Table 1.
Study characteristics of published cohort and case-control studies on vitamin C and E and bladder cancer
| Authors and publication year | Study design | Country | Study period | Sex | Age | Cases/subjects | Anatomical site | Parameters examined | Study quality* | Variables of adjustment |
|---|---|---|---|---|---|---|---|---|---|---|
| Risch et al. 1988 | PCC | Canada | 1977-1982 | M/W | 35-79 | 826/1618 | Bladder | Vitamin C: diet | 7 | Age, sex, area of residence, smoking, and history of diabetes |
| Steineck et al. 1990 | PCC | Sweden | 1985-1987 | M/W | 40-74 | 418/929 | Urothelium | Vitamin C: diet and supplement | 7 | Age, sex, and smoking |
| Nomura et al. 1991 | PCC | USA | 1977-1986 | M/W | 30-93 | 261/783 | Urothelium | Vitamin C: diet, supplement and total | 8 | Age, sex, ethics, and smoking |
| Riboli et al. 1991 | PCC | Spain | 1985-1986 | M | < 80 | 432/1224 | Bladder | Vitamin C: diet Vitamin E: diet | 8 | Age, sex, smoking, and total calories |
| Shibata et al. 1992 | Cohort | USA | 1981-1989 | M | 65-84 | 71/70159 | Bladder | Vitamin C: diet and supplement Vitamin E: supplement | 5 | Age and smoking |
| Bruemmer et al. 996 | PCC | USA | 1981-1984 | M/W | 45-65 | 262/667 | Bladder | Vitamin C: diet, supplement and total Vitamin E: diet, supplement and total | 8 | Age, sex, county, smoking, and calories |
| Michand et al. 2000 | Cohort | USA | 1986-1998 | M | 40-75 | 320/51529 | Bladder | Vitamin C: supplement and total Vitamin E: supplement and total | 7 | Age, energy, pack-years of smoking history, current smoking status, geographic region of the United States, cruciferous vegetable intake, and total fluid intake |
| Wakai et al. 2000 | HCC | Japan | 1996-1999 | M/W | 20-99 | 297/692 | Bladder | Vitamin C: diet and total Vitamin E: diet and total | 6 | Age, sex, and smoking and occupational history as a cook |
| Zeegers et al. 2001 | Cohort | Netherlands | 1986-1992 | M/W | 55-69 | 569/3692 | Urinary tract | Vitamin C: total Vitamin E: total | 8 | Age, sex, cigarette smoking amount and cigarette smoking duration |
| Michand et al. 2002 | Cohort | Finland | 1985-1998 | M | 50-69 | 344/27111 | Bladder | Vitamin C: diet Vitamin E: diet | 7 | Age, duration of smoking, smoking dose, total energy, and trial intervention |
| Castelao et al. 2004 | PCC | USA | 1987-1996 | M/W | 25-64 | 1592/3184 | Bladder | Vitamin C: diet | 8 | Age, sex, education, number of cigarettes smoked per day, number of years of smoking, smoking status, lifetime use of nonsteroidal anti-inflammatory drugs, and number of years employed as a hairdresser/barber |
| Holick et al. 2005 | Cohort | USA | 1980-2000 | W | 30-55 | 237/88796 | Bladder | Vitamin C: total Vitamin E: total | 7 | Age, pack-years of cigarette smoking, current smoking, and total caloric intake |
| Kellen et al. 2006 | PCC | Belgium | 1999-2004 | M/W | Not mentioned | 178/540 | Bladder | Vitamin C: diet Vitamin E: diet | 7 | Sex, age, smoking status, number of cigarettes smoked per day, number of years smoking and occupational exposure to PAH or aromatic amines, total fruit and vegetable consumption, intake of vitamin E and C and TAS |
| Garcı´a-Closas et al. 2007 | HCC | Spain | 1998-2001 | M/W | Not mentioned | 912/1789 | Bladder | Vitamin C: diet Vitamin E: diet | 6 | Age, gender, region, smoking status and duration of smoking |
| Roswall et al. 2009 | Cohort | Denmark | 1993-2006 | M/W | 50-64 | 322/55557 | Urothelium | Vitamin C: diet, supplement and total Vitamin E: diet, supplement and total | 8 | Age, intake of vitamin C, vitamin E, and beta-carotene, smoking status, smoking duration, smoking intensity, passive smoking, and work exposure |
| Brinkman et al. 2010 | PCC | USA | 1997-2001 | M/W | 25-74 | 322/561 | Bladder | Vitamin C: total Vitamin E: total | 8 | Age, sex, smoking status, and total energy intake |
| Hotaling et al. 2011 | Cohort | USA | 2000-2007 | M/W | 50-76 | 330/77050 | Bladder | Vitamin C: supplement Vitamin E: supplement | 8 | Age, sex, race, education, family history of bladder cancer, smoking status/recency of smoking, pack-years of smoking, servings per day of fruits, and servings per day of vegetables |
| Wu et al. 2012 | PCC | USA | 2001-2004 | M/W | 30-79 | 1418/2589 | Bladder | Vitamin C: diet Vitamin E: diet | 8 | Age, gender, region, race, Hispanic status, smoking status, usual BMI, and total energy |
| Ros et al. 2012 | Cohort (nested) | Eurpoe | 1990-2005 | M/W | 25-70 | 856/1712 | Urothelium | Vitamin C: diet | 8 | Age at blood collection, study center, sex, date of blood collection, time of blood collection, and fasting status and further adjusted for smoking status, duration, and intensity |
| Park et al. 2013 | Cohort | USA | 1993-2007 | M/W | 45-75 | 581/185885 | Bladder | Vitamin C: diet Vitamin E: diet | 8 | Age, ethnicity, total energy intake, family history, employment in a high-risk industry, smoking, number of years since quitting, interactions of ethnicity with status |
FFQ, food-frequency questionnaire; HCC, hospital-based case-control study; PCC, population-based case-control study;
*
evaluated by 9-star Newcastle-Ottawa Scale.