Clinical Significance of Tumor Surface Desmoplastic Reaction as a Predictor of Lymph Node Metastasis in Colorectal Cancer with Submucosal Invasion

Tomoo Watanabe, Shinji Kasamaki, Ken Kawai, Morio Sasaki, Mitsuhiro Matsuda, Yuichi Tomiki, Kazuhiro Sakamoto and Toshiki Kamano

Department of Coloproctological Surgery, Juntendo University School of Medicine

Purpose: We studied the usefulness of tumor desmoplastic reaction (DR) as a predictor of lymph node metastasis in colorectal cancers with submucosal invasion. Methods: Subjects were 59 patients who underwent surgical resection of colorectal cancer with submucosal invasion, 9 cases (15.3%) of whom were positive for lymph node metastasis (n). Clinicopathological factors and DR expression, especially DR expression on the tumor surface and DR expression in preoperative biopsy specimens were also studieded. DR was identified by immunohistochemistry, and a result of α-SMA (+) and desmin (-) was defined as DR-positive. Results: DR expression was observed in 50 of 59 cases (84.7%) of colorectal cancers with submucosal invasion, while DR expression on the tumor surface was found in 24 cases (41.4%). In the depth of cancer invasion, DR expression was observed in 8 of 14 (57.1%) sm1 cases compared to 42 of 43 (93.3%) sm2, 3 cases, with a significantly higher rate in sm2, 3 cases. DR expression on the tumor surface was seen in 16 of 50 (32%) n (-) cases compared to 8 of 9 (88.9%) n (+) cases, with a significantly higher rate in n (+) cases. Among 24 tumor surface DR-positive cases, preoperative biopsies were conducted in 21, yielding 45 samples. Some 22 of the 45 biopsy samples (48.8%) were also found to express DR. Among 9 n (+) cases, 7 underwent preoperative biopsies and 6 (85.71%) were DR-positive in biopsy samples. Conclusion: Our results indicated the usefulness of tumor surface DR expression as a predictor of lymph node metastasis in colorectal cancers with submucosal invasion, and suggests the possibility of predicting lymph node metastasis from DR expression in preoperative biopsy specimens.

Key words
colorectal cancer with submucosal invasion, desmoplastic reaction, lymph node metastasis, immunohistochemistry

Reprint requests
Tomoo Watanabe Department of Coloproctological Surgery, Juntendo University School of Medicine
2-1-1 Hongo, Bunkyo-ku, 113-8421 JAPAN

Accepted
May 25, 2005

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