Developing a second primary cancer is not uncommon, with second cancers making up 14% of all new cancers. As survival following a cancer diagnosis improves, more people will develop a second primary tumour.
A small number of people develop three unrelated primary cancers in their lifetime, while some can go on to develop even more primary cancers. Previous research has shown that among people diagnosed with three or more primary tumours (multiple primary cancers), less common tumour types appear more frequently than expected. Studying the genes of people diagnosed with three or more primary tumours provides a way to identify new and potentially rare genetic variants that may increase a person’s susceptibility to cancer. Previous research has identified that people who develop multiple primary cancers have a life expectancy similar to the general population, suggesting that in addition to an increased likelihood of developing cancer, these people may also have a different way to limit the growth or spread of the cancers that they do develop.
A study of participants selected from the FCP and Cancer Council Victoria’s Health 2020 Study with three or more primary cancer diagnoses is being led by collaborators at the Walter and Eliza Hall Institute of Medical Research, in addition to participants from their WEHI-Stafford Fox Rare Cancer Program.
This project was initiated through funding from a 2020 Venture Grant from Cancer Council Victoria, with additional funding recently obtained from the NHMRC and Perpetual Trustees. Genetic testing will be performed to identify genetic changes associated with these cancers. The researchers also plan to perform additional tests on diagnostic tumour tissue samples from a selection of participants to understand more about the immune signature of tumours. The aim of this analysis is to understand any underlying factors restricting cancer spread that might explain why longer survival is often observed in cohorts of people with multiple primary cancers.
Primary cancer – Most cancers start in a particular organ or tissue; this is called the primary cancer. With more people surviving cancer (a good thing), we see more people having a second cancer diagnosed in their lifetime that isn’t connected to their first diagnosis. These are known as ‘second primary cancers’.