Heyns C F, van der Merwe A
Department of Urology, University of Stellenbosch, Tygerberg Hospital, Tygerberg, South Africa.
Can J Urol. 2008 Feb;15(1):3899-908.
Accurate epidemiological data about the incidence and mortality of bladder cancer are unavailable for most African countries. Transitional cell carcinoma (TCC) of the bladder is probably less common in rural African regions than in industrialized countries, due to lower levels of exposure to carcinogenic chemicals. In areas with endemic schistosomiasis (bilharzia) caused by parasitic schistosomes (blood flukes), most bladder cancer cases are comprised of squamous cell carcinoma (SCC). However, with increased urbanization, industrialization, and cigarette smoking in many African countries, there is an increasing incidence of TCC relative to SCC of the bladder. SCC of the bladder presents in patients who are on average 10 to 20 years younger than those with TCC. In Egypt and other North African countries, SCC is more common in men (the male to female ratio ranges from 3:1 to 5:1), probably because boys and men performing agricultural work are more exposed to schistosomiasis-infested water. In some sub-Saharan countries, SCC of the bladder is equally common in men and women, probably due to equal schistosomiasis exposure of girls and boys, and because women obtain household water and perform most agricultural tasks. Although SCC of the bladder often presents at a locally advanced stage, the tumors are usually well differentiated, with a relatively low incidence of lymphatic and hematogenous metastases. Patients with localized SCC are ideal candidates for cystectomy and orthotopic neobladder construction, because they are relatively young and healthy, and there is no risk of urethral recurrence, unlike with TCC. Unfortunately, many patients in Africa still present with advanced and inoperable bladder cancer, and many do not have access to healthcare facilities that can provide a cure and a good quality of life by means of radical cystectomy and neobladder construction.
大多数非洲国家都没有关于膀胱癌发病率和死亡率的准确流行病学数据。由于接触致癌化学物质的水平较低,非洲农村地区膀胱移行细胞癌(TCC)的发病率可能低于工业化国家。在由寄生血吸虫(血吸虫)引起的地方性血吸虫病(血吸虫病)流行地区,大多数膀胱癌病例为鳞状细胞癌(SCC)。然而,随着许多非洲国家城市化、工业化进程的加快以及吸烟人数的增加,相对于膀胱SCC,TCC的发病率正在上升。膀胱SCC患者的平均年龄比TCC患者小10至20岁。在埃及和其他北非国家,SCC在男性中更为常见(男女比例在3:1至5:1之间),这可能是因为从事农业工作的男孩和男性更容易接触受血吸虫病感染的水。在一些撒哈拉以南国家,膀胱SCC在男性和女性中同样常见,这可能是因为女孩和男孩接触血吸虫病的机会均等,而且女性负责家庭用水并承担大部分农业任务。尽管膀胱SCC通常在局部晚期出现,但肿瘤通常分化良好,淋巴和血行转移的发生率相对较低。局限性SCC患者是膀胱切除术和原位新膀胱构建的理想候选者,因为他们相对年轻且健康,而且与TCC不同,不存在尿道复发的风险。不幸的是,非洲许多患者就诊时仍患有晚期且无法手术的膀胱癌,而且许多人无法获得能够通过根治性膀胱切除术和新膀胱构建提供治愈方法和良好生活质量的医疗设施。