I'm a cancer doctor and here is what I think about at-home genetics tests

The direct-to-consumer familial investigating market has helped tens of millions of Americans not conscionable larn astir their household lineage, but besides fixed them a microscopic presumption of their health.

Popular DIY tests – specified arsenic Ancestry DNA and 23&Me – connection a assortment of kits depending connected however overmuch of a heavy dive into your DNA you're hoping to do, ranging from $99 to $200. 

Kits that trial your feature swab for wellness markers whitethorn uncover genes that bespeak an increased likelihood of breast, ovarian, and prostate cancers, helping customers - whether they person a household past of cancer oregon not - summation a amended knowing of their idiosyncratic risk.

But oncologists caution the at-home tests are not for everyone.

Direct-to-consumer tests are reasonably constricted successful scope erstwhile it comes to variants they trial for. 23&Me, for instance, lone tests for 44 familial variants successful the BRCA1 and BRCA2 genes, which suggest a proneness to bosom cancer, but determination are much than 4,000 known variants that summation the risk. 

23&me besides tests for 2 variants successful genes that summation one's hazard of colorectal cancer, though determination are astir 25 acquired cistron mutations known to summation CRC risk. 

Dr Mikkael Sekeres, an adept successful humor cancers astatine the University of Miami, advised acrophobic customers to interaction their doctors for a much broad laboratory trial alternatively of archetypal trying an at-home test.

He added just a tiny proportionality of cancers – betwixt 5 and 10 percent – are believed to beryllium associated with familial variants, portion the remainder are caused by manner and biology factors similar smoking and aerial pollution, calling into question whether these tests genuinely are the crystal shot that radical want.

And doctors besides pass that galore radical untrained successful subject whitethorn misinterpret their results oregon stroke thing retired of proportion, starring to adjacent much undue anxiety.  

Dr Sekeres told the Washington Post doctors typically lone bid a circumstantial trial based connected whether the accusation from those tests volition really pb to a meaningful quality successful their care. 

If they cognize the illness hazard is debased and that it whitethorn origin added outgo and accent to the paint, they mightiness skip it.

He said: ‘When it comes to at-home tests, I counsel my patients to deliberation similar a doc successful this way.’

If the results are negative, the idiosyncratic volition apt respire a suspiration of relief, and their accent volition extremity there, adjacent though that antagonistic effect does not mean they volition ne'er get cancer. 

But if the trial shows a affirmative result, however mightiness that alteration their regular life, Dr Sekeres asked.

Will you archer your children of your familial predisposition? Will you slash your intoxicant intake and halt smoking to minimize your risk? Will you travel a strict clean-eating regimen and workout for 30 minutes oregon much daily? Will you retrieve each azygous time earlier leaving the location to slather yourself successful sunscreen?

Dr Sekeres said: ‘If the reply to these questions is “no,” you astir apt should not bid the test.’

According to the National Cancer Institute, radical who find they don’t transportation a familial variant that others successful their household bash tin engender ‘survivor’s guilt,' which tin origin utmost shame and a mendacious consciousness that a antagonistic result could person been prevented. 

And inconclusive results tin origin uncertainty and stress.

There is besides the hazard of false-positive results, which tin pb to accent and the fiscal outgo of getting capable follow-up investigating ordered by a physician. 

A 2018 study revealed a staggering 40 percent of earthy information from direct-to-consumer familial tests produced mendacious positives. 

And conscionable due to the fact that a trial effect mightiness amusement a definite mutation, that does not mean the idiosyncratic is destined to make cancer, though it does bespeak an accrued risk. 

Anyone who sees a mutation connected the BRCA1 gene, for instance, is apt to go highly distressed. Having a BRCA mutation does not marque crab a foregone conclusion. Rather, having the mutation increases crab hazard by 45 to 85 percent. 

At-home tests, which instrumentality into information a person's ethnicity, person different large shortcoming: they lone look for DNA changes passed down from parents. But, genes tin acquisition large changes passim our lives.

About 90 percent of crab mutations hap during a person’s beingness owed to factors similar aging, biology stressors, and random errors successful compartment part and growth, compared to astir 10 percent of crab genes passed down from our parents.

Dr Sekeres said: ‘It tin instrumentality decades to get the mutations that origin cancer, and frankincense the crushed astir crab is diagnosed successful older adults, astatine a median property of 66 years successful the United States.’

Just 3 to 5 percent of colorectal crab cases are linked to an inherited cistron change. The remaining 95 to 97 percent, meanwhile, are caused by acquired mutations.

About 5 to 10 percent of bosom crab cases are thought to beryllium hereditary, meaning that they effect straight from cistron changes. That means astir 90 percent of cases are caused by acquired mutations.

But the BRCA1 and BRCA2 genes are possibly the astir well-known mutated genes that summation women’s susceptibility to bosom crab and ovarian cancer, arsenic good arsenic prostate crab successful men.

About 1 successful 400 radical successful the wide colonisation transportation 1 of these genes, but the complaint is higher among those of Ashkenazi Jewish descent, with astir 1 successful 50 radical affected. 

The MLH1, MSH2, MSH6 and PMS2 cistron mutations tin pb to colorectal cancer, gastric, ovarian, and endometrial cancers and are colloquially known arsenic Lynch syndrome. Almost 1 successful 300 radical person 1 of these mutations.

And TP53, which leads to a wide scope of conditions including breast, bone, brushed tissue, brain, adrenal gland, and humor cancers, is known is Li-Fraumeni syndrome. Around 1 successful 5,000 radical person inherited this variant. 

Of those three, 23&me lone tests for BRCA mutations.  

Dr Sekeres said: ‘If you bash trial affirmative for a familial mutation, the bully quality is that, portion familial mutations tin spot america astatine higher hazard of processing cancer, determination are interventions we tin marque to mitigate that risk.

‘Talk to your doc astir the champion program for you, which whitethorn see aboriginal screening and taking medications specified arsenic oral contraceptives oregon aspirin.’