Young adults diagnosed with cancer may require different treatments than those received by older patients, according to a study that systematically compared the genomes of 14 different types of cancers affecting both younger and older adults. The results, published by Lee et al in Cell Reports, suggest that several genetic hallmarks may play key roles in identifying precise treatment options for young adult patients with cancer.
Study Background and Methodology
According to recent research, cancer diagnosis rates in young adults may be rising. However, as the authors of this study noted, most of what is known about treating various cancers is based on studies of older patients, creating an apparent knowledge gap that needs to be filled.
To address this, researchers compared the genomic data of 14 different types of tumors from 1,757 adult patients who were younger than age 50 with that of 3,608 who were older than age 50. The data used were from The Cancer Genome Atlas. For each tumor, the researchers systematically compared genetic mutations, chromosomal alterations, tumor immune system factors, and the potential to be treated with a known anticancer therapy. They then validated the results using additional samples from the International Cancer Genome Consortium.
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Differences Noted Between Younger and Older Patients
Overall, the results showed that each type of young adult tumor could be distinguished from later-onset cancer by a specific set of hallmarks. For example, the relative proportions of well-known mutations seen in low-grade gliomas shifted greatly with the patient’s age. Endometrial tumors from young adults, by contrast, tended to have more mutations than those from older patients.
Nevertheless, there were some common trends across cancer types. Most notably, the results suggested that young adults’ immune systems responded differently to most of the tumors. This included responses by macrophage and dendritic cells, which are often exploited by anticancer immunotherapies.
Finally, the researchers found several differences between how younger and older adult tumors may respond to different treatment options, such as to drugs designed against cancer-causing mutations in the BRAF gene. Here, the results suggested that anti-BRAF drugs may provide effective treatment options for a higher fraction of young adult patients with skin cancer than older ones who have the same tumors. In contrast, older patients with colon cancer may benefit more from anti-BRAF treatment options than the younger ones.
The study authors concluded, “Overall, while our results highlight age-related molecular drivers across cancer types, further studies are required to establish the mechanistical underpinning and clinical implications of their age associations in cancer.”
Disclosure: This study was supported by the National Institutes of Health and the Icahn School of Medicine at Mount Sinai. For full disclosures of the study authors, visit cell.com.
