Monitoring for organ effects: the tests explained

Before and during chemotherapy, your team uses a set of tests to check that your body is coping. Blood tests are the most common: they check blood counts, kidney function, liver function and salts, usually before each cycle. Depending on your medicines, you may also have heart scans, heart tracings, hearing tests, breathing tests, thyroid blood tests, urine tests, or checks of your nerves and eyes. Not everyone needs every test; the schedule is built around the medicines you receive and your own health.

These tests are how problems are caught early, often before you have any symptoms. A falling blood count may delay a cycle by a few days; a change in kidney function may lead to a lower dose or extra fluids; a drop in heart pumping strength may pause a particular medicine. The aim is always to keep treating the cancer as safely as possible. How often each test is repeated is decided by your team, and it is reasonable to ask why a test is being done.

Baseline tests come first

Tests before treatment set a starting point, so later results can be compared and small changes spotted.

Results guide each cycle

Blood results are usually reviewed before every cycle to decide whether it is safe to go ahead.

Symptoms still matter

Tests do not replace reporting symptoms. Tell your team about new problems between tests.

It cannot tell you exactly which tests you need or how often. Schedules vary with your medicines, cancer type, age and other conditions, and your team sets them. It also cannot interpret your results, because the same number can mean different things for different treatments.

It cannot tell you to delay or skip a test. Missed tests can delay treatment or allow problems to go unnoticed. If you cannot attend, contact your team to rearrange.

Why tests are repeated so often

Organ function can change between cycles. Repeat testing keeps treatment safe as your body responds.

Testing at a local lab

If you have blood tests near home, send results to your team in time and keep the same lab where possible so values are comparable.

Fasting and timing

Some tests need fasting or timing around medicines. Ask whether you need to prepare, and whether to take morning tablets first.

Hydration affects kidney results

Being dehydrated can make kidney tests look worse. Drink fluids as advised before testing unless told otherwise.

Long-term monitoring after treatment

Some tests, such as heart scans, thyroid tests and hearing checks, may continue after treatment ends, depending on the medicines you had.

Costs add up

Regular tests are a real expense. Ask your team which are essential and whether they can be combined with visits.

Ask what each result means

It is reasonable to ask whether results are normal, what any change means, and whether anything needs to be done.

Keep a results file

A single file of reports helps any doctor, including in an emergency, understand how your organs have coped with treatment.

Urine tests are part of monitoring

With some medicines, such as ifosfamide and cyclophosphamide, urine may be checked for blood or protein. Collect samples as instructed and tell your team if the urine looks pink, red or unusually dark.

Blood sugar checks on steroids

Steroids given with chemotherapy can raise blood sugar, even in people without diabetes. Your team may check sugar levels, especially if you feel very thirsty, pass a lot of urine or feel unusually tired.

Weight is monitored too

Doses of many medicines are based on your weight and height. Significant weight loss or gain can change doses, so weigh-ins at each visit matter.

What to do next

Ask your team which monitoring tests you need and why, keep every test appointment, prepare as advised, and keep a file of your results. Report new symptoms between tests, and seek help the same day for warning signs rather than waiting.