Tuesday, April 08, 2014

The Cancer genetic testing hype

There are many new personal genomics companies which are promising cancer patients that they can use genetic technology in order to help them manage their cancer better. This is new technology , which is being marketed to the consumer so actively for the first time in India.

We all know that cancer is a very emotional issue, and patients ( and their relatives) will often move heaven and earth in order to do something - anything – to help the patient. They are very vulnerable and are happy to grasp at straws – which is why there is so much quackery in this field.

My opinion is that these tests and technologies maybe highly “advanced” – but right now, given their limitation,  they are just sophisticated and expensive quackery, which are designed to take patients for a ride. The truth is that there is very little we can do to affect the natural history of over 95% of patients with cancer. Inspite of the “War Against Cancer”, we have made very few advances in the last 50 years.

However, doctors do need to treat patients – we cannot just right them off ! This is why we poison them with chemotherapy – even though it does not affect their over all life expectancy. This is one of those dirty little secrets which most oncologists do not share with their patients . ( It’s interesting to see how most oncologists will refuse to take chemo when they have a cancer themselves !)

While chemotherapy can cause a tumour to shrink, this is not the same as effective treatment ! The tumour just comes back with a vengeance after a few months. While we’ve tacked on a few additional months of life , the quality of that life is often extremely tacky.  This is something which is rarely discussed openly, because no one wants to take away the patient’s hope. Sadly, the case fatality rate remains the same, with or without chemotherapy.

The genetic testing company’s positioning is that their new technology will revolutionise the medical care of patients with cancer. They seem to promise heaven and earth – with the moon thrown in for free. Because it’s all couched in a very scientific terms, it’s very easy to fool patients – and oncologists as well !

While it’s true that these advanced tests can provide additional information, the key question is – will this additional information translate into better clinical results ? The answer is No, for the vast majority of patients. However, researchers will tom-tom their success stories ( which are few and far between) – and they try to extrapolate from these to cover a much wider group of patients – an extrapolation which is completely unscientific and false.

The marketing campaigns are very slick, and this is hardly surprising , because this is a for profit company. The tragedy is that there does not seem to be anyone to push back and protect the poor patients and prevent them from wasting their money on pointless tests. The testing has been cleverly packaged along with a second opinion program from experts. Guess what ? If you ask for a second opinion, their experts will ask you to get a genetic analysis done – after all, they are on the payroll of the company, and need to increase their sales funnel and their pipeline .

Sadly, most oncologists know precious little about genetics . They are quite happy to order the tests, because doctors are trained to order tests ! They often can't make any sense of the results , which are full of genetic gobbledygook, but because they cannot afford to acknowledge their ignorance to their patients, so they pretend to be well-informed .

While these tests may prove to be useful, the truth is that these are still research tools, which should be used only in the setting of a clinical trial, so we can learn more about their utility and limitations. While the company quotes a lot of medical journal articles in their ads, to back up their claims, the reality is that a lot of this research is not very reliable ( even if it has been published in respected medical journals), because it is paid for and sponsored by the genetic testing companies, who have an axe to grind

This has now become an extremely complicated situation – both for patients and their oncologists. By advertising directly to the consumer, the company has bypassed the oncologist. If a patient comes with the newspaper cutting and demands that the test be done, the oncologist is very unlikely to refuse because of the pressure from the patient. After all, what’s the harm in doing the test ? And if the patient is willing to pay for it, why should the doctor care ? ( It’ll be interesting to see if health insurance companies are willing to foot the bills for these unproven , experimental tests, which have not been shown to affect clinical outcomes as yet, in controlled clinical trials).

There will be many oncologists who will be happy to get on the bandwagon and order these tests, to show off to their patients how well informed they are. Doctors like to play the game of one upmanship , because they are very competitive ! The ones who are conservative and refuse to order the tests, because they are not convinced that they add any value, are likely to be perceived as old-fashioned fogeys, who have not kept up with the times.

I wish journalists would be more responsible , and help patients to find the truth. However, because they have limited scientific backgrounds, or insufficient bandwidth to do an in depth exploration of such a complex topic, they are unlikely to do so.

Ideally, these tests  should be offered in a clinical research setting , so that they can be used to gather more information , which can then be analysed, and used to treat patients in the future . It’s very unfair to charge patients for using them as guinea pigs, since we still do not know if the test results actually provide clinically useful information. Do they change the doctor’s treatment plan ? or decision-making process ? or provide any actionable information ? These are the questions patients and doctors should be asking , before ordering these expensive and unproven tests.


  1. Sefat-E-Mariam9:50 PM

    Beauty of truth...

  2. Anonymous12:52 PM

    Dr. Malpani,
    I found your blog really interesting and informative. I agree with you that majority of the doctors have very limited knowledge when it comes to genetics & molecular sciences. I would like to know more in detail information regarding the claims you have made about genetics testing based diagnosis & prognosis of cancers. Kindly provide me the evidences and literature related to the same so that I can educate people about these issues.
    Dr. Singh

  3. Anonymous5:39 PM

    to what extent do you understand genetics? are you a genetic expert or oncologist or something? basic genetics and advanced genetic science is far different. do you know the number of genes a person carries? to what extent have we advanced in genetics engineering today? what is the most recent technique to analyze DNA?
    i have a lot of patients and their relatives and even doctors with grey hairs and baldies with such queries. may be your information therapy pill can cure them!!!!

  4. Anonymous5:40 PM

    i you have guts let the criticism comments be shown below your blog!!

    1. Will be happy to do this - why don't you have the guts to display your name ?

  5. Anonymous11:35 AM

    I am a genetic counselor - it can help the patient because there are specific surveillance and management guidelines established for the more common cancer gene syndromes. Many patients also have genetic testing for the sake of their relatives. In a family suspected to have hereditary cancer, identification of the underlying genetic mutation allows predictive testing for at risk family members such as siblings, children, etc. Those that did not inherit the mutation would be at the general population risk to develop cancer. Those positive for the family's mutation may benefit from following the recommended screening/surveillance guidelines.

    1. This is exactly my point. When used selectively by a doctor, the tests may help some patients. The danger is when they are marketed and used promiscuously and indiscriminately for everyone ! The companies make money only when these tests are overused - that's the danger



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