Urinary tract infections, also called UTIs, are infections of the urinary system. The most common sites of UTIs are the bladder and the urethra (the tube inside the body that stems from the bladder and carries urine out). These infections are often caused by bacteria entering the body through the urethra where they can grow and multiply.1 The most common symptoms of UTIs are also common symptoms of bladder cancer, such as blood in the urine, a burning sensation when urinating, and painful urination.1,2 Up to 80% of all UTIs occur in women, and roughly 50% of all women will experience at least one UTI with accompanying symptoms in their lifetime.3 It’s also possible for a UTI to recur, as well as for an individual to have multiple UTIs throughout their life. Additionally, some individuals may experience chronic UTIs.
When a woman notices blood in her urine, she may think it’s related to her menstrual cycle, menopause, or to a UTI before she suspects bladder cancer. If the blood in the urine has no accompanying pain or goes away in a relatively short period of time, she may not seek treatment. Even when a woman does seek treatment for blood in her urine or painful urination, it’s possible that her primary care provider or OB-GYN physician may diagnose and treat her for a UTI rather than suspecting bladder cancer. If a woman’s bladder cancer-related urinary symptoms are continuously treated as a UTI, it’s possible that she may experience repeated UTI-like episodes that are misdiagnosed and mistreated. If these episodes become severe, she may be referred to a urologist who might then suspect and diagnose bladder cancer. This can lead to a delay in diagnosis of bladder cancer, and could contribute to the generally later age of diagnosis for women with bladder cancer when compared to their male counterparts.4-6
UTIs in men are less common, and may alert a male’s healthcare provider to suspect additional underlying issues immediately. This may lead a man to visiting a urologist sooner or to being diagnosed with bladder cancer earlier after urinary symptoms appear.4
The relationship between UTIs and bladder cancer
Many experts and individuals with bladder cancer have wondered if true UTIs are related to bladder cancer risk. Inflammation related to infection, most commonly due to the rare parasitic infection schistosomiasis or long-term use of a urinary catheter, has been thought to increase the risk of developing squamous cell carcinoma of the bladder. However, this type of bladder cancer makes up only a small portion of all bladder cancer cases. The most commonly diagnosed form of bladder cancer in the United States is urothelial carcinoma, with 90% of individuals with the condition being diagnosed with this type.7 As such, determining the relationship between UTIs and urothelial carcinoma is of interest to many in the urological field.
Currently, research into the relationship between UTIs and urothelial carcinoma has provided mixed results. Some experts have theorized that having a few, treated UTIs earlier in life may decrease an individual’s risk of developing the condition, as the antibiotics used to treat the UTI may also impede the development of cancerous cells and have a protect effect against cancer.3,8 Another theory is that developing a UTI promotes an immune system response in the body aimed at the urinary system that could also protect against bladder cancer. In addition to destroying bacterial invaders, the immune system may recognize cancerous cells that are developing and destroy these as well.8 This is similar to the mechanism of action behind the BCG vaccine treatment which initiates an immune system response against cancerous cells.
Conversely, other experts have suggested that chemicals like nitric oxide that are produced during an infection and its accompanying inflammation may promote cancerous cell and tumor growth, thus increasing an individual’s risk of developing bladder cancer or of bladder cancer becoming more severe.3 Much more research is needed to classify the relationship between UTIs and bladder cancer, if there is a relationship at all.
What should I do if I’m having repeated UTIs?
It may be difficult to determine if repeated UTIs immediately preceding a bladder cancer diagnosis are accurately diagnosed UTIs or if they are manifestations of the underlying cancer. If you are having repeated UTIs and have not received any other diagnosis but are concerned about your cancer risk, ask your doctor or healthcare provider about other diagnostic tests. Tests of the urine, even after UTI treatment or after bleeding during urination has subsided, may help indicate that a different, underlying condition is causing your symptoms.5 If you are having repeated UTIs and have received a diagnosis of bladder cancer, consult your doctor or healthcare provider to determine if there are any treatment options available for your situation, and to determine if any symptoms you are having are related to your bladder cancer or its treatment.
Urinary Tract Infection (UTI). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/urinary-tract-infection/symptoms-causes/syc-20353447. Published August 25, 2017. Accessed July 3, 2018.
Signs and Symptoms of Bladder Cancer. https://www.cancer.org/cancer/bladder-cancer/detection-diagnosis-staging/signs-and-symptoms.html. Published May 23, 2016. Accessed July 3, 2018.
Vermeulen SH, Hanum N, et al. Recurrent urinary tract infection and risk of bladder cancer in the Nijmegen bladder cancer study. Br J Cancer. 3 Feb 2015; 112(3), 594-600. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4453642/. Accessed July 3, 2018.
Richards KA, Ham S, Cohn JA, Steinberg GD. Urinary tract infection-like symptom is associated with worse bladder cancer outcomes in the Medicare population: Implications for sex disparities. International Journal of Urology. Jan 2016; 23(1), 42-7. Available from: https://onlinelibrary.wiley.com/doi/full/10.1111/iju.12959. Accessed July 3, 2018.
Could Persistent UTI-like Symptoms be Bladder Cancer? University of Rochester Medical Center. https://www.urmc.rochester.edu/patients-families/health-matters/june-2015/could-persistent-uti-like-symptoms-be-bladder-canc.aspx. Published June 23, 2015. Accessed July 3, 2018.
Women and Bladder Cancer. Bladder Cancer Advocacy Network. https://www.bcan.org/women-bladder-cancer. Published May 31, 2017. Accessed July 3, 2018.
Bladder Cancer. Cancer.net. https://www.cancer.net/cancer-types/bladder-cancer. Accessed July 3, 2018.
Jiang X, Castelao JE, et al. Urinary tract infections and reduced risk of bladder cancer in Los Angeles. Br J Cancer. 10 Mar 2009; 100(5), 834-9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2653778/. Accessed July 3, 2018.