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Friday, 9 October 2026dailybeirut.com
Tech & Science
A study in Cancer Discovery reveals that restricting genetic testing to patients under 50 excludes the majority of those carrying hereditary mutations.
Research published in the journal "Cancer Discovery" indicates that limiting hereditary cancer genetic screening to patients younger than 50 results in significant oversight. The study, conducted at the Memorial Sloan Kettering Cancer Center in the United States, analyzed data from 39,184 individuals diagnosed with solid tumors who underwent genetic testing regardless of their age.
Among the participants, 16.3 percent carried at least one pathogenic inherited genetic variant. If testing had been restricted solely to patients under the age of 50, 4,601 individuals possessing these variants would have been excluded. This figure represents 72 percent of all carriers within the study sample, though it does not account for the total population of cancer patients.
The genetic tests examined in the study identify inherited changes that may increase susceptibility to cancer, utilizing blood or saliva samples. Their primary value lies in providing actionable information to patients and their relatives, rather than confirming the presence of a new tumor. The National Cancer Institute clarifies that this process differs from somatic tumor analysis, which detects changes occurring during a person's lifetime to guide treatment choices. While tumor analysis might suggest an inherited change, it cannot replace dedicated hereditary risk assessment.
Researchers argue that relying heavily on age as a threshold risks missing older patients who carry clinically significant mutations. Lead researcher Zofia Stadel emphasized the need to evaluate what is lost when a uniform age limit is applied. Co-researcher Luis Diaz noted that hereditary cancers can manifest at any age, challenging the assumption that early-onset diagnosis is the sole indicator of genetic predisposition.
However, the findings do not imply that individuals over 50 should be denied testing, nor do they establish new clinical guidelines. The study was limited to a single center, and the participant pool showed uneven representation across cancer types, with a predominance of European and Ashkenazi Jewish ancestry. These factors restrict the generalizability of the results to broader populations.
According to the National Cancer Institute, a positive test result can help direct certain treatment options, assess risks for other cancers, and provide relatives with information to make decisions about their own screening and care. Crucially, identifying an inherited variant in a patient does not mean every family member carries it, nor does it guarantee that carriers will develop cancer. Specialists stress the importance of interpreting results professionally to avoid premature judgments about family health.
Conversely, a negative result does not always eliminate all genetic risks, particularly if there is a strong family history but the specific responsible variant remains unknown. Tests may also reveal "variants of uncertain significance," where current evidence is insufficient to determine the impact on cancer risk.
Patients are encouraged to discuss with their care teams whether genetic evaluation is appropriate for them and what insights it could add to their treatment or family monitoring. If tumor analysis has already been performed, patients should inquire whether it included screening for inherited changes. The American Cancer Society notes that considering testing after diagnosis depends on factors such as cancer type and personal or family history. The study opens discussion regarding the role of age in selecting candidates for genetic screening, without issuing a general recommendation for healthy individuals to undergo testing.
