Do stem cell transplants improve patients’ long-term survival?

This study examined the long-term survival of patients who received stem cell transplants (SCT) and compared them to the general population. The authors found that patients who received SCTs had almost the same chance of survival as the general population and identified factors that alter this chance.

Treatments such as chemotherapy can reduce the number of healthy immune cells. Immune cells are made by stem cells. Stem cell transplant (SCT) involves giving patients stem cells after they are finished treatment to remove cancer cells. 

Stem cells can be taken from a donor (allogeneic; allo-SCT) or from the patient before they start treatment (autologous; auto-SCT). Information on patients who survive long-term after SCT is useful to understand how to improve their care long-term.

Data was examined from patients who received SCT and survived without signs of cancer for more than 2 years. 1562 patients received allo-SCT and 3822 patients received auto-SCT from 2002 to 2011. Patients either had a type of leukemia, lymphoma, myelodysplastic syndrome (MDS), or myeloma. Patients were followed for 5.6 years on average. This data was compared to a previous study from 1992 to 2001 and statistics from the general population.

Compared to the general population, patients who received an allo-SCT had between a 96% to 99% chance of survival. Patients under 16 years old had a 42% higher chance of survival and patients with chronic myeloid leukemia (CML) had a 31% higher chance. Patients who received stem cells from donor blood had a 25% lower chance of survival. The 10-year overall survival (OS) rate in patients who had an allo-SCT was 78.4%. Compared to older data, the use of unrelated cells and of reduced-intensity chemotherapy have increased. 

Compared to the general population, patients who received an auto-SCT had an 89% to 96% chance of survival. Patients with lymphoma (91-97%) had a higher chance of survival compared to those with myeloma (88-96%). 10-years OS was 61.8% in patients with lymphoma who had an auto-SCT. Male patients and those older than 45 had a lower survival rate.

The authors concluded that allo-SCT improves patients’ chances of survival slightly more than auto-SCT.  They suggest that older patients and male patients should be more closely examined over the long-term.

Data in this study came from patients in Australia and New Zealand and may not accurately reflect other populations. Information such as the type of treatment used alongside SCT was not taken into account in the analysis. This might also affect the results.