Wednesday, September 15, 2010

Do Women Develop Bladder Cancer, and what are the Risks?

Like men, women can develop cancer of the bladder. The most common type is called urothelial carcinoma, previously known as transitional cell carcinoma. It is the 8th most common cancer in women, and of all new bladder cancer diagnoses a year, women make up 20% of them. It has been either under-diagnosed, under –appreciated or under-suspected in women because the usual presenting sign of bladder cancer, blood in the urine, can often be assumed to be a urinary tract infection, which women experience commonly, and thus not suspected.

Bladder cancer is most often non-invasive at diagnosis, but requires periodic bladder endoscopy, xrays and bladder treatments to reduce the risk of recurrence which can be high. In about 15% of cases, bladder cancer is diagnosed as being “muscle-invasive”, which in healthy patients is best treated by complete bladder removal. This requires either reconstructing a “new bladder”, or having a urinary ostomy to drain urine. Chemo and radiation are sometimes necessary when bladder cancer is invasive.

Risks for bladder cancer are toxins, most commonly smoking, environmental exposure to arsenic, and certain “aromatic amines”, or chemicals used in the coloring/dye industry, which are less common these days. Theories exist that certain nutrients, when excreted in the urine, and after contacting the bladder lining on a chronic basis, can lead to tumor formation. However, a recent report published in Cancer investigated whether eating meat contributes to bladder cancer, via potential carcinogenic compounds found in meat, related to cooking and processing. Prior evidence connecting meat and carcinogenesis has been inconsistent.

Nitrates and nitrites, found in meat, are hypothesized to promote carcinogenesis. They are used to preserve color and flavor. They are converted to compounds that have been shown to induce tumors in many different organs, including the bladder.

Following over 300,000 men and women over a 7 year period between the ages of 50 and 71, of whom a fraction developed bladder cancer, food questionnaires were answered as a part of a very large Diet and Health Study.

What was found?

There was a borderline, statistically significant increased risk of bladder cancer only for those who were the highest consumers of red meat, mainly from processed red meat and not unprocessed. No association was seen with beef, bacon, hamburger, sausage, or steak. Overall, there was only an association with dietary nitrites in those that were the highest consumers. The researchers conclude that this study provides some limited evidence for an association between dietary nitrites and bladder cancer. This underscores the common sense approach to eating, which is, all things in moderation, but it’s no reason to skip the BBQs.

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