Prevention is better than cure
Lifestyle changes and treatments that protect against cancer may be more effective than medical interventions after a cancer diagnosis
About one person in every two will get cancer during their lives. Surgery and chemotherapy have long been mainstays of cancer treatment. Both, however, have substantial downsides. Surgery may leave behind undetected cancer cells that can grow into new tumours. Furthermore, in response to chemotherapy drugs, some cancer cells may emerge that resist further treatment. There is therefore interest in whether preventive strategies — including lifestyle changes and medications — could reduce the likelihood of confronting a life-threatening cancer.
Now, Andrei Akhmetzhanov and Michael Hochberg have developed a mathematical model to help compare the effectiveness of preventive strategies and traditional cancer treatments. The model — which assumes that a person can only develop a single cancer from a single region of pre-cancerous cells — suggests that long-term cancer prevention strategies reduce the risk of a life-threatening cancer by more than traditional treatment that begins after a tumour is discovered. The preventive measures may be less effective in some cases compared to traditional treatments if they initially fail to stop a tumour growing, although on average they still work better than treating the cancer after detection.
According to Akhmetzhanov and Hochberg’s model, surgical removal followed by chemotherapy is less likely to be successful than prevention, and when successful, requires larger impacts on the cancer (and therefore creates more side-effects for the patient) to achieve the same level of control as prevention. The model also suggests that even at very low levels of impact on residual cancer cells, chemotherapies are likely to be counterproductive by boosting the subsequent emergence of treatment-resistant tumours.
Akhmetzhanov and Hochberg’s model predicts how effective preventive measures need to be in terms of slowing the growth of cancer cells to result in given reductions in the future risk of a life-threatening cancer. Future work should test this model by measuring the effects on tumour growth of prevention and of traditional therapies.
To find out more
Read the eLife research paper on which this eLife digest is based: “Dynamics of preventive vs post-diagnostic cancer control using low-impact measures” (June 25, 2015).
Read a commentary on this research paper by Natalia Komarova: “Cancer prevention: The benefits of treating undetectable tumours”.
