Preoperative chemoradiotherapy followed by local excision in clinical T2N0 rectal cancer

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.

Predictive value of changes in the level of carbohydrate antigen 19-9 in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

AIM

The aim of this work was to explore the predictive value of changes in the level of carbohydrate antigen 19-9 (CA19-9) after neoadjuvant chemoradiotherapy (nCRT) and after surgery in patients with locally advanced rectal cancer (LARC).

METHOD

Patients with LARC who underwent nCRT and radical surgery (between 2011 and 2016) were divided into three groups according to pre-nCRT and post-nCRT CA19-9 levels as follows: normal pre-nCRT CA19-9 (normal CA19-9 group), elevated pre-nCRT and normal post-nCRT CA19-9 (normalized group) and elevated pre-nCRT and elevated post-nCRT CA19-9 (nonnormalized group). The pathological nCRT response criteria included ypCR and downstaging (ypStages 0-I). Recurrence-free survival (RFS) and overall survival (OS) were analysed.

RESULTS

A total of 721 patients were identified. The normal CA19-9 group was significantly associated with ypCR (n = 159) and downstaging (n = 347) (P < 0.05). The normalized group (n = 76) had worse RFS and OS than the normal CA19-9 group (n = 622) and better RFS and OS than the nonnormalized group (n = 23) (5-year RFS 47.0% vs 66.9% vs 81.5%, P < 0.001; 5-year OS 47.0% vs 75.4% vs 85.0%, P < 0.001). In multivariate analysis, CA19-9 group and ypTNM stage were independent predictors of RFS and OS. Moreover, for the 23 patients with elevated post-nCRT CA19-9 levels, the RFS and OS of patients with normalized postoperative CA19-9 levels were significantly better than those of patients with elevated postoperative CA19-9 levels (P < 0.05).

CONCLUSION

Following nCRT, changes in the CA19-9 level are a strong prognostic marker for long-term survival, and they may be helpful in the selection of patients who prefer more conservative surgery after chemoradiotherapy.

Executive Summary of the American Radium Society Appropriate Use Criteria for Local Excision in Rectal Cancer

The goal of treatment for early stage rectal cancer is to optimize oncologic outcome while minimizing effect of treatment on quality of life. The standard of care treatment for most early rectal cancers is radical surgery alone. Given the morbidity associated with radical surgery, local excision for early rectal cancers has been explored as an alternative approach associated with lower rates of morbidity. The American Radium Society Appropriate Use Criteria presented in this manuscript are evidence-based guidelines for the use of local excision in early stage rectal cancer that include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) used by a multidisciplinary expert panel to rate the appropriateness of imaging and treatment procedures. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. These guidelines are intended for the use of all practitioners and patients who desire information regarding the use of local excision in rectal cancer.

Oncologic Outcome and Morbidity in the Elderly Rectal Cancer Patients After Preoperative Chemoradiotherapy and Total Mesorectal Excision: A Multi-institutional and Case-matched Control Study

OBJECTIVE

To determine the toxicity and oncologic outcome of neoadjuvant chemoradiotherapy (CRT) followed by curative total mesorectal excision (TME) in the elderly (≥70 yrs) and younger (<70 yrs) rectal cancer patients.

BACKGROUND

Sufficient data for elderly rectal cancer patients who received definitive trimodality have not been accumulated yet.

PATIENTS AND METHODS

A total of 1232 rectal cancer patients who received neoadjuvant CRT and TME were enrolled in this study. After propensity-score matching, 310 younger patients and 310 elderly patients were matched with 1:1 manner. Treatment response, toxicity, surgical outcome, recurrence, and survival were assessed and compared between the 2 groups of patients.

RESULTS

The median age was 58 years for the younger patient group and 74 years for the elderly group. Pathologic complete response rates were not significantly different between the 2 groups (younger and elderly: 17.1% vs 14.8%, P = 0.443). The 5-year recurrence-free survival (younger and elderly: 67.7% vs 65.5%, P = 0.483) and overall survival (younger and elderly: 82.9% vs. 79.5%, P = 0.271) rates were not significantly different between the 2 groups either. Adjuvant chemotherapy after surgery was less frequently delivered to the elderly than that to younger patients (83.9% vs 69.0%). Grade 3 or higher acute hematologic toxicity was observed more frequently in the elderly than that in the younger group (9.0% vs 16.1%, P = 0.008). Late complication rate was higher in the elderly group compared with that in the younger group without statistical significance (2.6% vs 4.5%, P = 0.193).

CONCLUSIONS

Although acute hematologic toxicity was observed more frequently in the elderly patients than that in the younger patients, elderly rectal cancer patients with good performance status who received preoperative CRT and TME showed favorable tumor response and recurrence-free survival similar to younger patients.

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.

Predictive value of carcinoembryonic antigen and carbohydrate antigen 19-9 related to downstaging to stage 0-I after neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Objective

To explore the value of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in predicting downstaging to stage 0–I cancer after neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer.

Materials and methods

We respectively investigated pretreatment CEA, pretreatment CA19-9, posttreatment CEA, posttreatment CA19-9, pre–post-CA19-9 ratio, and pre–post-CEA ratio in 674 patients with locally advanced rectal cancer receiving nCRT and determined the patients’ thresholds by using the receiver operating characteristic curve analysis. The association between downstaging (stage 0–I after nCRT), pathological complete response, and clinicopathological parameters was evaluated using the Pearson χ2 test. The clinicopathological parameters which were found to be significantly associated with downstaging were analyzed by logistic regression models and were incorporated into a scoring system.

Results

Multivariate analysis showed that pretreatment CA19-9 level, posttreatment CEA level, pre–post-CEA ratio, and pre–post-CA19-9 ratio were significantly correlated with downstaging. Area under the curve of the scoring system was higher than that of parameters alone.

Conclusion

The 4-factor scoring system with CA19-9 level, posttreatment CEA level, pre– post-CEA ratio, and pre–post-CA19-9 ratio is of more value in predicting downstaging to stage 0–I patients with locally advanced rectal cancer after nCRT than using the parameters alone.

Continuous Effect of Radial Resection Margin on Recurrence and Survival in Rectal Cancer Patients Who Receive Preoperative Chemoradiation and Curative Surgery: A Multicenter Retrospective Analysis

PURPOSE

To elucidate the proper length and prognostic value of resection margins in rectal cancer patients who received preoperative chemoradiotherapy (CRT) followed by curative total mesorectal excision (TME).

METHODS AND MATERIALS

A total of 1476 rectal cancer patients staging cT3-4N0-2M0 were analyzed. All patients received radiation dose of 50.4 Gy in 28 fractions with concurrent 5-fluorouracil or capecitabine. Total mesorectal excision was performed 4 to 8 weeks after radiation therapy.

RESULTS

The recurrence-free survival (RFS) at 5 years showed a significant difference between 3 groups: patients with circumferential resection margin (CRM) ≤1 mm, CRM 1.1 to 5 mm, and CRM >5 mm (46.2% vs 68.6% vs 77.5%, P<.001). Patients with CRM ≤1 mm showed a significantly higher cumulative incidence of locoregional recurrence (P<.001) and distant metastasis (P<.001) at 5 years compared with the other 2 groups. Patients with CRM 1.1 to 5 mm showed a significantly higher cumulative incidence of distant metastasis (P<.001), but not locoregional recurrence (P=.192), compared with those with CRM >5 mm. Distal resection margin (≤5 vs >5 mm) did not show any significant difference in cumulative incidence of locoregional recurrence (P=.310) and distant metastasis (P=.926).

CONCLUSION

Rectal cancer patients with CRM ≤1 mm are a high-risk group, with the lowest RFS. Patients with CRM 1.1 to 5 mm may be at intermediate risk, with moderately increased distant recurrence. Distal resection margin was not significantly associated with RFS in rectal cancer after neoadjuvant CRT and total mesorectal excision.

Clinical utility of pretreatment prediction of chemoradiotherapy response in rectal cancer: a review

Approximately 20% of all patients with locally advanced rectal cancer experience pathologically complete responses following neoadjuvant chemoradiotherapy (CRT) and standard surgery. The utility of radical surgery for patients exhibiting good CRT responses has been challenged. Organ-sparing strategies for selected patients exhibiting complete clinical responses include local excision or no immediate surgery. The subjects of this tailored management are patients whose presenting disease corresponds to current indications of neoadjuvant CRT, and their post-CRT tumor response is assessed by clinical and radiological examinations. However, a model predictive of the CRT response, applied before any treatment commenced, would be valuable to facilitate such a personalized approach. This would increase organ preservation, particularly in patients for whom upfront CRT is not generally prescribed. Molecular biomarkers hold the greatest promise for development of a pretreatment predictive model of CRT response. A combination of clinicopathological, radiological, and molecular markers will be necessary to render the model robust. Molecular research will also contribute to the development of drugs that can overcome the radioresistance of rectal tumors. Current treatments for rectal cancer are based on the expected prognosis given the presenting disease extent. In the future, treatment schemes may be modified by including the predicted CRT response evaluated at presentation.