Chemotherapy is a common treatment for cancer, but determining its effectiveness can be complex. There are key signs, tests, and factors to help you understand if chemotherapy is working and how to track progress.
If you or a loved one is in the midst of a chemotherapy treatment plan, you may wonder how you can tell if chemotherapy is working.
The only way to effectively know for sure is through follow-up tests with your doctor. These are given in regular intervals around each round of chemo.
Keep reading to learn how doctors measure and define the effectiveness of chemotherapy.
Throughout your treatment plan, your doctor will need to check your progress to measure the effectiveness of chemotherapy. Depending on the type of cancer and its stage, your doctor may use multiple techniques, such as:
| Diagnostic tests | What they detect |
|---|---|
| physical exams | identify visible lumps or lymph nodes that have shrunk in size |
| blood tests, including a complete blood count (CBC) | measure red and white blood cells, platelets, and more |
| magnetic resonance imaging (MRI), and computed tomography (CT) scans | measure cancer tumors to see if they’ve shrunk, grown, or spread |
| tumor marker (biomarker) tests | measure the amount of cancer cells via blood, tissue, or urine samples |
Not all of the tests above will be used for all cancer types, such as tumor markers. Discuss with your doctor the tests that will be used to monitor your progress, including what type of results they are looking for.
Depending on the type and stage of cancer you have, you may notice an improvement in cancer symptoms if the condition is being treated. Not feeling improvements to symptoms is not necessarily an indication that your treatment isn’t working, however.
Examples of improved symptoms may include:
- improved energy levels
- less pain
- reduced swelling in lymph nodes
Before each chemotherapy session, your doctor will perform an assessment to make sure that the treatment is safe to administer. If your CBC counts are too low, for example, your doctor may recommend that you reschedule your treatment for another day.
To determine that chemo is working, your doctor will also need to conduct blood and imaging tests after treatment cycles. Keep in mind that a full treatment cycle includes the days you receive chemotherapy, as well as the weeks you’re in recovery.
When determining the effectiveness of chemotherapy, your doctor will determine how your body is responding to this treatment method. They might determine that you have one of the following
- Complete response: This means that there’s no detectable cancer left in your body.
- Partial response: This means that the chemotherapy has helped shrink cancer tumors and prevent the spread of the condition, but cancer cells still exist in your body.
- Stable disease: This means that chemotherapy hasn’t changed the amount of cancer in your body, and that any tumors you had before haven’t shrunk or grown.
- Disease progression: In such cases, the cancer has grown and there’s evidence of more disease than before the start of your chemotherapy treatment. Testing may also indicate that cancer has spread to new areas.
Some types of cancer may respond more quickly to chemotherapy than others. Have an open discussion with your doctor about expected timelines.
Chemotherapy is administered over the course of several weeks. For example, your doctor
The goal is to target cancer cells when they may be most active while also allowing your body recovery time to build healthy cells.
Your exact treatment plan depends on the:
- type of cancer you have
- stage of cancer
- types of chemo drugs used, and whether you’re taking other drugs, such as targeted therapies
- primary reason you’re taking chemo — for example, to prevent tumor spread or to alleviate pain
- how your cancer responds to the treatment
- how you tolerate the treatment
- other possible health conditions you may have, such as diabetes or heart conditions
With all of these factors in mind, it’s difficult to predict an exact timeline for when chemotherapy will start working. This treatment may work immediately for some people, while it may take several rounds over the course of many months for others.
The best way to tell if chemotherapy is working for your cancer is through follow-up testing with your doctor. Throughout your treatment, you’ll have regular visits with an oncologist, and blood and imaging tests will be used to detect cancer cells and whether they’ve grown or shrunk.
It’s important to know that you can’t rely on symptoms alone when determining whether chemo is working. If you start feeling much worse after treatment, however, it’s important to talk with your doctor about your current plan and whether other drugs may help.