Locally Recurrent Rectal Cancer

Efficacy and safety of intraoperative radiotherapy in rectal cancer: A systematic review and meta-analysis

BACKGROUND

In recent years, intraoperative radiotherapy (IORT) has been increasingly used for the treatment of rectal cancer. However, the efficacy and safety of IORT for the treatment of rectal cancer are still controversial.

AIM

To evaluate the value of IORT for patients with rectal cancer.

METHODS

We searched PubMed, Embase, Cochrane Library, Web of Science databases, and conference abstracts and included randomized controlled trials and observational studies on IORT vs non-IORT for rectal cancer. Dichotomous variables were evaluated by odds ratio (OR) and 95% confidence interval (CI), hazard ratio (HR) and 95%CI was used as a summary statistic of survival outcomes. Statistical analyses were performed using Stata V.15.0 and Review Manager 5.3 software.

RESULTS

In this study, 3 randomized controlled studies and 12 observational studies were included with a total of 1460 patients, who are mainly residents of Europe, the United States, and Asia. Our results did not show significant differences in 5-year overall survival (HR = 0.80, 95%CI = 0.60-1.06; P = 0.126); 5-year disease-free survival (HR = 0.94, 95%CI = 0.73-1.22; P = 0.650); abscess (OR = 1.10, 95%CI = 0.67-1.80; P = 0.713), fistulae (OR = 0.79, 95%CI = 0.33-1.89; P = 0.600); wound complication (OR = 1.21, 95%CI = 0.62-2.36; P = 0.575); anastomotic leakage (OR = 1.09, 95%CI = 0.59-2.02; P = 0.775); and neurogenic bladder dysfunction (OR = 0.69, 95%CI = 0.31-1.55; P = 0.369). However, the meta-analysis of 5-year local control was significantly different (OR = 3.07, 95%CI = 1.66-5.66; P = 0.000).

CONCLUSION

The advantage of IORT is mainly reflected in 5-year local control, but it is not statistically significant for 5-year overall survival, 5-year disease-free survival, and complications.

Comparison of the diagnostic efficiency for local recurrence of rectal cancer using CT, MRI, PET and PET-CT: A systematic review protocol

BACKGROUND

The risk of local recurrence (LR) continues to threat patients with rectal cancer after surgery or chemoradiotherapy. The main reason is that there is frequently extensive scarring and reactive changes after radiotherapy and resection. Thus, the diagnosis of LR can be challenging. There are different imaging modalities that have been used in the follow-up of rectal cancer, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and positron emission tomography-computed tomography (PET-CT) in clinical practice.

METHODS

We will systematically search PubMed, EMBASE, the Cochrane Library, and Chinese Biomedical Literature Database for diagnostic trials using CT, MRI, PET, and PET-CT to detect LR of rectal cancer in April, 2018. Two review authors will independently screen titles and abstracts for relevance, assess full texts for inclusion, and carry out data extraction and methodological quality assessment using the QUADAS-2 tool. We will use bivariate meta-analysis to estimate summary sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of CT, MRI, PET, and PET-CT, as well as different sequences of MRI. For each index test, estimates of sensitivity and specificity from each study will be plotted in summary receive operating curve space and forest plots will be constructed for visual examination of variation in test accuracy. We will perform meta-analyses using the hierarchical summary receiver-operating characteristic model to produce summary estimates of sensitivity and specificity. Then, head-to-head and indirect comparison meta-analyses will be carried out.

DISCUSSION

This review will help determine the diagnostic accuracy of CT, MRI, PET, and PET-CT for the diagnosis of patients with LR of rectal cancer.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required, as this study is a systematic review.

PROSPERO REGISTRATION NUMBER

CRD42018104918.