Tsuji Shigetsugu, Doyama Hisashi, Kobayashi Nozomu, Ohata Ken, Takeuchi Yoji, Chino Akiko, Takamaru Hiroyuki, Tsuji Yosuke, Hotta Kinichi, Harada Keita, Ikematsu Hiroaki, Uraoka Toshio, Murakami Takashi, Katagiri Atsushi, Hori Shinichiro, Michida Tomoki, Suzuki Takuto, Fukuzawa Masakatsu, Kiriyama Shinsuke, Fukase Kazutoshi, Murakami Yoshitaka, Ishikawa Hideki, Saito Yutaka
Department of Gastroenterology, Ishikawa Prefectural Central Hospital, Ishikawa, Japan.
Department of Gastroenterology, Tochigi Cancer Center, Tochigi, Japan.
Dig Endosc. 2024 Dec;36(12):1369-1379. doi: 10.1111/den.14878. Epub 2024 Aug 8.
This study investigated the incidence of lymph node metastasis and long-term outcomes in patients with T1 colorectal cancer where endoscopic submucosal dissection (ESD) resulted in noncurative treatment. It is focused on those with deep submucosal invasion, a factor considered a weak predictor of lymph node metastasis in the absence of other risk factors.
This nationwide, multicenter, prospective study conducted a post-hoc analysis of 141 patients with T1 colorectal cancer ≥20 mm where ESD of the lesion resulted in noncurative outcomes, characterized by poor differentiation, deep submucosal invasion (≥1000 μm), lymphovascular invasion, high-grade tumor budding, or positive vertical margins. Clinicopathologic features and patient prognoses focusing on lesion sites and additional surgery requirements were evaluated. Lymph node metastasis incidence in the low-risk T1 group, identified by deep submucosal invasion as the sole high-risk histological feature, was assessed.
Lymph node metastasis occurred in 14% of patients undergoing additional surgery post-noncurative endoscopic submucosal dissection for T1 colorectal cancer. In the low-risk T1 group, in the absence of other risk factors, the frequency was 9.7%. The lymph node metastasis rates in patients with T1 colon and rectal cancers did not differ significantly (14% vs. 16%). Distant recurrence was observed in one patient (2.3%) in the ESD only group and in one (1.0%) in the additional surgery group, both of whom had had rectal cancer removed.
The risk of lymph node metastasis or distant occurrence was not negligible, even in the low-risk T1 group. The findings suggest the need for considering additional surgery, particularly for rectal lesions (Clinical Trial Registration: UMIN000010136).
本研究调查了经内镜黏膜下剥离术（ESD）治疗后未达到根治效果的T1期结直肠癌患者的淋巴结转移发生率及长期预后情况。研究聚焦于那些存在深层黏膜下浸润的患者，在没有其他风险因素的情况下，该因素被认为是淋巴结转移的弱预测指标。
这项全国性、多中心、前瞻性研究对141例病变大小≥20 mm的T1期结直肠癌患者进行了事后分析，这些患者经ESD治疗后未达到根治效果，其特征为分化差、深层黏膜下浸润（≥1000μm）、淋巴管浸润、高级别肿瘤芽生或切缘阳性。评估了临床病理特征以及聚焦于病变部位和额外手术需求的患者预后情况。对以深层黏膜下浸润作为唯一高危组织学特征的低风险T1组患者的淋巴结转移发生率进行了评估。
在接受T1期结直肠癌非根治性内镜黏膜下剥离术后接受额外手术的患者中，14%发生了淋巴结转移。在低风险T1组中，在没有其他风险因素的情况下，发生率为9.7%。T1期结肠癌和直肠癌患者的淋巴结转移率无显著差异（分别为14%和16%）。仅接受ESD治疗的组中有1例患者（2.3%）出现远处复发，接受额外手术的组中有1例患者（1.0%）出现远处复发，这两名患者均接受了直肠癌切除手术。
即使在低风险T1组中，淋巴结转移或远处转移的风险也不可忽视。研究结果表明需要考虑进行额外手术，尤其是对于直肠病变（临床试验注册号：UMIN000010136）。
