INDIANS CAN DO DIY TESTS TO IDENTIFY GENE MUTATIONS FOR SOME CANCERS, BUT ONCOLOGISTS SAY THERE ARE PROS AND CONS.
You wake up to an advertisement promoting a genetic test to detect cancer risks where all one has to do is give a saliva sample. You scroll on social media to find another quick cancer screening promise, this one with a few drops of blood drawn at home and sent off to the lab.
Home-based cancer screening kits are gaining ground in India, but oncologists warn that there’s a high chance they aren’t error-free and, even if they are, they might not give you the whole picture. “Doing such tests without expert advice from an oncologist would only make people worry more, as such tests have a very high possibility of false positives or false negatives, which can lead to a battery, of unnecessary investigations that are sometimes harmful.”
DO YOU REALLY NEED TO KNOW?
And not every average person needs to find out if they have a cancer-causing gene. Such tests are highly specialized and only for high-risk groups. “Currently, genetic tests for cancer are recommended only for those with a family history of multiple cancer cases, a diagnosis of cancer at a young age, two or more cancers in one individual, clinical signs of high-risk syndromes, or a relative with a known high-risk genetic mutation.”
WHAT ABOUT ACCURACY?
The 99% accuracy figure often claimed in ads can be misleading. “While blood and saliva-based genetic tests may be highly accurate in certain contexts (detecting gene mutations linked to cancer risk, for instance), they are not infallible. These tests focus on identifying genetic risk factors rather than directly diagnosing cancer,” adding that test sensitivity, specificity, and the type of cancer being screened can also influence their accuracy. They are useful tools but shouldn’t be relied upon as the sole means for early detection or cancer diagnosis.
But genetic cancer screening can be useful in some cases. A germline cancer test found a pathogenic variant in the BRCA1 gene, known to be associated with hereditary breast and ovarian cancer syndrome(HBOC). Saliva tests carried out at home are better at identifying men who are at higher risk of prostate cancer than the standard blood test.
However, in India, the regulatory landscape for genetic testing is still evolving. The Central Drugs Standard Control Organization oversees in vitro diagnostic devices, but many genetic tests fall outside strict regulatory control unless classified under specific diagnostic categories. While the Indian Council of Medical Research provides recommendations, t here is no mandatory approval process for direct-to-consumer genetic testing kits, raising concerns about accuracy and misuse.
All cancer screening tests must be reviewed and validated by regulatory bodies like the FDA before marketed directly to consumers. “The US FDA regulates these tests under different categories. For high-risk tests, such as those used in cancer screening, companies must submit a premarket approval application after rigorous clinical trials to validate the test’s ability to accurately detect cancer or associated risk factors.” That if a test uses new technology or novel biomarkers such as genetic variants, the FDA may require additional data to validate its clinical utility.
TRANSPARENCY IS KEY:
“If a company refuses to provide clinical data or relies on marketing claims alone, that’s a red flag.” If indeed such a test needs to be done, then it must be from an established lab with proper regulatory approvals.” Look for CAP (College of American Pathologists) and CLIA (Clinical Laboratory Improvement Amendments) accreditation, which are the highest certifications for labs. Most US labs have this, ensuring high standards and reliable validation.” But data validation alone is not enough. For a test to be adopted at the community level, it must undergo large-scale prospective studies to confirm its accuracy and sensitivity.”
Cancers of the breast, cervix, prostate, lung, and colon can be screened for early diagnosis.” But not all cancers are amenable in screening. Besides, screening guidelines are different for those at high risk and those with average risk of cancer.”
Genetic testing has come a long way, no doubt, but it’s important to recognize its limitations. “As research advances, new genetic mutations may be discovered, and findings will need to be revisited. Often, these tests detect variants of unknown significance that haven’t been linked to a specific disease, which can cause unnecessary anxiety,”
And genetic mutations are just one of the causes of cancer. “Before indiscriminately going for such tests, one must also be mindful of one’s lifestyle, diet, exercise, and environment, exposures (alcohol, smoking, pollution, pesticides) that can significantly influence a person’s cancer risks.”
