Addition of Platinum Derivatives to Fluoropyrimidine-Based Neoadjuvant Chemoradiotherapy for Stage II/III Rectal Cancer: Systematic Review and Meta-Analysis

Preoperative chemoradiotherapy using tegafur/uracil, oral leucovorin, and irinotecan (TEGAFIRI) followed by oxaliplatin-based chemotherapy as total neoadjuvant therapy for locally advanced rectal cancer: the study protocol for a phase II trial

BACKGROUND

Total neoadjuvant therapy (TNT) is a novel treatment strategy that is an alternative to preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). However, an optimal protocol for TNT has not yet been established. The present study will be an open-label, single-arm, single-center trial to develop a new protocol.

METHODS

Thirty LARC patients at high risk of distant metastasis will receive CRT consisting of long-course radiation, concurrent with tegafur/uracil, oral leucovorin, irinotecan (TEGAFIRI), followed by mFOLFOX-6 or CAPOX before undergoing surgery.

DISCUSSION

Since previous findings showed a high percentage of grade 3-4 adverse events with the TEGAFIRI regimen for CRT and TNT, the primary outcome of this study will be safety and feasibility. Our regimen for CRT consists of the biweekly administration of irinotecan for good patient compliance. The novel combination approach of this treatment may improve the long-term outcomes of LARC.

TRIAL REGISTRATION

Japan Registry of Clinical Trials jRCTs031210660.

Chemoradiation and Local Excision Versus Total Mesorectal Excision for T2N0 Rectal Cancer: Comparison of Short- and Long-Term Outcomes From 2 Prospective Studies

OBJECTIVE

Compare oncological long-term and short-term outcomes between patients with distal cT2NO rectal cancer treated with chemoradio-therapy and local excision (CRT + LE) and patients treated with total mesorectal excision (TME).

SUMMARY BACKGROUND DATA

Previous studies showed that CRT + LE is equivalent to TME in local tumor control and survival for T2N0 rectal cancer.

METHODS

Seventy-nine patients with cT2N0 rectal adenocarcinoma treated with CRT + LE in the ACOSOG Z6041 trial were compared to a cohort of 79 patients with pT2N0 tumors treated with upfront TME in the Dutch TME trial. Survival, short-term outcomes, and health-related quality of life (HRQOL) were compared between groups.

RESULTS

Three patients (4%) in the CRT + LE group required abdominoperineal resection, compared with 31 (40%) in the TME group. Forty TME patients (51%) required a permanent stoma. CRT-related toxicity occurred in 43% of the CRT + LE patients; however, TME patients had a higher rate of complications requiring reoperation (1 vs 9%; P = 0 .03). Five-year disease-free survival {88.2% [confidence interval (CI), 77.7%-93.9%] vs 88.3% [CI, 78.7%-93.7%]; P = 0.88} and overall survival [90.3% (CI, 80.8%-95.3%) vs 88.4% (CI, 78.9%-93.8%); P = 0 .82] were similar in the 2 groups. Compared to baseline, overall HRQOL decreased in the CRT + LE group and improved in the TME group. In both groups, patients with sphincter preservation had worse HRQOL scores 1 year after surgery. Conclusions: In patients who underwent CRT + LE, oncological outcomes were similar to those of patients who underwent TME, with fewer complications requiring reoperation but significant CRT toxicity. Although overall HRQOL decreased in the CRT + LE group and improved in TME patients, when considering anorectal function, results were worse in both groups.

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.

Neoadjuvant concurrent chemoradiotherapy using infusional gemcitabine in locally advanced rectal cancer: A phase II trial

INTRODUCTION

Gemcitabine is a well-known radiosensitizer. Herein, we tested the efficacy and toxicity of preoperative concurrent infusional gemcitabine and radiotherapy in locally advanced rectal cancer.

PATIENTS AND METHODS

This was a phase II, single-arm trial. Eligible patients had a diagnosis of rectal adenocarcinoma with clinical stage T3-T4 and/or nodal involvement, age ≥18 years, and no prior chemotherapy or radiotherapy. Patients received preoperative radiation at a dose of 50.4-54 Gy over 28 days with concurrent infusional gemcitabine administered at a dose of 100 mg/m² over the course of 24 h weekly for 6 weeks. The primary endpoint was pathological complete response (pCR).

RESULTS

Forty patients were recruited. Only one patient did not complete therapy due to death. Eight patients did not undergo surgery, one died, two progressed to nonresectable disease, and five withdrew consent. Five patients progressed prior to surgery, with two having unresectable metastases and three having resectable liver metastases. One was found to have peritoneal metastasis during surgery. Out of the 32 patients who underwent surgery, seven achieved pCR at a rate of 20%. With a median follow-up of 30 months, four additional patients had a distant relapse (one had a subsequent local relapse). The 3-year event-free and overall survival rates were 70% and 85%, respectively. The commonest preoperative grade 3-4 toxicity included lymphopenia (50%), neutropenia (41%), anemia (15%), diarrhea (12%), abdominal pain (12%), and proctitis (8%).

CONCLUSION

Concurrent preoperative chemoradiotherapy using infusional gemcitabine for locally advanced rectal cancer achieved an encouraging degree of local control with manageable toxicity.

Is There a Benefit of Oxaliplatin in Combination with Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer? An Updated Meta-Analysis

BACKGROUND

Neoadjuvant fluoropyrimidine (5FU or capecitabine)-based chemoradiotherapy (CRT) has been considered the standard of care for locally advanced rectal cancer (LARC). Whether addition of oxaliplatin (OXP) will further improve clinical outcomes is still unclear.

METHODS

To identify clinical trials combining oxaliplatin in preoperative CRT or perioperative chemotherapy for LARC published until March 2021, we searched PubMed and the Cochrane Library. We also searched for relevant ASCO conference abstracts. The primary endpoint was disease-free survival (DFS). Data were extracted from every study to perform a meta-analysis using Review Manager (version 5.3).

RESULTS

A total of seven randomized clinical trials (ACCORD-12, CARO-AIO-04, FOWARC, JIAO, NSABP, PETACC-6, and STAR-01) with 5782 stage II or III rectal cancer patients were analyzed, including 2727 patients with OXP + 5FU regimen and 3055 patients with 5FU alone. Compared with the 5FU alone group, the OXP + 5FU regimen improved DFS (HR = 0.90, 95% CI: 0.81-0.99, p = 0.03) and pathologic complete response (pCR) (OR = 1.21, 95% CI: 1.07-1.37, p = 0.002). Patients treated with the OXP + 5FU regimen had significantly less metastatic progression (OR = 0.79; 95% CI, 0.67 to 0.94; p = 0.007). Considering adverse events (AEs), there was more grade 3-4 diarrhea with OXP + 5FU (OR = 2.41, 95% CI: 1.74-3.32, p < 0.00001). However, there were no significant differences grade 3-4 hematologic AEs (OR = 1.16, 95% CI: 0.87-1.57, p = 0.31).

CONCLUSIONS

Our meta-analysis with long-term results from the randomized studies showed a benefit of the addition of OXP + 5FU regiment in terms of DFS, metastatic progression, and pCR rate that did not translate to improved OS.

Current status of total neoadjuvant therapy for locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) plus total mesorectal excision (TME) has been the standard regimen for treatment of patients with locally advanced rectal cancer (LARC), because it significantly reduces the rate of local recurrence and enables sphincter preservation. However, distant metastasis remains the major reason for treatment failure, and the value of postoperative chemotherapy is still controversial. Recent studies have examined the use of total neoadjuvant therapy (TNT), defined as induction and/or consolidation chemotherapy (CONCT) with radiotherapy (RT) or nCRT prior to surgery. The results indicated that TNT may increase the rates of chemotherapy compliance and pathological complete response (pCR), and probably improve the success rate of sphincter preservation surgery. TNT may also improve disease-free survival and overall survival, and even reduce the rate of relapse. Here, we critically appraise the existing literature on three different TNT schemes used for LARC patients.

Rectal MRI after neoadjuvant chemoradiation therapy: a pictorial guide to interpretation

Magnetic resonance imaging (MRI) is the current reference standard imaging modality for restaging rectal cancer after neoadjuvant chemoradiation and is used to guide clinical management decisions. This pictorial essay provides an illustrative atlas of the key MRI features used to assess rectal cancer after treatment. MRI findings of residual tumor including non-mucinous, mucinous, and signet-ring cell adenocarcinoma subtypes are correlated with histopathology. Imaging appearances of treatment changes that mimic residual tumor in the setting of confirmed pathological complete response at resection are illustrated. Treatment complications are also shown. Knowledge of these imaging findings and their importance may help radiologists comply with all elements of the structured reporting templates proposed by the Rectal Cancer Disease Focused Panel of the Society of Abdominal Radiology and by the European Society of Gastrointestinal and Abdominal Radiology.

Complete pathological response in rectal cancer utilising novel treatment strategies for neo-adjuvant therapy: A systematic review

BACKGROUND

Locally advanced rectal cancer is routinely treated with neo-adjuvant long course chemoradiotherapy or short course radiotherapy, followed by total mesorectal excision. Not all patients respond to this treatment and there has been an emergence of novel treatment strategies designed to improve outcomes for these patients. This systematic review aims to assess the current novel neo-adjuvant treatment strategies being utilised in the treatment of patients with rectal cancer and how these impact pathological complete response (pCR) rates.

METHODS

A systematic review of the literature was performed to evaluate pathological response in patients with rectal cancer receiving novel neo-adjuvant therapy. EMBASE and Medline electronic databases were searched for relevant articles. Articles published between January 2008 and February 2019 were retrieved. Included studies underwent critical appraisal and complete pathological response rates were recorded.

RESULTS

Of the initial 1074 articles identified, 217 articles fulfilled the inclusion criteria, of these 60 articles (4359 patients) were included. Neo-adjuvant therapy delivered included novel long course chemoradiation therapy, neoadjuvant chemotherapy alone, addition of a biological agent, total neo-adjuvant therapy, novel short course radiation therapy and studies utilising biomarkers to select patients for therapy. Complete pathological response rates ranged from 0 to 60%.

CONCLUSION

A validated novel neo-adjuvant therapy that significantly increases pCR rates in patients with rectal cancer has not been identified.

Association of Treatment Adherence With Oncologic Outcomes for Patients With Rectal Cancer: A Post Hoc Analysis of the CAO/ARO/AIO-04 Phase 3 Randomized Clinical Trial

Importance

Despite numerous published phase 3 trials, the association of treatment adherence with outcomes for patients with rectal cancer remains largely unexplored.

Objective

To analyze the association of treatment adherence with disease-free survival (DFS) among patients with rectal cancer in the CAO/ARO/AIO-04 trial.

Design, Setting, and Participants

This post hoc analysis of a phase 3 randomized clinical trial was conducted from July 25, 2006, to February 26, 2010, among 1232 patients from 80 centers with T3 to T4 or node-positive rectal adenocarcinoma. Statistical analysis was performed from May 5, 2019, to February 2, 2020.

Interventions

A total of 625 patients received neoadjuvant fluorouracil-based chemoradiotherapy (nCRT), and a total of 607 patients received fluorouracil-based nCRT with addition of oxaliplatin. Of the 1126 patients who underwent curative surgery, 439 started fluorouracil-based adjuvant chemotherapy and 419 started fluorouracil-based adjuvant chemotherapy with oxaliplatin.

Main Outcomes and Measures

The association of adherence with nCRT and adjuvant chemotherapy with DFS was assessed in both groups in the as-treated population.

Results

Among the 625 patients (442 men; mean age, 63.0 years) who received fluorouracil nCRT and the 607 patients (430 men; mean age, 63.0 years) who received fluorouracil-based nCRT with addition of oxaliplatin, after a median follow-up of 50 months (interquartile range, 38-61 months), 3-year DFS in the as-treated population was 71.1% in the fluorouracil group and 75.8% in the fluorouracil-oxaliplatin group (hazard ratio [HR], 0.803; 95% CI, 0.651-0.990; P = .04). Overall, 419 patients in the fluorouracil nCRT group (67.0%) and 434 patients in the fluorouracil-oxaliplatin nCRT group (71.5%) received full doses of preoperative nCRT. Likewise, 253 of 439 patients in the fluorouracil group (57.6%) and 134 of 419 patients in the fluorouracil-oxaliplatin group (32.0%) received full doses of adjuvant chemotherapy. Adherence to nCRT was associated with 3-year DFS in both the fluorouracil group (complete vs near complete: HR, 1.325; 95% CI, 0.959-1.832; P = .09; complete vs reduced: HR, 1.877; 95% CI, 1.147-3.072; P = .01) and the fluorouracil-oxaliplatin group (complete vs near complete: HR, 1.501; 95% CI, 0.980-2.299; P = .06; complete vs reduced: HR, 1.724; 95% CI, 1.144-2.596; P = .009) in multivariable analyses. In contrast, adjuvant chemotherapy was not associated with DFS in both the fluorouracil group (complete vs near complete: HR, 0.900; 95% CI, 0.559-1.448; P = .66; complete vs incomplete: HR, 1.057; 95% CI, 0.807-1.386; P = .69) and the fluorouracil-oxaliplatin group (complete vs near complete: HR, 1.155; 95% CI, 0.716-1.866; P = .56; complete vs incomplete: HR, 1.073; 95% CI, 0.790-1,457; P = .65).

Conclusions and Relevance

To our knowledge, this is the first analysis of a phase 3 trial to assess the association of treatment adherence with some clinical outcomes for patients with rectal cancer. The findings emphasize the need for appropriate trial design with optimized nCRT dose and schedule and supportive strategies to facilitate good adherence and precision delivery, especially for intensified nCRT.

Trial Registration

ClinicalTrials.gov Identifier: NCT00349076.

Quality of life in rectal cancer patients with or without oxaliplatin in the randomised CAO/ARO/AIO-04 phase 3 trial

BACKGROUND

The CAO/ARO/AIO trial has shown that oxaliplatin added to preoperative chemoradiotherapy and postoperative chemotherapy significantly improved disease-free survival in locally advanced rectal cancer (LARC). Here, we present a post-hoc analysis of quality of life (QoL) in disease-free patients.

PATIENTS AND METHODS

Between 2006 and 2010, 1236 patients with LARC were randomly assigned either to preoperative chemoradiotherapy followed by total mesorectal excision and postoperative chemotherapy (N = 623) or combined with oxaliplatin (N = 613). QoL questionnaires (EORTC QLQ-C30, colorectal module CR38) were completed at baseline, after postoperative chemotherapy and during follow-up. Analysis was performed according intent-to-treat.

RESULTS

Available questionnaires (baseline) were 82% (N = 512) in the control and 84% (N = 513) in the investigational group. Response rates were 49% (533 of 1086) at 1 year and 43% (403 of 928) at 3 years. Global health status (GHS) for disease-free patients was stable in both groups (range 0-100). At baseline: standard arm 62.0 (mean, SD 21.6; N = 491) versus oxaliplatin arm 63.2 (mean, SD 22; N = 503); at 3 years: 69.4 (SD 19.3; N = 187) versus 65.4 (SD 22.2; N = 202). After treatment and at 3 years, no significant differences (≥10 points) between groups were found in QoL subscales. Disease-free patients experiencing neurotoxic side-effects (grade 1-4) showed reduced GHS at 3 years versus patients without neurotoxicity (mean 59.2 versus 69.3; P < 0.001), while grade 3-4 rate was low.

CONCLUSION

The addition of oxaliplatin was not associated with worse overall QoL. This information is of interest to patients in many ongoing rectal cancer trials.

TRIAL REGISTRATION INFORMATION

NCT00349076.

Neoadjuvant treatment (FOLFOX4 plus hypofractionated tomotherapy) for patients with locally advanced rectal cancer: a multicenter phase II trial

AIMS

This study aims to evaluate the safety and efficacy of a new neoadjuvant regimen (FOLFOX4 plus hypofractionated tomotherapy) in patients with locally advanced rectal cancer.

METHODS

Patients with stage II-III rectal cancer were treated with the pre-operative chemoradiotherapy regimen comprising FOLFOX4 (two cycles), TomoTherapy (25 Gy in five consecutive fractions, one fraction per day in 5 days on the clinical target volume at the isodose of 95% of the total dose), FOLFOX4 (two cycles), followed by surgery with total mesorectal excision and adjuvant chemotherapy with FOLFOX4 (eight cycles). The primary endpoint was pathological complete response (pCR).

RESULTS

Fifty-two patients were enrolled and 50 patients were evaluable. A total of 46 (92%) patients completed chemoradiotherapy according to the study protocol and 49 patients underwent surgery. Overall, 12 patients achieved a pCR (24.5%, 95% CI 12.5-36.5). The most common grade 3 or more adverse events were neutropenia and alteration of the alvus. Adverse reactions due to radiotherapy, mainly grade 1-2 dermatitis, tenesmus, urinary dysfunction and pain, were tolerable and fully reversible. The most important surgical complications included infection, anastomotic leakage and fistula, all resolved with conservative treatment.

CONCLUSION

FOLFOX and hypofractionated TomoTherapy is effective and safe in patients with locally advanced rectal cancer. Long-term efficacy needs to be further evaluated.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02000050 (registration date: 26 November 2013) https://clinicaltrials.gov/ct2/show/NCT02000050.

Neoadjuvant chemotherapy with or without oxaliplatin after short-course radiotherapy in high-risk rectal cancer: A subgroup analysis from a prospective study

Aim

To evaluate the role of oxaliplatin in neoadjuvant chemotherapy delivered after short-course irradiation.

Background

Using oxaliplatin in the above setting is uncertain.

Patients and methods

A subgroup of 136 patients managed by short-course radiotherapy and 3 cycles of consolidation chemotherapy within the framework of a randomised study was included in this post-hoc analysis. Sixty-seven patients received FOLFOX4 (oxaliplatin group) while oxaliplatin was omitted in the second period of accrual in 69 patients because of protocol amendment (fluorouracil-only group).

Results

Grade 3+ acute toxicity from neoadjuvant treatment was observed in 30% of patients in the oxaliplatin group vs. 16% in the fluorouracil-only group (p = 0.053). The corresponding proportions of patients having radical surgery or achieving complete pathological response were 72% vs. 77% (odds ratio [OR] = 0.88; 95% confidence interval [CI]: 0.39-1.98; p = 0.75) and 15% vs. 7% (OR = 2.25; 95% CI: 0.83-6.94; p = 0.16), respectively. The long-term outcomes were similar in the two groups. Overall and disease-free survival rates at 5 years were 63% vs. 56% (p = 0.78) and 49% vs. 44% (p = 0.59), respectively. The corresponding numbers for cumulative incidence of local failure or distant metastases were 33% vs. 38% (hazard ratio [HR] = 0.89; 95% CI: 0.52-1.52; p = 0.68) and 33% vs. 33% (HR = 0.78; 95% CI: 0.43-1.40; p = 0.41), respectively.

Conclusion

Our findings do not support adding oxaliplatin to three cycles of chemotherapy delivered after short-course irradiation.

A Comprehensive Review of Randomized Clinical Trials Shaping the Landscape of Rectal Cancer Therapy

Colorectal carcinoma is the second leading cause of cancer-related deaths in the United States, with rectal cancer accounting for approximately one third of newly diagnosed cases. Surgery remains the cornerstone of curative therapy, with total mesorectal excision being the standard of care. Although minimally invasive procedures might be appropriate for a subset of patients with early-stage, superficial tumors, the standard of care for medically operable patients with nonmetastatic rectal cancer includes a comprehensive multimodality approach of neoadjuvant chemoradiotherapy, surgery with total mesorectal excision, and systemic chemotherapy. However, the morbidity and mortality related to both local and distant organ relapse have remained challenging. In the present review, we have discussed the trial-level evidence that has shaped the current clinical practice patterns in the treatment of curable, nonmetastatic rectal cancer. In addition, we have discussed the anticipated results of ongoing clinical trials and outlined pragmatic opportunities for future investigation to optimize the current status quo and, hopefully, provide prospective validation of novel approaches in the treatment of rectal cancer.

Outcome measures in multimodal rectal cancer trials

There is a large variability regarding the definition and choice of primary endpoints in phase 2 and phase 3 multimodal rectal cancer trials, resulting in inconsistency and difficulty of data interpretation. Also, surrogate properties of early and intermediate endpoints have not been systematically assessed. We provide a comprehensive review of clinical and surrogate endpoints used in trials for non-metastatic rectal cancer. The applicability, advantages, and disadvantages of these endpoints are summarised, with recommendations on clinical endpoints for the different phase trials, including limited surgery or non-operative management for organ preservation. We discuss how early and intermediate endpoints, including patient-reported outcomes and involvement of patients in decision making, can be used to guide trial design and facilitate consistency in reporting trial results in rectal cancer.

Pathological Complete Response Following Different Neoadjuvant Treatment Strategies for Locally Advanced Rectal Cancer: A Systematic Review and Meta-analysis

Background

Pathological complete response (pCR) following neoadjuvant treatment for locally advanced rectal cancer (LARC) is associated with better survival, less local recurrence, and less distant failure. Furthermore, pCR indicates that the rectum may have been preserved. This meta-analysis gives an overview of available neoadjuvant treatment strategies for LARC and analyzes how these perform in achieving pCR as compared with the standard of care.

Methods

Pubmed, Embase, and Cochrane Central bibliographic databases were searched. Randomized controlled trials in which patients received neoadjuvant treatment for MRI-staged nonmetastatic resectable LARC were included. The primary outcome was pCR, defined as ypT0N0. A meta-analysis of studies comparing an intervention with standard fluoropyrimidine-based chemoradiation (CRT) was performed.

Results

Of the 17 articles included in the systematic review, 11 were used for the meta-analysis. Addition of oxaliplatin to fluoropyrimidine-based CRT resulted in significantly more pCR compared with fluoropyrimidine-based CRT only (OR 1.46), but at the expense of more ≥ grade 3 toxicity. Other treatment strategies, including consolidation/induction chemotherapy and short-course radiotherapy (SCRT), did not improve pCR rates. None of the included trials reported a benefit in local control or OS. Five-year DFS was significantly worse after SCRT-delay compared with CRT (59% vs. 75.1%, HR 1.93).

Conclusions

All included trials fail to deliver high-level evidence to show an improvement in pCR compared with standard fluoropyrimidine-based CRT. The addition of oxaliplatin might result in more pCR but at the expense of more toxicity. Furthermore, this benefit does not translate into less local recurrence or improved survival.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08615-2) contains supplementary material, which is available to authorized users.