Restaging Patients with Rectal Cancer Following Neoadjuvant Chemoradiation: A Systematic Review

Background In the USA, most patients with clinical stage II/III rectal cancer receive neoadjuvant chemoradiation (chemo/XRT) over 5-6 weeks followed by a 6-10-week break before proctectomy. As chemotherapy is delivered at radio-sensitizing doses, there is essentially a 3-month window during which potential systemic disease is untreated. Evidence regarding the utility of restaging patients prior to proctectomy is limited. Methods PubMed, Scopus, Web of Science, and the Cochrane Library were searched for studies evaluating the utility of restaging patients with rectal cancer after completion of long-course chemo/XRT, and reporting associated changes in management. Studies that were non-English, included <50 patients, or examining the diagnostic accuracy of imaging modalities were excluded. Study quality was evaluated using the modified Newcastle Ottawa Scale. Results Eight studies were identified including a total of 1251 patients restaged between completion of chemo/XRT and proctectomy. All studies were retrospective. Restaging identified new metastatic disease in 72 (6.0%) patients, with 4 studies reporting specific sites: liver (n = 28), lung (n = 8), adrenal (n = 1), bone (n = 1), and multiple sites (n = 7). Overall progression (distant or local) was detected in 88 (7.0%) patients and resulted in a change in management in 77 (87.5%) of these patients. Tumor-related prognostic characteristics were inconsistently reported among studies, precluding meta-analysis. Conclusions Although restaging between completion of neoadjuvant chemo/XRT and proctectomy detects disease progression in only a small percentage of patients, findings alter the treatment plan in the vast majority of these patients. Multi-institutional collaboration with analysis of well-defined prognostic variables may better identify patients most likely to benefit from restaging.