Dose-Dense Chemotherapy

What is chemotherapy?

Chemotherapy is a type of medicine that is used to treat cancer. Cancer cells grow and reproduce (multiply) very quickly. Normal, healthy cells know to stop growing and reproducing when they touch other cells. Cancer cells keep growing, not knowing when to stop. RNA and DNA in the cell tell it how to grow and reproduce. Chemotherapy hurts the RNA or DNA, stopping the cancer from growing. A chemotherapy regimen is a group of medications given to treat certain types of cancer.

What is dose-dense chemotherapy?

Dose-Dense Chemotherapy (DDC) is a way to give chemotherapy regimens more often than normal. The goal of DDC is to kill as much of the tumor as it can. The actual dose of chemotherapy is not increased, but the time between doses is lessened. By giving the same doses of chemotherapy more often, the chemotherapy stops the rapid (quick) growth phase of the tumor cells. The medications hit the tumor cells at the time when they are just starting to grow again. This model was called the Norton-Simon model, after the researchers who first described it.

A concern of DDC is that giving chemotherapy more often would lead to low white blood counts and infection. Through the use of growth factors like Filgrastim (Neupogen®, G-CSF), Pegfilgrastim (Neulasta®), and Sargramostim (Leukine®, GM-CSF), your white blood cells can heal faster, lessening the chance of infection. DDC studies have shown a higher rate of anemia (low red blood cell count) and bone pain (likely linked to the use of a growth factor) with these regimens, but the DDC regimens also shorten the length of therapy by 4-6 weeks.

What types of cancer is DDC used in?

Studies have found that premenopausal women with high-risk breast cancer (hormone receptor-negative, Her2 positive, and lymph node-positive) see the most benefit from DDC. This study also found that the use of DDC does not seem to be linked with an added risk of treatment-induced/early menopause or amenorrhea (absence of menstrual periods). This is an important finding because early menopause can cause your ovaries to stop working, which can increase the risk of:

• Osteoporosis.
• Early heart disease.
• Infertility.
• Hot flashes.
• Vaginal dryness.
• Weight gain.

These side effects can be hard to cope with and have a harmful impact on women of childbearing age.

DDC is used to treat some high-risk lymphomas. Studies are still looking at DDC used with Rituximab (Rituxan®). Studies have also looked at using DDC in ovarian cancer.

There is a benefit to DDC for some patients. Deciding who will benefit is the focus of ongoing studies in these and other types of cancer. Longer follow-up of studies that were done before will help us learn more about DDC and its use.

If your treatment plan includes dose-dense chemotherapy, talk with your care team about any concerns you may have.