Systemic Chemotherapy as Salvage Treatment for Locally Advanced Rectal Cancer Patients Who Fail to Respond to Standard Neoadjuvant Chemoradiotherapy.

ABSTRACT

BACKGROUND: The potential of chemotherapy as salvage treatment after failure of neoadjuvant chemoradiotherapy for locally advanced rectal cancer (LARC) has never been explored. We conducted a single-center, retrospective analysis to address this question. PATIENTS AND METHODS: Patients with newly diagnosed LARC who were inoperable or candidates for extensive (i.e., beyond total mesorectal excision [TME]) surgery after long-course chemoradiotherapy and who received salvage chemotherapy were included. The primary objective was to estimate the proportion of patients who became suitable for TME after chemotherapy. RESULTS: Forty-five patients were eligible (39 candidates for extensive surgery and 6 unresectable). Previous radiotherapy was given concurrently with chemotherapy in 43 cases (median dose 54.0 Gy). Oxaliplatin- and irinotecan-based salvage chemotherapy was administered in 40 (88.9%) and 5 (11.1%) cases, respectively. Eight patients (17.8%) became suitable for TME after chemotherapy, 10 (22.2%) ultimately underwent TME with clear margins, and 2 (4.4%) were managed with a watch and wait approach. Additionally, 13 patients had extensive surgery with curative intent. Three-year progression-free survival and 5-year overall survival in the entire population were 30.0% (95% confidence interval [CI] 15.0-46.0) and 44.0% (95% CI 26.0-61.0), respectively. For the curatively resected and "watch and wait" patients, these figures were 52.0% (95% CI 27.0-73.0) and 67.0% (95% CI 40.0-84.0), respectively. CONCLUSION: Systemic chemotherapy may be an effective salvage strategy for LARC patients who fail to respond to chemoradiotherapy and are inoperable or candidates for beyond TME surgery. According to our study, one out of five patients may become resectable or be spared from an extensive surgery after systemic chemotherapy. IMPLICATIONS FOR PRACTICE High-quality evidence to inform the optimal management of rectal cancer patients who are inoperable or candidates for beyond total mesorectal excision surgery following standard chemoradiotherapy is lacking. We show for the first time that systemic chemotherapy may be beneficial and result in one out of five poor prognosis patients becoming resectable or being spared from an extensive surgical approach. Although mores studies are needed to confirm these data, administering salvage systemic chemotherapy in this setting may have the potential to minimize morbidity associated with extensive surgical procedures and improve long-term oncological outcome.