Overview of Autologous Stem Cell Transplant
A variety of factors ultimately influence a patient’s decision to receive treatment of cancer. The purpose of receiving cancer treatment may be to improve symptoms through local control of the cancer, increase the duration of survival, or ultimately improve the chance of cure. The potential benefits of receiving cancer treatment must be carefully balanced with the potential risks of receiving cancer treatment.
The following is a general overview of high-dose chemotherapy and autologous stem cell transplant for the treatment of inflammatory breast cancer. Circumstances unique to your situation and prognostic factors of your cancer may ultimately influence how these general treatment principles are applied to your situation. In addition to this treatment overview, the Cancer Treatment News web site feature presents the results of the actual clinical trials that determine the standard treatments of breast cancer and new treatment strategies as they have been discovered and applied by cancer physicians around the world.
All new treatments are developed in clinical trials. Participation in a clinical trial may offer access to better treatments and advance the existing knowledge about treatment of breast cancer. Remember, this web site information is intended to help educate you about your treatment options and to facilitate a mutual or shared decision-making process with your treating cancer physician.
Inflammatory breast cancer is a specific kind of breast cancer that is characterized by specific changes in the breast. Inflammatory cancers typically have large areas of skin changes or indurations and are characterized on biopsy as having subdermal lymphatic invasion by cancer. Traditional treatment of inflammatory breast cancer includes the use of chemotherapy, radiation, surgery and hormonal therapy. Various combinations of these treatments have resulted in approximately 30% of patients with inflammatory breast cancer surviving greater than 5 years without cancer recurrence.
High-dose chemotherapy and autologous stem cell transplantation has been incorporated into the overall treatment of women with inflammatory breast cancer. Several small clinical trials were published in 1998-99 that reported the results of incorporating high-dose chemotherapy into the overall treatment strategy of patients with inflammatory breast cancer. In general, patients were treated with a sequence of low-dose induction chemotherapy followed by high-dose chemotherapy and mastectomy, radiation and hormonal treatment with tamoxifen. Some doctors have performed mastectomy after induction chemotherapy instead of after high-dose chemotherapy. Approximately 64% of patients are reported to survive without recurrence of their cancer 2 1/2 to 3 years from treatment. Recently, doctors from France have reported 57% cancer-free survival rates 5 years from treatment with no patients relapsing after 3 years.
Doctors from a single hospital have reported their results of treatment of patients with inflammatory breast cancer with aggressive non-standard chemotherapy and high-dose chemotherapy and autologous stem cell transplant. They then adopted an approach using high-dose chemotherapy. When they compared the results of the intensive chemotherapy and high-dose chemotherapy approaches, patients treated with high-dose chemotherapy appeared to have a better outcome. Seventy-six percent of patients treated with high-dose chemotherapy were alive without cancer recurrence compared to 58% of patients treated with non-high-dose chemotherapy 4 years from treatment. Since inflammatory breast cancer accounts for 1-4% of all breast cancers, large clinical trials comparing one treatment strategy to another have not been and are unlikely to ever be performed.
Strategies to Improve Autologous Stem Cell Transplant:
The main reason patients with inflammatory breast cancer fail treatment is relapse. Relapse of inflammatory breast cancer occurs locally in the breast or distantly. Distant relapse occurs because the high-dose chemotherapy is either unable to kill all the cancer cells in the patient and/or because cancer cells “contaminating” the stem cells are infused back into the patient. The majority of distant relapses occur because all the cancer cells were not destroyed by the high-dose chemotherapy treatment. However, some relapses may be due to infusion of breast cancer contaminated stem cells. Local relapse occurs because the surgery and radiation were unable to destroy the cancer cells in the breast. Doctors are performing clinical trials designed to improve the treatment of breast cancer with high-dose chemotherapy that include the following approaches alone or in combination:
- Increased Treatment before High-Dose Chemotherapy: One strategy to improve outcomes is to increase the effectiveness of induction therapy so that patients have significant reduction in the number of malignant cells in the body before high-dose chemotherapy.
- Increased Dose Intensity: Since more treatment kills more cancer cells, increasing the intensity of treatment delivered to the cancer cells by utilizing high doses of anti-cancer therapies or by delivering multiple cycles of high-dose therapy is one strategy to improve cure rates. While increasing the intensity of treatment may kill more cancer cells, this approach may also damage normal cells and increase the toxicity or side effects of therapy.
- Monoclonal Antibodies: Monoclonal antibodies are a treatment that can locate cancer cells and kill them directly without harming normal cells. Herceptin® (trastuzumab) is the first monoclonal antibody approved by the Food and Drug Administration for the treatment of breast cancer. Herceptin® recognizes a protein on the cancer cell surface of 1 in 3 patients with breast cancer. In order to be treated with Herceptin® your doctor must test the breast cancer cells for the protein that Herceptin® recognizes. This protein is called Her 2-neu. Herceptin® or other monoclonal antibodies are not substitutes for other cancer treatments but have the advantage of being administered during or after high-dose chemotherapy and killing cancer cells by a different method than chemotherapy with the goal of improving the total treatment. Clinical trials are currently being performed to determine whether monoclonal antibodies administered during high-dose chemotherapy can improve survival or cure rates.
- Minimal Residual Disease: Following cancer treatment, patients often achieve a complete remission, (complete disappearance of the cancer). Unfortunately many patients in remission still experience a relapse of their cancer. This is because not all the cancer cells were destroyed. Doctors refer to the this as a state of “minimal residual disease”. Many doctors believe that applying additional cancer treatments when only a few cancer cells remain represents the best opportunity to prevent the cancer from returning. In addition to monoclonal antibodies, several centers are investigating vaccines which stimulate the body’s immune system to kill breast cancer cells. None of these vaccines are yet approved by the Food and Drug Administration but are being evaluated on clinical trials. Biologic modifiers that stimulate the immune system are being evaluated to prevent or delay relapses after autologous stem cell transplantation. One such agent that is being tested in patients with breast cancer is interleukin-2. Newer biologics agents are in the developmental phase.
- Cell Processing: When stem cells are collected from a patient for infusion after high-dose chemotherapy, cancer cells may contaminate the stem cell collection. Although the majority of cancer relapses occurring after high-dose chemotherapy and autologous stem cell transplant occur because the high-dose chemotherapy did not kill all the cancer cells, it is possible that some patients may also relapse from infusion of the cancer cells “contaminating” the stem cells. Many techniques are being evaluated that effectively remove cancer cells from the stem cell collection. It is currently unknown whether enough cancer cells can be removed to decrease relapse rates. To learn more about techniques for removing cancer cells from the stem cell product, select Autologous Stem Cell Collection and Processing.
- Improve Local Cancer Control: More intensive local treatment with different doses or schedules of radiation and evaluating the timing and sequence of radiation and surgery in the overall treatment plan are being evaluated in clinical trials in order to decrease the risk of local cancer recurrences.
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