correlation analyses showed that GOLPH3 was an independent indicator for judging tumor down-staging and postoperative TRG (tumor regression grade), indicating it could predict nCRT sensitivity. In addition, GOLPH3 expression was associated with mTOR levels. Multiple-factor analysis indicated that GOLPH3 was an independent prognosis indicator for 5 year-DFS (disease free survival) and OS (overall survival) in LARC. These results reveal that GOLPH3 is an independent predictive factor for nCRT sensitivity and prognosis in LARC, with a mechanism related to mTOR.

Short-course neoadjuvant chemoradiotherapy and surgery are beneficial in Chinese patients: A retrospective study

Preoperative neoadjuvant chemoradiotherapy (NACR) is used to reduce tumor size for easier resection or improved resectability rates. Considering the difficulties regarding health insurance and health resources in China, an evidence-based short-course neoadjuvant chemoradiotherapy with surgery to cure patients was performed. This study compared the postoperative effects between short-course neoadjuvant chemoradiotherapy and surgery and surgery without neoadjuvant chemoradiotherapy.The current retrospective study was based on a rectal cancer database, including 274 patients diagnosed with rectal cancer between January 2014 and October 2016. Data were analyzed with respect to curative rate, postoperative recovery indicators (times to nasogastric tube, urinary catheter, and drainage tube removal and times to first oral feeding and passing of flatus postsurgery), chemoradiotherapy-related indicators [white blood cell count (WBC) and carcinoembryonic antigen (CEA) levels], and adverse effects indicators, evaluated according to Common Terminology Criteria for Adverse Events Version 4.0.There was no significant difference between the combined therapy and surgery groups (P > .05) in terms of radical resection rates and the times to urinary catheter removal and passing flatus (P > .05). Statistically significant differences (P < .05) in terms of earlier time for removal of the nasogastric and drainage tubes and time to first oral feeding were observed in the combined therapy group. The decreases in WBC and CEA levels in the combined therapy group were significantly greater than those in the surgery group 1 week after surgery (P < .05); after 1 month, the CEA decrease in the combined therapy group was significantly greater than that in the surgery group (P < .05). More patients in the combined therapy group experienced vomiting, indigestion, dehydration, oral mucositis, sensory neuritis, and alopecia compared with those in the surgery group 1 week after surgery (P < .05); after 1 month, only the incidence of alopecia was higher in the combined therapy group (P < .05).The combined therapy group demonstrated earlier postoperative recovery compared with the surgery group. Short-course neoadjuvant chemoradiotherapy with surgery may lead to postoperative treatment-related adverse effects of varying degrees; however, these adverse effects eventually improve with time.

Predictive clinical model of tumor response after chemoradiation in rectal cancer

Survival improvement in rectal cancer treated with neoadjuvant chemoradiotherapy (nCRT) is achieved only if pathological response occurs. Mandard tumor regression grade (TRG) proved to be a valid system to measure nCRT response. The ability to predict tumor response before treatment may significantly have impact the selection of patients for nCRT in rectal cancer. The aim is to identify potential predictive pretreatment factors for Mandard response and build a clinical predictive model design. 167 patients with locally advanced rectal cancer were treated with nCRT and curative surgery. Blood cell counts in peripheral blood were analyzed. Pretreatment biopsies expression of cyclin D1, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and protein 21 were assessed. A total of 61 single nucleotide polymorphisms were characterized using the Sequenom platform through multiplex amplification followed by mass-spectometric product separation. Surgical specimens were classified according to Mandard TRG. The patients were divided as: "good responders" (Mandard TRG1-2) and "poor responders" (Mandard TGR3-5). We examined predictive factors for Mandard response and performed statistical analysis. In univariate analysis, distance from anal verge, neutrophil lymphocyte ratio (NLR), cyclin D1, VEGF, EGFR, protein 21 and rs1810871 interleukin 10 (IL10) gene polymorphism are the pretreatment variables with predictive value for Mandard response. In multivariable analysis, NLR, cyclin D1, protein 21 and rs1800871 in IL10 gene maintain predictive value, allowing a clinical model design.

CONCLUSION

It seems possible to use pretreatment expression of blood and tissue biomarkers, and build a model of tumor response prediction to neoadjuvant chemoradiation in rectal cancer.

A nomogram predicting pathological complete response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer: implications for organ preservation strategies

PURPOSE

To determine predictors of pathological complete response (pCR) in locally advanced rectal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT), and develop a predictive nomogram.

METHODS

A total of 522 locally advanced rectal cancer patients undergoing nCRT and curative resection between 2008 and 2014 were included. Uni- and multivariate analysis was performed to identify predictors of pCR. A nomogram was developed and validated by internal (n=425) and external validation (n=97).

RESULTS

With a median follow-up of 55 months, pCR was associated with better 5-year overall and disease-free survival, distant control, but similar local control. Logistic regression showed that post-CRT distance from the anal verge (OR =0.840, P = 0.022), post-CRT tumor size (OR = 0.565, P = 0.003), post-CRT circumferential extent of tumor (OR = 0.021, P < 0.001), pre-CRT CEA level (OR = 2.004, P = 0.033), and post-CRT CEA level (OR = 3.767, P = 0.038) were independently associated with pCR. A nomogram was developed with a C-index of 0.81 and 0.75 on internal and external validation, respectively.

CONCLUSION

pCR was associated with better long-term outcome. A nomogram was successfully developed to predict pCR. It could support decision-making in organ preservation strategies.

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.

Predictive and prognostic biomarkers for neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Locally advanced rectal cancer is regularly treated with trimodality therapy consisting of neoadjuvant chemoradiation, surgery and adjuvant chemotherapy. There is a need for biomarkers to assess treatment response, and aid in stratification of patient risk to adapt and personalise components of the therapy. Currently, pathological stage and tumour regression grade are used to assess response. Experimental markers include proteins involved in cell proliferation, apoptosis, angiogenesis, the epithelial to mesenchymal transition and microsatellite instability. As yet, no single marker is sufficiently robust to have clinical utility. Microarrays that screen a tumour for multiple promising candidate markers, gene expression and microRNA profiling will likely have higher yield and it is expected that a combination or panel of markers would prove most useful. Moving forward, utilising serial samples of circulating tumour cells or circulating nucleic acids can potentially allow us to demonstrate tumour heterogeneity, document mutational changes and subsequently measure treatment response.