Local excision for ypT2 rectal cancer following preoperative chemoradiation therapy: it should not be justified

Short- and long-term outcomes in ypT2 rectal cancer patients after neoadjuvant therapy and local excision: a multicentre observational study

BACKGROUND

Although local excision (LE) after neoadjuvant treatment (NT) has achieved encouraging oncological outcomes in selected patients, radical surgery still remains the rule when unfavorable pathology occurs. However, there is a risk of undertreating patients not eligible for radical surgery. The aim of this study was to evaluate the outcomes of patients with pathological incomplete response (ypT2) in a multicentre cohort of patients undergoing LE after NT and to compare them with ypT0-is-1 rectal cancers.

METHODS

From 2010 to 2019, all patients who underwent LE after NT for rectal cancer were identified from five institutional retrospective databases. After excluding 12 patients with ypT3 tumors, patients with ypT2 tumors were compared to patients with ypT0-is-1 tumors). The endpoints of the study were early postoperative and long-term oncological outcomes.

RESULTS

A total of 177 patients (132 males, 45 females, median age 70 [IQR 16] years) underwent LE following NT. There were 46 ypT2 patients (39 males, 7 females, median age 72 [IQR 18.25] years) and 119 ypT0-is-1 patients (83 males, 36 females, median age 69 [IQR 15] years). Patients with pathological incomplete response (ypT2) were frailer than the ypT0-is-1 patients (mean Charlson Comorbidity Index 6.15 ± 2.43 vs. 5.29 ± 1.99; p = 0.02) and there was a significant difference in the type of NT used for the two groups (long- course radiotherapy: 100 (84%) vs. 23 (63%), p = 0.006; short-course radiotherapy: 19 (16%) vs. 17 (37%), p = 0.006). The postoperative rectal bleeding rate (13% vs. 1.7%; p = 0.008), readmission rate (10.9% vs. 0.8%; p = 0.008) and R1 resection rate (8.7% vs. 0; p = 0.008) was significantly higher in the ypT2 group. Recurrence rates were comparable between groups (5% vs. 13%; p = 0.15). Five-year overall survival was 91.3% and 94.9% in the ypT2 and ypT0-is-1 groups, respectively (p = 0.39), while 5-year cancer specific survival was 93.4% in the ypT2 group and 94.9% in the ypT0-is-1 group (p = 0.70). No difference was found in terms of 5-year local recurrence free-survival (p = 0.18) and 5-year distant recurrence free-survival (p = 0.37).

CONCLUSIONS

Patients with ypT2 tumors after NT and LE have a higher risk of late-onset rectal bleeding and positive resection margins than patients with complete or near complete response. However, long-term recurrence rates and survival seem comparable.

Late Recurrence in a Rectal Cancer Patient Who Underwent Preoperative Chemoradiotherapy Followed by Local Excision: A Case Report

Some patients who have undergone preoperative chemoradiotherapy (CRT) following surgery have been diagnosed with late recurrence more than 5 years after treatment, raising questions about the possible benefit extending surveillance beyond the recommended 5 years. In 2011, a 71-year-old male patient was diagnosed with T3N+ low-lying rectal cancer located 3 cm from the anal verge before undergoing long-course preoperative CRT. After CRT, the patient was reexamined and diagnosed with ycT1–2N0 lesion, so local excision (LE) was performed. The patient underwent intensive surveillance for up to 5 years, and no evidence of recurrence was found. At 74 months after surgery, the patient was hospitalized for a hematochezia, and local recurrence at the excision site and peritoneal seeding nodules were identified. Considering the late recurrence in this patient, it might be necessary to long-term follow-up beyond 5 years in patients with preoperative CRT followed by LE.

Clinical predictors of pathological good response in locally advanced rectal cancer

Purpose

The aim of this study was to identify the clinical predictors of pathological good response (PGR) after neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC) to clarify the indications for local excision.

Methods and materials

A total of 173 patients with LARC (cT3–4/N +) who were treated with nCRT followed by surgery were enrolled in our retrospective study. Patients were categorized into two groups according to the different tumor responses of surgical pathology. Stage ypT0–1N0 was defined as the group with PGR, and stage ypT2–4N0/ypTanyN + was the defined as the pathological poor response (PPR) group, and the potential predictors were compared.

Results

Of 173 patients, PGR was achieved in 57 patients (32.95%). The distance from the inferior margin of the tumor to the anal verge, cT classification, pretreatment carcinoembryonic antigen (CEA) and the interval from the end of radiation to surgery were correlated with pathological response. In the multivariate analysis, the distance from anal verge < 5 cm (OR = 0.443, p = 0.019), pretreatment CEA < 5 ng/mL (OR = 0.412, p = 0.015) and the interval from the end of radiation to surgery ≥ 84 days (OR = 2.652, p = 0.005) were independent predictors of PGR.

Conclusions

The distance from the inferior margin of the tumor to the anal verge, pretreatment CEA and the interval from the end of radiation to surgery were significant predictors of PGR in LARC. A prospective study is needed to further validate these results in the future.

Local excision in mid-to-low rectal cancer patients who revealed clinically total or near-total regression after preoperative chemoradiotherapy; a proposed trial

Background

Preoperative chemoradiotherapy (pre-CRT) followed by total mesorectal excision (TME) is currently a standard therapy for locally advanced mid-to-low rectal cancer. Less aggressive, organ-preserving option such as local excision (LE) or watchful wait can alternatively be used for patients who respond well to pre-CRT. High-resolution rectal magnetic resonance imaging (MRI) is one of the most useful methods to assess pre-CRT response, and the MERCURY group has shown that the MR tumor regression grade (mrTRG) correlated with the pathologic TRG. The aim of this study is to compare postoperative complication and oncologic outcomes between LE and TME in mid-to-low rectal cancer patients whose tumors are mrTRG grade 1 (radiological complete remission) or 2 (predominant fibrosis; near-complete remission) after pre-CRT.

Methods

A prospective, double-arm, randomized, open-labeled, single center, clinical trial will be conducted in patients with mid-to-low rectal cancer whose tumors are mrTRG 1/2 after pre-CRT at the Asan Medical Center, Seoul, Korea, after approval from the Institution Review Board. Patient medical records will be de-identified using a serial number to protect personal information. Inclusion criteria will include rectal adenocarcinoma with an inferior border < 8 cm from the anal verge, mrTRG 1/2, age > 20, and provision of informed consent. Postoperative complications will be assessed by Clavien-Dindo Classification Grade. Oncologic and functional outcomes will be collected and risk factors related to these outcomes will be investigated.

Discussion

We believed that the rate of postoperative complication of LE will be comparable to that of TME in mid-to-low advanced rectal cancer patients with a favorable response after pre-CRT.

Trial registration

KCT0002579 (https://cris.nih.go.kr) Dec-2017.

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.

A systematic review and meta-analysis of pT2 rectal cancer spread and recurrence pattern: Implications for target design in radiation therapy for organ preservation

BACKGROUND

There are no guidelines on clinical target volume (CTV) delineation for cT2 rectal cancer treated with organ preservation.

MATERIALS AND METHODS

A systematic review and meta-analysis were performed to determine the extent of distal mesorectal (DMS) and distal intramural spread (DIS), the risk of lateral lymph node (LLN) metastases in pT2 tumours, and regional recurrence pattern after organ preservation.

RESULTS

The rate of DMS > 1 cm was 1.9% (95% CI: 0.4-5.4%), maximum extent: 1.3 cm. The rate of DIS > 0.5 cm was 4.7% (95% CI: 1.3-11.5%), maximum extent: 0.8 cm. The rate of LLN metastases was 8.2% (95% CI: 6.7-9.9%) for tumours below or at peritoneal reflexion and 0% for higher tumours. Regional nodal recurrences alone were recorded in 1.0% (95% CI: 0.5-1.7%) of patients after watch-and-wait and in 2.1% (95% CI: 1.2-3.4%) after preoperative radiotherapy and local excision. Thus, the following rules for CTV delineation are proposed: caudal border 1.5 cm from the tumour to account for DMS or 1 cm to account for DIS, whichever is more caudal; cranial border at S2/S3 interspace; inclusion of LLN for tumours at or below peritoneal reflexion. A planning study was performed in eight patients to compare dose-volume parameters obtained using these rules to that obtained using current guidelines for advanced cancers. The proposed rules led to a mean 18% relative reduction of planning target volume, which resulted in better sparing of organs-at-risk.

CONCLUSION

This meta-analysis suggests a smaller CTV for cT2 tumours than the current guidelines designed for advanced cancers.

Preoperative radiotherapy and local excision of rectal cancer: Long-term results of a randomised study

BACKGROUND AND PURPOSE

It is uncertain whether local control is acceptable after preoperative radiotherapy and local excision (LE). An optimal preoperative dose/fractionation schedule has not yet been established.

MATERIAL AND METHODS

In a phase III study, patients with cT1-2N0M0 or borderline cT2/T3N0M0 < 4 cm rectal adenocarcinomas were randomised to receive either 5 × 5 Gy plus 1 × 4 Gy boost or chemoradiation: 50.4 Gy in 28 fractions plus 3 × 1.8 Gy boost and 5-fluorouracil with leucovorin bolus. LE was performed 6-8 weeks later. Patients with ypT0-1R0 disease were observed. Completion total mesorectal excision (CTME) was recommended for poor responders, i.e. ypT1R1/ypT2-3.

RESULTS

Of 61 randomised patients, 10 were excluded leaving 51 for analysis; 29 in the short-course group and 22 in the chemoradiation group. YpT0-1R0 was observed in 66% of patients in the short-course group and in 86% in the chemoradiation group, p = 0.11. CTME was performed only in 46% of patients with ypT1R1/ypT2-3. The median follow-up was 8.7 years. Local recurrence incidences and overall survival at 10 years were respectively for the short-course group vs. the chemoradiation group 35% vs. 5%, p = 0.036 and 47% vs. 86%, p = 0.009. In total, local recurrence at 10 years was 79% for ypT1R1/T2-3 without CTME.

CONCLUSIONS

This trial suggests that in the LE setting, both local recurrence and survival are worse after short-course radiotherapy than after chemoradiation. Because of the risk of bias, a confirmatory study is desirable. Lack of CTME is associated with an unacceptably high local recurrence rate.