Influence of blood group type on the natural history of superficial bladder cancer

The blood group was correlated with the grade and stage at diagnosis, and with the subsequent clinical course in 494 patients with bladder cancer treated at our institution from 1977 to 1986 who were followed for a mean of 5.5 years (range 2 to 9 years). The distribution of blood groups was similar to that reported for the general population and to that of 100 consecutive patients with urolithiasis used as controls, and the distribution was not different among patients with superficial cancer (stages O and A) than in those with advanced disease (stage B or higher). However, among patients with superficial disease high grade (III or IV) lesions were more frequent in those with blood group O (36 per cent) than in those with other blood groups (13 to 18 per cent) (p less than 0.001). In addition, in patients with superficial cancer of all grades progression to advanced disease was significantly greater among those with blood group O (37 per cent) than in those with other groups (12 to 16 per cent) (p less than 0.05). More importantly, in patients with low grade (I or II) superficial cancer development of advanced disease was significantly more frequent among those with blood group O (24 per cent) than in those with other blood groups (0 to 7 per cent) (p less than 0.004). Our findings suggest that individual genetic factors influence the natural history of superficial bladder cancer. The molecular basis of this phenomenon remains to be elucidated.