Tumor Lysis Syndrome: Patient Action Guide

This page is for people starting a cancer treatment that carries a risk of tumor lysis syndrome, and for the people helping them. It covers warning signs, who is more at risk, and how teams prevent it.

• You pass very little urine, or none at all, or your urine turns dark or cloudy.
• Muscle cramps, spasms or twitching start in the first days of treatment, or you get tingling in your lips, tongue, fingers or feet. MedlinePlus lists these as signs of low blood calcium.
• Your heart skips, races, or pounds at rest.
• You have a seizure, faint, or become confused.
• Nausea and vomiting stop you keeping fluids down after a new treatment started.
• You have a fever, chills or shortness of breath with any of the above.

The venetoclax label tells patients to report signs like these right away. Going to the emergency department is the safer route when you cannot reach your team fast.

If someone has a seizure, faints, or becomes confused, call 911 or your local emergency number rather than driving them. Say the words "possible tumor lysis" at the desk. Then say which treatment you started and when.

The National Cancer Institute (NCI) describes tumor lysis syndrome as a condition that can happen after treatment of a fast-growing cancer, especially certain leukemias and lymphomas. As cancer cells die, they break apart and release their contents into the blood. That changes certain chemicals in the blood and can damage organs, including the kidneys, heart and liver.

The chemicals teams watch are the ones the venetoclax label names: potassium, uric acid, phosphorus, calcium and creatinine (a marker of kidney function).

Uric acid comes from breaking down part of the cells' genetic material. The rasburicase label notes that in humans, uric acid is the last step in that breakdown and does not dissolve well. When too much builds up, it can harm the kidneys.

Risk depends on the cancer, the treatment, and the person. NCI says it is most linked to fast-growing cancers, especially certain leukemias and lymphomas.

FDA labels give examples of what raises risk:

• A large amount of cancer. The venetoclax label measures this by lymph node size and blood lymphocyte count. The obinutuzumab label names high tumor burden and a lymphocyte count above 25,000 per microliter.
• Kidney problems. Both labels say reduced kidney function raises risk.
• An enlarged spleen, which the venetoclax label says may add to risk in chronic lymphocytic leukemia.

Some drugs carry a known risk. Venetoclax for chronic lymphocytic leukemia is started on a five-week ramp-up rather than at full strength. The FDA label says that schedule "is designed to gradually reduce tumor burden (debulk) and decrease the risk of TLS." The label says blood changes can start as early as 6 to 8 hours after the first dose and after each dose increase. The obinutuzumab label also warns of tumor lysis syndrome, including deaths.

Ask your team before treatment starts whether this is a risk for you, and which of your results put you in a higher-risk group.

Teams may tell you that your blood tests show tumor lysis before you feel anything. The venetoclax label says blood chemistry changes need prompt management. So a lab result is not a false alarm, even if you feel fine. It is the stage where treatment can still stop things getting worse.

Fluids come first. The venetoclax label calls for extra fluids before treatment starts, by mouth and sometimes by vein for people at higher risk. For people taking it at home, the label advises drinking about 6 to 8 glasses of water a day, starting 2 days before the first dose. Follow the amount your own team gives you.

Blood tests are timed by risk. For venetoclax, the label sets tests before the dose and again several hours and a day after the first doses, with more tests, and sometimes a hospital stay, for people at higher risk. Ask how often your blood will be tested and who calls you with the results.

Two drugs lower uric acid, and they work in different ways.

• Allopurinol lowers how much uric acid the body makes, according to its label and MedlinePlus. The venetoclax label says to start allopurinol or a similar drug 2 to 3 days before the first dose. The allopurinol label says the dose is lowered when the kidneys are not working well.
• Rasburicase is an enzyme given by vein. Its label says it turns uric acid into a substance that dissolves more easily. The venetoclax label says to consider it for higher-risk people whose uric acid is already high.

Ask which medicine you will get to protect your kidneys, and when it starts.

Rasburicase has one firm reason not to use it, worth knowing by name. It is G6PD deficiency, an inherited enzyme problem. The label explains that the reaction makes hydrogen peroxide, which can cause red blood cells to burst (hemolysis) in people with this deficiency. It can also cause methemoglobinemia, where the blood cannot carry oxygen well. The label says to screen people at higher risk, such as people of African or Mediterranean ancestry, before starting. Ask whether you have been tested.

Allopurinol has its own warning. MedlinePlus says to stop it and call your doctor right away or get emergency care for a rash, peeling or blistering skin, swelling of the lips or mouth, or fever with swollen glands.

Do not start an over-the-counter anti-inflammatory such as ibuprofen or naproxen, an electrolyte drink, or a supplement during this window without asking your team. If you already take an anti-inflammatory that was prescribed to you, raise it with the team rather than stopping it yourself. Which of your regular medicines pause and which continue is their call, and stopping some abruptly causes its own problems.

The venetoclax label also says some other medicines can raise venetoclax levels and the risk of tumor lysis. Give your team and pharmacist a full list of everything you take. Kidney problems during cancer treatment covers how kidney function is tracked.

• Is tumor lysis syndrome a risk with my treatment, and which of my results affect that?
• Will I get allopurinol or rasburicase, and why that one?
• Have I been tested for G6PD deficiency if rasburicase is planned?
• How much should I drink, and starting when?
• How often will blood tests be drawn in the first days? And who calls me with the results?

• NCI Dictionary of Cancer Terms — tumor lysis syndrome
• DailyMed — VENCLEXTA (venetoclax) prescribing information
• FDA — VENCLEXTA (venetoclax) prescribing information (PDF)
• DailyMed — ELITEK (rasburicase) prescribing information
• DailyMed — ZYLOPRIM (allopurinol) prescribing information
• DailyMed — GAZYVA (obinutuzumab) prescribing information
• MedlinePlus — Allopurinol
• MedlinePlus — Calcium blood test