For cancer survivors the fear of a subsequent cancer diagnosis is very common. Sometimes the original cancer wasn’t completely eliminated, and it recurs after patients finish treatment. In addition, around a fifth of cancer survivors will develop totally new independent tumours – so their fears are sadly not unreasonable.
Why do some cancers come back?
Many of the new tumours that cancer survivors get are caused by the therapies that were used to treat their original cancer.
In basic terms, cancer treatments like chemotherapy and radiotherapy work by inducing DNA damage. Cells respond to the DNA damage by triggering a self-destruction process called apoptosis.
Apoptosis hopefully eliminates the cancer – but it can also damage the genetic material of non-cancerous cells. When these damaged cells survive they can grow into second malignancies.
New research from La Trobe Institute for Molecular Science (LIMS) has focused on the development of drugs that directly engage apoptosis pathways. Scientist Dr Christine Hawkins reasoned that because direct apoptosis inducing drugs don’t need to damage DNA to kill tumour cells, they would cause fewer mutations and be less likely to cause subsequent cancers. Dr Hawkins:
‘We found that new anti-cancer agents designed to target “Bcl-2” or “IAP” proteins failed to provoke mutations in surviving cells, in contrast to chemotherapy drugs that were highly mutagenic.
Preliminary clinical trials have revealed that some of these agents can successfully treat patients with types of cancers that tend not to respond to chemotherapy. Our data suggest that these drugs may offer a second advantage over chemotherapy and radiotherapy, hopefully sparing cancer survivors from the cruel irony of therapy-related new cancers.’
The findings were very positive and provide hope that cancer survivors will be at less risk of getting sick again in the future.
Interested in working on life changing research? Find out about the courses and research programs at LIMS.
Photo: Dr Christine Hawkins