Understanding Treatment Response and Outcomes

Treatment for blood cancer can last many months or years, depending on the type of blood cancer and how well the blood cancer responds to the treatment. During treatment, doctors measure the treatment response – how effective the treatment is against the blood cancer – and may adjust the dose of medications or change therapies based on the results. Side effects of treatment are also measured, and 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:

  • 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 biopsy1,2
  • Imaging tests, like computed tomography (CT) scan or positron emission tomography (PET) scan3

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, which can be seen using imaging tests. Other blood cancers, like leukemia and myelodysplastic syndromes, do not cause tumors, but the cancer cells can be seen and counted in a blood test.

Types of responses

There are different types of responses that doctors may look for in people who are receiving treatment for blood cancer, including:

  • Hematologic – a response seen in the blood, usually measured by a complete blood count (CBC)
  • Cytogenetic – a response seen in the levels of specific chromosomal indicators, such as the Philadelphia chromosome; measured by cytogenetic testing or FISH
  • Molecular – a response seen in the levels of cancer cells with specific genetic mutations, measured by PCR1,2

The response of a blood cancer to treatment may be categorized as partial or complete. A partial response indicates the treatment has reduced the number of cancer cells, although some cancer cells are still detected. A complete response indicates that blood counts are normal and no cancer cells are detected.1

Additional treatment

In certain cases, a blood cancer doesn’t respond to the first type of treatment. The blood cancer may be termed “resistant.” 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 a different type of treatment, like targeted therapy or immunotherapy. Another option for some patients may be enrolling in a clinical trial. Clinical trials recruit specific patients based on the type of cancer and previous treatments (or before other treatments) and provide an opportunity for patients to receive the latest medications or interventions that are being researched.

Goals of treatment

Everyone wants a cure for cancer, but in certain cases, curing blood cancer isn’t possible. The goals of treatment may change during a person’s cancer journey from striving for a cure or remission to controlling the cancer, keeping it from progressing for as long as possible. For people with advanced cancer or blood cancer that hasn’t responded to treatments, the goal may shift to one of comfort, using palliative care to treat symptoms and keep the individual as comfortable as possible.4

Written by: Emily Downward | Last reviewed: March 2018
View References
  1. Treatment outcomes, Leukemia & Lymphoma Society. Available at https://www.lls.org/leukemia/chronic-myeloid-leukemia/treatment/treatment-outcomes. Accessed 2/8/18.
  2. Leukemia – chronic myeloid – CML: treatment options, ASCO. Available at https://www.cancer.net/cancer-types/leukemia-chronic-myeloid-cml/treatment-options. Accessed 2/8/18.
  3. Stenger M. RECIL 2017: new response evaluation criteria in lymphoma clinical trials, The ASCO Post. Available at http://www.ascopost.com/News/55651. Accessed 2/8/18.
  4. Cancer treatment decisions: 5 steps to help you decide, Mayo Clinic. Available at https://www.mayoclinic.org/diseases-conditions/cancer/in-depth/cancer-treatment/art-20047350. Accessed 2/12/18.