Outcomes of Patients With Local Regrowth After Nonoperative Management of Rectal Cancer After Neoadjuvant Chemoradiotherapy

BACKGROUND: Clinical complete responders after chemoradiation for rectal cancer are increasingly being managed by a watch-and-wait strategy. Nonetheless, a significant proportion will experience a local regrowth, and the long-term oncological outcomes of these patients is not totally known. OBJECTIVE: The purpose of this study was to analyze the outcomes of patients who submitted to a watch-and-wait strategy and developed a local regrowth, and to compare these results with sustained complete clinical responders. DESIGN: This was a retrospective study. SETTING: Single institution, tertiary cancer center involved in alternatives to organ preservation. PATIENTS: Patients with a biopsy-proven rectal adenocarcinoma (stage II/III or low lying cT2N0M0 at risk for an abdominoperineal resection) treated with chemoradiation who were found at restage to have a clinical complete response. INTERVENTIONS: Rectal cancer patients treated with chemoradiation who underwent a watch-and-wait strategy (without a full thickness local excision) and developed a local regrowth were compared to the remaining patients of the watch-and-wait strategy. MAIN OUTCOME MEASURES: Overall survival between groups, incidence of regrowth, and results of salvage surgery. RESULTS: There were 67 patients. Local regrowth occurred in 20 (29.9%) patients treated with a watch-and-wait strategy. Mean follow-up was 62.7 months. Regrowth occurred at mean 14.2 months after chemoradiation, half of them within the first 12 months. Patients presented with comparable initial staging, lateral pelvic lymph-node metastasis, and extramural venous invasion. The regrowth group had a statistically nonsignificant higher incidence of mesorectal fascia involvement (35.0% vs 13.3%, p = 0.089). All regrowths underwent salvage surgery, mostly (75%) a sphincter-sparing procedure. 5-year overall survival was 71.1% in patients with regrowth and 91.1% in patients with a sustained complete clinical response (p = 0.027). LIMITATIONS: This study was limited by its retrospective evaluation of patient selection for a watch-and-wait strategy and outcomes, as well as its small sample size. CONCLUSIONS: Local regrowth is a frequent event when following a watch-and-wait policy (29.9%); however, patients could undergo salvage surgical treatment with adequate pelvic control. In this series, overall survival showed a statistically significant difference from patients managed with a watch-and-wait strategy who experienced a local regrowth compared to those who did not.