Sunday, July 5, 2020


   IN medicine ,we often get new tests  and many a times they are useful and sometimes create problems I had talked about a test in past called liquid biopsy. It was testing tumor DNA. This test is being used successfully in diagnosing recurrence and also the follow up of treatment . In the beginning this was started as early diagnosis of lung  and breast cancer with nodule. The problem that happens is what do you do when nodules are small or not there  and one finds tumor DNA , then what do you do ?The same that has happened to me in one of the patients that I see.
    There is a new test that was approved recently . It is for the diagnosis of lung cancer , But it is not for the diagnosis but to get a probability of cancer when someone has lung nodule.Now a days we have been doing more CT scans of the chest as there was screening Low dose radiation CT scan approved be medicare  and other insurances  and so we can do a CT scan in patients who are smokers or ex smokers for 14 years  and so on, . So there are calculators developed based on the size , location, smoking history  and age  and sex and type of nodule. Theses do not give any diagnosis of cancer ,but give the probability of cancer . They are used in making a decision  on further course of action. So a new test was added . So one calculates the probability based on the above mentioned criteria  and then blood test is added as additional factor in calculating the probability of the same
So I saw this patient who had quit smoking 30 years ago and had CT scan of chest She is 70 years old  and had not much pulmonary symptoms  and had some cough  and so during work up CT scan was done . She had some nodules  and one was 10 mm. This is minimal size for doing PET SCAN . So I did PET SCAN  and that was OK which means the nodule did not pick up glucose , which means it was not hyper metabolic. So I decided to watch it with CT scans . over period of time we did do new CT scans  and they were stable but the radiologist reported the size to be 8 or 9 mm instead of 10 mm . The last CT scan it was reported as increased by 1 mm. Just to clarify , 25 mm make  and inch . So this was very small  and I did not know what to say . So I did new PET scan and that did not show any glucose uptake.That was good but radiologist reported that slow growing cancer may not pick up on PET scan. But then I did the new blood test, The probability calculated based on all the factors before the blood test was done, For those who may be interested there is Mayo clinic calculator which you can google.After the blood test the PROBABILITY OF NODULE BEING CANCER INCREASED ALMOST DOUBLE. So now the problem
    She has not smoked for 30 years . The nodule is barely if at all increased by 1 mm in 10 months  and she has no symptoms . So what should be done . The bronchoscopy would not give diagnosis - which I have done . The needle biopsy may be attempted but with given size may not give the diagnosis. So should I do open biopsy ?
    So in this case it has created more questions than answers!

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