The essential problem of over-measuring the depth of submucosal invasion in pT1 colorectal cancer

• Published in: Virchows Archiv : an international journal of pathology 2022-02, Vol.480 (2), p.323-333
• Main Authors: Aizawa, Daisuke, Sugino, Takashi, Oishi, Takuma, Hotta, Kinichi, Imai, Kenichiro, Shiomi, Akio, Notsu, Akifumi, Ikegami, Masahiro, Shimoda, Tadakazu
• Format: Article
• Language: English
• Subjects: Cancer; Colon; Colon cancer; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - pathology; Endoscopy; Humans; Invasiveness; Lymph nodes; Lymphatic Metastasis; Medicine; Medicine & Public Health; Metastases; Neoplasm Invasiveness - pathology; Original Article; Pathology; Patients; Rectal Neoplasms; Retrospective Studies; Risk analysis; Risk Factors
• ISSN: 0945-6317; 1432-2307
• DOI: 10.1007/s00428-021-03221-3

A depth of submucosal invasion (DSI) of ≥1000 μm is an important risk factor for lymph node metastasis (LNM) in patients with submucosal invasive (pT1) colorectal cancer (CRC), according to the European Society of Gastrointestinal Endoscopy and the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines. According to the latter, if the location of the muscularis mucosae in the invasive area is not confirmed, the DSI can be measured from the surface. In these cases, a ‘remaining intramucosal lesion’ (rIL), which is in the invasive area, is sometimes observed. To avoid over-measuring the DSI, we proposed a ‘modified DSI’ (mDSI), which excludes the rIL from the JSCCR DSI. We investigated the characteristics and effectiveness of the rIL and mDSI by grouping cases with polypoid growth (PG) and non-polypoid growth (NPG) histologically. Three hundred and thirty-nine consecutive patients with pT1 CRC were examined. LNM was detected in 37 cases. The distribution of the DSI and rIL was significantly higher in PG than in NPG cases ( P