Prolonged neoadjuvant chemotherapy without radiation versus total neoadjuvant therapy for locally advanced rectal cancer: A propensity score matched study

Xuan Zhao; Peiyi Han; Luyang Zhang; Junjun Ma; Feng Dong; Lu Zang; Zirui He; Minhua Zheng

doi:10.3389/fonc.2022.953790

Prolonged neoadjuvant chemotherapy without radiation versus total neoadjuvant therapy for locally advanced rectal cancer: A propensity score matched study

Front Oncol. 2022 Sep 16:12:953790. doi: 10.3389/fonc.2022.953790. eCollection 2022.

Authors

Xuan Zhao^{1

2}, Peiyi Han^{1

2}, Luyang Zhang^{1

2}, Junjun Ma^{1

2}, Feng Dong^{1

2}, Lu Zang^{1

2}, Zirui He^{1

2}, Minhua Zheng^{1

2}

Affiliations

¹ Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
² Shanghai Minimally Invasive Surgery Center, Shanghai, China.

Abstract

Background: Although neoadjvuant chemoradiotherapy (CRT) improves the local control rate of locally advanced rectal cancer (LARC), it fails to significantly improve disease-free survival (DFS) and overall survival (OS). We explored the efficacy of prolonged neoadjuvant chemotherapy (pNCT) without radiation and compared this schema with total neoadjuvant therapy (TNT).

Material and methods: Patients diagnosed with LARC and received TNT (4 cycles of induction CapeOX/FOLFOX followed with CRT) or pNCT (6~8 cycles of CapeOX/FOLFOX) between June 2016 and October 2021 were retrospective analyzed. All patients underwent total mesorectal excision (TME). A 1:1 propensity score match was performed to adjust baseline potential confounders. The tumor response, toxicity, recurrence-free survival (RFS) and OS were observed.

Results: A total of 184 patients with 92 patients in each group were finally enrolled. The median follow-up time was 35 months. TNT showed better pathological complete response (pCR) rate (25.0% vs 16.3%) and objective regression rate (73.9% vs 59.8%) than pNCT. TNT and pNCT produce similar 3-year RFS and OS rates in patients with mid-to-upper rectal cancer. TNT was associated with improved tumor responsiveness in all patients and improved 3-year RFS rates in those with low rectal cancer.

Conclusion: pNCT is an option for patients with mid-to-upper rectal cancer, but radiation is still necessary for low rectal cancer. To determine optimal schema for neoadjuvant therapy and patient selection, additional randomized controlled studies are needed.

Keywords: chemoradiotherapy; neoadjuvant chemotherapy; propensity score; rectal cancer; recurrence.