Oncologic Outcomes according to the Treatment Strategy in Radiologic Complete Responders after Neoadjuvant Chemoradiation for Rectal Cancer

Abstract

Objective: This study aimed to compare the oncologic outcomes between treatment strategies for rectal cancer [radical surgery, local excision (LE), and the wait-and-see approach] in radiologic complete responders after neoadjuvant chemoradiation (nCRT). Methods: We retrospectively reviewed rectal cancer patients and included 52 radiologic complete responders after nCRT defined as no residual tumor or residual fibrosis and no suspicious metastatic lymph nodes on magnetic resonance imaging (MRI). Clinicopathologic features and oncologic outcomes were compared according to the treatment strategies. Results: The median follow-up period was 41 months (range, 6-80). Twenty-eight patients underwent radical surgery, whereas 16 underwent LE, and 8 were closely monitored without initial surgery. The pathologic complete response rate was 40.9%. Patients who underwent radical surgery showed better prognosis compared to those who underwent LE or wait-and-see (3-year disease-free survival: radical surgery 85.0% vs. LE 62.5%, wait-and-see 75.0%, p = 0.019; 3-year local recurrence-free survival: radical surgery 96.4% vs. LE 67.0%, wait-and-see 75.0%, p = 0.009). After recurrence, patients who underwent salvage surgery showed a relatively good oncologic outcome. Conclusion: Pursuing LE or the wait-and-see approach instead of radical surgery in rectal cancer patients undergoing nCRT may bring about a detrimental oncologic outcome if clinical complete response is solely determined by MRI.

Wait-and-see treatment strategies for rectal cancer patients with clinical complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

“…The male/female ratio was 144/107 and 196/132 in the two groups, respectively. Observation group patients seemed to be older than those in the radical surgery group [2, 4, 7–9, 13]. Except for one observation group patient with liver metastasis in Smith et al [8], no patients had distant metastasis (DM) according to the study descriptions.…”

“…Several papers by Habr-Gama and colleagues describing studies of Brazilian patients were examined [4, 14, 15, 18, 20, 22, 23, 26], but only one of them that included all data of interest was recruited for this meta-analysis [4]. Finally, nine comparative studies of 26 trials which focused on oncologic outcome in patients with cCR in a wait-and-see group compared to those with pCR in a radical surgery group were identified [2, 4–9, 11, 13] (Table 2). Tables 2 and 3 show the main characteristics of these nine comparative studies.…”

“…The risk of 1, 2, 3, and 5-year DM was similar in nonoperation and radical surgery groups (RR 3.93, 95% CI 0.60-0.25.95, P = 0.160; RR 0.71, 95% CI 0.31-1.62, P = 0.420; RR 0.93, 95% CI 0.44-1.96, P = 0.12; RR 0.95, 95% CI 0.47-1.91, P = 0.88, respectively). Two articles that did not mention DFS and OS after surgery were excluded from this analysis [11, 13]. Patients in the observation and surgery groups had similar 1, 2, 3, and 5-year DFS (RR 0.95, 95% CI 0.91-0.99, P = 2.23; RR 0.97, 95% CI 0.92-1.03, P = 0.280; RR 0.95, 95% CI 0.85-1.06, P = 0.39; RR 0.96, 95% CI 0.85-1.08, P = 0.850, respectively).…”

Nonoperative Management or ‘Watch and Wait’ for Rectal Cancer with Complete Clinical Response After Neoadjuvant Chemoradiotherapy: A Critical Appraisal

“…13–27 Eight studies reported data for an adequate control proctectomy group, but there was significant variation. Four used a post-surgical pathological complete response (pCR) group for comparison 14,16,25,26 , 2 used cCR tumors undergoing surgery, 19,20 1 used both, 22 and 1 used a surgical group matched for clinical stage (regardless of tumor response). 23 Outcome data for incomplete response, non-response, and local excision were excluded from comparisons as these were not regarded as adequate control group data.…”

“…Concurrent chemotherapy was fluoropyrimidine based in all instances. In contrast, the use of consolidation or adjuvant chemotherapy was highly variable, ranging from frequent use, 18,25,26 to use only if staged as node positive prior to neoadjuvant treatment, 15,21 infrequent use, 14,20,23 and complete omission. 13,16,17,19,22 Consolidation or adjuvant chemotherapy, when used, was most commonly 5-FU based with the addition of Oxaliplatin in two studies.…”