Table 2.

ORs and 95% CIs for bladder cancer associated with family history of cancer, stratified by selected characteristics of relatives

Cancer in relativesCases, n (%)Controls, n (%)OR* (95% CI)
First-degree relative with cancer
    None694 (59.9)808 (64.9)Reference (—)
    Any464 (40.1)436 (35.1)1.32 (1.11-1.59)
No. first-degree relatives with cancer
    1339 (29.3)345 (27.7)1.23 (1.01-1.50)
    ≥2125 (10.8)91 (7.4)1.67 (1.23-2.29)
Age at diagnosis of cancer in family member§
    ≤4562 (6.0)57 (4.9)1.42 (0.95-2.11)
    >45280 (27.0)288 (25.0)1.25 (1.01-1.54)
Family member with history of cancer
    Parents308 (30.7)287 (26.2)1.39 (1.13-1.71)
        Mother135 (16.3)124 (13.3)1.38 (1.03-1.85)
        Father191 (21.6)183 (18.5)1.42 (1.11-1.82)
    Siblings203 (22.6)187 (18.8)1.27 (1.00-1.62)
        Sister88 (11.3)74 (8.4)1.36 (0.96-1.94)
        Brother138 (16.6)131 (14.0)1.21 (0.91-1.60)
    Offspring25 (3.5)12 (1.5)2.24 (1.07-4.66)
        Daughter14 (2.0)8 (1.0)2.12 (0.86-5.27)
        Son11 (1.6)4 (0.5)2.46 (0.71-8.47)
  • * After adjustment by unconditional logistic regression for age, gender, area, and smoking status of the subjects and average lifetime trihalomethane levels (μg/L).

  • Reference category for all comparisons.

  • χ2 test for trend, P = 0.0004.

  • § If more than one first-degree relative had cancer, the youngest at age at diagnosis was considered.