Colorectal cancer survivors face elevated risk

Colorectal cancer (CRC) survivors face an elevated risk of developing multiple primary cancers (MPCs), recent Australian research from Flinders University has revealed. The study, published in Cancer Medicine, was based on South Australian Cancer Registry data. Using thousands of individual CRC cases diagnosed between 1982 and 2017, 26,729 CRC survivors were included, with the study involving researchers analysing the likely incidence and risk of MPCs.

“While patient outcomes have improved over time, CRC survivors already face an increased risk of developing one or more cancers in another part of the colon or other primary sites,” said Mulugeta Melku, from FHMRI’s (Flinders Health and Medical Research Institute) Bowel Health Service and the study’s leader. “This study shows that CRC survivors are at increased risk of subsequent cancers compared to the general population, highlighting the need for targeted surveillance, particularly for early detection and treatment of prostate, lung, breast and blood cancers.”

PhD candidate Mulugeta Melku, who led the research.

The most common MPCs that CRC survivors were at risk of over time were: prostate cancer, subsequent CRC, lung cancer, haematological malignancies, breast cancer, urinary tract organ cancers and skin melanoma. “Estimating the incidence, trend and risk of other kinds of MPCs after a diagnosis of CRC will help service delivery, testing and treatment in the coming years, as the population continues to age and survivors live longer,” said Associate Professor Erin Symonds, senior researcher and also from the Southern Adelaide Local Health Network.

Senior cancer researcher Associate Professor Erin Symonds.

As the fourth most diagnosed cancer in Australia, and second-highest cause of cancer-related death, in the last 40 years there has been significant advances in screening for early detection of CRC, more targeted treatment options, and improved diagnostic tools and awareness in the community about cancer and prevention that have improved survival rates — risen from 54.9% in 1991–5 to 71.3% in 2016–2020. “Further research will also help to improve treatment outcomes and overall survival,” Symonds said.

Symonds also said that studies such as this increase understanding of MPCs risks. Something that can, in turn, help develop suitable strategies to enhance and refine surveillance programs for early detection of subsequent cancers. This study — titled ‘Incidence, risk and trends of multiple primary cancers in patients with colorectal cancer: evidence from the South Australian Cancer Registry’ — was published open access and can be read at doi.org/10.1002/cam4.70984. A second paper has also been recently published open access by the researchers; it covers some of the MPCs risk factors for CRC survivors and can be read at doi.org/10.3390/cancers17132145.

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