Adjuvant chemotherapy after preoperative (chemo)radiotherapy and surgery for patients with rectal cancer: a systematic review and meta-analysis of individual patient data

Evaluation of Predictive and Prognostic Importance of Lung Immune Prognostic Index in Locally Advanced Rectal Cancer Patients Treated With Neoadjuvant Chemoradiotherapy

OBJECTIVE

The systemic inflammatory response (SIR) is known as an important factor associated with tumorigenesis and tumor progression, and can be reflected by inflammatory markers. One of the markers that reflect this is the lung immune prognostic index (LIPI). It is based on a derived neutrophil-to-lymphocyte ratio (dNLR) and lactate dehydrogenase (LDH) level. We aimed to investigate the significance of LIPI in locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (NACRT).

METHODS

In this retrospective study, we stratified the patients according to LIPI score as good LIPI and intermediate (int)/poor LIPI. According to pathological response to NACRT, we divided the patients into two groups as those with complete response (CR) or near-CR, and those with partial response (PR) or poor/no response. We classified CR and near-CR as good response. We evaluated the predictive and prognostic significance of LIPI for NACRT response, disease-free survival (DFS), and overall survival (OS) by univariate and multivariate analyses.

RESULTS

We included 137 patients in the results, with 72 (52.6%) having good LIPI and 65 (47.4%) having int/poor LIPI. The median follow-up period was 44.7 months (range: 10-105 months). Thirteen patients (18.0%) in the good LIPI group and 22 patients (34.0%) in the int/poor LIPI group achieved good response. In multivariate analysis, we found only the LIPI score as an independent risk factor (hazard ratio (HR): 2.4, p = 0.04) for NACRT response. Median DFS was 89.2 months (95% CI: 11.4-167.0) in the int/poor LIPI group; however, the DFS of all study populations and patients in the good LIPI group did not reach the median value. In multivariate analysis for DFS, we identified abdominoperineal resection (APR) (HR: 2.21, p = 0.02), presence of tumor deposit (HR: 2.96, p = 0.003), and int/poor LIPI score (HR: 2.07, p = 0.02) as separate risk variables. OS of all study populations and the patients in the LIPI groups did not reach the median value. In multivariate analysis for OS, we identified APR (HR: 2.74, p = 0.02), surgical margin positivity (HR: 12.94, p < 0.001), and adjuvant CT (HR: 0.20, p = 0.002) as separate risk variables for OS.

CONCLUSION

This is the first study investigating the predictive and prognostic significance of LIPI in LARC patients treated with NACRT. The results revealed that int/poor LIPI was associated with a higher rate of good response but shorter DFS compared to good LIPI. The baseline LIPI score serves as an easily accessible and useful prognostic index, and it has significant potential for making appropriate treatment decisions in LARC.

New Opportunities for Minimizing Toxicity in Rectal Cancer Management

Advances in multimodal management of locally advanced rectal cancer (LARC), consisting of preoperative chemotherapy and/or radiotherapy followed by surgery with or without adjuvant chemotherapy, have improved local disease control and patient survival but are associated with significant risk for acute and long-term morbidity. Recently published trials, evaluating treatment dose intensification via the addition of preoperative induction or consolidation chemotherapy (total neoadjuvant therapy [TNT]), have demonstrated improved tumor response rates while maintaining acceptable toxicity. In addition, TNT has led to an increased number of patients achieving a clinical complete response and thus eligible to pursue a nonoperative, organ-preserving, watch and wait approach, thereby avoiding toxicities associated with surgery, such as bowel dysfunction and stoma-related complications. Ongoing trials using immune checkpoint inhibitors in patients with mismatch repair-deficient tumors suggest that this subgroup of patients with LARC could potentially be treated with immunotherapy alone, sparing them the toxicity associated with preoperative treatment and surgery. However, the majority of rectal cancers are mismatch repair-proficient and less responsive to immune checkpoint inhibitors and require multimodal management. The synergy noted in preclinical studies between immunotherapy and radiotherapy on immunogenic tumor cell death has led to the design of ongoing clinical trials that explore the benefit of combining radiotherapy, chemotherapy, and immunotherapy (mainly of immune checkpoint inhibitors) and aim to increase the number of patients eligible for organ preservation.

Identification of patients with locally advanced rectal cancer eligible for neoadjuvant chemotherapy alone: Results of a retrospective study

BACKGROUND AND OBJECTIVES

Neoadjuvant chemotherapy (nCT) appears in a few clinical studies as an alternative to neoadjuvant chemoradiation (nCRT) in selected patients with locally advanced rectal cancer (LARC). We aimed to compare the clinical outcomes of nCT with or without nCRT in patients with LARC and to identify patients who may be suitable for nCT alone.

MATERIALS AND METHODS

A total of 155 patients with LARC who received neoadjuvant treatment (NT) were retrospectively analysed from January 2016 to June 2021. The patients were divided into two groups: nCRT (n = 101) and nCT (n = 54). More patients with locally advanced disease (cT4, cN+ and magnetic resonance imaging-detected mesorectal fascia [mrMRF] positive [+]) were found in the nCRT group. Patients in the nCRT group received a dose of 50 Gy/25 Fx irradiation with concurrent capecitabine, and the median number of nCT cycles was two. In the nCT group, the median number of cycles was four.

RESULTS

The median follow-up duration was 30 months. The pathologic complete response (pCR) rate in the nCRT group was significantly higher than that in the nCT group (17.5% vs. 5.6%, p = 0.047). A significant difference was observed in the locoregional recurrence rate (LRR); 6.9% in the nCRT group and 16.7% in the nCT group (p = 0.011). Among patients with initial mrMRF (+) status, the LRR in the nCRT group was significantly lower than that in the nCT group (6.1% vs. 20%, p = 0.007), but not in patients with initial mrMRF negative (-) (10.5% in each group, p = 0.647). Compared with the nCT group, a lower LRR was observed in patients in the nCRT group with initial mrMRF (+) converted to mrMRF (-) after NT (5.3% vs. 23%, p = 0.009). No significant difference was observed between the two groups regarding acute toxicity and overall and progression-free survivals. Multivariate analysis showed that nCRT and ypN stage were independent prognostic factors for the development of LRR.

CONCLUSION

Patients with initial mrMRF (-) may be suitable for nCT alone. However, patients with initial mrMRF (+) converted to mrMRF (-) after nCT are still at high risk of LRR, and radiotherapy is recommended. Prospective studies are required to confirm these findings.

Radiomics for the Prediction of Pathological Complete Response to Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer: A Prospective Observational Trial

(1) Background: An increasing amount of research has supported the role of radiomics for predicting pathological complete response (pCR) to neoadjuvant chemoradiation treatment (nCRT) in order to provide better management of locally advanced rectal cancer (LARC) patients. However, the lack of validation from prospective trials has hindered the clinical adoption of such studies. The purpose of this study is to validate a radiomics model for pCR assessment in a prospective trial to provide informative insight into radiomics validation. (2) Methods: This study involved a retrospective cohort of 147 consecutive patients for the development/validation of a radiomics model, and a prospective cohort of 77 patients from two institutions to test its generalization. The model was constructed using T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI to understand the associations with pCR. The consistency of physicians' evaluations and agreement on pathological complete response prediction were also evaluated, with and without the aid of the radiomics model. (3) Results: The radiomics model outperformed both physicians' visual assessments in the prospective test cohort, with an area under the curve (AUC) of 0.84 (95% confidence interval of 0.70-0.94). With the aid of the radiomics model, a junior physician could achieve comparable performance as a senior oncologist. (4) Conclusion: We have built and validated a radiomics model with pretreatment MRI for pCR prediction of LARC patients undergoing nCRT.

The use of adjuvant chemotherapy is not associated with recurrence or cancer-specific death following curative resection for stage III rectal cancer: a competing risks analysis

BACKGROUND

The role of adjuvant chemotherapy (AC) in stage III rectal cancer (RC) has been argued based on evidence from its use in colon cancer. Previous trials have analysed disease-free and overall survivals as endpoints, rather than disease recurrence. This study compares the competing risks incidences of recurrence and cancer-specific death between patients who did and did not receive AC for stage III RC.

METHODS

Consecutive patients who underwent a potentially curative resection for stage III RC (1995-2019) at Concord Hospital, Sydney, Australia, were studied. AC was considered following multidisciplinary discussion. Primary outcome measures were the competing risks incidences of disease recurrence and cancer-specific death. Associations between these outcomes and use of AC (and other variables) were tested by regression modelling.

RESULTS

Some 338 patients (213 male, mean age 64.4 years [SD12.7]) were included. Of these, 208 received AC. The use of AC was associated with resection year (adjusted OR [aOR] 1.74, 95%CI 1.27-2.38); age ≥75 years (aOR0.04, 95%CI 0.02-0.12); peripheral vascular disease (aOR0.08, 95%CI 0.01-0.74); and postoperative abdomino-pelvic abscess (aOR0.23, 95%CI 0.07-0.81). One hundred fifty-seven patients (46.5%) were diagnosed with recurrence; death due to RC occurred in 119 (35.2%). After adjustment for the competing risk of non-cancer death, neither recurrence nor RC-specific death was associated with AC (HR0.97, 95%CI 0.70-1.33 and HR0.72, 95%CI 0.50-1.03, respectively).

CONCLUSION

This study found no significant difference in either recurrence or cancer-specific death between patients who did and did not receive AC following curative resection for stage III RC.

Total neoadjuvant treatment to increase the clinical complete response rate for distal locally advanced rectal cancer (TESS): A study protocol of a prospective, open-label, multicenter, single-arm, phase 2 trial

BACKGROUND

Standard treatment of locally advanced rectal cancer (LARC) was neoadjuvant chemoradiotherapy (CRT), followed by total mesorectal excision (TME). Total neoadjuvant treatment (TNT), a new concept, attempts to deliver both systemic chemotherapy and neoadjuvant CRT prior to surgery. Patients treated with neoadjuvant chemotherapy were more likely to show higher tumor regression. The objective of this trial was to increase complete clinical rate (cCR) for LARC patients by optimizing tumor response, using TNT regimen as compared to conventional chemoradiotherapy. TESS, a prospective, open-label, multicenter, single-arm, phase 2 study, is underway.

METHODS

Main inclusion criteria include cT3-4aNany or cT1-4aN+ rectal adenocarcinoma aged 18-70y; Eastern Cooperative Oncology Group (ECOG) performance 0-1; location ≤5 cm from anal verge. Ninety-eight patients will receive 2 cycles of neoadjuvant chemotherapy Capeox (capecitabine + oxaliplatin) before, during, and after radiotherapy 50Gy/25 fractions, before TME (or other treatment decisions, such as Watch and Wait strategy) and adjuvant chemotherapy capecitabine 2 cycles. Primary endpoint is the cCR rate. Secondary endpoints include ratio of sphincter preservation strategy; pathological complete response rate and tumor regression grade distribution; local recurrence or metastasis; disease-free survival; locoregional recurrence-free survival; acute toxicity; surgical complications; long-term anal function; late toxicity; adverse effect, ECOG standard score, and quality of life. Adverse events are graded per Common Terminology Criteria for Adverse Events V5.0. Acute toxicity will be monitored during antitumor treatment, and late toxicity will be monitored for 3 years from the end of the first course of antitumor treatment.

DISCUSSION

The TESS trial aims to explore a new TNT strategy, which is expected to increase the rate of cCR and sphincter preservation rate. This study will provide new options and evidence for a new sandwich TNT strategy in patients with distal LARC.

Organ preservation strategy: new therapeutic alternative in rectal cancer

BACKGROUND

The therapeutic modalities for nonmetastatic rectal cancer are presently undergoing major changes. The standard treatment is multidisciplinary, combining radiotherapy, chemotherapy, and surgery. The aim of this minireview is to provide an update on the place of organ preservation in the treatment of nonmetastatic rectal cancer in 2022.

MAIN TEXT

The multimodal strategy based on initial radiochemotherapy followed by radical surgery with excision of the mesorectum has improved oncological results but at the expense of morbidity and sequelae altering life quality. The strategy of rectal preservation has been proposed since the 2000s after the publication of the results of the Brazilian study that proposed a simple surveillance after radiochemotherapy without surgery in good responders. In fact, preoperative radiochemotherapy was able to obtain a complete histological response in 10 to 30% of case. In view of this non-negligible percentage of tumor sterilization, which may well increase with the standardization of total neoadjuvant treatment, a strategy of organ preservation can be proposed in these patients to avoid morbidity and postoperative sequelae.

SHORT CONCLUSION

This nonoperative approach is currently widely studied in certain patients who have a complete response (clinical, endoscopic, and radiological). However, the selection of these patients is not simple and still complex.

Current status of locally advanced rectal cancer therapy and future prospects

Rectal cancer treatment has been evolving ever since the beginning of the 20th century. Surgery was originally the only available method regardless of the extent of tumor invasion or nodal involvement status. Total mesorectal excision was established as the standard procedure in the early 1990s. Advances in the utilization of radiation for rectal cancer led to the addition of radiotherapy (RT) combined with chemotherapy to the postoperative treatment algorithm. The promising results of the Swedish short-course preoperative RT set the basis for a number of large randomized trials investigating the efficacy of neoadjuvant RT or chemoradiotherapy (CRT) for advanced rectal cancer. Both short-course RT and long-course preoperative CRT compared favorably to adjuvant treatment and became the standard of choice for patients with extramural invasion or lymph node involvement. Recently, the focus of clinical research has been shifted towards total neoadjuvant therapy (TNT), delivering the whole course of RT and chemotherapy before surgery, and showing good tolerance and encouraging efficacy. Although targeted therapies haven't displayed a benefit in the neoadjuvant setting, preliminary evidence suggests impressive efficacy of immunotherapy in rectal carcinomas with mismatch-repair deficiency. In this review, we provide an in-depth critical overview of all significant randomized trials that have shaped the current treatment guidelines for locally advanced rectal cancer and discuss future trends for the treatment of this common malignancy.

Total neoadjuvant treatment and organ preservation strategies in the management of localized rectal cancer: a narrative review and evidence-based algorithm

The multimodal approach with total mesorectal excision preceded by neoadjuvant (chemo)radiotherapy represented the mainstay treatment for locally advanced rectal cancer (LARC) for a long time. However, the benefit of adjuvant chemotherapy in terms of distant relapse reduction is limited. Recently, chemotherapy regimens administered before surgery and incorporated with (chemo)radiotherapy in total neoadjuvant treatment protocols have been established as new options in the management of LARC. Meanwhile, patients with clinical complete response to neoadjuvant treatment can benefit from organ preservation strategies, aimed at sparing surgery and long-term post-operative morbidities, while preserving an adequate disease control. However, the introduction of a non-operative management in clinical practice is a matter of debate with some concerns regarding the risk of local recurrence and long-term outcomes. In this review, we discuss how these recent advances are reshaping the multimodal management of localized rectal cancer and propose an algorithm to place them in the clinical practice.

Advances in Radiotherapy for Rectal Cancer

The current preferred standard of care management for patients with locally advanced rectal cancer is total neoadjuvant therapy, in which all chemotherapy and radiotherapy is delivered before surgery. Within this approach, developed in response to persistently high distant failure rates despite excellent local control with preoperative chemoradiotherapy, there remains questions regarding the optimal radiotherapy regimen (short course vs long course) and sequencing of chemotherapy (induction vs consolidation).

The value of post-operative chemotherapy after chemoradiotherapy in patients with high-risk locally advanced rectal cancer-results from the RAPIDO trial

BACKGROUND

Pre-operative chemoradiotherapy (CRT) rather than radiotherapy (RT) has resulted in fewer locoregional recurrences (LRRs), but no decrease in distant metastasis (DM) rate for patients with locally advanced rectal cancer (LARC). In many countries, patients receive post-operative chemotherapy (pCT) to improve oncological outcomes. We investigated the value of pCT after pre-operative CRT in the RAPIDO trial.

PATIENTS AND METHODS

Patients were randomised between experimental (short-course RT, chemotherapy and surgery) and standard-of-care treatment (CRT, surgery and pCT depending on hospital policy). In this substudy, we compared curatively resected patients from the standard-of-care group who received pCT (pCT+ group) with those who did not (pCT- group). Subsequently, patients from the pCT+ group who received at least 75% of the prescribed chemotherapy cycles (pCT ≥75% group) were compared with patients who did not receive pCT (pCT-/- group). By propensity score stratification (PSS), we adjusted for the following unbalanced confounders: age, clinical extramural vascular invasion, distance to the anal verge, ypT stage, ypN stage, residual tumour, serious adverse event (SAE) and/or readmission within 6 weeks after surgery and SAE related to pre-operative CRT. Cumulative probability of disease-free survival (DFS), DM, LRR and overall survival (OS) was analysed by Cox regression.

RESULTS

In total, 396/452 patients had a curative resection. The number of patients in the pCT+, pCT >75%, pCT- and pCT-/- groups was 184, 112, 154 and 149, respectively. The PSS-adjusted analyses for all endpoints demonstrated hazard ratios between approximately 0.7 and 0.8 (pCT+ versus pCT-), and 0.5 and 0.8 (pCT ≥75% versus pCT-/-). However, all 95% confidence intervals included 1.

CONCLUSIONS

These data suggest a benefit of pCT after pre-operative CRT for patients with high-risk LARC, with approximately 20%-25% improvement in DFS and OS and 20%-25% risk reductions in DM and LRR. Compliance with pCT additionally reduces or improves all endpoints by 10%-20%. However, differences are not statistically significant.

The impact of adjuvant chemotherapy on survival in mucinous and non-mucinous rectal adenocarcinoma patients after TME surgery

INTRODUCTION

The value of adjuvant chemotherapy for rectal cancer patients is debated and varies in different subgroups. One such subgroup is mucinous adenocarcinoma (MAC), which is more treatment resistant compared to non-mucinous adenocarcinoma (NMAC). To date, mucinous histology is not taken into account when deciding on adjuvant treatment strategy. This is the first study to exclusively include patients with rectal cancer, then separate MAC and NMAC and compare the survival in patients that had or did not have adjuvant chemotherapy.

MATERIAL AND METHODS

The study included retrospective register data from 365 Swedish patients with stage II-IV rectal adenocarcinoma, 56 patients with MAC and 309 patients with NMAC. All patients were considered curative, had surgery with total mesorectal excision in 2004-2013, and were followed up until death or 2021.

RESULTS

Patients with MAC that had adjuvant chemotherapy had better overall survival (OS, HR 0.42; CI 95%: 0.19-0.93; p = 0.032) and a trend towards better cancer-specific survival (CSS, HR 0.41 CI 95%: 0.17-1.03; p = 0.057) compared to patients without chemotherapy (HR 0.42; CI 95%: 0.19-0.93; p = 0.032). The difference in OS was still significant even after adjusting for sex, age, stage, differentiation, neoadjuvant chemotherapy and preoperative radiotherapy (HR 0.40; CI 95%: 0.17-0.92; p = 0.031). There was no such difference in the NMAC patients except in the stage-by-stage subgroup analyses where patients in stage IV had better survival after adjuvant chemotherapy.

CONCLUSIONS

There may be a difference in treatment response to adjuvant chemotherapy between MAC and NMAC patients. Patients with MAC could possibly benefit from adjuvant chemotherapy in stages II-IV. Further studies are however needed to confirm these results.

Circulating tumour DNA as biomarker for rectal cancer: A systematic review and meta-analyses

Background

Circulating tumour DNA (ctDNA) has been established as a promising (prognostic) biomarker with the potential to personalise treatment in cancer patients. The objective of this systematic review is to provide an overview of the current literature and the future perspectives of ctDNA in non-metastatic rectal cancer.

Methods

A comprehensive search for studies published prior to the 4^th of October 2022 was conducted in Embase, Medline, Cochrane, Google scholar, and Web of Science. Only peer-reviewed original articles and ongoing clinical trials investigating the association between ctDNA and oncological outcomes in non-metastatic rectal cancer patients were included. Meta-analyses were performed to pool hazard ratios (HR) for recurrence-free survival (RFS).

Results

A total of 291 unique records were screened, of which 261 were original publications and 30 ongoing trials. Nineteen original publications were reviewed and discussed, of which seven provided sufficient data for meta-analyses on the association between the presence of post-treatment ctDNA and RFS. Results of the meta-analyses demonstrated that ctDNA analysis can be used to stratify patients into very high and low risk groups for recurrence, especially when detected after neoadjuvant treatment (HR for RFS: 9.3 [4.6 - 18.8]) and after surgery (HR for RFS: 15.5 [8.2 - 29.3]). Studies investigated different types of assays and used various techniques for the detection and quantification of ctDNA.

Conclusions

This literature overview and meta-analyses provide evidence for the strong association between ctDNA and recurrent disease. Future research should focus on the feasibility of ctDNA-guided treatment and follow-up strategies in rectal cancer. A blueprint for agreed-upon timing, preprocessing, and assay techniques is needed to empower adaptation of ctDNA into daily practice.

Implications of recent neoadjuvant clinical trials on the future practice of radiotherapy in locally advanced rectal cancer

Over the last two decades, the standard treatment for locally advanced rectal cancer (LARC) has been neoadjuvant chemoradiotherapy plus total mesorectal excision followed by adjuvant chemotherapy. Total neoadjuvant treatment (TNT) and immunotherapy are two major issues in the treatment of LARC. In the two latest phase III randomized controlled trials (RAPIDO and PRODIGE23), the TNT approach achieved higher rates of pathologic complete response and distant metastasis-free survival than conventional chemoradiotherapy. Phase I/II clinical trials have reported promising response rates to neoadjuvant (chemo)-radiotherapy combined with immunotherapy. Accordingly, the treatment paradigm for LARC is shifting toward methods that increase the oncologic outcomes and organ preservation rate. However, despite the progress of these combined modality treatment strategies for LARC, the radiotherapy details in clinical trials have not changed significantly. To guide future radiotherapy for LARC with clinical and radiobiological evidence, this study reviewed recent neoadjuvant clinical trials evaluating TNT and immunotherapy from a radiation oncologist’s perspective.

Prognostic role of platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte, and lymphocyte-to-monocyte ratio in operated rectal cancer patients: systematic review and meta-analysis

BACKGROUND

Inflammation plays an important role in tumor growth. Novel serum blood biomarkers, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR), have been proposed as useful prognostic indexes in cancer patients. However, their role in rectal cancer is controversial.

METHODS

A comprehensive literature review was conducted including MEDLINE/Pubmed, EMBASE, SCOPUS, and the Cochrane Database of Systematic Reviews through May 2022. The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Quality was appraised with the Methodological Index for Non-Randomized Studies (MINORS) tool. Aim of the study was to summarize available literature on PLR, NLR, and LMR in patients with rectal cancer undergoing resection.

RESULTS

Forty-seven observational studies (14,205 patients) were included; there were 42 retrospective and 5 prospective cohort studies with an average MINORS score of 14.6 (range: 12-18). Worse overall survival was associated with high NLR (HR 1.81; 95%CI 1.52-2.15; p < 0.001), high PLR (HR 1.24; 95%CI 1.06-1.46; p = 0.009), and low LMR (HR 0.67; 95%CI 0.49-0.91; p = 0.01). High NLR and low LMR were also associated with disease-free-survival (HR 1.68; 95%CI 1.35-2.08; p < 0.001 and HR 0.71; 95%CI 0.58-0.87; p < 0.001, respectively).

CONCLUSIONS

NLR, PLR, and LMR are independent clinical predictors for overall survival in patients with rectal cancer treated with curative surgery. NLR and LMR are also good predictors for disease free survival. These biomarkers, which are readily available, appear optimal prognostic indexes and may help clinicians predict the prognosis of rectal cancer and develop individualized treatment strategies.

Magnetic resonance imaging radiomics modeling predicts tumor deposits and prognosis in stage T3 lymph node positive rectal cancer

PURPOSE

To develop a magnetic resonance imaging radiomics model to predict tumor deposits (TDs) and prognosis in stage T3 lymph node positive (T3N+) rectal cancer (RC).

METHODS

This retrospective study included 163 patients with pathologically confirmed T3N + RC from December 2013 to December 2015. The patients were divided into two groups for training and testing. Extracting radiomic features from MR images and selecting features using principal component analysis (PCA), then radiomic scores (rad-scores) were obtained by logistic regression analysis. Finally, a combined TDs prediction model containing rad-scores and clinical features was developed. A receiver operating characteristic (ROC) curve was used to assess the prediction performance. The overall survival (OS) rate in patients with high-risk and low-risk TDs predicted by rad-scores was validated by Kaplan-Meier survival curves.

RESULTS

Of the 163 patients included, histological TDs was diagnosed in 45 patients. The area under the curve (AUC) of the final model was 0.833 (training) and 0.844 (testing). The patients with rad-scores predicted high-risk were associated with OS. In addition, postoperative adjuvant therapy improved the OS of the high-risk TDs group (P < 0.05).

CONCLUSION

MRI-based radiomics modeling helps in the preoperative prediction of patients with TDs+ in T3N + RC and provides risk stratification for neoadjuvant therapy. In addition, the rad-scores of TDs could suggest different survival benefits of postoperative adjuvant therapy for T3N + RC patients and guide clinical treatment.

Does the Gain of Total Neoadjuvant Therapy Outweigh the Harm in Rectal Cancer? Importance of the ATRESS (neoAdjuvant Therapy-RElated Shortening of Survival) Phenomenon: A Systematic Review

BACKGROUND

We aimed to evaluate whether total neoadjuvant therapy (TNT) results in long-term overall survival (OS) or quality of life (QoL) benefit compared with chemoradiation if all patients are being considered for radical resection, and whether the ATRESS phenomenon (i.e., reduction in post-metastatic survival) impacts OS after TNT.

METHODS

Systematic review of randomised trials comparing TNT with neoadjuvant (chemo)radiation.

RESULTS

Six trials were identified. Follow-ups were too short to resolve whether TNT improves long-term OS. QoL analysis in one trial showed worse long-term neurotoxicity-related QoL (any neurotoxicity: 14% vs. 3%), higher rate of grade III+ acute toxicity (48% vs. 25%), longer duration of neoadjuvant treatment (19 vs. 6 weeks) and higher rate of locoregional failure (10% vs. 7%) in TNT vs. chemoradiation. This should be weighed against an absolute 8% reduction in the incidence of distant metastases (DM) after TNT. ATRESS could explain a discrepancy between reduction of DM and the absence of OS improvement after TNT in one trial.

CONCLUSION

In the light of unproven OS benefit, the gain of TNT (reduction of DM) does not seem to outweigh the harm (excess of toxicity). ATRESS can be a reason for the absence of the OS benefit despite the reduction in DM.

Nanoheterojunction-Mediated Thermoelectric Strategy for Cancer Surgical Adjuvant Treatment and β-Elemene Combination Therapy

As an indispensable strategy for tumor treatment, surgery may cause two major challenges: tumor recurrence and wound infection. Here, a thermoelectric therapeutic strategy is provided as either an independent cancer therapy or surgical adjuvant treatment. Bi_0.5 Sb_1.5 Te₃ (BST) and Bi₂ Te_2.8 Se_0.2 (BTS) nanoplates composed of Z-scheme thermoelectric heterojunction (BST/BTS) are fabricated via a two-step hydrothermal processes. The contact between BST and BTS constructs an interfacial electric field due to Fermi energy level rearrangement, guiding electrons in the conductive band (CB) of BTS combine with the holes in the valance band (VB) of BST, leaving stronger reduction/oxidation potentials of electrons and holes in the CB of BST and the VB of BTS. Moreover, under a mild temperature gradient, another self-built-in electric field is formed facilitating the migration of electrons and holes to their surfaces. Based on the PEGylated BST/BTS heterojunction, a novel thermoelectric therapy platform is developed through intravenous injection of BST/BTS and external cooling of the tumors. This thermoelectric strategy is also proved effective for combination cancer therapy with β-elemene. Moreover, the combination of heterojunction and hydrogel is administrated on the wound after surgery, achieving efficient residual tumor treatment and antibacterial effects.

Clinical outcome after total neoadjuvant treatment (CAO/ARO/AIO-12) versus intensified neoadjuvant and adjuvant treatment (CAO/ARO/AIO-04) a comparison between two multicenter randomized phase II/III trials

BACKGROUND

Total neoadjuvant therapy (TNT) can enhance local tumor regression, but its survival benefits compared to intensified chemoradiotherapy (CRT) followed by adjuvant chemotherapy (CT) remain unclear.

METHODS

This is a secondary comparison between 607 patients treated with intensified 5-FU/Oxaliplatin neoadjuvant CRT and adjuvant CT within the experimental arm of the CAO/ARO/AIO-04 phase III trial, and 306 patients treated with TNT within the CAO/ARO/AIO-12 phase II trial. Comparison between clinical-pathological characteristics, surgical quality, and post-surgical complications were analyzed using the Pearson's Chi-squared or Mann-Whitney U test. Oncological outcome was examined with log-rank, Gray's test, and multivariate cox regression. In addition, further subgroup analyses and propensity score matching were performed to optimize the balance of baseline covariates.

FINDINGS

Patients treated with CRT followed by consolidation CT had a significantly higher rate of pathological complete remission (pCR) compared to patients treated within the experimental arm of the CAO/ARO/AIO-04 trial (25.3 % vs 17.3 %, P = 0.04). Post-surgical complications were less common in the CAO/ARO/AIO-12 trial. After a median follow-up of 46 months, clinical outcome did not differ significantly in the overall cohort, in any subgroup or after propensity score matching. In multivariate analysis, disease-free survival (DFS) was similar between the experimental arm of the CAO/ARO/AIO-04 trial and treatments arms of the CAO/ARO/AIO-12 trial (vs arm A: HR 0.92 [95 % CI 0.62-1.37], P = 0.69; vs arm B: HR 1.06 [95 % CI 0.72-1.58], P = 0.76).

INTERPRETATION

Notwithstanding the limitations of intertrial comparison, TNT did not improve long term oncological outcome in our study compared to the intensified neoadjuvant CRT and adjuvant CT treatment in the CAO/ARO/AIO-04 trial. Improved response rates after TNT offers an attractive option to explore organ preservation in selective patients with locally advanced rectal cancer.

The preoperative geriatric nutritional risk index predicts long-term prognosis in elderly locally advanced rectal cancer patients: a two-center retrospective cohort study

BACKGROUND

The objective is to explore the value of preoperative geriatric nutritional risk index (GNRI) in evaluating long-term prognosis in elderly locally advanced rectal cancer (LARC) patients who accepted neoadjuvant chemoradiotherapy (NCRT) and to compare GNRI with established nutritional markers, including prognostic nutritional index (PNI) and controlling nutritional status (CONUT) score.

METHODS

Preoperative GNRI was retrospectively assessed in 172 LARC patients aged ≥ 60 years who underwent radical resection after NCRT at two centers. Optimal cutoff value of GNRI was determined by X-tile program. The association of GNRI with clinicopathological parameters and nutritional markers was analyzed. The survival ability of markers was evaluated using time-dependent receiver-operating characteristic (ROC) curve analysis. Finally, survival analysis was performed using Kaplan-Meier and Cox regression analysis.

RESULTS

GNRI was highly correlated with nutritional markers. An optimal cutoff value for the GNRI was 96. In the time-dependent ROC curve, GNRI demonstrated a stable predictive ability for both disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that GNRI was the only nutritional marker that independently predicted DFS (HR 2.457, 95% CI 1.066-5.665, P = 0.035) and OS (HR 9.002, 95% CI 3.100-26.146, P < 0.001). As an additional benefit, GNRI was able to stratify survival in subgroups of ypTNM and tumor response.

CONCLUSION

Preoperative GNRI is a promising predictor of long-term survival for elderly LARC patients undergoing NCRT, superior to the established nutritional markers.

Total Neoadjuvant Chemotherapy in Rectal Cancer: Current Facts and Future Strategies

Despite preoperative chemoradiotherapy (CRT) and total mesorectal excision improving the local control for locally advanced rectal cancer (LARC), oncologic outcomes and survival were not significantly improved because the main prognostic factor is distant metastasis. Thus, total neoadjuvant chemotherapy (TNT) as a novel approach has been proposed to improve chemotolerance. Since the first randomized phase II trial of TNT versus standard CRT demonstrated in 2012, many prospective and retrospective studies have been published. The initial consensus from TNT studies was that pathological complete response, pathological response of the main tumor, and local control are more favorable at TNT than at CRT. Furthermore, recent studies such as the PAPIDO trial and PRODIGE 23 trial made a major breakthrough of the treatment of TNT, showing that TNT improves the disease-free survival compared to standard treatment with long-course CRT. In addition, several innovative findings of TNT were clarified by prospective phase II trial. In this review, we summarize the most recent advances in TNT based on the findings of pivotal clinical trials for patients with LARC.

Circulating tumour DNA in the evolving treatment landscape of locally advanced rectal cancer: where does it fit in?

The management of locally advanced rectal cancer (LARC) requires multimodality treatment, typically with neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision. However, the treatment landscape is rapidly evolving with total neoadjuvant therapy and non-operative management for selected patients emerging as other novel treatment approaches. With so many treatment options, there is a need for biomarkers to direct a more personalised treatment strategy for patients with LARC. In this review, we summarise the available data regarding the use of circulating tumour DNA (ctDNA) in patients with LARC, as both a marker of treatment response to neoadjuvant therapy and as a marker of minimal residual disease (MRD) after patients have completed definitive local treatment. To date, the ability of ctDNA status to predict for pathologic complete response at any timepoint during multimodality treatment has been variably reported. The most consistent finding across available studies is the ability of ctDNA to detect MRD after CRT and surgery, the presence of which confers a significantly poor prognosis, with increased risk of cancer recurrence and worse overall survival. It is yet to be determined if providing additional therapies to patients with MRD improves outcomes. The available studies assessing the potential utility of ctDNA in LARC are limited by significant heterogeneity in the choice of ctDNA assay, timepoint at which ctDNA was collected, treatment that patients received and length of follow-up, leading to uncertainties about how to implement it into daily clinical practice. As the treatment landscape evolves, larger randomised trials assessing the role of ctDNA in LARC are needed.

Development and validation of a prognostic nomogram for rectal cancer patients who underwent surgical resection

Objective: The purpose of this study was to develop and validate a nomogram model for the prediction of survival outcome in rectal cancer patients who underwent surgical resection. Methods: A total of 9,919 consecutive patients were retrospectively identified using the Surveillance, Epidemiology, and End Results (SEER) database. Significant prognostic factors were determined by the univariate and multivariate Cox analysis. The nomogram model for the prediction of cancer-specific survival (CSS) in rectal cancer patients were developed based on these prognostic variables, and its predictive power was assessed by the concordance index (C-index). Calibration curves were plotted to evaluate the associations between predicted probabilities and actual observations. The internal and external cohort were used to further validate the predictive performance of the prognostic nomogram. Results: All patients from the SEER database were randomly split into a training cohort (n = 6,944) and an internal validation cohort (n = 2,975). The baseline characteristics of two cohorts was comparable. Independent prognostic factors were identified as age, pT stage, lymph node metastasis, serum CEA level, tumor size, differentiation type, perineural invasion, circumferential resection margin involvement and inadequate lymph node yield. In the training cohort, the C-index of the nomogram was 0.719 (95% CI: 0.696-0.742), which was significantly higher than that of the TNM staging system (C-index: 0.606, 95% CI: 0.583-0.629). The nomogram had a C-index of 0.726 (95% CI: 0.691-0.761) for the internal validation cohort, indicating a good predictive power. In addition, an independent cohort composed of 202 rectal cancer patients from our institution were enrolled as the external validation. Compared with the TNM staging system (C-index: 0.573, 95% CI: 0.492-0.654), the prognostic nomogram still showed a better predictive performance, with the C-index of 0.704 (95% CI: 0.626-0.782). Calibration plots showed a good consistency between predicted probability and the actual observation in the training and two validation cohorts. Conclusion: The nomogram showed an excellent predictive ability for survival outcome of rectal cancer patients, and it might provide an accurate prognostic stratification and help clinicians determine individualized treatment strategies.

Is There a Role for Adjuvant Chemotherapy in Pathologic Node-Negative Locally Advanced Rectal Cancer After Neoadjuvant Chemoradiation Therapy?

BACKGROUND

Neoadjuvant chemoradiation therapy (NCRT, 5-fluorouracil and radiation) followed by resection and adjuvant chemotherapy (AC) is one of the standard treatment paradigms for locally advanced rectal adenocarcinoma. However, the utility of AC in patients with pathologic lymph node (pLN)-negative disease is unclear. Our aim is to assess the value of AC stratified by pLN status.

METHODS

The US Rectal Cancer Consortium database (2007-2017) was retrospectively reviewed for patients with clinical stage II and III rectal adenocarcinoma who received neoadjuvant chemoradiation (NACR) and curative-intent resection. Those who received neoadjuvant systemic chemotherapy or underwent local resection were excluded. Patients were categorized by pLN status. Primary outcome was overall survival (OS).

RESULTS

Of 213 patients, 70% had pLN-negative disease and 30% pLN-positive disease. Median age was 57 years, 65% were male, and median follow-up was 31 months. Among patients with pLN-negative disease, 74% received AC. Receipt of AC was not associated with improved 5-year OS (82% versus 74%, respectively; p = 0.16). This finding persisted on multivariable analysis. Of patients with pLN-positive disease, 83% received AC. Patients with pLN-positive disease demonstrated improved 5-year OS with receipt of AC (72% compared with 0% with no adjuvant chemotherapy, p = 0.04).

CONCLUSION

After receiving neoadjuvant chemoradiation, adjuvant chemotherapy for patients with pLN-negative disease does not appear to be associated with improved survival. Further validation and prospective studies are needed to evaluate the utility of adjuvant chemotherapy in this setting.

Changing patterns of neoadjuvant therapy for locally advanced rectal cancer: A narrative review

Standard treatment for patients with locally advanced rectal cancer has been the multidisciplinary approach of neoadjuvant chemoradiotherapy, followed by total mesorectal excision (TME) and postoperative adjuvant chemotherapy. This reduces the local recurrence rate, but the challenge of distant metastasis still persists. The improvement in treatment approach has always been the focus of clinical research and studies have been conducted worldwide in recent years. On one hand, evidence suggests that increasing the intensity of treatment can result in better tumor regression, for example by adding a second drug to the neoadjuvant chemoradiotherapy, or extending the interval between neoadjuvant therapy and surgery, or incorporating chemotherapy and chemoradiotherapy in the neoadjuvant setting. On the other hand, neoadjuvant immunotherapy and selective omission of neoadjuvant radiotherapy may improve the quality of life of patients. In this article, we review the key clinical research progresses in neoadjuvant therapy for locally advanced rectal cancer, hoping to provide some valuable views on the individualized treatment for rectal cancer.

Total neoadjuvant treatment and PD-1/PD-L1 checkpoint inhibitor in locally advanced rectal cancer

For local advanced rectal cancer (LARC), total neoadjuvant treatment (TNT) has shown more complete response (CR), reduced risk of distant metastasis (DM) and increase of the sphincter preservation rate. Now it is the one and only recommendation for high-risk group of LARC according to National Comprehensive Cancer Network (NCCN) rectal cancer guideline, while it is also preferentially recommended for low-risk group of LARC. TNT is also beneficial for distant rectal cancer patients who have need for organ preservation. Even though the prognostic value of programmed cell death-ligand 1 (PD-L1) in the neoadjuvant chemoradiotherapy (NACRT) of LARC patients is undetermined yet, the combination of NACRT and programmed cell death-1 (PD-1)/PD-L1 antibodies seem bring new hope for mismatch repair proficient (pMMR)/microsatellite stable (MSS) LARC patients. Accumulating small sample sized studies have shown that combining NACRT with PD-1/PD-L1 antibody yield better short-term outcomes for pMMR/MSS LARC patients than historic data. However, ideal total dose and fractionation of radiotherapy remains one of unresolved issues in this combination setting. Thorough understanding the impact of radiotherapy on the tumor microenvironment and their interaction is needed for in-depth understanding and exquisite design of treatments combination model.

Adjuvant chemotherapy and survival outcomes in rectal cancer patients with good response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery: A retrospective nationwide analysis

Background

For rectal cancer, it remains unclear how to incorporate tumor response to neoadjuvant chemoradiotherapy (nCRT) when deciding whether to give adjuvant chemotherapy. In this study, we aim to determinate the survival benefit of adjuvant chemotherapy for rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Methods

The study cohort included 720 rectal cancer patients who had good response (ypT0-2N0) after nCRT and surgery, who did or did not receive adjuvant chemotherapy between January 2007 and December 2017, from the Taiwan Cancer Registry and National Health Insurance Research database. The Kaplan-Meier method, log-rank tests, and Cox regression analysis were performed to investigate the effect of adjuvant chemotherapy on 5-year overall survival (OS) and disease-free survival (DFS).

Results

Of 720 patients, 368 (51.1%) received adjuvant chemotherapy and 352 (48.9%) did not. Patients who received adjuvant chemotherapy were more likely to be female, younger (≤ 65), with advanced clinical T (3-4)/N (1-2) classification and ypT2 classification. No significant difference in 5-year OS (p=0.681) or DFS (p=0.942) were observed by receipt of adjuvant chemotherapy or not. Multivariable analysis revealed adjuvant chemotherapy was not associated with better OS (adjusted hazard ratio [aHR], 1.03; 95% Confidence Interval [CI], 0.88-1.21) or DFS (aHR, 1.05; 95% CI, 0.89-1.24). Stratified analysis for OS and DFS found no significant protective effect in the use of adjuvant chemotherapy, even for those with advanced clinical T or N classification.

Conclusion

Adjuvant chemotherapy may be omitted in rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Prognostic value of final pathological stage in colon adenocarcinoma after neoadjuvant chemotherapy: A propensity score-matched study

Background

Neoadjuvant chemotherapy (NAC) could improve local tumor control of locally advanced colon cancer (LACC), but the prognostic value of yp stage in colon cancer remains unknown. Here, we aimed to ascertain yp stage as an indicator for LACC prognosis after NAC.

Methods

The data of patients diagnosed with colon adenocarcinoma between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results database. After 1:2 propensity score matching, cancer-specific survival (CSS) and overall survival (OS) were compared between the NAC and Non-NAC groups of different stage classifications. The correlation between clinical and pathological factors and CSS was identified.

Results

A total of 49, 149, and 81 matched pairs of stage 0-I, II, and III patients, respectively, were generated for analysis. For stage 0-I (p = 0.011) and III (p = 0.015), only CSS in the NAC groups were inferior. Receiving NAC was an independent prognostic risk factor for patients with stage 0-I (hazard ratio, 7.70; 95% confidence interval, 1.820-32.5; p = 0.006) and stage III (hazard ratio, 1.73; 95% confidence interval, 1.11-2.68; p = 0.015).

Conclusions

The CSS was poorer among LACC patients who underwent NAC than among those who did not. The yp stage of colon cancer after NAC has distinctive significance, which may contribute to predicting the prognosis and guiding the treatment of LACC patients after NAC.

Graphdiyne-Related Materials in Biomedical Applications and Their Potential in Peripheral Nerve Tissue Engineering

Graphdiyne (GDY) is a new member of the family of carbon-based nanomaterials with hybridized carbon atoms of sp and sp², including α, β, γ, and (6,6,12)-GDY, which differ in their percentage of acetylene bonds. The unique structure of GDY provides many attractive features, such as uniformly distributed pores, highly π-conjugated structure, high thermal stability, low toxicity, biodegradability, large specific surface area, tunable electrical conductivity, and remarkable thermal conductivity. Therefore, GDY is widely used in energy storage, catalysis, and energy fields, in addition to biomedical fields, such as biosensing, cancer therapy, drug delivery, radiation protection, and tissue engineering. In this review, we first discuss the synthesis of GDY with different shapes, including nanotubes, nanowires, nanowalls, and nanosheets. Second, we present the research progress in the biomedical field in recent years, along with the biodegradability and biocompatibility of GDY based on the existing literature. Subsequently, we present recent research results on the use of nanomaterials in peripheral nerve regeneration (PNR). Based on the wide application of nanomaterials in PNR and the remarkable properties of GDY, we predict the prospects and current challenges of GDY-based materials for PNR.

Injectable magnetic montmorillonite colloidal gel for the postoperative treatment of hepatocellular carcinoma

Bioactive materials have been extensively developed for the adjuvant therapy of cancer. However, few materials can meet the requirements for the postoperative resection of hepatocellular carcinoma (HCC) due to massive bleeding and high recurrence. In particular, combination therapy for HCC has been highly recommended in clinical practice, including surgical resection, interventional therapy, ablation therapy and chemotherapy. Herein, an injectable magnetic colloidal gel (MCG) was developed by controllable electrostatic attraction between clinically available magnetic montmorillonites and amphoteric gelatin nanoparticles. The optimized MCG exhibited an effective magnetic heating effect, remarkable rheological properties, and high gel network stability, realizing the synergistic treatment of postoperative HCC by stimuli-responsive drug delivery, hemostasis and magnetic hyperthermia. Furthermore, a minimal invasive MCG-induced interventional magnetic hyperthermia therapy (MHT) under ultrasound guidance was realized on hepatic tumor rabbits, providing an alternative therapeutics to treat the postoperative recurrence. Overall, MCG is a clinically available injectable formulation for adjuvant therapy after HCC surgical resection.

Is short-course radiotherapy and total neoadjuvant therapy the new standard of care in locally advanced rectal cancer? A sensitivity analysis of the RAPIDO clinical trial

BACKGROUND

The results of the RAPIDO trial have been accepted as evidence in favour of short-course radiotherapy (SC-RT) followed by chemotherapy before total mesorectal excision in high-risk locally advanced rectal cancer. A noteworthy concern is that the RAPIDO trial did not ensure that all patients in the control arm received adjuvant chemotherapy. This may bias statistical estimates in favour of the experimental arm if adjuvant chemotherapy is active in rectal cancer. Moreover, the 5-year update revealed an increase in the risk of local relapse in the experimental arm.

MATERIALS AND METHODS

We carried out sensitivity analyses to determine how plausible effects of adjuvant chemotherapy, adjusted by the proportion of patients in the standard arm receiving adjuvant treatment, would have influenced the observed treatment effect estimate of the RAPIDO trial. The most plausible values for the benefit of adjuvant chemotherapy were determined by Bayesian re-analysis of a prior meta-analysis.

RESULTS

The meta-analysis suggested that oxaliplatin/fluorouracil-based adjuvant chemotherapy may improve disease-free survival (DFS) in rectal cancer although the signal is weak [hazard ratio (HR) 0.84, 95% credible interval, 0.57-1.15]; probability of benefit (HR <1) was 91.2%. In the sensitivity analysis, the HR for disease-related treatment failure would remain <1, thus favouring total neoadjuvant therapy (TNT), on most occasions, but the null hypothesis would not have been rejected in various credible settings. For the RAPIDO data to be consistent with the null effect, a moderate benefit of adjuvant chemotherapy (HR for DFS between 0.75 and 0.80) and 70%-80% of exposed participants would suffice.

CONCLUSION

The decision to make adjuvant chemotherapy optional in the standard arm may have biased the results in favour of the experimental arm, in a scenario in which TNT does not offset the increase in local recurrences after SC-RT.

Multimodal Treatment of Rectal Cancer

BACKGROUND

Colorectal cancer is one of the three most common types of cancer in Germany. Approximately 30% of these cancers are located in the rectum, corresponding to about 18 000 new cases per year.

METHODS

This review is based on publications retrieved by a selective search in the PubMed database, including current guidelines and recommendations.

RESULTS

Specialized imaging, particularly magnetic resonance imaging, is essential for treatment planning. In very early stages of this disease, tumors without risk factors can be excised locally. Otherwise, radical surgical resection with lymphadenectomy remains the standard treatment, and can be performed either minimally invasive or open. At present, neoadjuvant treatment plans are evolving in the direction of total neoadjuvant therapy. In addition, recent studies investigate whether the improved efficacy of neoadjuvant therapy might now enable patients with a complete clinical remission to be spared from surgical resection (organ-preserving watch-and-wait strategy).

CONCLUSION

The treatment of rectal cancer is a prime example of an interdisciplinary, multimodal approach. In the past, the focus was mainly on improving oncologic outcomes; at present, increasing attention is being devoted to the patients' quality of life as well and the functional aspects of the various modes of treatment.

Total Neoadjuvant Therapy for Rectal Cancer in the CAO/ARO/AIO-12 Randomized Phase 2 Trial: Early Surrogate Endpoints Revisited

Background: Early efficacy outcome measures in rectal cancer after total neoadjuvant treatment are increasingly investigated. We examined the prognostic role of pathological complete response (pCR), tumor regression grading (TRG) and neoadjuvant rectal (NAR) score for disease-free survival (DFS) in patients with rectal carcinoma treated within the CAO/ARO/AIO-12 randomized phase 2 trial. Methods: Distribution of pCR, TRG and NAR score was analyzed using the Pearson’s chi-squared test. Univariable analyses were performed using the log-rank test, stratified by treatment arm. Discrimination ability of non-pCR for DFS was assessed by analyzing the ROC curve as a function of time. Results: Of the 311 patients enrolled, 306 patients were evaluable (Arm A:156, Arm B:150). After a median follow-up of 43 months, the 3-year DFS was 73% in both groups (HR, 0.95, 95% CI, 0.63–1.45, p = 0.82). pCR tended to be higher in Arm B (17% vs. 25%, p = 0.086). In both treatment arms, pCR, TRG and NAR were significant prognostic factors for DFS, whereas survival in subgroups defined by pCR, TRG or NAR did not significantly differ between the treatment arms. The discrimination ability of non-pCR for DFS remained constant over time (C-Index 0.58) but was slightly better in Arm B (0.61 vs. 0.56). Conclusion: Although pCR, TRG and NAR were strong prognostic factors for DFS in the CAO/ARO/AIO-12 trial, their value in selecting one TNT approach over another could not be confirmed. Hence, the conclusion of a long-term survival benefit of one treatment arm based on early surrogate endpoints should be stated with caution.

MiR-199a/b-3p inhibits colorectal cancer cell proliferation, migration and invasion through targeting PAK4 and BCAR3

Background

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. P21 activated kinase 4 (PAK4) and Breast cancer anti-estrogen resistance 3 (BCAR3) have been reported to be involved in numerous aspects in tumorous progression. In this study, we propose to screen multi-targeted microRNAs. (miRNAs), which simultaneously inhibit neoplastic evolution through suppressing the transcription of target genes.

Methods

MTT and Colony formation assays measured cell’s viability and proliferation. Scratch wound and Transwell assays detected the ability in migration and invasion for SW116 cells. The multi-targeted microRNAs of PAK4 and BCAR3 were predicted using bioinformatics analysis and verified by conducting dual luciferase reporter assay, western blot and qRT-PCR that could detect the expression levels of miR-199a/b-3p.

Results

The knockdown of PAK4 significantly impeded proliferation and colony formation of SW1116 cells when the knockdown of BCAR3 hindered migration and invasion of SW1116 cells. MiR-199a/b-3p directly targeted the 3'-UTR of PAK4 and BCAR3, further effected proliferation, colony formation, migration, and invasion of SW1116 cells. PAK4 or BCAR3 overexpression could partially reversed inhibitory effects of miR-199a/b-3p.

Conclusions

These results provided a new multi-targeted cite for cancerous suppressant to improve the prognosis of CRC inpatients.

Oncologic benefit of adjuvant chemotherapy for locally advanced rectal cancer after neoadjuvant chemoradiotherapy and curative surgery with selective lateral pelvic lymph node dissection: An international retrospective cohort study

INTRODUCTION

Intensive local treatment comprising total mesorectal excision (TME) with selective lateral pelvic lymph node dissection (LPND) after neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) has received attention among clinicians treating rectal cancer. It remains unclear whether adjuvant chemotherapy (ACT) after intensive local treatment is beneficial for these patients. We evaluated the oncologic benefit of ACT for patients with LARC who received intensive local treatment.

MATERIALS AND METHODS

This international multicentre retrospective cohort study included 737 patients treated in Japan and Korea between 2010 and 2017. The effectiveness of ACT on recurrence-free survival (RFS) was evaluated using univariable and multivariable Cox proportional hazards models, with subgroup analyses to identify subpopulations potentially benefiting from ACT.

RESULTS

The median follow-up was 49 months; the 5-year RFS and local recurrence rates for the entire cohort were 72.1% and 4.9%, respectively; 514 patients (69.7%) received adjuvant chemotherapy, without an oncologic benefit (hazard ratio, 1.14; 95% confidence interval [CI]: 0.79-1.68) demonstrated in the multivariable Cox regression analysis. In subgroup analyses, the distributions of the 95% CI in patients aged ≥70 years and those with ypStage 0 tended to place a disproportionate emphasis that favoured the non-ACT treatment strategy.

CONCLUSION

Despite achieving good local control with intensive local treatment strategy, the effectiveness of ACT for the LARC patients with CRT followed by TME with selective LPND was not proved. Elderly patients and those with ypStage0 may not receive benefit from ACT after CRT and TME ± LPND.

Nonoperative versus Operative Approach According to the Response to Neoadjuvant Chemoradiotherapy for Rectal Cancer: A Prospective Cohort Study

•

Watch-and-wait patients after chemoradiotherapy for rectal cancer have good functional outcome.

•

No survival differences were seen between patients undergoing surgery versus patients in a watch-and-wait protocol.

•

There is a subset of patients that has initial favorable response but will recur with distant metastases afterwards.

•

A previously published model predicting (near)-complete response could not be validated.

Purpose

To report on organ preservation following chemoradiotherapy (CRT) in a prospective cohort of locally advanced rectal cancer patients.

Methods and materials

Fifty-two patients received CRT. MRI and ¹⁸F-FDG-PET/CT were performed prior to CRT. Response assessment was done 6 and 12 weeks after CRT using digital rectal examination, MRI, ¹⁸F-FDG-PET/CT and endoscopy. For clinical complete response or minimal residual disease, a watch-and-wait (W&W) protocol was started.

Regrowth-free survival (ReFS), Total Mesorectal Excision-free disease-free survival, distant metastasis-free survival (DMFS) and overall survival (OS) were evaluated using Kaplan-Meier method. Functional outcome was compared with the Wilcoxon signed-rank test using EORTC QLQ-C30, MSKCC BFI, LARS and IIEF-5/FSFI-5 questionnaires. A previously developed prediction model performance was tested using receiver operating characteristic analysis.

Results

29/52 patients entered a W&W protocol. There was no difference in two-year DMFS (81.1 % vs 78.8 %, p = 0.82), two-year OS (96.4 % vs 100 %, p = 0.38) and two-year DFS (77.5 % vs 78.8 %, p = 0.87) between W&W patients and those who underwent surgery at 12 weeks after CRT. Two-year DMFS differed between W&W with local regrowth, W&W with sustained response and patients who had surgery (66.7 % vs 88.0 % vs 78.8 %; p = 0.04). At 6 and 12 months, W&W patients reported good QoL and bowel function. The model validation reached an AUC of 0.627.

Conclusion

Good functional outcome in patients with rectal cancer allocated to surveillance after CRT needs to be balanced against potentially worse DMFS in a subset of patients without sustained clinical complete response. Reliable prediction of patients eligible for surveillance programs needs further investigation.

Nonoperative Management Following Complete Response in Rectal Cancer After Short-course Radiation Therapy and Consolidation Chemotherapy: Clinical Outcomes and Quality of Life Measures

PURPOSE

The purpose of his study was to report on a cohort of patients managed with nonoperative management (NOM) with a watch-and-wait strategy after achieving complete response (CR) to sequential short-course radiation therapy (SCRT) and consolidation chemotherapy.

METHODS

This was a retrospective study of patients treated SCRT and chemotherapy who achieved a CR and were managed with NOM. Bowel function was assessed with European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30, EORTC Quality of Life Questionnaire-Colorectal Cancer 29, and the low anterior resection syndrome (LARS) questionnaires. Endpoints included overall survival (OS), freedom from local failure (FFLF), freedom from distant metastasis, and disease-free survival (DFS).

RESULTS

Twenty-six patients met inclusion criteria. Seven (26.9%) patients developed local failure at a median of 6.8 months following CR, of which 5 were successfully salvaged. Median FFLF was not reached, with 6-month, 1-, and 2-year FFLF rates of 100.0%, 82.3%, and 71.3%. Median OS was not reached, with 6-month, 1-, and 2-year OS rates of 100%. Median DFS was not reached, with 6-month, 1-, and 2-year DFS rates of 100%, 95.0%, and 89.4%. Questionnaire response rate was 83.3%. Median LARS score was 27. Major, minor, and no LARS occurred in 3 (20%), 6 (40%), and 6 (40%) patients, respectively. There were no differences in questionnaire scores between patients who had the majority of their anal sphincter complex irradiated and those who did not.

CONCLUSION

NOM with a watch-and-wait strategy is safe and feasible in patients with locally advanced rectal cancer who achieve CR after sequential SCRT and chemotherapy, with evidence for good anorectal function.

Microsatellite instability in rectal cancer: what does it mean? A study of two randomized trials and a systematic review of the literature

Currently, compelling evidence illustrates the significance of determining microsatellite instability (MSI) in colorectal cancer (CRC). The association of MSI with proximal CRC is well established, however, its implications in patients with rectal cancer remain undefined. We therefore aimed to determine the role of MSI with respect to incidence and outcome in patients with rectal cancer, by the examination of patients from two prospective phase III trials: TME trial and PROCTOR-SCRIPT trial (n=1250). No differences in terms of overall survival (HR 1.00, 95%CI 0.69-1.47) and disease-free survival (HR 1.00, 95%CI 0.68-1.45) were observed in patients with MSI compared to microsatellite stable (MSS) rectal cancer. In addition, we performed a literature review to evaluate the overall prevalence, the effect on survival and the response to neo-adjuvant treatment in patients with MSI rectal cancer compared with MSS rectal cancer. The total number of MSI cases in the included studies (including our own) was 1220 (out of 16526 rectal cancer patients), with an overall prevalence of 6.7% (SE 1.19%). Both for overall survival as for disease-free survival there was no impact of MSI status on prognosis (HR 1.00, 95%CI 0.77-1.29 and HR 0.86, 95% CI 0.60-1.22, respectively). The risk ratio for downstaging and pCR showed also no impact of MSI status (RR 1.15, 95% CI 0.86-1.55 and RR 0.81, 95% CI 0.54-1.22 respectively). In conclusion, rectal cancer patients with MSI form a distinct and rare subcategory, however, there is no prognostic effect of MSI in rectal cancer patients.

Assessment of Textbook Oncologic Outcomes Following Proctectomy for Rectal Cancer

BACKGROUND

Outcomes of rectal adenocarcinoma vary considerably. Composite "textbook oncologic outcome" (TOO) is a single metric that estimates optimal clinical performance for cancer surgery.

METHODS

Patients with stage II/III rectal adenocarcinoma who underwent single-agent neoadjuvant chemoradiation and proctectomy within 5-12 weeks were identified in the National Cancer Database (NCDB). TOO was defined as achievement of negative distal and circumferential resection margin (CRM), retrieval of ≥ 12 nodes, no 90-day mortality, and length of stay (LOS) < 75th percentile of corresponding year's range. Multivariable logistic regression was used to identify predictors of TOO.

RESULTS

Among 318,225 patients, 8869 met selection criteria. Median age was 62 years (IQR 54-71), and 5550 (62.6%) were males. Low anterior resection was the most common procedure (LAR, 6,037 (68.1%) and 3084 (34.8%) were treated at a high-volume center (≥ 20 rectal resections/year). TOO was achieved in 3967 patients (44.7%). Several components of TOO were achieved commonly, including negative CRM (87.4%), no 90-day mortality (98.0%), no readmission (93.0%), and no prolonged hospitalization (78.8%). Logistic regression identified increasing age, non-private insurance, low-volume centers, open approach, Black race, Charlson score ≥ 3, and abdominoperineal resection (APR) as predictors of failure to achieve TOO. Over time, TOOs were attained more commonly which correlated with increased minimally invasive surgery (MIS) adoption. TOO achievement was associated with improved survival.

CONCLUSIONS

Rectal adenocarcinoma patients achieve TOO uncommonly. Treatment at high-volume centers and MIS approach were among modifiable factors associated with TOO in this study.

Constructing and Validating a Prognosis Predictive Nomogram for Cancer-Specific Survival in Rectal Cancer Patients Receiving Preoperative Radiotherapy

Background A predictive tool is required to identify the cancer-specific survival in rectal cancer (RC) patients who have opted to receive preoperative radiotherapy.Methods A database containing the data on RC patients' records of Surveillance, Epidemiology, and End Results (SEER) receiving surgery during 2000-2014 was selected. All patients received neoadjuvant radiotherapy (NR). The correlation of clinicopathological parameters was analyzed using the Chi-square test and the survival risk factors were analyzed using the Cox proportional hazards analysis (univariate and multivariate). Finally, the nomogram was developed and validated to visually represent an accurate prediction of the probability of 3- and 5-year cancer-specific survival (CSS) based on the screened variables of the cohort.Results 11,499 rectal cancer patients were included in our cohort. Patients' records were randomly allocated to either the development or validation cohorts based on an equal ratio (1:1). Performing the multivariate Cox regression analysis incorporating these variables in the development cohort determined 11 independent prognostic factors. Statistically significant differences were recorded among subgroups using log-rank tests, which confirmed the appropriateness and acceptability of factor stratifications. Then, the nomogram was constructed and its concordance index (C-index) values in the development cohort (0.720) and validation cohort (0.717) were evaluated to be higher (P<0.05) than those of the AJCC stage (0.631 and 0.633 respectively). Also, the 3-year AUC values of this nomogram were higher than those of the AJCC stage in both the development cohort (0.746 vs. 0.631) and the validation cohort (0.745 vs. 0.640). Using DCA curves, the predictive potential of the currently developed nomogram outperformed the conventional AJCC staging system.Conclusion The nomogram model might be a more reliable tool to predict prognosis accurately in rectal cancer patients receiving preoperative radiotherapy.

The Multimodal Management of Locally Advanced Rectal Cancer: Making Sense of the New Data

In the past 40 years, the treatment of locally advanced rectal cancer has evolved with the addition of radiotherapy or chemoradiotherapy and providing (neo)adjuvant systemic chemotherapy to major surgery. However, recent trends have focused on improving our ability to risk-stratify patients and tailoring treatment to achieve the best oncologic outcome while limiting the impact on long-term quality of life. Therefore, there has been increasing interest in pursuing a watch-and-wait approach to achieve organ preservation. Several retro- and prospective studies suggest safety of the watch-and-wait approach, though it is still considered controversial due to limited clinical evidence, concerns about tumor regrowth, and subsequent distant progression. To further reduce treatment, MRI risk stratification, together with patient characteristics and patient preferences, can guide personalized treatment and reserve radiation and chemotherapy for a select patient population. Ultimately, improved options for reassessment during neoadjuvant treatment may allow for more adaptive therapy options based on treatment response. This article provides an overview of some major developments in the multimodal treatment of locally advanced rectal cancer. It reviews some relevant, controversial issues of the watch-and-wait approach and opportunities to personally tailor and reduce treatment. It also reviews the overall neoadjuvant treatment, including total neoadjuvant therapy trials, and how to best optimize for a potential complete response. Finally, it provides an algorithm as an example of how such a personalized, tailored, adaptive, and reduced treatment could look like in the future.

The Characterization and Outcomes of Colorectal Malignancy in Patients ≤40 Years of Age: A Single-Center Experience

BACKGROUND

Implementation of screening modalities has led to a decreased incidence of colorectal malignancies. Unfortunately, overall incidence has remained unchanged as cases have increased in patients below the suggested screening age. Therefore, we evaluated characteristics and oncological outcomes of malignancies in patients ≤40 years of age.

METHODS

Single-center retrospective analysis of prospectively collected data of malignancies in patients ≤40 years evaluated in our institution between 2010 and 2016. Basic descriptors for demographic, clinical, histologic, and genetic data were collected. Disease-free survival (DFS) and 5-year overall survival (OS) were compared for patients between 30-40 years and <30 years.

RESULTS

Fifty-six patients ≤40 years were identified, 44 of whom (96.5%) had adenocarcinomas. Most common malignancy location was the rectum (64.3%). Despite aggressive tumor characteristics such as moderate/poor differentiation (88.6%), lymphovascular invasion (26.8%), perineural invasion (21.4%), and advanced tumor stage T3/T4 (60.7%), OS rate was 94.6%. Both age groups had similar oncologic characteristics. There was a trend toward worse OS (2/11 and 1/45, P = .06) but not for DFS (7/11 and 15/43, P = .18) in patients <30 years of age compared to 30-40 years. There were no differences in OS (3/44 vs 0/88, P = .44) or DFS (17/42 vs 3/8, P = .80) between sporadic vs non-sporadic malignancies, respectively.

CONCLUSIONS

Patients ≤40 years of age with malignancy have advanced tumor stages and aggressive tumor characteristics at diagnosis. Although there is higher OS risk for patients <30 compared to those aged 30-40 years, no differences were found for DFS between these two groups.

Survival After Induction Chemotherapy and Chemoradiation Versus Chemoradiation and Adjuvant Chemotherapy for Locally Advanced Rectal Cancer

BACKGROUND

Total neoadjuvant therapy (TNT) improves tumor response in locally advanced rectal cancer (LARC) patients compared to neoadjuvant chemoradiotherapy alone. The effect of TNT on patient survival has not been fully investigated.

MATERIALS AND METHODS

This was a retrospective case series of patients with LARC at a comprehensive cancer center. Three hundred and eleven patients received chemoradiotherapy (chemoRT) as the sole neoadjuvant treatment and planned adjuvant chemotherapy, and 313 received TNT (induction fluorouracil and oxaliplatin-based chemotherapy followed by chemoradiotherapy in the neoadjuvant setting). These patients then underwent total mesorectal excision or were entered in a watch-and-wait protocol. The proportion of patients with complete response (CR) after neoadjuvant therapy (defined as pathological CR or clinical CR sustained for 2 years) was compared by the χ2 test. Disease-free survival (DFS), local recurrence-free survival, distant metastasis-free survival, and overall survival were assessed by Kaplan-Meier analysis and log-rank test. Cox regression models were used to further evaluate DFS.

RESULTS

The rate of CR was 20% for chemoRT and 27% for TNT (P=.05). DFS, local recurrence-free survival, metastasis-free survival, and overall survival were no different. Disease-free survival was not associated with the type of neoadjuvant treatment (hazard ratio [HR] 1.3; 95% confidence interval [CI] 0.93-1.80; P = .12).

CONCLUSIONS

Although TNT does not prolong survival than neoadjuvant chemoradiotherapy plus intended postoperative chemotherapy, the higher response rate associated with TNT may create opportunities to preserve the rectum in more patients with LARC.