3 signs chemotherapy is working

If you’re currently undergoing chemotherapy, you are most likely looking closely for signs that it is working. 

Though they can vary depending on the individual and the condition, some key indicators can show treatment effectiveness, including tumor shrinkage, improvement in blood test results, and improvement in tumor marker tests. 

Chemotherapy, or chemo, destroys cancer cells in the body. The duration and other aspects of your chemo treatment plan will depend on the type of cancer you have and how it may be progressing in your body. The prescribing doctor will also take your individual health status into account. 

Typically, chemo is given in multiple cycles. Doctors may perform certain tests every so often throughout your treatment to ensure the chemotherapy is effective. Three main types of tests can offer signs that chemotherapy is working.

Tumor shrinkage

Measuring cancer cells to see whether they have shrunk is one of the primary ways to evaluate the effectiveness of chemo treatment. In fact, research finds that early tumor shrinkage is a good predictor of the overall effectiveness of chemotherapy in some kinds of cancer.

Tumors can be measured using different types of scans, including MRI scans, CT scans, PET/CT scans, or even ultrasounds, depending on the type of cancer.

What’s more, if you have breast cancer and haven’t yet had surgery to remove the tumor, a clinical breast exam can show your body’s response to chemotherapy because doctors will be able to feel the tumor shrinking.

Some research into gastric cancer finds that early tumor shrinkage can be determined as early as around 8 weeks into therapy. Yet every form of cancer is different, so responses can vary and have different monitoring plans.

Improved blood test results

A complete blood count (CBC) test shows increases and decreases in your red and white blood cells and platelets. 

For example, a low white blood cell count can be a sign of a lowered level of immunity caused by either cancer or cancer treatments. A low level of red blood cells could be a sign of a certain type of cancer, such as leukemia or lymphoma. 

A 2022 study found that an elevated platelet count has been associated with higher cancer risk and can show a lack of response to cancer treatments like chemotherapy. But high platelets can also be a sign of inflammation or infection.

A CBC can help a doctor determine whether your body is responding to chemo if you have certain forms of blood cancer like leukemia. In general, though, it may not be as helpful if you have other forms of cancer. Blood tests are more often taken to ensure that it is safe to give the next cycle of chemo.

Tumor marker tests

Tumor marker tests, or biomarker tests, measure protein or other substances made in higher amounts by cancer cells than by healthy cells. Looking at these biomarkers helps doctors understand the amount of cancer cells in the blood, urine, or tissues of the body.

According to medical experts, it is generally better to track how the level of a marker is changing over time, called serial measurement. That’s why doctors often repeat these tests multiple times after each cycle of treatment.

If a test shows a steady decrease in the level of a tumor marker, it can mean that the treatment is working. However, it’s important to note that not all cancers overexpress tumor markers, so these tests aren’t helpful in every situation.

Can you tell if it is working at home? 

Though tests are the best indicator, you may be able to notice certain effects in your body without the help of a doctor. Your energy levels may be better, or you may notice a reduction in pain or swelling of the lymph nodes.

Depending on your type of cancer, you might notice some signs at home that the treatment is working. For example, if you have a breast tumor that you haven’t had surgically removed, you may be able to feel it shrinking. If you have lung cancer that is causing shortness of breath, you might notice these symptoms reducing as the tumor shrinks.

Some people may believe that if you experience strong side effects from chemotherapy, like nausea and hair loss, then it must be working. Similarly, if you don’t experience these, you might worry that it isn’t effective.

According to the National Cancer Institute, the presence or absence of side effects has no relation to the effectiveness of chemotherapy. The previously mentioned medical tests are the only reliable way to know if your treatment is working as it should.

How long does it usually last?

According to the American Cancer Society, chemo cycles for cancers such as breast cancer are typically 2 or 3 weeks. These cycles are intended to target cancer cells during their most active phase. Four to eight cycles, over a period of 3–6 months, is typical.

That said, the duration of your treatment plan will vary depending on the type of cancer, the exact chemo drugs used, and the stage of cancer, among other factors. 

It’s also important to give your body time between cycles to recover from the side effects of chemotherapy. 

Other treatments

While chemotherapy is considered by medical experts to be the first line of treatment for some cancers, healthcare professionals may consider other treatments as well.

These include targeted therapies, which are drugs that target the proteins or genes in cancer cells. These can be used as a treatment for breast, brain, and gastrointestinal cancers.

The most common targeted drug therapy used to treat HER2-positive breast cancer is trastuzumab, which is given intravenously. A 2022 study showed that only 3% of people using trastuzumab for breast cancer had a recurrence of the disease, compared with 12% of those who did not receive the drug. 

Other drug types used to treat cancer include immunotherapy medications, like pembrolizumab (Keytruda), which boosts your immune system’s ability to destroy cancer cells and inhibit growth, and hormone therapy, which stops cancers from using hormones to grow.

Hormone therapy medications include leuprolide (Eligard), flutamide (Eulexin), and bicalutamide (Casodex).

If you need help covering the cost of medications, the free Optum Perks Discount Card could help you save up to 80% on prescription drugs. Plus, you can now get them delivered to your home in as little as 3 days. Search for your medication here.

Summary

Chemotherapy is a commonly used and well-studied treatment for many types of cancers, and the tests used to measure its effectiveness can help guide doctors in adapting your treatment plan.

The only way to know for sure if chemotherapy is working is through medical tests like tumor bioimaging or a CBC if you have a blood cancer like leukemia. The presence or absence of side effects can’t tell you whether it’s working, but you might feel a reduction in pain.

Download the free Optum Perks Discount Card to save up to 80% on many prescription medications. Plus, you can now get them delivered to your home in as little as 3 days. Search for your medication here.