Prognostic factors and patterns of failure after surgery for T4 rectal cancer in the beyond total mesorectal excision era

Excluding external iliac node irradiation during neoadjuvant radiotherapy decreases lower intestinal toxicity without compromising efficacy in T4b rectal cancer patients with tumours involving the anterior structures

PURPOSE

To explore the impact of excluding the external iliac node (EIN) from the clinical target volume (CTV) during preoperative radiotherapy in T4b rectal cancer with anterior structure invasion.

METHODS

We retrospectively identified 132 patients with T4b rectal cancer involving the anterior structures who received radiotherapy followed by surgery between May 2010 and June 2019. Twenty-nine patients received EIN irradiation (EIN group), and 103 did not (NEIN group). Failure patterns, survival and toxicities were compared between the two groups.

RESULTS

The most common failure was distant metastasis (23.5%). 11 (8.3%) patients developed locoregional recurrence, 10 (9.7%) patients were in the NEIN group, and 1 (3.4%) was in the EIN group (P = 0.34). The EIN region failure was rare (1/132, 0.8%). The locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), overall survival (OS) and progression-free survival (PFS) rates were 96.3% vs. 90.5%, 82.1% vs.73.7%, 75.9% vs. 78.0% and 72.4% vs. 68.3% (all P > 0.05) for the EIN group and NEIN group, respectively. The incidence of grade 3-4 acute toxicity in the lower intestine was significantly higher in the EIN group than in the NEIN group (13.8% vs. 1.9%, P = 0.02). The Dmax, V35 and V45 of the small bowel was decreased in the NEIN group compared to the EIN group.

CONCLUSIONS

Exclusion of the EIN from the CTV in T4b rectal cancer with anterior structure invasion could reduce lower intestinal toxicity without compromising oncological outcomes. These results need further evaluation in future studies.

Short-term results after robot-assisted surgery for primary rectal cancers requiring beyond total mesorectal excision in multiple compartments

AIM

Rectal cancers requiring beyond total mesorectal excision (bTME) are traditionally operated using an open approach, but the use of minimally invasive robot-assisted procedures is increasing. Introduction of minimal invasive surgery for complex cancer cases could be associated with compromised surgical margins or increased complication rates. Therefore, reporting results both clinical and oncological in large series is important. Since bTME procedure reports are heterogeneous, comparing results is often difficult. In this study, a magnetic resonance imaging (MRI) classification system was used to describe the bTME surgery according to pelvic compartments.

METHODS

Consecutive patients with primary rectal cancer operated with laparoscopic robot-assisted bTME were prospectively included for 2 years. All patients had tumors that threatened the mesorectal fascia, invaded adjacent organs, and/or involved metastatic pelvic lateral lymph nodes. Short-term clinical outcomes and oncological specimen quality were registered. Surgery was classified according to pelvic compartments resected.

RESULTS

Clear resection margins (R0 resection) were achieved in 95 out of 105 patients (90.5%). About 26% had Accordion Severity Grading System of Surgical Complications grade 3-4 complications and 15% required re-operations. About 7% were converted to open surgery. The number of compartments resected ranged from one to the maximum seven, with 83% having two or three compartments resected. All 10 R1 resections occurred in the lateral and posterior compartments.

CONCLUSIONS

The short-term clinical outcomes and oncological specimen quality after robot-assisted bTME surgery were comparable to previously published open bTME surgery. The description of surgical procedures using the Royal Marsden MRI compartment classification was feasible.

Impact of minimally invasive total mesoesophageal excision and minimally invasive esophagectomy on failure patterns of locally advanced esophageal squamous cell carcinoma: a matched cohort study with long-term follow-up

BACKGROUND

The effects of minimally invasive total mesoesophageal excision (MITME) on the long-term prognosis of locally advanced esophageal squamous cell carcinoma (ESCC) remain unknown. The objective of this study was to compare the static and dynamic failure patterns of MITME and minimally invasive esophagectomy (MIE) for locally advanced ESCC.

METHODS

We use propensity score matching (PSM) method to analyze the postoperative failure patterns of the two groups. Cumulative event curves were analyzed for cumulative incidence of failure between different groups, and independent prognostic factors were assessed using time-dependent multivariate analyses. The risk of dynamic failure calculated at 12-month intervals was compared between the two groups using the lifetime table.

RESULTS

A total of 366 ESCC patients were studied by 1:1 PSM for T stage and TNM stage (MITME group, n = 183; MIE group, n = 183). In the matched cohort, there was significant differences between the MITME and MIE groups in the failure pattern of regional lymph node recurrence (0.5 vs 3.8%, P = 0.032) and non-tumor death (10.9 vs 31.7%, P < 0.001). The cumulative event curve found that the 5-year cumulative failure rate was lower in the MITME group than in the MIE group (3.3 vs 17.1%, P = 0.026) after 5 years of survival. In addition, multivariate Cox regression analysis showed that MIE was an independent poor prognostic factor for a high cumulative failure rate in locally advanced ESCC patients at 5 years after surgery (HR:4.110; 95% CI 1.047-16.135; P = 0.043). The dynamic risk curve showed that the MITME group had a lower risk of failure within 5 years after surgery than the MIE group.

CONCLUSION

Considering that MITME can significantly improve the postoperative failure pattern and the benefit lasts for at least 5 years, it is feasible to use MITME as a treatment for locally advanced ESCC.

Outcomes of extended total mesorectal excision in patients with locally advanced rectal cancer

AIM

Extended total mesorectal excision (eTME) is a complex procedure involving en bloc resection of the structures surrounding the various quadrants of the rectum. This study, presenting the largest series so far of patients undergoing eTME, aimed to assess the surgical and survival outcomes of patients following treatment with eTME and to compare these outcomes with historical data on pelvic exenteration.

METHOD

The study is a retrospective review of all patients with locally advanced rectal cancer requiring an eTME (2014-2020). The database includes the demographic profile, operative details, histopathological features and follow-up.

RESULTS

One hundred and sixty three patients who underwent eTME were analysed. The overall Clavien-Dindo complication rate of > IIIa was 21.1%. The anterior quadrant was the most common anatomical site resected (68.5%). The R1 resection rate was 10.4%. After a median follow-up of 28 months, there were 51 recurrences in the study and twenty two deaths were recorded. The local recurrence rate was 7.3% among the study population. The disease-free survival (DFS) and overall survival were 66.7% and 80.4%, respectively, at 3 years. The majority of the recurrences were distant metastasis (84.3%). In univariate analysis, the quadrant involved did not affect survival. In multivariate analysis, signet ring histology, metastatic presentation, inadequate tumour response and R1 resection affected DFS.

CONCLUSION

The recurrence pattern, R1 resection rate and survival outcomes of patients in the present study were comparable with those for patients undergoing an exenteration. Therefore, eTME is probably a safe alternative to pelvic exenterations when R0 resection is achievable and when the procedure is performed in high-volume specialist tertiary care centres.

Adjuvant chemotherapy does not improve cancer-specific survival for pathologic stage II/III rectal adenocarcinoma after neoadjuvant chemoradiotherapy and surgery: evidence based on long-term survival analysis from SEER data

PURPOSE

Adjuvant chemotherapy is controversial in rectal cancer, especially after neoadjuvant chemoradiotherapy (NCRT). This retrospective study aims at evaluating adjuvant chemotherapy's long-term survival benefits in stage II and stage III rectal adenocarcinoma (RC).

METHODS

This study obtained data from the Surveillance, Epidemiology, and End Results (SEER) database registered between 2010 and 2015. The survival analyses used the Kaplan-Meier method and were compared by log-rank test. The factors that affect survival outcomes were analyzed by univariate and multivariate Cox regression. The propensity score matching (1:4) was used to ensure the balance of variables between different groups.

RESULTS

The median follow-up time for overall patients was 64 months. The 5-year overall survival (OS) and cancer-specific survival (CSS) rates were 51.3% and 67.4% in the adjuvant chemotherapy (-) group and 73.9% and 79.6% in the adjuvant chemotherapy ( +) group (p < 0.001, p = 0.002). However, subgroup analysis showed adjuvant chemotherapy after NCRT improved the 5-year OS but not CSS rates in stage II and stage III RC (p = 0.003, p = 0.004; p = 0.29, p = 0.3). Univariate and multivariate analyses found adjuvant chemotherapy after NCRT was an independent prognosis factor of OS but not CSS (HR 0.8, 95%CI 0.7-0.92, p < 0.001; p = 0.276).

CONCLUSION

The survival benefits from adjuvant chemotherapy were associated with the status of NCRT for pathological stage II and III RC. For patients who did not receive NCRT, adjuvant chemotherapy is needed to significantly improve long-term survival rates. However, adjuvant chemotherapy after NCRT did not significantly improve long-term CSS.

An International Multicenter Prospective Study Evaluating the Long-term Oncological Impact of Adjuvant Chemotherapy in ypN+ Rectal Cancer

OBJECTIVE

To assess the oncological benefit of adjuvant chemotherapy (AC) in node positive (ypN+) rectal cancer after neoadjuvant chemoradiotherapy and radical surgery.

BACKGROUND

The evidence for AC after total mesorectal excision for locally advanced rectal cancer is conflicting and the net survival benefit is debated.

METHODS

An international multicenter comparative cohort study was performed comparing oncological outcomes in tertiary rectal cancer centers from the Netherlands and France. Patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by total mesorectal excision surgery and with positive lymph nodes on histologic examination (ypN+) were included for analysis. Kaplan-Meier curves were generated to compare disease-free (DFS) and overall survival in AC and non-AC groups.

RESULTS

Of 1265 patients screened, a total of 239 rectal cancer patients with ypN+ disease were included. Demographic and clinical characteristics were similar in both groups. Higher systemic recurrence rates were observed in the non-AC group compared with those who received AC [32.0% (n=40) vs 17.5% (n=11), respectively, P =0.034]. DFS at 1 and 5 years postoperatively were significantly better in the AC group (92% vs 80% at 1 year; 72% vs 51% at 5 years, P =0.024), whereas no difference in overall survival was observed.

CONCLUSIONS

In this multicenter comparative cohort study, we identified an oncological benefit of AC in both systemic recurrence and DFS in ypN+ rectal cancer patients. From this data, systemic chemotherapy continues to confer oncological benefit in locally advanced ypN+ rectal cancer.

Updated systematic review of the approach to pelvic exenteration for locally advanced primary rectal cancer

OBJECTIVES

To review the evidence regarding surgical advances in the management of primary locally advanced rectal cancer.

BACKGROUND

The management of rectal cancer has evolved significantly in recent decades, with improved (neo)adjuvant treatment strategies and enhanced perioperative protocols. Centralization of care for complex, advanced cases has enabled surgeons in these units to undertake more ambitious surgical procedures.

METHODS

A Pubmed, Ovid, Embase and Cochrane database search was conducted according to the predetermined search strategy. The review protocol was prospectively registered with PROSPERO (CRD42021245582).

RESULTS

14 studies were identified which reported on the outcomes of 3,188 patients who underwent pelvic exenteration (PE) for primary rectal cancer. 50% of patients had neoadjuvant radiotherapy. 24.2% underwent flap reconstruction, 9.4% required a bony resection and 34 patients underwent a major vascular excision. 73.9% achieved R0 resection, with 33.1% experiencing a major complication. Median length of hospital stay ranged from 13 to 19 days. 1.6% of patients died within 30 days of their operation. Five-year overall survival (OS) rates ranged 29%-78%.

LIMITATIONS

The studies included in our review were mostly single-centre observational studies published prior to the introduction of modern neoadjuvant treatment regimens. It was not possible to perform a meta-analysis on the basis that most were non-randomized, non-comparative studies.

CONCLUSIONS

Pelvic exenteration offers patients with locally advanced rectal cancer the chance of long-term survival with acceptable levels of morbidity. Increased experience facilitates more radical procedures, with the introduction of new platforms and/or reconstructive options.

Association of tumor size in pathological T4 colorectal cancer with desmoplastic reaction and prognosis

Background

Tumor size in pathological T4 (pT4) colorectal cancer (CRC) is associated with oncological prognosis; however, its relation to epithelial‐mesenchymal transition (EMT)‐associated histology is unclear. We aimed to investigate the association of tumor size with oncological prognosis and EMT.

Methods

We performed a retrospective analysis of 95 patients with primary CRC who underwent radical surgery and were consecutively diagnosed with pT4.

Results

Both 3‐y disease‐free survival (DFS) and cancer‐specific survival (CSS) were significantly higher in patients with tumor size ≥50 mm than in those with tumor size <50 mm (P = .009 and P = .011, respectively). The independent factors identified in the multivariate analysis for DFS were pathological lymph node metastasis (hazard ratio [HR], 2.551; 95% confidence interval [CI], 1.031–6.315; P = .043), distant metastasis (HR, 2.511; 95% CI, 1.140–5.532; P = .022), tumor size (HR, 0.462; 95% CI, 0.234–0.913; P = .026), and adjuvant chemotherapy (HR, 0.357; 95% CI, 0.166–0.766; P = .008). The independent factors identified in multivariate analysis for CSS were tumor location (HR, 10.867; 95% CI, 2.539–45.518; P = .001) and tumor size (HR, 0.067; 95% CI, 0.014–0.321; P < .001). In pT4 CRC, smaller tumor size was associated with nonmature desmoplastic reaction and EMT‐related histology.

Conclusions

Tumor size ≥50 mm was associated with a better DFS and CSS than that of <50 mm, in patients with pT4 CRC. Smaller tumor size with advanced invasion likely reflects a more biologically aggressive phenotype in pT4 CRC.

Therapeutic effects and limitations of chemoradiotherapy in advanced lower rectal cancer focusing on T4b

PURPOSE

This study aimed to elucidate the benefits and limitations of preoperative chemoradiotherapy (CRT) in rectal cancer treatment, specifically in T4b rectal cancer.

METHODS

This retrospective cohort study reviewed 1014 consecutive patients with clinical T3/4a/T4b adenocarcinomas of the lower rectum, who underwent total mesorectal excision at the Department of Surgical Oncology of the University of Tokyo Hospital and 22 referral institutions affiliated with the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer. Patients were divided into two cohorts: cohort 1 comprised 298 consecutive patients who underwent CRT followed by radical surgery and cohort 2 comprised 716 consecutive patients who underwent curative surgery without preoperative therapy. We assessed the prognostic differences between the two cohorts, focusing particularly on T stages.

RESULTS

In T3/4a patients, cohort 1 showed a significantly lower local recurrence rate than cohort 2 (4.8% vs. 9.4%, p=0.024), but not in T4b patients (23.5% vs. 16.0%, p=0.383). In contrast, no significant differences in survival were observed between T3/4a and T4b patients. T4b classification was found to be an independent predictive factor of local recurrence in cohort 1, but not in cohort 2.

CONCLUSION

In T4b rectal cancer, preoperative CRT demonstrated a limited benefit for local control and survival. In cases of suspected T4b rectal tumors, additional therapies such as induction chemotherapy to conventional CRT may contribute to better outcomes.

Short-course radiotherapy with consolidation chemotherapy versus conventionally fractionated long-course chemoradiotherapy for locally advanced rectal cancer: randomized clinical trial

BACKGROUND

The trial hypothesis was that, in a resource-constrained situation, short-course radiotherapy would improve treatment compliance compared with conventional chemoradiotherapy for locally advanced rectal cancer, without compromising oncological outcomes.

METHODS

In this open-label RCT, patients with cT3, cT4 or node-positive non-metastatic rectal cancer were allocated randomly to 5 × 5 Gy radiotherapy and two cycles of XELOX (arm A) or chemoradiotherapy with concurrent capecitabine (arm B), followed by total mesorectal excision in both arms. All patients received a further six cycles of adjuvant chemotherapy with the XELOX regimen. The primary endpoint was treatment compliance, defined as the ability to complete planned treatment, including neoadjuvant radiochemotherapy, surgery, and adjuvant chemotherapy to a dose of six cycles.

RESULTS

Of 162 allocated patients, 140 were eligible for analysis: 69 in arm A and 71 in arm B. Compliance with planned treatment (primary endpoint) was greater in arm A (63 versus 41 per cent; P = 0.005). The incidence of acute toxicities of neoadjuvant therapy was similar (haematological: 28 versus 32 per cent, P = 0.533; gastrointestinal: 14 versus 21 per cent, P = 0.305; grade III-IV: 2 versus 4 per cent, P = 1.000). Delays in radiotherapy were less common in arm A (9 versus 45 per cent; P < 0.001), and overall times for completion of neoadjuvant treatment were shorter (P < 0.001). The rates of R0 resection (87 versus 90 per cent; P = 0.554), sphincter preservation (32 versus 35 per cent; P = 0.708), pathological complete response (12 versus 10 per cent; P = 0.740), and overall tumour downstaging (75 versus 75 per cent; P = 0.920) were similar. Downstaging of the primary tumour (ypT) was more common in arm A (P = 0.044). There was no difference in postoperative complications between trial arms (P = 0.838).

CONCLUSION

Reduced treatment delays and a higher rate of compliance were observed with treatment for short-course radiotherapy with consolidation chemotherapy, with no difference in early oncological surgical outcomes. In time- and resource-constrained rectal cancer units in developing countries, short-course radiotherapy should be the standard of care.

A matched cohort study of the failure pattern after laparoscopic and open gastrectomy for locally advanced gastric cancer: does the operative approach matter?

BACKGROUND

Due to lacking evidence for confirming the efficacy of performing laparoscopic surgery for locally advanced gastric cancer (LAGC). Therefore, this study aimed to compare the static and dynamic failure patterns after laparoscopic gastrectomy (LG) and open gastrectomy (OG) in LAGC.

METHODS

A total of 1792 LAGC patients who underwent radical resection between January 2010 and January 2017 were divided into the LG group (n = 1557) and the OG group (n = 235). Propensity score matching was performed to balance the two groups. Dynamic hazard rates of failure were calculated using the hazard function. Early and late failure were defined as failure occurring before and after 2 years since surgery, respectively.

RESULTS

A total of 1175 patients with LAGC were included after matching (LG group, n = 940; OG, n = 235). The failure rate of the whole cohort was 43.2% (508/1175), accounting for 41.4% (389/940) and 50.6% (119/235) in the LG and OG groups, respectively. Although the two groups showed no significant differences in failure rate for any failure type, landmark analysis showed a lower early distant recurrence rate in the stage IIa-IIIb subgroup of the LG group (OG versus LG: 30.3% versus 21.1%, P = 0.004). The dynamic hazard rate peaked at 9.4 months (peak rate = 0.0186) before gradually declining. In stage IIa-IIIb patients, the hazard rate of the OG group remained significantly higher than that of the LG group within the first 2 years in terms of distant recurrence (peak rate: OG versus LG, 0.0091 versus 0.0055).

CONCLUSION

Given the differences in early failure between LG and OG, more intensive surveillance for distant recurrence within the first 2 years should be considered for patients with stage IIa-IIIb after OG.

Gender aspects of survival after abdominoperineal resection for low rectal cancer: a retrospective study

PURPOSE

The difference in prognosis between genders after abdominoperineal resection (APR) for low rectal cancer (LRC) is unclear. This study aimed to compare survival outcomes between genders in patients with LRC who underwent curative APR.

METHODS

This retrospective cohort study used a database of consecutive colorectal resections. Patients who received curative APR with LRC were grouped according to their gender. Female patients were frequency-matched 1:1 on American Joint Committee on Cancer (AJCC) stage to male patients. Overall survival (OS), disease-free survival (DFS), and their independent risk factors were examined.

RESULTS

A total of 140 patients with APR for LRC were included after matching: 70 (50.0%) males and 70 (50.0%) females. No significant differences were found between the groups in terms of age, operation methods, AJCC stage, and adjuvant therapy (all P > 0.05). Median follow-up was 39 (range: 3-128) months. Male gender was independently associated with worse OS (adjusted hazard ratio [HR] = 2.755, 95% CI: 1.507-5.038, P = 0.001) and worse DFS (adjusted HR = 2.440, 95% CI: 1.254-4.746, P = 0.009). Subgroup analysis revealed that female patients with stage III disease had better OS (P = 0.001) and DFS (P < 0.001) than male patients.

CONCLUSION

Gender affects survival after a curative APR for LRC. Compared with females, male patients with LRC after curative APR had worse prognosis, especially for stage III disease.

Total neoadjuvant therapy for locally advanced rectal cancer: the fuse is lit

Explosively disrupting

Robotic-assisted resection for beyond TME rectal cancer: a novel classification and analysis from a specialized center

Locally advanced rectal cancer often requires an extended resection beyond the total mesorectal excision plane (bTME) to obtain clear resection margins. We classified three types of bTME rectal cancer following local disease diffusion: radial (adjacent pelvic organs), lateral (pelvic lateral lymph nodes) and longitudinal (below 3.5 cm from the anal verge, submitted to intersphincteric resection). The primary aim of this study was to evaluate the application of robotic surgery to the three types of bTME regarding the short and long-term oncological outcomes. Secondary aim was to identify survival prognostic factors for bTME rectal cancers. A total of 137 patients who underwent robotic-assisted bTME procedures between 2008 and 2018 were extracted from a prospectively collected database. Patient-related, operative and pathological factors were assessed. Morbidity was moderately high with 66% of patients reporting postoperative complications. Median follow up was 47 months (IQR, 31.5-66.5). Local recurrence rate was 15.3% with a statistical difference between the three types of bTME (p = 0.041). Disease progression/distant metastasis rate was 33.6%. Overall survival was significantly different (p = 0.023) with 1- and 3-years rates of: 77.8% and 55.0% (radial; n = 19); 96.6% and 84.8% (lateral; n = 30); 97.7% and 86.9% (longitudinal; n = 88). No statistical difference was observed for disease-free survival (p = 0.897). Local recurrence-free survival was significantly different between the groups (p = 0.031). Multivariate analysis showed that (y)pT (p = 0.028; HR (95% CI) 5.133 (1.192-22.097)), (y)pN (p = 0.014; HR (95% CI) 2.835 (1.240-6.482)) and type of bTME were associated to OS whilst (y)pT (p = 0.072) and type of bTME were not associated to LRFS.

Outcomes of extended radical resections for locally advanced and recurrent pelvic malignancy involving the aortoiliac axis

AIM

Currently, there is no clear consensus on the role of extended pelvic resections for locally advanced or recurrent disease involving major vascular structures. The aims of this study were to report the outcomes of consecutive patients undergoing extended resections for pelvic malignancy involving the aortoiliac axis.

METHODS

Prospective data were collected on patients having extended radical resections for locally advanced or recurrent pelvic malignancies, with aortoiliac axis involvement, requiring en bloc vascular resection and reconstruction, at a single institution between 2014 and 2018.

RESULTS

Eleven patients were included (median age 60 years; range 31-69 years; seven women). The majority required resection of both arterial and venous systems (n = 8), and the technique for vascular reconstruction was either interposition grafts or femoral-femoral crossover grafts. The median operative time was 510 min (range 330-960 min). Clear resection margins (R0) were achieved in nine patients. The median length of stay was 25 days (range 7-83 days). Seven patients did not suffer an early complication. There was one serious complication (Clavien-Dindo ≥ 3), an arterial graft occlusion secondary to thrombus in the immediate postoperative period, requiring a return to theatre and thrombectomy. The median length of follow-up in this study was 22 months (range 4-58 months).

CONCLUSION

This series demonstrates that en bloc major vascular resection and reconstruction can be performed safely and can achieve clear resection margins in selected patients with locally advanced or recurrent pelvic malignancy at specialist surgery centres.

"Watch and Wait" for complete clinical response after neoadjuvant chemoradiotherapy for rectal cancer

The management of rectal cancer has evolved substantially over recent decades, becoming increasingly complex. This was once a disease associated with high mortality and limited treatment options that typically necessitated a permanent colostomy, has now become a model for multidisciplinary evaluation, treatment and surgical advancement. Despite advances in the rates of total mesorectal excision, decreased local recurrence and increased 5-year survival rates, the multimodal treatment of rectal cancer is associated with a significant impact on long-term functional and quality of life outcomes including risks of bowel, bladder and sexual dysfunction, and potential need for a permanent stoma. There is great interest in strategies to decrease the toxicity of treatment, including selective use of radiation, chemotherapy or even surgery. The modern concept of selective use of surgery for patients with rectal cancer are based on the observed pathological complete response in approximately 10-20% of patients following long-course chemoradiation therapy. While definitive surgical resection remains the standard of care for all patients with non-metastatic rectal cancer, a growing number of studies are providing supportive evidence for a watch-and-wait, organ preserving approach in highly selected patients with rectal cancer. However, questions regarding the heterogeneity of patient selection, optimal method for inducing pathological complete response, methods and intervals for assessing treatment response and adequacy of follow-up remain unanswered. The aim of this review is to provide an up-to-date summary of the current evidence for the watch-and-wait management of rectal cancer following a complete clinical response after neoadjuvant chemoradiation.