Bladder Cancer Statistics and Characteristics
In the US, bladder cancer accounts for around 7% of all cancer cases and accounts for about 3% of all fatalities (Kumar and Robbins 662).
Types of Bladder Cancer
Urothelial carcinomas account for around 90% of bladder malignancies, which are the most common type. With a 3:1 male to female ratio, men are more likely than women to develop bladder cancer. Furthermore, industrialized nations have higher rates of these tumors, possibly as a result of carcinogen buildup in the urinary tract. The population in cities is more prevalent. Approximately 80% of the patients are in the 50–80 age range. In America, only about seven percent of the cancers of the bladder are urothelial carcinomas, making about ninety percent. The prevalence of bladder carcinoma is more in men than in women with a male to female ratio of 3:1. Furthermore, these cancers are more common in industrialized countries, possibly because of accumulations of carcinogens in the urinary tract. The urban population shows more prevalence. The majority of patients (about 80%) are between 50-80 years of age. In America, only about seven percent of the cancers of the bladder are squamous cell carcinomas (SCC). However, the prevalence of SCC is much more common in areas where urinary schistosomiasis is more common. Examples of such countries are Egypt and Sudan. Carcinomas have extensive keratinization. They are usually associated with longstanding irritation of the bladder and its infection. The adenocarcinomas of bladders (rare) have histological similarity with those of gastrointestinal tract. Some adenocarcinomas come from the remains of the urecha in the dome of the bladder. Others, however, are found in association with large metaplasia of the intestines (Kumar and Robbins 662).
Risk Factors for Bladder Cancer
There are many potential risk factors for bladder cancer. The most common predisposing factor is cigarette smoking. There are many potential carcinogens in cigarette including nitrosamine, 2-naphthylamine, and 4-aminobiphenyl. Another risk factor is industrial exposure to aromatic amines in dyes, paints, solvents, leather dust, inks, combustion products, rubber, and textiles. There is documentation that previous irradiation, for example, radiotherapy treatment in the pelvic area predisposing to bladder carcinoma. Moreover, exposure to acrolein increases the probability of getting carcinoma of cancer. This compound is a urinary metabolite of cyclophosphamide. Lastly, artificial sweeteners like saccharin and cyclamate have implication in bladder cancer exposure (Kumar and Robbins 664).
Genetic Alterations in Bladder Cancer
There are many alterations in the genetic component in bladder cancers. In about 30 to 60 percent of the cases, there is monosomy of chromosome 9. There are also the deletions of the long and short arm of chromosome 9. However, there are deletions of other chromosomal arms including 17p, 13q, 11p, and 14q. In the superficial papillary tumors, the only genetic change is the deletion of chromosome 9. Such is also the case for flat noninvasive tumors. The deletions of the short arm of chromosome 9, subsection 21, relates to p16 which is a tumor suppressor gene. This gene encodes an inhibitor of CDK and p15, which is a related tumor suppressor gene (Kumar and Robbins 667). The locus of second tumor suppressor on the 9th chromosome is unknown. Mutations in the p53 gene have great contribution in the progression of this carcinoma. Such is because the genetic analysis show deletions of short arm of chromosome 17 including the region that codes for p53 gene and actual mutation of p53 itself. The alterations of p53 gene is also in Carcinoma in situ (Martin-Doyle and Kwiatkowski 60). On reviewing the alterations in the order of frequency, the TCGA and Beijing groups found mutations in TP53 (encodes p53) in 49% and 24% of bladder cancers respectively. (The Cancer Genome Atlas Research Network)
Mortality and Prognosis
The mortality of bladder cancer is dependent on the histologic grade and the stage at diagnosis. Late diagnosis has poorer outcome because of metastasis. The 10-year survival rate of low-grade cancer is 98%. This percentage survival is irrespective of the frequency of recurrences. On the hand, high-grade cancers cause death in 25% of the cases (Kumar nd Robbins 667). Patients, who have primary Carcinoma in situ, are less likely to progress to muscle-invasive carcinoma. On the other hand, patients who have infiltrating carcinoma show more progression towards muscle-invasive cancers. The 45% of the later population die of cancer as opposed to only 9% in the group with non-invasive forms. Once there is an invasion of by lamina propria, there is thirty percent (30%) mortality rate. As a rule, squamous cell carcinoma and adenocarcinoma have a worse prognosis in comparison to urothelial carcinoma. However, a stage for the stage of all these cancers is similar. Metastasis, chemotherapy complications, and renal failure cause great mortality and mortality in these patients (Kumar and Robbins 667).
Treatment Options
The treatment option is either medical or surgical. Medical therapy, intravesical immunotherapy and the use of Bacille Calmette-Guérin (BCG) immunotherapy are the medical treatment options for the early stage of cancer (Lee and Wood 93). They reduce the progression and reoccurrence rate of cancer. They also treat carcinoma in situ or superficial tumors that are unresectable. There are two options for surgical care. The surgical treatment for the superficial cancer is endoscopic resection and fulguration of the bladder. For this case, there is a need for continuous surveillance as the bladder cancer is polyclonal field change defect. For the bladder cancer that is within the confines of the organ (muscle-invasive bladder cancer, for example, those in T2 and T3 stages), there is the performance of radical cystectomy with urinary diversion. For metastatic cancer, there is the use of chemotherapy. Several neoplastic agents are in use. These include Methotrexate, Vinblastine, Adriamycin, and Cisplatin. In fact, the M-VAC regimen (the combination of the above agents) is the standard treatment of metastatic bladder cancer (Lee and Wood). In a study by Grace et al, a combination of fluorouracil and mitomycin and radiotherapy improve the rate (2-year) of DFS in comparison to when there was the administration of radiotherapy alone. This combination also led to a reduction of salvage cystectomy rate. Lastly, it led to good long-term bladder function (Cheung et al. 11).
Presentation and Conclusion
Patients with bladder cancer commonly present with painless global hematuria, which is mostly gross but may be microscopic. They may also have irritative urinary symptoms like dysuria, frequency, and urgency during micturition. Others may present with obstructive urinary symptoms especially if the tumor is around the bladder neck. These symptoms include poor stream, straining, and incomplete emptying. They may have a passage of tissue particles. Patients with adenocarcinoma may present with mucosuria. In the advanced stages, they may have renal failure and present with symptoms like edema. Conclusively, bladder cancer is one of the highest causes of morbidity and mortality, accounting for 7% of all the cancers. Cigarette smoking is a known risk factor. There are several mutations that result in its pathogenesis. The treatment can be medical or surgical, with chemotherapy being the choice in case of metastasis. Patients commonly present with painless hematuria. The prognosis is dependent on the stage and grade at diagnosis.
Works Cited
Cheung, Grace et al. “Recent Advances in the Diagnosis and Treatment of Bladder Cancer”. BMC Medicine, vol 11, no. 1, 2013, Springer Nature, doi:10.1186/1741-7015- 11-13.
Kumar, Vinay and Stanley L Robbins. Robbins Basic Pathology. 1st ed., Philadelphia, PA, Saunders/Elsevier, 2007.
Lee, Cheryl T, and David P. Wood. Bladder Cancer: Diagnosis, Therapeutics, and Management. New York, NY: Humana Press, 2010. Print.
Martin-Doyle, William, and David J. Kwiatkowski. “Molecular Biology of Bladder Cancer.” Hematology/oncology clinics of North America 29.2 (2015): 191–203. PMC. Web. 2 Feb. 2017.
The Cancer Genome Atlas Research Network. Comprehensive molecular characterization of urothelial bladder carcinoma. Nature. 2014; 507:315–22.
