The prognostic value of the HNK-1 (Leu-7) antigen in prostatic cancer--an immunohistochemical study

Abstract

前立腺癌組織におけるHNK-1抗原の発現を抗HNK-1抗体を用いてABC法での免疫組織化学的に検討した。HNK-1抗原は52例中49例に陽性で, その反応性は癌の組織分化度と相関した。高分化癌で陽性癌細胞の比率が最も高く, 低分化癌でもっとも低かった。進行癌での反応性は弱くなる傾向があったが, 各臨床病期間に統計学的に有意な反応性の違いはなかった。内分泌療法を受けた33例のstage D2症例について, HNK-1抗原が3分の2以上陽性のグループが3分の2未満のグループに比べて有意に良好な生存率と非進展率を示した

The anti-HNK-1 (Leu-7) monoclonal antibody (MAb) was revealed to be reactive with noncancerous and cancerous prostatic epithelial cells, although this antibody was originally found to be reactive against natural killer cells. However, the prognostic significance of HNK-1 antigen in prostatic cancer patients remains unknown. The expression of HNK-1 antigen on prostatic cancer was investigated immunohistochemically using the avidin-biotin-peroxidase complex (ABC) method with the anti-HNK-1 monoclonal antibody. Of the 52 patients with prostatic cancer, 49 patients (94%) showed reactivity to anti-HNK-1 MAb and the immunoreaction was associated with the histological differentiation of prostatic cancer. Well differentiated cancer showed the highest percentage of positively stained cancer cells and poorly differentiated cancer showed the lowest percentage. No statistically significant differences existed between groups classified by stage, although the more advanced cancers tended to have weaker reactions. The five-year survival rate and interval free of progression were then studied using the Kaplan-Meier method on 33 patients with stage D2 disease who had received endocrine therapy. The findings indicated that a high survival rate and a longer interval free of progression were associated with a higher fraction of positively stained cancer cells. In conclusion, the expression of HNK-1 antigen on prostatic cancer may be a useful prognostic factor in patients with prostatic cancer.