world cancer report - iarc
world cancer report - iarc
world cancer report - iarc
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BLADDER CANCER<br />
SUMMARY<br />
> Bladder <strong>cancer</strong> is the ninth most common<br />
<strong>cancer</strong> <strong>world</strong>wide, with 330,000<br />
new cases and more than 130,000<br />
deaths per year.<br />
>Bladder <strong>cancer</strong> is primarily attributable<br />
to smoking, which accounts for 65% of<br />
male and 30% of female cases in some<br />
developed countries. Other less important<br />
causes include analgesic abuse<br />
(phenacetin), some types of <strong>cancer</strong><br />
chemotherapy and, historically, occupational<br />
exposure to chemicals such as 2naphthylamine.<br />
In Egypt and some Asian<br />
regions, chronic cystitis caused by<br />
Schistosoma haematodium infection is<br />
a major risk factor.<br />
> Treatment based on endoscopy, surgery,<br />
radiotherapy and cytotoxic drugs often<br />
permits long-term survival in developed<br />
countries, where 65% of patients live for<br />
at least five years after diagnosis.<br />
Definition<br />
More than 90% of bladder <strong>cancer</strong>s are<br />
transitional cell carcinomas. Much less<br />
common are adenocarcinoma (6%), squamous<br />
cell carcinoma (2%) and small cell<br />
carcinoma (less than 1%).<br />
Epidemiology<br />
Bladder <strong>cancer</strong> accounts for approximately<br />
two-thirds of all urinary tract <strong>cancer</strong>s. By<br />
incidence, bladder <strong>cancer</strong> is the ninth most<br />
common <strong>cancer</strong> <strong>world</strong>wide, although in the<br />
USA, for example, bladder <strong>cancer</strong> is the<br />
fourth most frequent tumour among men.<br />
Approximately 336,000 new cases<br />
occurred in 2000, two-thirds of which were<br />
in developed countries [1]. Incidence and<br />
mortality rise sharply with age and about<br />
two-thirds of cases occur in people over the<br />
age of 65. The male:female ratio is approximately<br />
3:1. High incidence rates (>12 per<br />
100,000 men and >3 per 100,000 women)<br />
228 Human <strong>cancer</strong>s by organ site<br />
< 3.2<br />
< 5.3<br />
Fig. 5.81 The global incidence of bladder <strong>cancer</strong> in men. Although the majority of cases occur in developed<br />
countries, bladder <strong>cancer</strong> also occurs at high rates in some developing countries, including parts<br />
of Northern Africa and South America.<br />
are observed throughout Southern,<br />
Western and Northern Europe, North<br />
America, Australia, Western Asia, Northern<br />
Africa and Uruguay (Fig. 5.81) Bladder <strong>cancer</strong><br />
incidence is either rising moderately or<br />
is steady in most developed countries.<br />
About 132,000 people each year die from<br />
bladder <strong>cancer</strong>, men throughout the <strong>world</strong><br />
having a mortality rate of 10 per 100,000<br />
population, and women 2.4, although these<br />
values nearly double for developed countries.<br />
Etiology<br />
The most important risk factor for bladder<br />
<strong>cancer</strong> is cigarette smoking, which<br />
accounts for approximately 65% of male<br />
cases and 30% of female cases in populations<br />
of developed countries [2]. It is likely<br />
that smokers of black (air-cured) tobacco<br />
are at a greater risk than smokers of<br />
blond (flue-cured) tobacco and this may<br />
explain some of the disparity observed in<br />
European incidence rates and also the<br />
high incidence observed in Uruguay. The<br />
< 9.2<br />
< 15.5<br />
Age-standardized incidence/100,000 population<br />
< 45.3<br />
risk associated with tobacco smoking, and<br />
in particular with black tobacco smoking,<br />
is likely to be due to the presence in the<br />
smoke of aromatic amines including benzidine,<br />
4-aminobiphenyl, 2-naphthylamine<br />
and 4-chloro-ortho-toluidine. Bladder <strong>cancer</strong><br />
risk increases approximately linearly<br />
with duration of smoking, reaching a fivefold<br />
risk after 40 years (Fig. 5.82). The risk<br />
also increases with the number of cigarettes<br />
smoked, up to approximately 20<br />
cigarettes per day; above that level, no further<br />
increase in risk is observed. Upon<br />
smoking cessation, a substantial decrease<br />
in risk of bladder <strong>cancer</strong> is observed within<br />
several years, implying an effect in late<br />
stages of the carcinogenic process.<br />
Work in the rubber and dyestuff industries<br />
and specifically occupational exposure to<br />
aromatic amines, particularly including 2naphthylamine<br />
and benzidine, are correlated<br />
with a high risk of bladder <strong>cancer</strong> [3].<br />
Exposure to polycyclic aromatic hydrocarbons,<br />
polychlorinated biphenyls, formaldehyde,<br />
asbestos and solvents, and work in