Table 1.
Characteristics of studies that analyzed red meat or processed meat consumption and bladder cancer.
| Type of Study |
Number of Patients Enrolled |
Exposure Variable (Definition) | OR | RR | HR | 95% CI | Years of Follow-Up (Median) |
Adjustments | Remarks | References |
|---|---|---|---|---|---|---|---|---|---|---|
| MA | 1,520,308 | Total red meat | - | 1.15 | - | 0.97–1.36 | - | Age, sex, smoking, geographic region, total energy, BMI, study design | increased by 25% the risk of BC for red meat in the population of USA | [21] |
| CC | 744 | Salted meat | 18.3 | - | - | 4.6–71.9 | 1 | Age, sex, smoking, BMI, total calories, education, urban/rural status and ‘mate’ drinking | the risk was especially elevated among long-term smokers | [22] |
| CC | 1660 | Salami/pastrami/corned beef or liver | 1.76 | - | - | 1.09–2.85 | 9 | Age, gender, race/ethnicity | associated with risk of BC, particularly among nonsmokers | [23] |
| CO H | 135,893 | Beef, pork or lamb | - | 1.59 | - | 1.06–2.37 | 22 | Age, smoking, caloric intake, geographic region and total fluid intake | elevated risk among men and women who consumed 5 servings of bacon/wk | [24] |
| CC | 956 | Red meat | 1.8 | - | - | 1.1–3.0 | 3 | sex, age, smoking status, smoking duration, smoking amount | consumption of red meat at least 5 times a week induced a 2-fold increase OR than the consumption of meat less than once a week | [25] |
| MA | processed meat (salting, fermentation | - | - | - | Age, gender, smoking | [26] | ||||
| 1,066,027 | Smoking or other processes | 1.20 | 1.06–1.37 | A 20% increase in the risk of BC is associated with an increase of 50 g of processed meat per day | ||||||
| CC | 13,050 | Salted meat | 2.23 | - | 1.63–3.04 | 7 | Age, sex, residence, education, family history of BC, high-risk occupation, body mass index, years smoked, and total energy intake | intake of salted meat is associated with a greater risk of BC | [27] | |
| CC | 3149 | processed meat | 1.23 | - | - | 1.03–1.47 | 7 | sex, age, education, smoking, alcohol drinking, BMI, vegetable and fruit consumption, and total energy intake | a moderate risk of hormone-dependent tumors in women with an elevated processed meat intake | [28] |
| CC | 1355 | processed meat (stewed and roasted) | 1.57 (read meat) 1.47 (stewed) 1.41 (roasted) |
- | - | 1.07–2.31 1.03–2.09 1.00–1.99 |
11 | sex and smoking | consumption of meat increased the risk of BC, especially when it is roasted or stewed | [29] |
| CO H | 82,002 | Red meat (beef, pork, meatballs, hamburger, veal and kidney or liver) | - | - | 1.05 (Total meat) 1.0 (Red meat) 1.01 (Processed meat) |
0.71–1.55 0.71–1.41 0.80–1.28 |
9 | Age, sex, smoking, education and total energy intake | no association between the intake of total or any specific type of meat | [30] |
| CO H | 481,419 | Meat intake | - | - | 1.06 | 0.99–1.13 | Total energy intake, smoking, education and BMI | no overall association between intake of red meat and BC | [31] | |
| MA | 7022 | Meat intake | - | 1.08 | - | 0.82–1.42 | - | Smoking | a diet with a high content in fruits and vegetables may prevent bladder cancer | [32] |
| MA | - | Meat intake | - | 1.04 | - | 0.80–1.27 | - | Age, sex and smoking | A low increase in the risk of BC with high processed meat consumption | [33] |
| CO H | 1,922,817 | Meat intake | - | - | 1.22 | 0.96–1.54 | 9 | Age, sex, smoking, vegetables beverages fruit and total energy | possible increased risk of BC with PhIP (2-amino-1-methyl-6-phenylimidazo [4, 5-b]pyridine) exposure | [34] |
| CC | 2589 | Meat and processed meat intake | 1.28 (Meat) 1.41 (Processed meat) |
- | - | 1.00–1.65 1.08–1.84 |
3 | Gender, age, education, race, smoking, BMI, and total energy | meat cooking methods are not associated with BC risk | [35] |
| CC | 273 | Meat intake | - | 1.20 | - | 0.7–2.1 | - | Age, sex, smoking, energy | an increased cancer risk when the intake of heterocyclic amines is high (above 1900 ng daily) | [36] |
| COH | 518,545 | Meat intake | - | - | 1.18 | 1.03–1.36 | - | age, sex, smoking, total energy intake, and vegetables and fruits consumption | meat consumption may be associated with BC development | [37] |
| COH | 101,721 | Processed meat | - | 1.47 | - | 1.12–1.93 | 12.5 | age, sex, race, BMI, smoking, alcohol drinking, total energy intake, and family history of any cancer type | a higher risk of BC is associated with intake of processed red meat | [38] |
CC: Case-Control; COH: Cohort study; MA: Meta-analysis; BC: bladder cancer.