Gram Research analysis shows that patients with advanced bladder cancer receiving immunotherapy drugs had significantly better treatment responses when their urine was more alkaline (pH 6.5 or higher), with a 40% response rate compared to 16% in patients with more acidic urine. In a 2026 study of 45 patients, higher urinary pH was also associated with longer survival without cancer progression after adjusting for other health factors. However, researchers caution that this is preliminary exploratory research and many factors influence urine pH, so it should not yet be used to guide treatment decisions.
Researchers discovered that a simple urine pH test, which measures how acidic or alkaline urine is, might help predict how well certain cancer drugs work in patients with advanced bladder cancer. In a study of 45 patients receiving immunotherapy drugs, those with higher urinary pH (more alkaline urine) had better treatment responses and lived longer without their cancer progressing. While this finding is promising, the researchers caution that many factors affect urine pH, so it should be seen as an interesting clue rather than a definitive predictor. This low-cost test could eventually help doctors personalize cancer treatment plans.
Key Statistics
A 2026 study of 45 patients with advanced bladder cancer found that those with urinary pH of 6.5 or higher had a 40% response rate to immunotherapy drugs, compared to only 16% in patients with lower urinary pH.
According to research reviewed by Gram, patients with higher baseline urinary pH had significantly longer progression-free survival (time before cancer worsened) after adjusting for health risk factors, with a hazard ratio of 0.39.
Among 32 patients with early urinary pH measurements in the 2026 study, those whose pH remained high throughout early treatment had a 41.7% response rate to cancer drugs, while patients whose pH stayed low had zero responses.
The Quick Take
- What they studied: Whether a simple urine pH measurement could predict how well immunotherapy drugs work in patients with advanced bladder cancer.
- Who participated: 45 patients with advanced bladder cancer who received immunotherapy drugs (pembrolizumab or avelumab). Researchers looked at 32 of these patients for additional urine pH measurements over time.
- Key finding: Patients with higher urinary pH (7 or above, meaning more alkaline urine) had a 40% response rate to cancer drugs, compared to only 16% in patients with lower pH. Higher pH was also linked to longer survival without cancer progression.
- What it means for you: If confirmed in larger studies, a simple urine test could help doctors predict which patients will benefit most from certain cancer treatments. However, this is early research and should not replace current treatment decisions.
The Research Details
This was a retrospective study, meaning researchers looked back at medical records of 45 patients who had already received cancer treatment. They measured the pH of patients’ urine when they started immunotherapy drugs and tracked how well the drugs worked. The researchers divided patients into two groups based on whether their urine pH was 6.5 or higher (more alkaline) or below 6.5 (more acidic). They used statistical methods to account for other factors that might affect treatment success, like the patient’s overall health status measured by something called the Bellmunt risk score. For 32 patients, they also looked at how urine pH changed early in treatment to see if those changes predicted outcomes.
This research approach is important because it explores a simple, inexpensive test that could help personalize cancer treatment. Instead of waiting weeks to see if a drug works, doctors might eventually use a urine pH test to predict success early. The study design allowed researchers to examine real-world patient data and look for patterns that could guide future research.
This is an exploratory study with a relatively small sample size (45 patients), which means the findings are preliminary and need confirmation in larger studies. The retrospective design means researchers couldn’t control all variables as they could in a planned experiment. The researchers themselves note that many factors influence urine pH, including kidney function, infections, medications, hydration, and diet, so the results should be interpreted cautiously. The findings were somewhat weaker when looking only at patients who received one specific drug (pembrolizumab), suggesting the pattern may not be universal.
What the Results Show
Among the 45 patients studied, 20 had higher urinary pH (6.5 or above) and 25 had lower pH (below 6.5). The higher pH group had a much better response to cancer drugs: 40% of patients in the high pH group showed tumor shrinkage or improvement, compared to only 16% in the low pH group. When researchers adjusted for other health factors, patients with higher urinary pH lived significantly longer without their cancer getting worse. The median time before cancer progression was much longer in the high pH group. The association with overall survival (how long patients lived overall) was weaker, suggesting that urinary pH may be more helpful for predicting short-term drug response than long-term survival. When researchers examined 32 patients with additional urine pH measurements taken early in treatment, they found that patients whose pH stayed high throughout early treatment had the best outcomes (41.7% response rate), while patients whose pH stayed low had no responses at all.
The study found that changes in urinary pH early in treatment appeared to matter. Patients whose pH increased from low to high during early treatment had intermediate response rates (28.6%), suggesting that pH dynamics might be worth monitoring. When the researchers focused only on patients who received pembrolizumab (one of the two drugs studied), the pattern held but was less pronounced, indicating that the urinary pH effect might be drug-specific or influenced by other variables.
This appears to be among the first studies examining urinary pH as a predictor of immunotherapy response in bladder cancer. Previous research has shown that tumor acidity affects how well immune therapies work, but measuring tumor acidity directly is invasive and expensive. This study explores whether urine pH, which is easily measured, might reflect tumor conditions. The findings align with biological theory suggesting that more alkaline environments may support better immune system function, though this connection remains speculative.
The study is small with only 45 patients, making it difficult to draw firm conclusions. It’s retrospective, meaning researchers couldn’t control how urine samples were collected or measured. Many factors influence urine pH beyond tumor characteristics, including kidney function, urinary tract infections, medications, how much water patients drink, and diet. The researchers couldn’t separate the effect of urinary pH from these other factors. The findings were weaker when examining only one drug type, suggesting the pattern may not apply equally to all immunotherapy drugs. The study lacks a control group of patients who didn’t receive these drugs. These limitations mean the findings should be seen as hypothesis-generating rather than definitive.
The Bottom Line
Based on this exploratory research, urinary pH should not yet be used to make treatment decisions. Patients should continue following their oncologist’s recommendations for immunotherapy. However, this research suggests that future studies should investigate whether simple urine pH testing could help predict treatment response. If you have advanced bladder cancer and are considering immunotherapy, discuss all available treatment options with your cancer doctor, and mention this research if you’re interested in participating in future studies that might validate these findings.
This research is most relevant to patients with advanced bladder cancer considering immunotherapy drugs like pembrolizumab or avelumab, and to oncologists treating these patients. It may also interest researchers studying how to personalize cancer treatment. This research does not apply to other cancer types or other treatment approaches. People without bladder cancer should not interpret these findings as relevant to their health.
If this finding is validated in larger studies, it could take 2 to 5 years before urinary pH testing might be incorporated into clinical practice. Any changes to treatment protocols would require confirmation in multiple large studies and approval from medical authorities. For now, patients should expect that standard treatment approaches will continue unchanged.
Frequently Asked Questions
Can a urine pH test predict how well immunotherapy will work for bladder cancer?
A 2026 study suggests urinary pH may help predict immunotherapy response, with higher pH linked to better outcomes. However, this is preliminary research in only 45 patients and should not yet guide treatment decisions. Talk to your oncologist about your individual situation.
What does urinary pH measure and why might it matter for cancer treatment?
Urinary pH measures how acidic or alkaline your urine is on a scale of 0 to 14. Research suggests that tumor acidity affects how well immune-based cancer drugs work, and urine pH might reflect these conditions. However, many other factors also influence urine pH.
If my urine pH is low, does that mean immunotherapy won’t work for me?
No. This exploratory study found an association between higher pH and better outcomes, but many patients with lower pH still responded to treatment. Urinary pH is just one factor among many that affect treatment success. Your doctor should consider your complete medical picture.
What factors besides tumors affect urinary pH?
Kidney function, urinary tract infections, medications, hydration level, and diet all influence urine pH. Because so many factors affect it, researchers caution that urinary pH should be interpreted as a hypothesis-generating signal rather than a direct measure of tumor conditions.
When might doctors start using urine pH testing to guide bladder cancer treatment?
This is early exploratory research. Before urine pH testing could be used clinically, larger studies would need to confirm these findings and show the test reliably predicts treatment outcomes. This process typically takes several years.
Want to Apply This Research?
- If you have advanced bladder cancer and are receiving immunotherapy, track your urinary pH weekly using a home test kit (available at pharmacies) and log the results in your health app. Record the date, pH reading, and any symptoms or changes you notice. Share these trends with your oncologist at each visit.
- Work with your healthcare team to maintain consistent hydration and monitor factors that affect urine pH, such as diet (acidic foods like citrus versus alkaline foods like leafy greens) and any urinary tract infections. Use the app to set reminders for consistent urine testing at the same time each day for more reliable measurements.
- Create a simple chart in your health app showing weekly urinary pH measurements alongside your treatment timeline and any clinical assessments from your doctor. Look for patterns over months rather than day-to-day changes. Share this data with your oncology team to help them understand your individual response to treatment.
This article summarizes exploratory research and should not be interpreted as medical advice. Urinary pH testing is not currently recommended for guiding bladder cancer treatment decisions. If you have advanced bladder cancer or are considering immunotherapy, consult with your oncologist about treatment options appropriate for your individual situation. Do not change your treatment plan based on this research without discussing it with your healthcare team. This study was small and preliminary; larger studies are needed to confirm these findings before they can be applied in clinical practice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.