Understanding Treatment Response and Outcomes
Reviewed by: HU Medical Review Board | Last reviewed: May 2023 | Last updated: September 2023
Treatment for blood cancer can last many months or years, depending on the type of blood cancer and how well it responds to the treatment.
During treatment, doctors measure the treatment response. This is how effective the treatment is against the blood cancer. Doctors may adjust the dose of medicines or change therapies based on the results. Side effects of treatment are also measured. Treatment may be changed or delayed to allow the body to recover from side effects.
Treatment response may be measured by several different tests, including:1-3
- Blood tests, like a complete blood count (CBC), peripheral blood smear, cytogenetic tests, polymerase chain reaction (PCR), and fluorescent in situ hybridization (FISH)
- Bone marrow biopsy
- Imaging tests, like computed tomography (CT) scan or positron emission tomography (PET) scan
- Flow cytometry, which examines millions of cells, one at a time, and report out certain characteristics of the cells that allow doctors to tell if they are cancerous cells
Some blood cancers, like multiple myeloma and lymphoma, can cause tumors to form. Treatment response can be measured by the shrinking or disappearance of the tumors. This can be seen using imaging tests.
Other blood cancers, like leukemia and myelodysplastic syndrome (MDS), do not cause tumors. But the cancer cells can be seen and counted in a blood test. For MDS and leukemia, the cancer cells can be seen and counted on a blood test or bone marrow biopsy. Sometimes the cancer cells are so few that they cannot be seen under the microscope. But they can be detected by more sensitive methods such as flow cytometry, PCR, cytogenetics, or FISH.1-3
Types of responses
Doctors may look for different types of responses in people who are receiving treatment for blood cancer, including:1,2
- Hematologic – A response seen in the blood. It is usually measured by a CBC.
- Cytogenetic – A response seen in levels of specific chromosomal indicators, such as the Philadelphia chromosome. This response is measured by cytogenetic testing or FISH.
- Molecular – A response seen in levels of cancer cells with specific genetic mutations. This is measured by PCR testing.
The response of blood cancer to treatment may be categorized as partial or complete. A partial response indicates the treatment has reduced the number of cancer cells. However, some cancer cells are still detected. A complete response indicates that no cancer cells are detected.1
In some cases, blood cancer does not respond to the first type of treatment. The blood cancer may be termed resistant or refractory. When another type of treatment is given, it is called second-line treatment. Second-line treatment may be a different combination of chemotherapy drugs. Or, it may include different types of treatment, like targeted therapy or immunotherapy.1-3
Another option for some people may be enrolling in a clinical trial. Clinical trials recruit specific people based on the type of cancer and previous treatments. They provide an opportunity for people to receive the latest treatments or interventions that are being researched.1-3
Goals of treatment
Everyone wants a cure for cancer. However, in certain cases, curing blood cancer is not possible. The goals of treatment may change during a person’s cancer journey. They may go from striving for a cure or remission to controlling the cancer and keeping it from progressing for as long as possible.4
For people with advanced cancer or blood cancer that has not responded to treatments, the goal may shift to one of comfort. Treatment may include palliative care to treat symptoms and keep the person as comfortable as possible.4
Talk to your doctor if you have questions about your treatment, including your goals of treatment.