Anterior tumour location as a risk factor for local recurrence after laparoscopic surgery for stage I ultra-low rectal cancers: exploratory analysis of the Ultimate trial.
Anterior tumour location is an established risk factor for local recurrence (LR) in advanced rectal cancer, but its significance in stage I ultra-low rectal cancer remains unclear.
This exploratory supplemental analysis used data from Ultimate trial, a multicentre prospective phase II study across 47 Japanese institutions (2014-2017). Patients with cT1-2 N0 M0 ultra-low rectal cancer (≤ 5 cm from the anal verge) underwent laparoscopic resection. Tumour location was categorized as anterior (10-2 o'clock) or non-anterior (2-10 o'clock). The primary endpoint was LR; secondary endpoints included recurrence-free survival, overall survival, and stoma-free survival.
Of 300 enrolled patients, 297 were analysed (median follow-up 37.2 months); 93 tumours (31.3%) were anterior. Baseline characteristics, operative outcomes, and pathological findings were similar between the two groups. The 3-year cumulative LR rate was 11.9% for anterior tumours and 3.0% for non-anterior tumours (hazard ratio (HR) 4.46; 95% confidence interval (c.i.) 1.67 to 11.89; P = 0.001). Multivariable analysis showed an independent association between anterior location and LR (HR 4.68; 95% c.i. 1.72 to 12.74); subgroup analysis revealed no difference in clinical (c) T1 patients, but a significantly higher LR rate for anterior tumours in cT2 patients (25.3% versus 4.7%; P < 0.001). Three-year recurrence-free survival (83.9% for anterior tumours versus 88.9% for non-anterior tumours; P = 0.222), overall survival (> 95%), and stoma-free survival were comparable between the two groups.
Anterior tumour location in the ultra-low rectum was associated with an increased risk of LR, particularly in cT2 patients, highlighting the need for a more refined treatment strategy and vigilant monitoring.
This exploratory supplemental analysis used data from Ultimate trial, a multicentre prospective phase II study across 47 Japanese institutions (2014-2017). Patients with cT1-2 N0 M0 ultra-low rectal cancer (≤ 5 cm from the anal verge) underwent laparoscopic resection. Tumour location was categorized as anterior (10-2 o'clock) or non-anterior (2-10 o'clock). The primary endpoint was LR; secondary endpoints included recurrence-free survival, overall survival, and stoma-free survival.
Of 300 enrolled patients, 297 were analysed (median follow-up 37.2 months); 93 tumours (31.3%) were anterior. Baseline characteristics, operative outcomes, and pathological findings were similar between the two groups. The 3-year cumulative LR rate was 11.9% for anterior tumours and 3.0% for non-anterior tumours (hazard ratio (HR) 4.46; 95% confidence interval (c.i.) 1.67 to 11.89; P = 0.001). Multivariable analysis showed an independent association between anterior location and LR (HR 4.68; 95% c.i. 1.72 to 12.74); subgroup analysis revealed no difference in clinical (c) T1 patients, but a significantly higher LR rate for anterior tumours in cT2 patients (25.3% versus 4.7%; P < 0.001). Three-year recurrence-free survival (83.9% for anterior tumours versus 88.9% for non-anterior tumours; P = 0.222), overall survival (> 95%), and stoma-free survival were comparable between the two groups.
Anterior tumour location in the ultra-low rectum was associated with an increased risk of LR, particularly in cT2 patients, highlighting the need for a more refined treatment strategy and vigilant monitoring.
Authors
Kohyama Kohyama, Ohnuma Ohnuma, Tsukada Tsukada, Unno Unno, Watanabe Watanabe, Fukunaga Fukunaga, Hirano Hirano, Sakamoto Sakamoto, Hamamoto Hamamoto, Yoshimitsu Yoshimitsu, Horie Horie, Matsuhashi Matsuhashi, Kuriu Kuriu, Nagai Nagai, Hamada Hamada, Yoshioka Yoshioka, Hayama Hayama, Otsuka Otsuka, Inoue Inoue, Ueda Ueda, Toiyama Toiyama, Maruyama Maruyama, Yamaguchi Yamaguchi, Tanaka Tanaka, Suzuki Suzuki, Misumi Misumi, Naitoh Naitoh, Watanabe Watanabe, Ito Ito,
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