ABC of Urology: UROLOGICAL MALIGNANCY—II: UROTHELIAL TUMOURS

Epidemiology of urothelial tumours

Tumours of the urinary tract vary in type. Less than 1% of cases of bladder cancer in Britain are due to squamous cell carcinoma (although 75% of cases in Egypt are), and less than 2% of primary bladder cancers are adenocarcinomas. Adenocarcinomas of the rectum, uterus, breast, ovary, and prostate may metastasise to the bladder, and very rarely adenocarcinoma may also arise in a urachal remnant.

Most bladder cancers are transitional cell carcinomas, and the incidence in men is nearly three times that in women. Bladder cancer is currently the fourth most common cancer in men, after prostate cancer, lung cancer, and colorectal cancer).

Several factors are associated with the development of bladder cancer. Occupational exposure to chemicals is thought to precipitate up to one third of bladder cancers. The risk of developing bladder cancer in people who smoke is four times that in nonsmokers, and a third of all bladder cancers may be related to cigarette smoking. (Nitrosamines and 2-naphthylamine have been found in cigarette smoke and may be the causative agents.) All patients with bladder cancer should be told of this relation to smoking and be strenuously encouraged to stop smoking immediately. Chronic cystitis, from any cause, increases the risk of developing squamous cell carcinoma of the bladder. Cystitis related to schistosomiasis is worldwide the most common cause of this form of cancer. Bladder calculi may cause a chronic cystitis and over a long period may predispose to squamous cell carcinoma.

Symptoms and signs of bladder tumours

Most patients with bladder cancer present with painless haematuria. Some patients present with pronounced irritative bladder symptoms, and …