Outcome of Local Excision Following Preoperative Chemoradiotherapy for Clinically T2 Distal Rectal Cancer: A Multicenter Retrospective Study (KROG 12-06)

Towards personalized treatment of T2N0 rectal cancer: A systematic review of long-term oncological outcomes of neoadjuvant therapy followed by local excision

BACKGROUND AND AIM

Total mesorectal excision (TME) remains the treatment of choice in T2N0 tumors. However, evidence suggest that one-size-fits-all approach is not always beneficial for this group of patients. The aim of this study is to synthesize data on long-term outcomes after neoadjuvant therapy (NAT) followed by local excision (LE) in T2N0 rectal cancer patients in the perspective of a rectal-preserving strategy.

METHODS

A systematic search of PubMed/MEDLINE, SCOPUS, and Web of Science databases was conducted until October 2021 to identify studies comparing LE after NAT and TME or reporting oncologic outcomes after conservative approach. A pooled analysis was conducted using a fixed-effect model in the case of non-significant heterogeneity (P > 0.1), and a random effect model (DerSimonian-Laird method) when significant heterogeneity was present (P < 0.1) CRD42022300344.

RESULTS

Nine studies were included in the analysis. Three of them were comparative studies. The pooled 3-year DFS, 5-year DFS, 3-year OS, 5-year OS, local and distant recurrence rates were 92.8% (95% CI 81.6-99.5%), 91.3% (95% CI 88.3-94.3%), 96.1% (95% CI 90.5-100%), 72.6% (95% CI 57.5-87.7%), 4% (95% CI 18-63%), and 4.9% (95% CI 2-7.8%), respectively, in subjects treated with NAT followed by LE. No heterogeneity was found for all these analyses, except for the 5-year OS sub-analysis (I² 95.5%, P < 0.001). Complete pathological response (ypT0) rate after NAT and LE ranges from 26.7% to 59%.

CONCLUSION

LE following neoadjuvant CRT may provide comparable survival benefit to radical surgery for patients with clinical stage T2N0 in selected patients although the evidence is still limited to provide solid recommendations. A personalized therapeutic approach taking into account tumor and patient-related factors should be considered.

Preoperative concurrent chemoradiotherapy MRI characteristics favouring pathologic complete response in patients with rectal cancer: Usefulness of MR T2-stage as an ancillary finding for predicting pathologic complete response

INTRODUCTION

This study sought to assess preoperative concurrent chemoradiotherapy (CRT) magnetic resonance imaging (MRI)-based findings according to a structured MRI report template for primary staging of rectal cancer, and to evaluate the prognostic relevance of the pre-CRT MRI-based findings in patients with rectal cancer after CRT.

METHODS

We retrospectively evaluated pre- and post-CRT MRI data of patients with pathologically proven rectal adenocarcinoma, between January 2008 and October 2019. Image interpretation was performed independently by two radiologists and each reviewer assessed the cancer characteristics on MRI, based on the structured MRI report for primary staging. MRI-based findings associated with pathologic complete tumour regression grade (TRG) after CRT were analysed by univariate and multivariate analysis. Significant factors from pre-CRT MRI were weighted to score mrTRG in post-CRT MRI.

RESULTS

On univariate analysis, MR T-stage, tumour infiltration, mesorectal fascia involvement, extramural vascular invasion and serum carcinoembryonic antigen level correlated significantly with pathologic complete response (pCR). Multivariate analysis identified that only MR T-stage was independently associated with pCR (odds ratio, 3.89, 95% confidence interval, 1.18-12.84; P = 0.0278). Adding MRI-based T2-stage as an ancillary finding to mrTRG statistically significantly improved the sensitivity as compared to using only mrTRG for considering a CR. T2_mrTRG was significantly different in terms of the time to tumour progression between the CR and non-CR group.

CONCLUSIONS

The MR T2-stage was independently associated with pCR after CRT in patients with rectal cancer and was helpful as ancillary predictive factor, adding to mrTRG for prediction of pCR.

MR prediction of pathologic complete response and early-stage rectal cancer after neoadjuvant chemoradiation in patients with clinical T1/T2 rectal cancer for organ saving strategy

To evaluate the ability of magnetic resonance imaging (MRI) to predict pathologic complete response (pCR) after neoadjuvant chemoradiation therapy (CRT) in patients with clinical T1/T2 rectal cancer to indicate candidates for organ-saving strategies.Between 2012 and 2016, 38 patients with clinical T1/T2 rectal cancer received neoadjuvant CRT. Radiologic complete response (rCR) was assigned when dense fibrotic tissue without tumor signal intensity was observed on post-CRT MRI. Surgical pathologic assessment was used to evaluate tumor regression. The association between rCR and the mural extent of the primary tumor, pCR, and pathologic T stage were analyzed.In rCR patients, the pCR rate was higher; the odds of achieving pCR were 8.00 times higher than for non-rCR patients (P = .02). rCR patients were also more likely to have early-stage cancer than non-rCR patients (P = 0.01). Patients with partial extent of the primary tumor on post-CRT MRI were more likely to be diagnosed with early-stage cancer than those with transmural extent (P = .01).rCR indicated by post-CRT MRI can be used as a supportive factor to predict pCR after neoadjuvant CRT in patients with clinical T1/T2 rectal cancer and can guide management decisions around organ-saving treatments.

Neoadjuvant chemoradiation followed by transanal local excision for T2 rectal cancer confers equivalent survival benefit as traditional transabdominal resection

BACKGROUND

Despite clinical guidelines classifying T2 rectal cancer as a contraindication for transanal local excision attributable to unacceptably high rates of local recurrence, it is a practice that persists clinically. Recent clinical trials have suggested that transanal local excision in addition to neoadjuvant chemoradiation is an acceptable alternative in select patients.

METHODS

The 2004-2015 National Cancer Database was queried for patients with clinical stage T2N0M0 rectal adenocarcinoma who underwent surgical intervention. Patients were stratified by treatment with transabdominal resection or transanal local excision, both with and without neoadjuvant chemoradiation. Propensity matching was performed, and, using the Kaplan-Meier and Cox proportional hazard models, survival was compared between the groups.

RESULTS

A total of 12,021 patients met inclusion criteria, including 1,761 and 6,629 patients who underwent transabdominal resection with and without neoadjuvant chemoradiation, respectively, and 695 and 2,936 patients who underwent local transanal excision with and without neoadjuvant chemoradiation, respectively. In unadjusted analysis, patients undergoing induction therapy followed by transabdominal resection or local excision had equivalent survival. Similarly, on multivariate Cox proportional hazard regression after propensity matching, local excision was not an independent predictor of patient mortality compared with transabdominal resection (hazard ratio 0.93, 95% confidence interval 0.75-1.16).

CONCLUSION

Local transanal excision in addition to neoadjuvant chemoradiation may provide comparable survival benefit to transabdominal resection for patients with clinical stage T2N0M0 rectal cancer. Therefore, patients who refuse or are poor candidates for transabdominal resection should be considered for neoadjuvant therapy followed by transanal local excision.

Does total regression of primary rectal cancer after preoperative chemoradiotherapy represent "no tumor" status?

Purpose

Insistence that total regression of primary tumor would not represent long-term oncologic outcomes has been raised. Therefore, this study aimed to evaluate the outcomes of these patients after preoperative chemoradiotherapy (PCRT) and radical surgery and to evaluate the associated risk factors.

Methods

We included 189 patients with rectal cancer who showed total regression of the primary tumor after PCRT, followed by radical resection, between 2001 and 2012. Recurrence-free survival (RFS) was calculated using the Kaplan-Meier method, and the results were compared with 77 patients with Tis rectal cancer who received only radical resection. Factors associated with RFS were evaluated using Cox regression analysis.

Results

Sphincter-saving resection was performed for 146 patients (77.2%). Adjuvant chemotherapy was administered to 168 patients (88.9%). During the follow-up period, recurrence occurred in 17 patients (9%). The 5-year RFS was 91.3%, which was significantly lower than that of patients with Tis rectal cancer without PCRT (P = 0.005). In univariate analysis, preoperative CEA and histologic differentiation were associated with RFS. However, no factors were found to be associated with RFS.

Conclusion

RFS was lower in patients with total regression of primary rectal cancer after PCRT than in those with Tis rectal cancer without PCRT, and it would not be considered as the same entity with early rectal cancer or "disappeared tumor" status.

Watch-and-Wait as a Therapeutic Strategy in Rectal Cancer

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.

Total Mesorectal Excision Versus Local Excision After Preoperative Chemoradiotherapy in Rectal Cancer With Lymph Node Metastasis: A Propensity Score-Matched Analysis

PURPOSE

To determine whether local excision (LE) outcomes were comparable to total mesorectal excision (TME) outcomes in node-positive (cN+) rectal cancer patients who were good responders.

METHODS AND MATERIALS

This retrospective study included clinical T2-3 and cN+ low rectal cancer patient who received preoperative chemoradiotherapy (PCRT) followed by TME or LE. Clinical stage T1 or T4 tumors, upper-to-middle rectal tumors (>7 cm from anal verge), and synchronous distant metastases were excluded. Lymph nodes ≥5 mm in size were defined as tumor-positive, and patients with metastatic lymph nodes >20 mm in size were excluded. Preoperative chemoradiotherapy comprised radiation (50-50.4 Gy/25-28 fractions over 5 weeks) with 2 cycles of 5-fluorouracil or oral capecitabine. Propensity scores were computed from tumor and patient variables and used for 1-to-1 matched analysis. Local recurrence-free survival, disease-free survival, and overall survival were compared between the 2 matched groups.

RESULTS

Between January 2007 and December 2013, 563 and 55 patients underwent TME and LE, respectively. The median follow-up period was 54 months. In propensity score-matched analysis, 48 patients were included in each group. No statistical differences were observed in 3-year local recurrence-free survival (97.9% vs 97.9%, P = .994), 3-year disease-free survival (91.5% vs 91.4%, P = .968), or 3-year OS (93.7% vs 97.9%, P = .809) between the TME and LE groups.

CONCLUSIONS

In clinical N+ rectal cancer patients, oncologic outcomes of PCRT followed by LE were comparable to those of TME; this finding might be applicable only to those patients with good response in the primary tumor and small lymph node metastases.

Status for clinically complete remission rectal cancer after concomitant chemo-radiotherapy in Taiwan

Treatment for Rectal cancer changed after the induction of concomitant chemo-radiotherapy, CCRT. Complete remission of the tumor leads to debate of the necessity of surgical intervention. We evaluate the treatment outcome to know if operation is beneficial to these patients. Patients received long course concomitant chemo-radiotherapy for advanced rectal cancer between 2004 and 2013 in Taiwan were enrolled. Total 2780 patients diagnosed advanced rectal cancer were enrolled. In these patients, 2578 received surgical intervention and 202 were in wait and see for complete remission tumor. Higher local recurrence rate was found with wait and see group (8.9% vs. 2.7%). Also, better overall survival, disease free survival and local recurrence free survival were seen with the surgical intervention group. Surgical intervention may be benefit for some misdiagnosed completed response to CCRT.

Are We Predicting Disease Progress of the Rectal Cancer Patients without Surgery after Neoadjuvant Chemoradiotherapy?

Purpose

There are patients who do not undergo surgery, regardless of tumor response for neoadjuvant chemoradiotherapy (nCRT) in rectal cancer. However, there have been few reports focused on how oncologic outcomes are worse in these patients. We sought to investigate oncologic outcomes for these non-operated patients with rectal cancer after nCRT.

Materials and Methods

A total of 1,063 records of patients with rectal cancer who were treated with nCRT from January 2002 to December 2013 were retrospectively reviewed. We categorized patients into the non-operated group (n=77), transanal local excision (TLE) group (n=54), ortotal mesorectal excision (TME) group (n=932) and compared each group using propensity score matching.

Results

In the non-operated group, the most common reason for no surgery was patient refusal (n=64). Eleven patients were considered to have achieve clinical complete response (cCR), which was an independent prognostic factor of progression-free survival (p=0.045). In patients with disease progression in the non-operated group, the overall survival did not improved according to salvage treatments (p=0.451). The non-operated group showed worse survivals compared to the TLE or TME group before and after matching (p < 0.001). This finding was also noted in the analysis of survival only in patients with cCR.

Conclusion

In this study, non-operated patients did not secure oncologic safety regardless of cCR after nCRT. Our results suggest that a non-operative management must be carefully considered even if cCR is achieved.

Local Excision Techniques for Rectal Cancer After Neoadjuvant Chemoradiotherapy: What Are We Doing?

BACKGROUND

Recent evidence shows that the majority of rectal cancers demonstrate occult tumor scatter after neoadjuvant chemoradiotherapy that can extend for several centimeters under adjacent normal-appearing mucosa beside the residual mucosal abnormality or scar.

OBJECTIVE

This systematic review aimed to determine all of the published selection criteria and technical descriptions for local excision to date with regard to this phenomenon.

DATA SOURCES

PubMed, MEDLINE, and Embase were searched using the following key words: rectal cancer, local excision, radiotherapy, and neoadjuvant.

STUDY SELECTION

Studies that assessed local excision of rectal cancer after neoadjuvant chemoradiotherapy were included. Duplicate series were excluded from final analysis.

INTERVENTION

All of the data points were tabulated and analyzed using Microsoft Excel.

MAIN OUTCOME MEASURES

Criteria for patient selection, surgical technique, clinical restaging, pathologic assessment, and indications for completion surgery were analyzed.

RESULTS

After exclusions, data from 25 studies that in total evaluated local excision in 1001 patients were included. Compared with the single accepted technique of total mesorectal excision, described techniques for local excision after neoadjuvant therapy demonstrate significant variability in many critical technical issues, such as marking/tattooing original tumor margins before neoadjuvant therapy, using pretreatment tumor size/stage as exclusion criteria, and specifically stating lateral excision margins. Where detailed, the majority of local recurrences occurred in patients with clear pathological margins, yet significant variation existed for pathological assessment and reporting, with few studies detailing R status and some not reporting margin status at all. Significant variability also existed for adverse tumor features that mandated completion surgery, and, importantly, many series describe patients refusing completion surgery where indicated.

LIMITATIONS

We were unable to perform meta-analysis because studies lacked sufficient methodologic homogeneity to synthesize.

CONCLUSIONS

The observations from this study prompt additional study, standardization of technique, and cautious use of local excision of rectal cancer in the setting of neoadjuvant chemoradiotherapy.

A Systematic Review of Local Excision After Neoadjuvant Therapy for Rectal Cancer: Are ypT0 Tumors the Limit?

BACKGROUND

Neoadjuvant therapy reduces local recurrence after radical surgery for rectal cancer with complete pathological response in 15% to 25% of patients. Radical surgery is associated with significant morbidity that may be avoided by local excision in selected cases.

OBJECTIVE

This systematic review aimed to determine the oncological outcomes and morbidity of local excision after neoadjuvant therapy.

DATA SOURCES

Data sources included MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials databases.

STUDY SELECTION

A systematic search of the databases using validated terms for rectal cancer, neoadjuvant therapy, and local excision was conducted.

INTERVENTIONS

Neoadjuvant therapy and local excision were the included interventions.

MAIN OUTCOME MEASURES

Pooled local recurrence, median survival, and pooled morbidity were measured.

RESULTS

Twenty unique studies were included (14 cohort, 5 comparative cohort, and 1 randomized controlled trial), describing 1068 patients. Patient choice, prohibitive comorbidity, good clinical response, and early stage disease were the most frequent indications for local excision. Pretreatment T2 and T3 tumors accounted for 46.4% and 30.7% of cases. Long-course treatment was administered in all of the studies, except to a cohort of 64 patients who received short-course radiotherapy. Pooled complete clinical response was 45.8% (95% CI, 31.4%-60.5%), and pooled complete pathological response was 44.2% (95% CI, 36.4%-52.0%). Median follow-up was 54 months (range, 12-81 months). ypT0 tumors had a pooled local recurrence rate of 4.0% (95% CI, 1.9%-6.9%) and a median disease-free survival rate of 95.0% (95% CI, 87.4%-100%). Pooled local recurrence and median disease-free survival rates for ypT1 tumors or higher were 21.9% (95% CI, 15.9%-28.5%) and 68.0% (58.3%-69.0%). Pooled incidence of complications was 23.2% (95% CI, 15.7%-31.7%), with suture-line dehiscence reported in 9.9% (95% CI, 4.8%-16.7%).

LIMITATIONS

Limitations included study quality, high risk of selection bias and detection bias in study designs, and limited sample sizes.

CONCLUSIONS

Local excision after neoadjuvant therapy should only be considered a curative treatment if complete pathological response is obtained. Given the high rate of local recurrence among incomplete responders, future studies should focus on predicting patients who will achieve complete pathological response.

Preoperative chemoradiotherapy followed by local excision in clinical T2N0 rectal cancer

Purpose

To investigate whether preoperative chemoradiotherapy (PCRT) followed by local excision (LE) is feasible approach in clinical T2N0 rectal cancer patients.

Materials and Methods

Patients who received PCRT and LE because of clinical T2 rectal cancer within 7 cm from anal verge between January 2006 and June 2014 were retrospectively analyzed. LE was performed in case of a good clinical response after PCRT. Patients’ characteristics, treatment record, tumor recurrence, and treatment-related complications were reviewed at a median follow-up of 49 months.

Results

All patients received transanal excision or transanal minimally invasive surgery. Of 34 patients, 19 patients (55.9%) presented pathologic complete response (pCR). The 3-year local recurrence-free survival and disease free-survival were 100.0% and 97.1%, respectively. There was no recurrence among the patients with pCR. Except for 1 case of grade 4 enterovesical fistula, all other late complications were mild and self-limiting.

Conclusion

PCRT followed by an LE might be feasible as an alternative to total mesorectal excision in good responders with clinical T2N0 distal rectal cancer.

Oncologic Safety of Local Excision Compared With Total Mesorectal Excision for ypT0-T1 Rectal Cancer: A Propensity Score Analysis

Good oncologic outcomes, demonstrated by a complete pathologic response after preoperative chemoradiotherapy (PCRT), have led to local excision (LE) in selected patients with rectal cancer. We evaluated the oncologic safety of LE compared with total mesorectal excision (TME) in patients with ypT0-T1 rectal cancer.A retrospective review of 304 patients who underwent PCRT, followed by LE or TME, for ypT0-T1 rectal cancer was performed. Propensity scores were computed and used to match groups (LE:TME = 1:1), and analysis of disease-free survival (DFS) and overall survival (OS) was made by comparing patients who underwent LE or TME. Prognostic factors of relapse were analyzed for all patients.Tumor categories were ypT0 in 25 (61.9%) cases, ypTis in 6 (14.3%) cases, and ypT1 in 11 (26.2%) cases for the LE group, and ypT0 in 28 (66.7%) cases, ypTis in 4 (9.5%) cases, and ypT1 in 10 (23.8%) cases for the matched TME patients. There was no significant difference between the matched LE and TME groups in relapse (4.8% and 7.14%, respectively; P = 0.646), 5-year DFS (95.2% vs 91.6%; P = 0.33) and 5-year OS (96.6% vs 88.0%; P = 0.238). In the multivariate Cox regression analysis, tumor distance from the anal verge (hazard ratio [HR] = 0.78; 95% confidence interval (CI) = 0.616-0.992) and the tumor grade (HR = 4.29; 95% CI = 1.430-12.886) were significantly associated with the recurrence risk.LE results in oncologic outcomes that are comparable to those achieved by TME in selected patients with ypT0-T1 rectal cancer after PCRT.

[Lymph node metastases in ypT1/2 rectal cancer after neoadjuvant chemoradiotherapy : The Achilles heel of organ-preserving operative procedures?]

BACKGROUND

For patients with rectal cancer and complete remission (ypT0) or with good response and residual tumor restricted only to the bowel wall (ypT1-2) after neoadjuvant chemoradiotherapy (CRT), local excision has been suggested as an alternative to avoid the significant morbidity and functional deficits associated with total mesorectal excision (TME). The aim of this investigation was to investigate the incidence, distribution and tumor-related localization of mesorectal lymph node (LN) metastases in TME specimens with complete remission (ypT0), intramural (ypT1-2) and extramural (ypT3-4) residual tumor tissue.

PATIENTS AND METHODS

Specimens of TME from 81 patients with locally advanced rectal cancer (UICC II-III) undergoing neoadjuvant CRT within the phase III German rectal cancer trial CAO/ARO/AIO-04 were prospectively evaluated. The entire mesorectal compartment was microscopically screened after complete paraffin embedding. The number and localization of all detectable LN metastases were documented in relation to the primary tumor.

RESULTS

Whereas 50 patients (62 %) had ypT3-4 rectal cancer after neoadjuvant CRT, 20 patients (25 %) presented with residual tumor within the bowel wall (ypT1-2), 11 patients (14 %) had pathological complete remission (ypT0), an average of 28 ± 13.7 LN were detected per specimen and 25 patients (31 %) had residual LN metastases after CRT. Although the incidence of LN metastases was higher in the ypT3-4 group (40 %), 25 % of patients in the ypT1-2 group with intramural residual tumor had a mean number of 2.2 residual LN metastases of which 55 % were located far from the primary lesion in the proximal mesorectum. None of the patients with ypT0 status (complete response) had residual LN metastases.

CONCLUSION

Even in patients with good response and post-CRT tumor tissue restricted only to the bowel wall (ypT1-2), there is still a considerable risk for residual LN metastases. Local excision of residual rectal cancer was accompanied by a higher rate of local failure and radical surgery with TME should remain the standard treatment in these patients. To date, valid selection criteria for patients eligible for organ-sparing surgery are still lacking.

Implications for selecting local excision in locally advanced rectal cancer after preoperative chemoradiation

Local excision may offer the possibility of organ preservation for the management of locally advanced rectal cancer after neoadjuvant chemoradiotherapy (CRT). However, the oncological outcomes of this strategy have been largely associated with the risk of nodal metastases. In this study, Surveillance, Epidemiology, and End Results Program (SEER)-registered rectal cancer patients, and patients from Fudan University Shanghai Cancer Center (FUSCC) after preoperative chemoradiation were combined to analyze the incidence of lymph node metastasis. The results showed that there was a high risk for residual lymph node metastasis among patients even with complete pathologic response of primary tumor after preoperative CRT (12.6–13.2%). However, in the selected group of patients with pre-CRT MRI staging cN0 rectal cancer, there was only one ypN+ case (3.3%) in ypT0–1 group. These results suggest that pre-CRT MRI staging cN0 patients achieved ypT0–1 of bowel wall tumor may be suitable for local resection.

Transanal Minimally Invasive Surgery: Review of Indications and Outcomes from 75 Consecutive Patients

BACKGROUND

Transanal minimally invasive surgery (TAMIS) is an advanced local excision platform that helps overcome technical limitations and morbidity associated with other resection methods. Our goal was to review the indications and outcomes of TAMIS in a large series.

STUDY DESIGN

A review of a prospective database identified patients who underwent TAMIS from 2010 to 2014. Demographic, perioperative, short-term outcomes, and recurrence data were analyzed.

RESULTS

There were 75 patients with 76 lesions analyzed. Mean age was 64.0 years (SD 11.6 years) and mean BMI was 27.4 kg/m(2) (SD 4.7 kg/m(2)). Median American Society of Anesthesiologists (ASA) score was 2 (range 1 to 4). There were 59 benign (77.3%) and 17 malignant (22.7%) lesions: 6 pT0, 6 pT1, 4 pT2, and 1 pT3. Median lesion distance from the anal verge was 10 cm (range 6 to 16 cm). Mean operative time was 76.0 minutes (SD 36.1 minutes). Three patients had intraperitoneal entry; all were closed transanally, but 2 had temporary diverting ileostomies fashioned to ensure healing. Median length of stay was 1 day (range 0 to 6). One patient had a fragmented lesion (1.3%). Five patients had positive margins: 2 in palliative pT2 resections, and 3 in pT1, pT2, and gastrointestinal stromal tumor (GIST) patients. They were managed with radical resection (pT1 and pT2 lesions) and surveillance/medical oncology (GIST). Postoperatively, 3 patients had complications (bleeding, rectal stricture, and recto-vaginal fistula), and all were managed nonoperatively. After median follow-up of 39.5 months (range 10.5 to 65.3 months), 1 pT1 patient with negative margins developed a local recurrence and underwent salvage APR.

CONCLUSIONS

Transanal minimally invasive surgery is a viable option for excision of benign or early stage rectal masses, with mid-term oncologic outcomes comparable to those of radical resection. Further, TAMIS minimizes the morbidity and can allow more patients to benefit from the minimally invasive approach.

Influence of Preoperative Chemoradiotherapy on the Surgical Strategy According to the Clinical T Stage of Patients With Rectal Cancer

The aim of this study was to evaluate the pathologic responses and changes to surgical strategies following preoperative chemoradiotherapy (PCRT) in rectal cancer patients according to their clinical T stage (cT).The use of PCRT has recently been extended to less advanced disease.The authors enrolled 650 patients with cT2 to 4 mid and low rectal cancer who received both PCRT and surgical resection. The rate of total regression and the proportion of local excision were compared according to the cT category. The 3-year recurrence-free survival (RFS) rate was compared using the log-rank test according to patient cT category, pathologic stage, and type of surgical treatment.Patients with cT2 were older (P = 0.001), predominately female (P = 0.028), and had low-lying rectal cancer (P = 0.008). Pathologic total regression was achieved most frequently in cT2 patients (54% of cT2 versus 17.6% of cT3 versus 8.2% of cT4; P < 0.001). Local excision was performed on 42 cT2 (42%) and 24 cT3 (5.2%) patients (P < 0.001). The 3-year RFS rates differed according to both cT (P < 0.001) and ypT stage (P < 0.001). Among patients with ypT0 to 1 disease, the 3-year RFS did not differ according to the type of surgical treatment received (P = 0.5).Total regression of the primary tumor and a change in the surgical strategy after PCRT are most commonly seen in cT2 disease. Although PCRT is not generally indicated for cT2 rectal cancer, optimal surgical treatment may be achieved with the tailored use of PCRT.

Prediction of pathologic staging with magnetic resonance imaging after preoperative chemoradiotherapy in rectal cancer: pooled analysis of KROG 10-01 and 11-02

BACKGROUND AND PURPOSE

The reported overall accuracy of MRI in predicting the pathologic stage of nonirradiated rectal cancer is high. However, the role of MRI in restaging rectal tumors after neoadjuvant CRT is contentious. Thus, we evaluate the accuracy of restaging magnetic resonance imaging (MRI) for rectal cancer patients who receive preoperative chemoradiotherapy (CRT).

METHODS AND MATERIALS

We analyzed 150 patients with locally advanced rectal cancer (T3-4N0-2) who had received preoperative CRT. Pre-CRT MRI was performed for local tumor and nodal staging. All patients underwent restaging MRI followed by total mesorectal excision after the end of radiotherapy. The primary endpoint of the present study was to estimate the accuracy of post-CRT MRI as compared with pathologic staging.

RESULTS

Pathologic T classification matched the post-CRT MRI findings in 97 (64.7%) of 150 patients. 36 (24.0%) of 150 patients were overstaged in T classification, and the concordance degree was moderate (k=0.33, p<0.01). Pathologic N classification matched the post-CRI MRI findings in 85 (56.6%) of 150 patients. 54 (36.0%) of 150 patients were overstaged in N classification. 26 patients achieved downstaging (ycT0-2N0) on restaging MRI after CRT. 23 (88.5%) of 26 patients who had been downstaged on MRI after CRT were confirmed on the pathological staging, and the concordance degree was good (k=0.72, p<0.01).

CONCLUSIONS

Restaging MRI has low accuracy for the prediction of the pathologic T and N classifications in rectal cancer patients who received preoperative CRT. The diagnostic accuracy of restaging MRI is relatively high in rectal cancer patients who achieved clinical downstaging after CRT.