There is a link between chemotherapy treatment and an increased risk of developing acute leukaemia. But it seems this is closely linked to the type of cancer which has been treated and how much treatment you have has. If chemotherapy is given for cancer which has developed during childhood or for Hodgkin lymphoma or a non-Hodgkin lymphoma then there is a greater risk of developing acute leukaemia years later.
Some studies following children treated with chemotherapy for cancer have suggested as many as 1 in 10 could develop an acute leukaemia between two and a half to 10 years later. For people who had chemotherapy for Hodgkin lymphoma or non-Hodgkin lymphomas the figures range from 1 in 20 to 1 in 50 in different reports.
Nowadays doctors are aware of the particular factors related to chemotherapy treatment which seem to increase the risk of leukaemia years later:
- Type of cancer being treated. Hodgkin lymphoma or non Hodgkin lymphoma treated with intensive chemotherapy.
- Chemotherapy drug used. Most cases of leukaemia are linked with a group of drugs called alkylating agents which includes cyclophosphamide, melphalan and chlorambucil. Other drugs occasionally linked are etoposide and doxorubicin and epirubicin.
- Risk seems greatest if these drugs are given regularly over a long time.
- Chemotherapy given along with radiotherapy sometimes appears to increase risk.
As a result of this treatments have been adapted to lower risk factors. Certain drugs which used to be given over long periods of months or years are no longer given in this way. With these changes it is likely that the risk of developing leukaemia as a result of chemotherapy is likely to be decreasing.
It's important to remember that chemotherapy has transformed the outlook for the cancers where a leukaemia risk has been clearly shown. In the 1950s childhood cancer was almost always incurable and now 7 out of 10 children survive their illness. Similarly Hodgkin lymphoma and non-Hodgkin lymphoma used to be generally fatal cancers and today most people will be cured.