Neoadjuvant Radiotherapy Versus No Radiotherapy for Stage IV Rectal Cancer: a Systematic Review and Meta-analysis

Locally advanced mid/low rectal cancer with synchronous resectable liver metastases: systematic review of the available strategies and outcome

The management of patients with locally advanced mid/low rectal cancer with resectable liver metastases is complex because of the need to combine the optimal treatment of both tumors. This study aims to review the available treatment strategies and compare their outcome, focusing on radiotherapy (RT) and liver-first approach (LFA). A systematic review was performed in PubMed, Embase, and web sources including articles published between 2000 and 02/2023 and reporting mid-/long-term outcomes. Overall, twenty studies were included (n = 1837 patients). Three- and 5-year overall survival (OS) rates were 51-88% and 36-59%. Although several strategies were reported, most patients received RT (1448/1837, 79%; > 85% neoadjuvant). RT reduced the pelvic recurrence risk (5.8 vs. 13.5%, P = 0.005) but did not impact OS. Six studies analyzed LFA (n = 307 patients). LFA had a completion rate similar to the rectum-first approach (RFA, 81% vs. 79%) but the interval strategy-an LFA variant with liver surgery in the interval between radiotherapy and rectal surgery-had a better completion rate than standard LFA (liver surgery/radiotherapy/rectal surgery, 92% vs. 75%, P = 0.011) and RFA (79%, P = 0.048). Across all series, LFA achieved the best survival rates, and in one paper it led to a survival advantage in patients with multiple metastases. In conclusion, different strategies can be adopted, but RT should be included to decrease the pelvic recurrence risk. LFA should be considered, especially in patients with high hepatic tumor burden, and RT before liver surgery (interval strategy) could maximize its completion rate.

Meta analysis of the second course of radiotherapy for recurrent esophageal cancer1

BACKGROUND

How to improve efficacy and reduce side effects in treating recurrent esophageal cancer by applying the second course of radiotherapy alone and its combination with chemotherapy has been attracting broad research interest.

OBJECTIVE

This review paper aims to systematically evaluate efficacy and side effects of applying the second course of anterograde radiotherapy alone and its combination with chemotherapy in treating recurrent esophageal cancer.

METHODS

First, the relevant research papers are retrieved from PubMed, CNKI and Wanfang databases. Next, Redman 5.3 software is used to calculate the relative risk and 95% confidence interval to evaluate the efficacy and adverse reactions of applying the single-stage radiotherapy with and without combining single/multi dose chemotherapy to treat recurrent esophageal cancer. Then, a meta data analysis is applied to examine the effectiveness and side effects of radiation alone and re-course radiotherapy plus chemotherapy in treating esophageal cancer recurrence after the first radiotherapy.

RESULTS

Fifteen papers are retrieved, which included 956 patients. Among them, 476 patients received radiotherapy combined with single drug/multi drug chemotherapy (observation) and others received only radiotherapy (control). Data analysis results show that the incidence of radiation induced lung injury and bone marrow suppression is high in the observation group. Subgroup analysis also shows the higher effective rate or one-year overall survival rate of patients treated with the second course radiotherapy combined with single drug chemotherapy.

CONCLUSION

The meta-analysis result demonstrates that combining the second course of radiotherapy with single-drug chemotherapy has advantages in treating recurrent esophageal cancer with the manageable side effects. However, due to insufficient data, it is not possible to conduct the further subgroup analysis comparing the side effects of restorative radiation with the combined chemotherapy using between a single drug and multiple drugs.

Effectiveness of radiotherapy for local control in T3N0 rectal cancer managed with total mesorectal excision: a meta-analysis

Introduction: The total mesorectal excision (TME) significantly improved rectal cancer outcomes. Radiotherapy’s benefit in T3N0 rectal cancer patients managed with TME has not been clearly demonstrated. A systematic review and meta-analysis were undertaken to determine whether radiotherapy altered the risk of locoregional recurrence (LR) in T3N0 rectal cancer patients managed with a TME.

Materials and Methods: Studies indexed on PubMed or Embase were systematically searched from inception to October 18, 2020. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were observed for the literature search, study screening, and data extraction; the Newcastle Ottawa Scale evaluated bias; Grades of Recommendation, Assessment, Development, and Evaluation Working Group system evaluated certainty; and all were performed independently by at least two investigators. Studies that reported LR data specific to T3N0 rectal cancer patients managed with TME, treated with and without radiotherapy, were included. Data was pooled using a random-effects model. Meta-analyses of the relative risk of local recurrence were conducted.

Results: Five retrospective cohort studies involving 932 unique patients reported LR outcomes; no prospective studies met eligibility criteria. Median follow-up ranged from 38.4–78 months. Adjuvant radiotherapy was provided in 3 studies. Chemotherapy was delivered and reported in 4 studies, providing both concurrent and adjuvant chemotherapy. A non-significant LR reduction with radiotherapy alongside TME was estimated, mean relative risk (RR) 0.63 (95% Confidence Interval 0.31–1.29; I² = 41.8%).

Conclusions: A non-significant LR benefit with radiotherapy’s addition was estimated. Meta-analysis of exclusively retrospective cohort studies was concerning for biased results. Adequately powered randomized trials are warranted.

No benefit after neoadjuvant chemoradiation in stage IV rectal cancer: A propensity score-matched analysis on a real-world population

BACKGROUND

Stage IV rectal cancer occurs in 25% of patients and locoregional control of primary tumor is usually poorly considered, since priority is the treatment of metastatic disease.

AIMS

This study evaluates impact of neoadjuvant chemoradiation followed by surgery (nCHRTS) vs. upfront surgery on locoregional control and overall survival in stage IV rectal cancer.

METHODS

All patients diagnosed with stage IV rectal carcinoma between 2009 and 2019, undergone elective surgery at the National Cancer Institute of Milan (Italy), were included. Propensity score-based matching was performed between the two study groups. Loco-regional recurrence-free survival (LRRFS) and overall survival (OS) were analysed using Kaplan-Meyer method.

RESULTS

A total of 139 patients were analyzed. After propensity score matching, 88 patients were included in the final analysis. The 3-yr LRRFS rates were 80.3% for nCHRTS vs. 90.4% for upfront surgery patients (p = 0.35). The 3-yr OS rates were respectively 81.8% vs. 58% (p = 0.36). KRAS mutation (HR 2.506, p = 0.038) and extra-liver metastases (HR 4.308, p = 0.003) were both predictive of worse OS in univariate analysis.

CONCLUSION

The present study failed to demonstrate a significant impact of nCHRTS on LRRFS or OS in stage IV rectal cancer.

The optimal timing for the interval to surgery after short course preoperative radiotherapy (5 ×5 Gy) in rectal cancer - are we too eager for surgery?

BACKGROUND

The improved overall survival (OS) after short course preoperative radiotherapy (SCPRT) using 5 × 5 Gy reported in the early rectal cancer trials could not be replicated in subsequent phase III trials. This original survival advantage is attributed to poor quality of surgery and the large differential in local recurrence rates, with and without SCPRT. Immuno-modulation during and after SCPRT and its clinical implications have been poorly investigated. We propose an alternative explanation for this survival benefit in terms of immunological mechanisms induced by SCPRT and the timing of surgery, which may validate the concept of consolidation chemotherapy.

MATERIAL AND METHODS

We reviewed randomized controlled trials (RCTs) and studies of SCPRT from 1985 to 2019. We aimed to examine the precise timing of surgery in days following SCPRT and identify evidence for immune modulation, neo-antigens and memory cell induction by radiation.

RESULTS

Considerable variability is reported in randomised trials for median overall treatment time (OTT) from start of SCPRT to surgery (8-14 days). Only three early trials showed a benefit in terms of OS from SCPRT, although the level of benefit in preventing local recurrence was consistent across all trials. Different patterns of immune effects are observed within days after SCPRT depending on the OTT, but human leukocyte antigen (HLA)-1 expression was not upregulated.

CONCLUSIONS

SCPRT has a substantial immune-stimulatory potential. The importance of the timing of surgery after SCPRT may have been underestimated. An optimal interval for surgery after 5 × 5 Gy may lead to better outcomes, which is possibly exploited in total neoadjuvant therapy schedules using consolidation chemotherapy. Individual patient meta-analyses from appropriate SCPRT trials examining outcomes for each day and prospective trials are needed to clarify the validity of this hypothesis. The interaction of SCPRT with tumour adaptive immunology, in particular the kinetics and timing, should be examined further.