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Tolerability and Safety Assessment of Adjuvant Chemoradiotherapy with S-1 after Limited Surgery for T1 or T2 Lower Rectal Cancer
by
, ,
Norikatsu Miyoshi
1,2,*,†, 
Mamoru Uemura
1,*,
Shingo Noura
3,†,
Masayoshi Yasui
4,
Junichi Nishimura
4,
Mitsuyoshi Tei
5,
Chu Matsuda
6,
Shunji Morita
7,
Akira Inoue
8,
Hiroki Tamagawa
9,
Yukako Mokutani
10,
Shinichi Yoshioka
11,
Makoto Fujii
12,
Shinya Kato
1,
Yuki Sekido
1,
Takayuki Ogino
1,
Hirofumi Yamamoto
1,
Kohei Murata
13,
Yuichiro Doki
1 and
Hidetoshi Eguchi
1
on behalf of Multicenter Clinical Study Group of Osaka University, Colorectal Group (CSGO-CG) 1
Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
2
Department of Innovative Oncology Research and Regenerative Medicine, Osaka International Cancer Institute, Osaka 541-8567, Japan
3
Department of Surgery, Sakai City Medical Center, Sakai, Osaka 593-8304, Japan
4
Department of Gastroenterological Surgery, Osaka International Cancer Institute, Osaka 541-8567, Japan
5
Department of Surgery, Osaka Rosai Hospital, Osaka 252-3561, Japan
6
Department of Surgery, Osaka Police Hospital, Osaka 543-0035, Japan
7
Department of Surgery, Itami Municipal Hospital, Itami Hyogo 664-0015, Japan
8
Department of Gastroenterological Surgery Osaka General Medical Center, Osaka 558-8558, Japan
9
Department of Gastroenterological Surgery, Otemae Hospital, Osaka 540-0008, Japan
10
Department of Surgery, Higashiosaka City Medical Center, Osaka 578-8588, Japan
11
Department of Surgery, Yao Municipal Hospital, Yao, Osaka 581-0069, Japan
12
Department of Mathematical Health Science, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
13
Department of Gastroenterological Surgery, Kansai Rosai Hospital, Hyogo 660-0064, Japan
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Cancers 2024, 16(19), 3360; https://doi.org/10.3390/cancers16193360
Submission received: 24 August 2024
/
Revised: 14 September 2024
/
Accepted: 26 September 2024
/
Published: 30 September 2024
(This article belongs to the Special Issue The Survival of Colon and Rectal Cancer)
Simple Summary
The study evaluated the long-term outcomes of chemoradiotherapy (CRT) with S-1 after limited surgery for T1 or T2 lower rectal cancer. The 3-year and 5-year relapse-free survival rates were 90.17% and 85.87%, respectively, showing favorable outcomes for T1 cancer patients, with effective anal function preservation. However, further treatment is needed to improve outcomes for T2 cancer patients.
Abstract
Background: The short-term outcomes of chemoradiotherapy (CRT) with S-1 (a combination of tegafur, gimeracil, and oteracil) following limited surgery for patients with T1 or T2 lower rectal cancer have shown encouraging results. Objectives: This study was designed to delve deeper into the long-term outcomes of CRT with S-1 after limited surgery, with the goal of evaluating both the long-term efficacy and potential risks associated with this treatment approach in patients diagnosed with T1 or T2 lower rectal cancer. Methods: This was conducted as a multicenter, single-arm, prospective phase II trial. The patient population consisted of individuals clinically diagnosed with either T1 or T2 lower rectal or anal canal cancer, with a maximum tumor diameter of 30 mm and classified as N0 or M0. Patients underwent local excision or endoscopic resection. After surgery, CRT with S-1 was administered to patients meeting several criteria, including the confirmation of well-differentiated or moderately differentiated adenocarcinoma, negative surgical margins, submucosal invasion depth of ≥1000 µm, and high tumor-budding grade (2/3). The primary endpoint of this study was relapse-free survival, while secondary endpoints included local recurrence-free survival, overall survival, anal sphincter preservation rate, and safety. Results: A total of 52 patients were included, with pathological diagnoses revealing T1 in 36 patients and T2 in 16 patients. The 3-year and 5-year relapse-free survival rates were 90.17% and 85.87%, respectively. The 3-year and 5-year local recurrence-free survival rates were 90.17% and 88.07%, respectively, while the 3-year and 5-year overall survival rates were 94.03% and 91.94%, respectively. Conclusions: CRT with S-1 after limited surgery for T1 lower rectal cancer demonstrated favorable outcomes in terms of recurrence, survival, and local control rates while effectively maintaining anal function in patients. However, further treatment approaches may be necessary to improve outcomes for patients diagnosed with stage T2 lower rectal cancer
