卡介苗(BCG)之膀胱湒注治療在減少淺層膀胱癌預防復發以及治療膀胱原位癌(Carcinoma in situ)之價值已受肯定。為進一步了解BCG在膀胱癌作用之機轉，我們致力於以MBT-2膀胱癌細胞生長於C3H/HeN鼠之動物糢式的一些研究，我們的初步結果包括：1.有適當劑量之BCG與MBT-2細胞之混合液可使其植於動物上之腫瘤生長受到抑制。2.BCG菌可吸附於MBT-2細胞之細胞膜上，而其吸附於腫瘤細胞之多少與其吸附於腫瘤之能力有關。3.當BCG與MBT-2細胞之混合培養時，BCG對腫瘤細胞並無毒殺作用或生長抑制之作用。4. 當BCG與MBT-2細胞之混合液種植於CH3/HeN鼠上後，不僅可抑制原之腫瘤生長，亦可抑制異位之腫瘤生長。由以上之發現暗示著”BCG”與腫瘤細胞之接觸可使動物產生強的免疫作足以抑制種植之腫瘤生長。

Bacillus Calmette-Guerin (BCG) intravesical therapy has been confirmed its value in reducing the recurrent rate of superficial bladder cancer and in inducing the remission of carcinoma in situ. For better understanding the mechanism of BCG on bladder cancer, we have devoted some studies using the MBT-2 tumor cells and C3H/HeN mice models. Our primitive results demonstrated: 1.Only appropriate dose of BCG-tumor cells mixture could induce the suppression of implanted tumor growth. 2. BCG could attach to the cell membrane of MBT-2 tumor cell. The bacteria-tumor cells adhesion is correlated to its antitumor activity. 3. There is no evidence of cytotoxicity or change the growth rate of MBT-2 tumor cells when it is cocultured with BCG. 4. Implantation of BCG-tumor cells mixture in one site of animal could prevent the rumor growth not only in the original site but also in the other site. These findings imply that direct contact of BCG to the tumor cells might induce strong systemic immunity enough to suppress the growth of implanted tumors.