Tobacco smoking is the main known contributor to urinary<unk> ; in most populations, smoking is associated with over half of<unk>  cases in men and one-third of cases among women, however these proportions have reduced over recent years since there are fewer smokers in Europe and North America. There is an almost linear relationship between smoking duration (in years), pack years and<unk>  risk. A risk plateau at smoking about 15 cigarettes a day can be observed (meaning that those who smoke 15 cigarettes a day are approximately at the same risk as those smoking 30 cigarettes a day). Smoking (cigar, pipe, Egyptian waterpipe and smokeless tobacco) in any form increases the risk for<unk> . Quitting smoking reduces the risk. Risk of<unk>  decreases by 30% within 1–4 years and continues to decrease by 60% at 25 years after smoking cessation. However, former smokers will most likely always be at a higher risk of<unk>  compared to people who have never smoked. Passive smoking also appear to be a risk. Opium consumption increases the risk of<unk>  by 3-fold and concurrent use of opium and smoking increases the risk of<unk>  by 5 times compared to the general population. Thirty percent of<unk>  tumors probably result from occupational exposure in the workplace to carcinogens. Occupational or circumstantial exposure to the following substances has been implicated as a cause of<unk> ; benzidine (dyes manufacturing), 4-aminobiphenyl (rubber industry), 2-naphtylamine (azo dyes manufacturing, foundry fumes, rubber industry, cigarette smoke and cancer research), phenacetin (analgesic), arsenic and chlorinated aliphatic hydrocarbons in drinking water, auramine (dye manufacturing), magenta (dye manufacturing), ortho-toluidine (dye manufacturing), epoxy and polyurethane resin hardening agents (plastics industry), chlornaphazine, coal-tar pitch. Occupations at risk are bus drivers, rubber workers, painters, motor mechanics, leather (including shoe) workers, blacksmiths, machine setters, and mechanics. Hairdressers are thought to be at risk as well because of their frequent exposure to permanent hair dyes. Infection with Schistosoma haematobium (bilharzia or schistosomiasis) may cause<unk> , specially of the squamous cell type. Schistosoma eggs induces a chronic inflammatory state in the<unk>  wall resulting in tissue fibrosis. Higher levels of N-nitroso compounds has been detected in urine samples of people with schistosomiasis. N-Nitroso compounds have been implicated in the pathogenesis of schistosomiasis related<unk> . They cause alkylation DNA damage, specially Guanine to Adenine transition mutations in the HRAS and p53 tumor suppressor gene. Mutations of p53 are detected in 73% of the tumors, BCL-2 mutations accounting for 32% and the combination of the two accounting for 13%. Other causes of squamous cell carcinoma of the<unk>  include chronic catheterizations in people with a spinal cord injury and history of treatment with cyclophosphamide. Ingestion of aristolochic acid present in many Chinese herbal medications has been shown to cause urothelial carcinoma and kidney failure. Aristolochic acid activates peroxidase in the urothelium and causes transversion mutation in the TP53 tumor suppressor gene. People who undergo external beam radiotherapy (EBRT) for prostate cancer have a higher risk of developing invasive<unk> . In addition to these major risk factors there are also numerous other modifiable factors that are less strongly (i.e. 10–20% risk increase) associated with<unk> , for example, obesity. Although these could be considered as minor effects, risk reduction in the general population could still be achieved by reducing the prevalence of a number of smaller risk factor together.
Bladder cancer
Interstitial cystitis
Urethral cancer
Ureteral cancer
Acute prostatitis
Prostate cancer
Penile cancer
Pyonephrosis