Locally advanced rectal cancer: Preliminary results of rectal preservation after neoadjuvant chemoradiotherapy

Neoadjuvant immunotherapy for colorectal cancer: Right regimens, right patients, right directions?

Neoadjuvant chemoradiotherapy (NACRT) or chemotherapy (NACT) followed by radical resection and then adjuvant therapy is considered the optimal treatment model for locally advanced colorectal cancer (LACRC). A recent total neoadjuvant therapy (TNT) strategy further improved the tumour regression rate preoperatively and reduced local-regional recurrence in locally advanced rectal cancer (LARC). However, distant metastasis was still high, and little overall survival benefit was obtained from these preoperative treatment models. According to mismatch repair protein expression, MSI-H/dMMR and non-MSI-H/pMMR statuses were defined in colorectal cancer (CRC) patients. Due to the special features of biologics in MSI-H/dMMR CRC patients, this subgroup of patients achieved little treatment efficacy from chemoradiotherapy but benefited from immune checkpoint inhibitors (ICIs). The KEYNOTE-177 trial observed favourable survival outcomes in metastatic CRC patients treated with one-line pembrolizumab with tolerable toxicity. Given the better systemic immune function, increased antigenic exposure, and improved long-term memory induction before surgery, neoadjuvant ICI (NAICI) treatment was proposed. The NICHE trial pioneered the use of NAICI treatment in LACRC, and recent reports from several phase II studies demonstrated satisfactory tumour downsizing in CRC. Preclinical rationales and preliminary early-phase human trials reveal the feasibility of NAICI therapy and the therapeutic efficacy provided by this treatment model. Better tumour regression before surgery also increases the possibility of organ preservation for low LARC. However, the optimal treatment strategy and effective biomarker identification for beneficiary selection remain unknown, and potential pitfalls exist, including tumour progression during neoadjuvant treatment due to drug resistance and surgery delay. Given these foundations and questions, further phase II or III trials with large samples need to be conducted to explore the right regimens for the right patients.

Outcomes after the watch-and-wait strategy and local excision treatment for rectal cancer: a meta-analysis

BACKGROUND

The watch-and-wait (W&W) strategy and local excision (LE) have been used in patients with clinical complete response (cCR) for rectal cancer, but the comparative outcomes of the two strategies are controversial. We compared the efficacy of the W&W strategy with LE for rectal cancer patients after neoadjuvant chemoradiotherapy (nCRT) or total neoadjuvant therapy (TNT).

RESEARCH DESIGN AND METHODS

Several domestic and foreign databases were searched for the relevant literature on comparative trials of the W&W strategy and LE surgery for rectal cancer after neoadjuvant therapy with the following outcomes; differences in local recurrence (LR), distant metastasis (DM/DM+LR), 3-year disease-free survival (DFS), 3-year local recurrence-free survival (LRFS) and 3-year overall survival (OS).

RESULTS

Nine articles, were analyzed. Overall, 442 patients were included, with 267 and 175 patients in the W&W and LE groups, respectively. Meta-analysis results showed no significant differences the between W&W and LE groups with respect to LR, DM/DM+LR, 3-year DFS, 3-year LRFS, and 3-year OS. This study has been registered in PROSPERO (registration number: CRD42022331208).

CONCLUSION

The W&W strategy may be preferred for some rectal cancer patients who select LE and reach cCR or near cCR after nCRT or TNT.

Development of a Patient Decision Aid for Rectal Cancer Patients with Clinical Complete Response after Neo-Adjuvant Treatment

Surgery is the primary component of curative treatment for patients with rectal cancer. However, patients with a clinical complete response (cCR) after neo-adjuvant treatment may avoid the morbidity and mortality of radical surgery. An organ-sparing strategy could be an oncological equivalent alternative. Therefore, shared decision making between the patient and the healthcare professional (HCP) should take place. This can be facilitated by a patient decision aid (PtDA). In this study, we developed a PtDA based on a literature review and the key elements of the Ottawa Decision Support Framework. Additionally, a qualitative study was performed to review and evaluate the PtDA by both HCPs and former rectal cancer patients by a Delphi procedure and semi-structured interviews, respectively. A strong consensus was reached after the first round (I-CVI 0.85-1). Eleven patients were interviewed and most of them indicated that using a PtDA in clinical practice would be of added value in the decision making. Patients indicated that their decisional needs are centered on the impact of side effects on their quality of life and the outcome of the different options. The PtDA was modified taking into account the remarks of patients and HCPs and a second Delphi round was held. The second round again showed a strong consensus (I-CVI 0.87-1).

Rectal Sparing Approaches after Neoadjuvant Treatment for Rectal Cancer: A Systematic Review and Meta-Analysis Comparing Local Excision and Watch and Wait

Local Excision (LE) or Watch and Wait (WW) for patients with complete clinical response or near-complete clinical response after neoadjuvant chemoradiotherapy (nCRT) were proposed to avoid morbidity and impairment of quality of life after rectal resection. The aim of this study is to perform a systematic review of the literature, and to compare rectal-sparing approaches, in terms of rectum-preservation rate, local control, and distant recurrences. A systematic review and meta-analysis were performed of studies published until July 2022 (PROSPERO, registration CRD42022341480), and the quality of evidence was assessed using a GRADE approach. Seven retrospective studies and one prospective trial were included. In six studies, patients were treated with standard long-course nCRT, and in two with Total Neoadjuvant Therapy (TNT). Overall, there were 213 and 188 patients in WW and LE group, respectively, and no difference was found between WW and LE when considering rectum-preservation rate (OR 0.80 95%CI 0.31-2.01, p = 0.63), local disease (OR 1.60 95%CI 0.75-3.42, p = 0.22), locoregional failure (OR 0.85 95%CI 0.20-3.66, p = 0.83) and distant recurrence (OR 0.76 95%CI 0.37-1.55, p = 0.45). Studies directly comparing WW and LE are still lacking, even though no differences between WW and LE in terms of rectum-preservation, local control, and distant recurrences have been found.

A meta-analysis of the watch-and-wait strategy versus total mesorectal excision for rectal cancer exhibiting complete clinical response after neoadjuvant chemoradiotherapy

Background

Some clinical researchers have reported that patients with cCR (clinical complete response) status after neoadjuvant chemoradiotherapy (nCRT) could adopt the watch-and-wait (W&W) strategy. Compared with total mesorectal excision (TME) surgery, the W&W strategy could achieve a similar overall survival. Could the W&W strategy replace TME surgery as the main treatment option for the cCR patients? By using the meta-analysis method, we evaluated the safety and efficacy of the W&W strategy and TME surgery for rectal cancer exhibiting cCR after nCRT.

Methods

We evaluated two treatment strategies for rectal cancer with cCR after nCRT up to July 2021 by searching the Cochrane Library, PubMed, Wanfang, and China National Knowledge Infrastructure (CNKI) databases. Clinical data for primary outcomes (local recurrence, cancer-related death and distant metastasis), and secondary outcomes (disease-free survival (DFS) and overall survival (OS)) were collected to evaluate the efficacy and safety in the two groups.

Results

We included nine studies with 818 patients in the meta-analysis, and there were five moderate-quality studies and four high-quality studies. A total of 339 patients were in the W&W group and 479 patients were in the TME group. The local recurrence rate in the W&W group was greater than that in the TME group in the fixed-effects model (OR 8.54, 95% CI 3.52 to 20.71, P < 0.001). The results of other outcomes were similar in the two groups.

Conclusion

The local recurrence rate of the W&W group was greater than that in the TME group, but other results were similar in the two groups. With the help of physical examination and salvage therapy, the W&W strategy could achieve similar treatment effects with the TME approach.

Trial registration

Protocol registration number: CRD42021244032.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02415-y.

The efficacy and safety of different radiotherapy doses in neoadjuvant chemoradiotherapy for locally advanced rectal cancer

Background

This study aimed to evaluate efficacy and adverse effects of different radiotherapy (RT) doses in neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

Methods

Fifty-nine patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy in hospital between January 2015 and May 2017 were enrolled in retrospective analysis. The patients were divided into the 56-Gy group and the 50-Gy group. The concurrent chemotherapy regimen was based on capecitabine. All patients received one cycle of oxaliplatin combined with capecitabine induction chemotherapy. All patients completed neoadjuvant chemoradiotherapy and received radical surgery.

Results

Of the patients in this study, 29 patients and 30 patients received a radiation dose of 56- and 50-Gy, respectively. All clinical characteristics were matched between the two groups. All patients received surgery 6 to 8 weeks after completing RT. The therapeutical effective rate in the 56-Gy group was 93.10% (27/29), compared with 66.67% in the 50-Gy group (20/30); the difference between the two groups was statistically significant (χ²=6.36, P=0.01). The pathological complete remission (pCR) rate in the 56-Gy group (37.93%, 11/29) was statistically significantly higher than that in the 50-Gy group (13.33%, 4/30) (χ²=4.71, P=0.030). The anal preservation rate in the 56-Gy group (65.5%, 19/29) was statistically significantly higher than that in the 50-Gy group (33.33%, 10/30) (χ²=6.11, P=0.01). The 56-Gy group had a local recurrence rate of 0% (0/29) and a distant metastasis rate of 10.34% (3/29), while the 50-Gy group had a local recurrence rate of 6.67% (2/30) and a distant metastasis rate of 16.67% (5/30); no significant difference existed between the two groups (χ²=2.00, 0.50, P=0.16, 0.48). The incidence of adverse reactions (gastrointestinal reactions, bone marrow suppression, and perianal skin reactions) in the 56-Gy group was not significantly different from that in the 50-Gy group (P>0.05).

Conclusions

Increasing the radiation dose can significantly improve the anal preservation and pCR rates of patients with locally advanced rectal cancer, thus improving their life quality. Moreover, it does not increase the rates of recurrence or adverse reactions. Our findings have certain clinical significance, but further prospective study is needed.

Analysis of long-term oncological results of clinical versus pathological responses after neoadjuvant treatment in locally advanced rectal cancer

Background

Nonoperative management after neoadjuvant treatment in low rectal cancer enables organ preservation and avoids surgical morbidity. Our aim is to compare oncological outcomes in patients with clinical complete response in watch and wait strategy with those who received neoadjuvant therapy followed by surgery with a pathological complete response.

Methods

Patients with non-metastatic rectal cancer after neoadjuvant treatment with clinical complete response in watch and wait approach (group 1, n = 26) and complete pathological responders (ypT0N0) after chemoradiotherapy and surgery (group 2, n = 22), between January 2011 and October 2018, were included retrospectively, and all of them evaluated and followed in a multidisciplinary team. A comparative analysis of local and distant recurrence rates and disease-free and overall survival between both groups was carried out. Statistical analysis was performed using log-rank test, Cox proportional hazards regression model, and Kaplan-Meier curves.

Results

No differences were found between patient’s demographic characteristics in both groups. Group 1: distance from the anal verge mean 5 cm (r = 1–12), 10 (38%) stage III, and 7 (27%) circumferential resection margin involved. The median follow-up of 47 months (r = 6, a 108). Group 2: distance from the anal verge mean 7 cm (r = 2–12), 16 (72%) stage III, and 13 (59%) circumferential resection margin involved. The median follow-up 49.5 months (r = 3, a 112). Local recurrence: 2 patients in group 1 (8.3%) and 1 in group 2 (4.8%) (p = 0.6235). Distant recurrence: 1 patient in group 1 (3.8%) and 3 in group 2 (19.2%) (p = 0.2237). Disease-free survival: 87.9% in group 1, 80% in group 2 (p = 0.7546). Overall survival: 86% in group 1 and 85% in group 2 (p = 0.5367).

Conclusion

Oncological results in operated patients with pathological complete response were similar to those in patients under a watch and wait strategy mediating a systematic and personalized evaluation. Surgery can safely be deferred in clinical complete responders.

Watch and wait approach in rectal cancer: Current controversies and future directions

According to the main international clinical guidelines, the recommended treatment for locally-advanced rectal cancer is neoadjuvant chemoradiotherapy followed by surgery. However, doubts have been raised about the appropriate definition of clinical complete response (cCR) after neoadjuvant therapy and the role of surgery in patients who achieve a cCR. Surgical resection is associated with significant morbidity and decreased quality of life (QoL), which is especially relevant given the favourable prognosis in this patient subset. Accordingly, there has been a growing interest in alternative approaches with less morbidity, including the organ-preserving watch and wait strategy, in which surgery is omitted in patients who have achieved a cCR. These patients are managed with a specific follow-up protocol to ensure adequate cancer control, including the early identification of recurrent disease. However, there are several open questions about this strategy, including patient selection, the clinical and radiological criteria to accurately determine cCR, the duration of neoadjuvant treatment, the role of dose intensification (chemotherapy and/or radiotherapy), optimal follow-up protocols, and the future perspectives of this approach. In the present review, we summarize the available evidence on the watch and wait strategy in this clinical scenario, including ongoing clinical trials, QoL in these patients, and the controversies surrounding this treatment approach.

Controversies in Rectal Cancer Treatment and Management

Incorporation of new treatment modalities has significantly increased the complexity of the treatment and management of rectal cancer, including perioperative therapy for local advanced disease and organ preservation for those with response to the preoperative treatment. This review may help practitioners better understand the rationale and selection.

Organ-saving surgery for rectal cancer after neoadjuvant chemoradiation: Analysis of failures and long-term results

BACKGROUND

To analyze long-term results and risk of relapse in the clinical TNM stages II and III, mid-low rectal cancer patients (RC pts), treated with transanal local excision (LE) after major response to neoadjuvant chemoradiation (n-CRT).

METHODS

Thirty-two out of 345 extraperitoneal cT3-4 or N+ RC pts (9.3%) underwent LE.

INCLUSION CRITERIA

extraperitoneal RC, adenocarcinoma, ECOG Performance Status ≤2. Pts with distant metastases were excluded.

RESULTS

All pts showed histologically clear margins of resection and 81.2% were restaged ypT0/mic/1. Nine out of 32 (28.1%) pts relapsed: 7 (21.8%) showed a local recurrence, of which 5 (15.6%) at the endorectal suture, 1 (3.1%) pelvic and 1 (3.1%) mesorectal. Two pts (6.2%) relapsed distantly. Among the pT0/1, 11.5% relapsed vs 100% of the pT2 and pT4 ones. The six pts relapsing locally or in the mesorectal fat underwent a salvage total mesorectal excision surgery. The old patient with pelvic recurrence relapsed after 108 months and underwent a re-irradiation; the two pts with distant metastases were treated with chemotherapy followed by radical surgery.

CONCLUSIONS

Presently combined approach seems a valid option in major responders, confirming its potential curative impact in the ypT0/mic/1 pts. A strict selection of pts is basic to obtain favourable results.

Oncological and Survival Outcomes in Watch and Wait Patients With a Clinical Complete Response After Neoadjuvant Chemoradiotherapy for Rectal Cancer: A Systematic Review and Pooled Analysis

OBJECTIVE

The aim of this study was to evaluate the oncological and survival outcomes of a Watch and Wait policy in rectal cancer after a clinical complete response (cCR) following neoadjuvant chemoradiotherapy.

BACKGROUND

The detection of a cCR after neoadjuvant treatment may facilitate a nonoperative approach in selected patients. However, the long-term safety of this strategy remains to be validated.

METHOD

This is a systematic review of the literature to determine the oncological outcomes in Watch and Wait patients. The primary outcome was the cumulative rate of local regrowth, success of salvage surgery, and incidence of metastases. We also evaluated survival outcomes. A pooled analysis of manually extracted summary statistics from individual studies was carried out using inverse variance weighting.

RESULTS

Seventeen studies comprising 692 patients were identified; incidence of cCR was 22.4% [95% confidence interval (CI),14.3-31.8]. There were 153 (22.1%) local regrowths, of which 96% (n = 147/153) manifested in the first 3 years of surveillance. The 3-year cumulative risk of local regrowth was 21.6% (95% CI, 16.0-27.8). Salvage surgery was performed in 88% of patients, of which 121 (93%) had a complete (R0) resection. Fifty-seven metastases (8.2%) were detected, and 35 (60%) were isolated without evidence of synchronous regrowths; 3-year incidence was 6.8% (95% CI, 4.1-10.2). The 3-year overall survival was 93.5% (95% CI, 90.2-96.2).

CONCLUSION

In rectal cancer patients with a cCR following neoadjuvant chemoradiotherapy, a Watch and Wait policy appears feasible and safe. Robust surveillance with early detection of regrowths allows a high rate of successful salvage surgery, without an increase in the risk of systemic disease, or adverse survival outcomes.

Organ Preservation Strategies After Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

Standard use of neoadjuvant chemoradiotherapy, total mesorectal excision, and postoperative adjuvant chemotherapy in locally advanced rectal cancer has tremendously improved oncologic outcomes over the past several decades. However, these improvements come with costs of significant morbidity and poor quality of life. Along with developments in imaging techniques, clinical experience and evidence have identified a certain subgroup of patients that have exceptionally good clinical outcomes while preserving quality of life. Driven by patient demand and interest in preserving quality of life, numerous organ preservation treatment strategies for managing rectal cancer are rapidly evolving. Herein, the flow of research in organ preservation strategies and counter arguments are discussed.

Non-operative treatment outcome for rectal cancer patient with clinical complete response after neoadjuvant chemoradiotherapy

BACKGROUND

Among rectal cancer patients, some of good responders after neoadjuvant chemoradiotherapy (nCRT) are considered for non-operative treatments to avoid postoperative morbidities and permanent stoma. However, oncologic feasibility of non-operative treatment has not been fully understood.

METHODS

From 2008 to 2017, we retrospectively reviewed patient's records who had lower or mid rectal cancer and diagnosed to clinical complete response by magnetic resonance imaging after nCRT. Clinical differences and oncologic outcomes were compared among Radical surgery (RS), Local excision (LE) and Wait-and-see (WS) group.

RESULTS

Number of 129, 25, 15 patients included to RS, LE, WS groups. Local recurrence was frequent type of recurrence in both of LE and WS group (RS; 31.3%, LE; 80%, WS; 66.7%), and many patients in WS group omitted salvage treatment (RS; 75%, LE; 100%, WS; 33.3%). 5-years local-recurrence/disease-free survival rate (LRFS, DFS) between RS and LE were similar between each group, but WS showed significantly inferior outcomes than that of RS (LRFS; p = 0.001, DFS; p = 0.001). In multivariate analysis, WS protocol (OR; 7.163, 95% CI; 1.995-25.715) and cT4 stage (OR; 8.206, 95% CI; 1.596-42.198) were independent factors for LRFS.

CONCLUSIONS

Wait-and-see group showed high rate of rejection of salvage treatments for recurrence, and poor oncologic outcomes. However, recent low-level evidences reported favorable outcome of WS protocol when salvage treatment was followed after recurrence. It seems that the application of WS protocol should be postponed until the results of randomized-controlled trials are available. Local excision seems to be good alternative option to radical surgery when salvage treatment is followed.

Factors affecting local regrowth after watch and wait for patients with a clinical complete response following chemoradiotherapy in rectal cancer (InterCoRe consortium): an individual participant data meta-analysis

BACKGROUND

In patients with rectal cancer who achieve clinical complete response after neoadjuvant chemoradiotherapy, watch and wait is a novel management strategy with potential to avoid major surgery. Study-level meta-analyses have reported wide variation in the proportion of patients with local regrowth. We did an individual participant data meta-analysis to investigate factors affecting occurrence of local regrowth.

METHODS

We updated search results of a recent systematic review by searching MEDLINE and Embase from Jan 1, 2016, to May 5, 2017, and used expert knowledge to identify published studies reporting on local regrowth in patients with rectal cancer managed by watch and wait after clinical complete response to neoadjuvant chemoradiotherapy. We restricted studies to those that defined clinical complete response using criteria equivalent to São Paulo benchmarks (ie, absence of residual ulceration, stenosis, or mass within the rectum on clinical and endoscopic examination). The primary outcome was 2-year cumulative incidence of local regrowth, estimated with a two-stage random-effects individual participant data meta-analysis. We assessed the effects of clinical and treatment factors using Cox frailty models, expressed as hazard ratios (HRs). From these models, we derived percentage differences in mean θ as an approximation of the effect of measured covariates on between-centre heterogeneity. This study is registered with PROSPERO, number CRD42017070934.

FINDINGS

We obtained individual participant data from 11 studies, including 602 patients enrolled between March 11, 1990, and Feb 13, 2017, with a median follow-up of 37·6 months (IQR 25·0-58·7). Ten of the 11 datasets were judged to be at low risk of bias. 2-year cumulative incidence of local regrowth was 21·4% (random-effects 95% CI 15·3-27·6), with high levels of between-study heterogeneity (I²=61%). We noted wide between-centre variation in patient, tumour, and treatment characteristics. We found some evidence that increasing cT stage was associated with increased risk of local regrowth (random-effects HR per cT stage 1·40, 95% CI 1·00-1·94; p_trend=0·048). In a subgroup of 459 patients managed after 2008 (when pretreatment staging by MRI became standard), 2-year cumulative incidence of local regrowth was 19% (95% CI 13-28) for stage cT1 and cT2 tumours, 31% (26-37) for cT3, and 37% (21-60) for cT4 (random-effects HR per cT stage 1·50, random-effects 95% CI 1·03-2·17; p_trend=0·0330). We estimated that measured factors contributed 4·8-45·3% of observed between-centre heterogeneity.

INTERPRETATION

In patients with rectal cancer and clinical complete response after chemoradiotherapy managed by watch and wait, we found some evidence that increasing cT stage predicts for local regrowth. These data will inform clinician-patient decision making in this setting. Research is needed to determine other predictors of a sustained clinical complete response.

FUNDING

None.

'Watch and wait' in rectal cancer: summary of the current evidence

BACKGROUND

The management of rectal cancer has evolved considerably over the last few decades with increasing use of neoadjuvant chemoradiotherapy (nCRT). Complete clinical response (cCR) and even complete pathological response (pCR) have been noted in a proportion of patients who had surgery after nCRT. This raises the concern that we may have been 'over-treating' some of these patients and lead to an increasing interest in 'watch and wait' (W&W) approach for patients who had cCR to avoid the morbidity associated with rectal surgery.

METHODS

A review of the literature in English pertaining to rectal cancer in the context of W&W, organ preservation and active surveillance.

RESULTS

Evidence available to support W&W approach comes from non-randomised controlled trials (RCTs) with no current consensus on patients' selection criteria, lack of viable predictors of both cCR and pCR and lack of universal definitions of cCR and pCR. Also, there is no agreed protocol for disease surveillance.

CONCLUSION

Even though there has been increasing reports on the outcomes of W&W in rectal cancer, the current evidence cannot support its routine use in clinical practice. This approach should be used in clinical trials settings or after thorough counselling with the patient on the outcomes of various treatment options.

Watch-and-Wait as a Therapeutic Strategy in Rectal Cancer. Curr Colorectal Cancer Rep. 2018;14:37-55. [PMID: 29576755 PMCID: PMC5857277 DOI: 10.1007/s11888-018-0398-5]

Purpose of Review

Pathological complete response is seen in approximately one fifth of rectal cancer patients following neoadjuvant chemoradiation. Since these patients have excellent oncological outcomes, there has been a rapidly growing interest in organ preservation for those who develop a clinical complete response. We review the watch-and-wait strategy and focus on all aspects of this hot topic, including who should be considered for this approach, how should we identify treatment response and what are the expected outcomes.

Recent Findings

The major challenges in interpreting the data on watch-and-wait are the significant heterogeneity of patients selected for this approach and of methods employed to identify them. The evidence available comes mostly from retrospective cohort studies, but has shown good oncological outcomes, including the rate of successful salvage surgery, locoregional control and overall survival.

Summary

There is currently not enough and not robust enough evidence to support watch-and-wait as a standard approach, outside a clinical trial, for patients achieving clinical complete response following neoadjuvant chemoradiation. Furthermore, there is a lack of data on long-term outcomes. However, the results we have so far are promising, and there is therefore an urgent need for randomised control studies such as the TRIGGER trial to confirm the safety of this strategy.

Management of the Complete Clinical Response

Organ preservation is considered in the management of selected patients with rectal cancer. Complete clinical response observed after neoadjuvant chemoradiation for rectal cancer is one of these cases. Patients who present complete clinical response are candidates to the watch-and-wait approach, when radical surgery is not immediately performed and is offered only to patients in the event of a local relapse. These patients are included in a strict follow-up, and up of 70% of them will never be operated during the follow-up. This strategy is associated with similar oncological outcomes as patients operated on, and the advantage of avoiding the morbidity associated to the radical operation. In this article we will discuss in detail the best candidates for this approach, the protocol itself, and the long-term outcomes.

New Strategies in Rectal Cancer

In recent years, our understanding of rectal cancer has improved, including how locally advanced disease responds to chemotherapy and radiation. This has led to new innovations and advances in the treatment of rectal cancer, which includes organ-preserving strategies for responsive disease, and minimally invasive approaces for the performance of total mesorectal excision/protectomyh for persistently advanced disease. This article discusses new strategies for rectal cancer therapy, including Watch and Wait, local excision, minimally invasive proctectomy, and transanal total mesorectal excision particularly in the setting of preoperative multimodality treatment.

A watch-and-wait approach for locally advanced rectal cancer after a clinical complete response following neoadjuvant chemoradiation: a systematic review and meta-analysis

BACKGROUND

A watch-and-wait approach for patients with clinical complete response to neoadjuvant chemoradiation could avoid the morbidity of conventional surgery for rectal cancer. However, the safety of this approach is unclear. We synthesised the evidence for watch-and-wait as a treatment for rectal cancer.

METHODS

We systematically searched MEDLINE, Embase, and the grey literature (up to June 28, 2016) for studies of patients with rectal adenocarcinoma managed by watch-and-wait after complete clinical response to neoadjuvant chemoradiation. We determined the proportion of 2-year local regrowth after watch-and-wait. We assessed non-regrowth recurrence, cancer-specific mortality, disease-free survival, and overall survival from studies comparing patients who had watch-and-wait versus those who had radical surgery after detection of clinical complete response or versus patients with pathological complete response.

FINDINGS

We identified 23 studies including 867 patients with median follow-up of 12-68 months. Pooled 2-year local regrowth was 15·7% (95% CI 11·8-20·1); 95·4% (95% CI 89·6-99·3) of patients with regrowth had salvage therapies. There was no significant difference between patients managed with watch-and-wait after a clinical complete response and patients with pathological complete response identified at resection with respect to non-regrowth recurrence (risk ratio [RR] 1·46, 95% CI 0·70-3·05) or cancer-specific mortality (RR 0·87, 95% CI 0·38-1·99). Although there was no significant difference in overall survival between groups (hazard ratio [HR] 0·73, 95% CI 0·35-1·51), disease-free survival was better in the surgery group (HR 0·47, 95% CI 0·28-0·78). We found no significant difference between patients managed with watch-and-wait and patients with clinical complete response treated with surgery in terms of non-regrowth recurrence (RR 0·58, 95% CI 0·18-1·90), cancer-specific mortality (RR 0·58, 95% CI 0·06-5·84), disease-free survival (HR 0·56, 95% CI 0·20-1·60), or overall survival (HR 3·91, 95% CI 0·57-26·72).

INTERPRETATION

Most patients treated by watch-and-wait avoid radical surgery and of those who have regrowth almost all have salvage therapy. Although we detected no significant differences in non-regrowth cancer recurrence or overall survival in patients treated with watch-and-wait versus surgery, few patients have been studied and more prospective studies are needed to confirm long-term safety.

FUNDING

None.

Nonoperative Management or 'Watch and Wait' for Rectal Cancer with Complete Clinical Response After Neoadjuvant Chemoradiotherapy: A Critical Appraisal

BACKGROUND

There is increasing interest in nonoperative management (NOM) for rectal cancer with complete clinical response (cCR) after neoadjuvant chemoradiation (nCRT).

OBJECTIVE

The aim of this systematic review was to summarize the available data on NOM, with the intention of formulating standardized protocols on which to base future investigations.

METHODS

A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted. A highly sensitive literature search identified all relevant studies published between January 2004 and December 2016. Data extraction and quality assessment was performed independently by two authors, and resolved by consensus with a third reviewer.

RESULTS

In total, 15 studies, including 920 patients, met the inclusion criteria; 575 (62.5%) of these patients underwent NOM after cCR, with the remaining patients forming a surgical control group. The weighted mean follow-up was 39.4 (12.7) months in the NOM group and 39.8 (5.1) months in the surgery group. The pooled regrowth rate in the NOM group was 21.3% at a mean of 15.6 (7.0) months. Surgical salvage was possible and was undertaken in 93.2% of these patients. Overall survival in the NOM group was 91.7%, while disease-free survival was 82.7%. For the comparison proctectomy group, pooled rates of local recurrence, overall survival, and disease-free survival were 8.4, 92.4, and 87.5%, respectively.

CONCLUSION

NOM may be a feasible option for surgically eligible rectal cancer patients with cCR after nCRT. Before such a strategy can be widely implemented, further prospective data are required with standardized definitions, diagnostic criteria, and management protocols, with an emphasis on shared patient-provider decision making and patient-centered outcomes.