Pathologist’s Corner – Dr. Fajardo on Bladder Cancer
Published July 11, 2014, Daniel Fajardo, MD, PhD, FCAP
What is “bladder cancer”?
Bladder cancer is a malignancy that develops in the urinary bladder. The National Cancer Institute estimates 74,690 new cases of bladder cancer and 15,580 deaths resulting from bladder cancer in the United States for the year of 2014. Bladder cancer occurs mainly in older people. About 9 out of 10 people with this cancer are over the age of 55. The average age at the time of diagnosis is 73. Bladder cancer is 3-4 x more common in males than in females and is twice as common in Caucasians than in African Americans.
There are many different types of “bladder” cancers. By far the most common is urothelial cell carcinoma (also called transitional cell carcinoma) which encompasses 90% of malignant bladder tumors. Urothelial carcinoma is a cancer that develops from the urothelial cells that line the bladder, ureters, urethra, and renal pelvis. The remainder of the article will focus on urothelial carcinoma.
What are the symptoms of bladder cancer?
The most common symptom for bladder cancer is blood in the urine (hematuria). It is important to note that there are other more common causes, such as infection or kidney stones, which may result in hematuria. Other symptoms may include change in bladder habits such as urinary frequency (having to urinate more frequently than usual), dysuria (pain or burning during urination), and urinary urgency (the feeling of having to go right away, even when the bladder is not full). Just like in hematuria these symptoms are more likely to be caused by benign conditions such as infection, bladder stones, enlarged prostate (in males), and overactive bladders. However, if these symptoms are present it is important to be evaluated by a physician so the cause can be determined and treated if necessary. In the rare cases where the urothelial cancer has been left undetected and has spread to distant sites (approximately 4% of urothelial cancer cases) it can cause other symptoms such as loss of appetite, weight loss, bone pain, inability to urinate, lower back pain on one side, and swollen feet.
How is bladder cancer diagnosed?
There are several screening tests (tests that are performed on patients that do not have symptoms) that may detect bladder cancer early. Currently there are no recommendations for bladder cancer screening in patients of average risk. Screening for bladder cancer may be recommended for patients that are at high risk (people who have exposure to chemicals known to increase the risk of bladder cancer, people with bladder birth defects, or who have a previous diagnosis of bladder cancer). The screening tests include urinalysis for the detection of blood in the urine, urine cytology (look for cancer cells in the urine), and commercial urine tests for tumor markers (such as Urovysion™, NMP22 BladderChek®, and Immunocyt™). These tests may detect some bladder cancers early but may miss other cancers as well. Also, patients may have abnormal tests but not have cancer.
The definite diagnosis is made by cystoscopy with a biopsy. Cystoscopy is a procedure performed by a urologist in which a camera is inserted through the urethra to look into the bladder. If there are suspicious areas they will be biopsied. The biopsy or biopsies are sent to a pathologist who makes the diagnosis and generates a pathology report. The results of the pathology report help the urologist and oncologist to determine the best course of treatment if treatment is necessary.
What is the information given in a pathology report?
The most important information given in a pathology report is whether the findings are benign (not cancer) or malignant (cancer). If a diagnosis of urothelial carcinoma is given it will have the following information: the architecture of a tumor (is the tumor flat or papillary), the grade of the tumor (low grade versus high grade), whether the tumor is invasive or non-invasive (in situ), the presence or absence of the muscularis propria (a muscle layer in the bladder, it is important in staging the tumor), if the tumor is invasive it will give the degree of invasion (into the lamina propria or into the muscularis propria).
How is bladder cancer treated?
There are different treatment modalities that depend on the characteristics of the bladder cancer. Low grade tumors that are non-invasive or minimally invasive may be treated by intravesical therapy in which medicine is put directly into the bladder via catheter.
Transurethral resection is used for non-muscle invasive cancer. A resectoscope is placed through the urethra and into the bladder and the tumor is resected. The tumor fragments are collected and sent to a pathologist. Furthermore the urologist may fulgurate (burn the base of the tumor) to further ensure the tumor has been destroyed.
If the tumor invades into the muscularis propria then either part of the bladder (partial cystectomy used for smaller localized tumor) or the entire bladder (radical cystecomy used for large tumors or multiple tumors) are the surgical options.
Chemotherapy and radiation therapy may also be given after surgery, to treat cancers that have spread, or used for patients who cannot have surgery.
What can I do to prevent bladder cancer?
There are multiple risk factors associated with bladder cancer. Some such as age, male gender, genetics, and bladder birth defects cannot be changed. However, there are some risk factors that can be controlled such as quitting smoking (smokers have 3 times the risk of developing bladder cancer compared to nonsmokers), drinking plenty of water (low fluid consumption has been shown to be a risk factor for developing bladder cancer), be aware of what supplements you are taking (dietary supplements containing aristolochic acid have been linked to bladder cancer), and limit exposure to chemicals known to increase risk of bladder cancer (diesel fumes and chemicals called aromatic amines, such as benzidine and beta-naphthylamine, which are sometimes used in the dye industry).
References:
Bladder Cancer Guide American Cancer Society. 2014
What you need to know about bladder cancer. National Cancer Institute. 2014.
