What are stem cells?
Stem cells are found in the bone marrow, which is a spongy tissue inside the bones and help in producing different types of blood cells like:
- Red blood cells
- White blood cells
- Making more stem cells
What are autologous stem cells?
These are your own healthy stem cells, which can be collected and cryopreserved (frozen).
What is an autologous stem cell transplant (SCT)?
Autologous stem cell transplant is done to treat cancers such as multiple myeloma and lymphoma.
How does autologous stem cell transplant work?
- First a high dose of chemotherapy regimen is administered to destroy as many of the cancer cells as possible.
- The chemotherapy will destroy the bone marrow as well and hence, blood cell production is reduced.
- To replenish the blood cells, your own stem cells will be infused through an intravenous route. This infusion is called autologous stem cell transplant. This will enable your bone marrow to grow back and start making blood cells again.
- The infusion of stem cells is a 'rescue',since it prevents normal bone marrow from dying. With an autologous stem cell transplant, the oncologist can plan for a higher dose of chemotherapy to kill cancer cells.
Steps in autologous stem cell transplant
Step 1: Are you a suitable candidate for autologous stem cell transplant?
The treating team will evaluate the overall health and status of cancer before suggesting an autologous SCT. The stage of cancer, how much of the cancer cells remain and if your body can handle the transplant will be assessed by a number of blood and imaging tests and other procedures.
Step 2: Stem cell mobilisation
This is the step where your stem cells will be mobilised into the blood stream from bone marrow.
- Stem cells live in the bone marrow and need to be collected from the blood stream. A drug called filgrastim is used for this process.
- In some cases, the chemotherapy drugs are used along with filgrastim to mobilise the stem cells into the blood stream.
- Your stem cells will be collected and cryopreserved before the high dose of chemotherapy is commenced.
Step 3: Aphaeresis or stem cell collection
During this process, your blood is run via an intravenous line into the aphaeresis machine where the stem cells are removed from the blood and collected. The rest of the blood is returned to your body. The stem cells are then frozen (cryopreserved) till you are ready for the transplant.
Step 4: Placement of a Hickman's line or central line
This is a special intravenous line that is inserted into one of the large veins under the collar bone or in your neck and is used to:
- Take blood for various tests during the transplant
- Give high dose of chemotherapy
- To infuse your stem cells
- To transfuse blood products, fluids, antibiotics and supplements
Step 5: Admission
You may be admitted for a high dose of chemotherapy and transplant.
Step 6: Hospital stay
A periodic reassessments by the treating team will be done, to assess if you need any:
- Fluid and electrolyte replacement
- Infection status
Step 7: Chemotherapy
A high dose of chemotherapy may be given in one or multiple doses to destroy your cancer cells, but your bone marrow may also be destroyed in the process. Side effects of chemotherapy like nausea and vomiting will be treated with medication.
Step 8: Stem cell infusion
After a high dose of chemotherapy treatment, you will have to wait at least 24 hours for the body to flush out the chemotherapy drugs,before your stem cells are reintroduced through the Hickman’s line into your blood stream. This is the actual SCT.
Step 9: Follow-up
The hospital stay will be for 16-20 days. Follow-up is important as the treatment will need to be assessed if:
- The blood cells are being adequately produced
- You are getting adequate fluids
- There are any side effects
- You have any signs of infection / bleeding etc.