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Clinical Case 117: Cancer Fishin’

OK – this case is for all the GPs and Internal Medicine types out there.  This is a relatively common scenario…  how do you play it?

Here’s the case.

Bruce is a 53 y.o. accountant.  He is a little overweight at 89 kg (BMI 31).  He is otherwise relatively well, he cycles to the cafe each morning in lycra and drinks a cappuccino in his helmet… why do they do that?

He has hypertension which is controlled by ramipril 5 mg daily.  No other meds or relevant medical history.  He is interested in his health and even has annual “Mens’ Health checks”.  He was in last month for one – which was unremarkable other than a borderline BP and his prostate screen (post full consent and shared decision-making) revealed a normal DRE and PSA level.

Today he has come to see you with a discharge letter from the local hospital.  He was admitted for work-up of “unilateral leg swelling” which occurred spontaneously last Friday.

The letter reads:

Dear Dr Leeuwenburg,

Thanks for following up Bruce who had an unprovoked DVT diagnosed on Doppler.  US showed a 5 cm proximal DVT at the Femoral-saphenous junction (L) leg.

He also had a series of tests: FBP, UECr, LFTs, Ca, Mg, PO4, CRP, TFTs, a prothrombotic screen was unhelpful and serum rhubarb – these were all normal.  WE did a CXR to be sure and this was also reported as normal.  

Bruce was commenced on enoxaparin until his warfarin was therapeutic.  He’s on 8 mg nocte with an INR of 2.3 today .  Please chase his subsequent INRs

Oh – and – please screen for occult malignancy as we have not found anything yet.

Yours truly….

So Bruce is sitting in front of you looking a bit worried.  He says that he feels fine, and the leg swelling is improving.  He was a bit spooked when the “young-looking” hospital doctor told him that DVTs “like this” are usually due to some underlying problem “like cancer”.  He really wants to know what to do next.  Does he have cancer?

OK – so here are my questions to you:

Q1:  What is the chances that Bruce has an occult malignancy?

Q2:  what screening tests, inquiries, imaging etc would you recommend / order for Bruce?

Specifically will you get a CT of the torso?

Q3:  Does it really matter if he has an asymptomatic cancer? Will it reveal itself in time anyway?

Let me know your thoughts…

But in case you were wondering.  Here is the link to the recently published SOME trial out of Canadia in the NEJM in June 2015

They looked at a limited vs. “limited + CT ado-pelvis” strategy and found not much difference.  Both groups had about a 1% cancer rate at work up and had a similar “diagnosis rate” of cancer in the following year.  So the CT didn’t help reduce the time lag to diagnosis much.

However, there is of course a risk of finding incidentalomas and the harms associated with those and their further IX or Rx…

So for me it si back to simple thorough Hx, Exam, do the things you would normally do for a 50 yo bloke and watch him.  Really a great case for Shared decision-making here now that we have some rough numbers that we can present to the patient as risk ?

Thoughts
Casey

Comments

  1. Will Horwood says:

    Hi Casey,

    Long time reader, first time poster (I’m “just” a GP reg…)

    This case triggered a memory of Richard Lehman’s BMJ blog (I’d be interested to hear if you read this, I find it pretty interesting). Anyway, he wrote this entry a few weeks ago

    “Three months ago, a Cochrane review appeared that had us all talking over the (excellent) coffee at our weekly meeting in the UK Cochrane Centre. It concluded that “there is currently insufficient evidence to draw definitive conclusions concerning the effectiveness of testing for undiagnosed cancer in patients with a first episode of unprovoked venous thromboembolism (DVT or PE) in reducing cancer and VTE-related morbidity and mortality. The results are imprecise and could be consistent with either harm or benefit. Further good quality large scale randomised controlled trials are required before firm conclusions can be made.” We were all struck by this big gap in the evidence on a common and potentially life threatening situation. But now the gap has been plugged. A big Canadian study compared two strategies following an episode of unprovoked VTE. The first was limited screening for cancer, largely by clinical examination plus chest X ray, and the second consisted of this plus a CT scan of the abdomen and pelvis. The pick-up rate was less than half that seen in previous studies, and it was the same in both groups.” (http://blogs.bmj.com/bmj/2015/06/29/richard-lehmans-journal-review-29-june-2015/)

    This is the link to the original study: http://www.nejm.org/doi/full/10.1056/NEJMoa1506623

    On the basis of this I’d probably leave Bruce alone to continue the MAMIL dream.

    • Hi Will
      Well you certainly made your first comment a great one!

      Thanks for the article… you have spoiled my punch line! You will note that the patient above fits the “average demography” of the patients in the Canadian SOME trial published in the NEJM last month. http://www.nejm.org/doi/full/10.1056/NEJMoa1506623

      Love this type of trail as it attempts to answer a real world question -- its about a whole strategy rather than a single test etc -- and that is how we roll as GPs !
      Keep the comments coming mate
      Casey

  2. Karen Price
    More history
    ?social history.
    ? Recent travel
    ? Recent injury
    ? Recent surgery

    Smoker?
    Drugs of addiction.

    What was he doing beforehand. ?

    Family history?
    6 hrs · Like

    Karen Price In answer to your Questions.
    1. I don’t know.
    2. Fe and HB are normal as is DRE. But ?fam hx. Could consider FOB +/- colonoscopy but depends on what else is in the history.
    Skin check full examination ?clotting profile. Factor V AT3 etc. stop smoking his cigars.
    No I wouldn’t do aCT Abdo.

    3. Review regularly. And keep a close eye on him. Wouldn’t go hunting beyond above and regular history plus examination consider regular weigh ins.

    Usually with these I find something in the history somewhere.

    How tight is his Lycra?
    Did he compress his Femoral vein?

    • The case is of course fictional -- so the Lycra is as tight as you want it Karen!

      No other risk factors, just as stated. He’s an ex-smoker. No FHx and he’s been screened for Prothrombotic tendency
      Casey

  3. Richard Pincus says:

    On reading your post, my suspicion was that we have no good answer to you q1, that is what are the chances this man has an occult cancer to find, or even whether the chances are higher for him as against a patient who has fallen off his bike, or whether if we found an occult cancer it would have had any bearing on the clot.

    Reading the posted responses does little to change my view. I would have to read the Canadian study myself and I do not intend to do so, but I suspect it could not have and did not prove anything relevant to my patient’s plight.

    So, I would tell my patient the truth: if he wanted my opinion I would give it as follows: In my inexpert, but highly experienced, view he probably has more risk from a CT than by not having it.

    I am thinking not of the issue of whether in the latest study done more or fewer occult cancers were found, but of weighing the tiny risk a treatable occult cancer would be found which later might have become untreatable, against the risk of the many harms done by doing CTs without good reason, starting with the certainty that he will be very worried by the “need” for a CT due to the “suspicion” he might have cancer.

    I would not elaborate about any of this unless he asked, and if he asked I would offer to send him to someone whose business it is to know about all these issues, that is to a haematologist with an interest in clots. (Pardon the pun.)

    Ladies and gentlemen, let us remember our limitations -- we may well know more than some haematologists since thanks to your posts, we know that studies have not yet shown a value in CT of some patient groups with an unexplained DVT, but that does not entitle us to play specialist.

    And just because i believe cancer screening is bad, apart from a very few highly controversial situations, and this is not one of them, I should let the patient decide, not me.

    Thank you for this, and the many thought-provoking posts I have not commented on.

  4. Hard to give the numbers. For phlegmasia, occult malignancy rates of 40% have been described and you’d seriously go looking in that case. It’s a left leg, so maybe adjust that number down or go looking for May-Thurner. Does the report mean that the DVT is in the femoral vein above, or below the SFJ?

  5. Donald Howarth says:

    Maybe another way of looking at the case as presented by you is that it is easy for someone else involved in your patient’s care to make a remark that creates work for you and makes them appear very smart and caring. The remark that a DVT can indicate an underlying malignancy with the unstated remark -- but I am not going to look for it your GP can do that, is a not uncommon situation. Not creating neurotic futile searches for the unlikely is an important part of the art of medicine.

  6. Jenni brown says:

    Thanks Casey

    My otherwise very healthy 80 yr old Dad has just had a small unprovoked PE. Clearly long term risk from CT is lower in an older person and rates of occult malignancy are higher. His discharge summary doesn’t ask his GP to go fishing for cancer. I had wondered if I should consider raising the possibility with her but on balance am reasonably comfortable not too. What was the age range of patients in the study?

    • Hi Jen
      The trial is free online access here: http://www.nejm.org/doi/full/10.1056/NEJMoa1506623
      The ages of the patients was younger than 80 -- mean 53 +/- 14 years -- although they didn’t exclude older folk as far as I can tell. So I don’t think it can answer the question of an 80 yo. with an unprovoked DVT.
      Having said that the risk of overdiagnosis of an incidental (yet harmless) tumour in an 80 yo is probably higher. Do we really want to diagnose an 80 yo with a slow-growing prostate Ca if they are not going to die “of it” but rather “with it”?
      Tough question
      Casey

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