Can you tell if someone has cancer from blood test?

Do you get scared every time the word ‘cancer’ comes up? Do you feel like it’s a death sentence waiting to happen? Well, fear not! Thanks to medical advancements in recent years, there are various methods of detecting cancer early. One such method is a blood test. Yes, that’s right! A simple blood test can detect signs of cancer even before your body starts showing symptoms. But how does this work and what should you expect? Read on to find out!

How Does It Work?

A cancerous tumor releases different proteins into your bloodstream than regular cells do. That means if we measure these proteins during a blood test, we might be able to identify those who would otherwise go unnoticed for months or maybe years.

There are two types of biomarkers doctors look for when testing for potential cancers:

Tumor Markers

Detection of higher-than-normal levels (based on age groups) of certain substances produced by tumours in the bloodstream can denote popular tumour markers:

  • Carcinoembryonic antigen (CEA)
  • Human chorionic gonadotropin (HCG)
  • Alpha-fetoprotein (AFP)

Non-tumor Markers

Markers found outside tumour tissues can include inflammation which may occur with certain cancers.

Professionals consider C-reactive protein as an indicator here.

That all sounds pretty straightforward, doesn’t it? But let me assure you – there’s so much more going on beneath the surface than just taking some measurements!

As I mentioned earlier – screening isn’t always possible due to many factors which could affect values / results as outcome analysis becomes intricate depending upon stage/ grade with comparative normal values; however if caught early enough then treatment options tend towards successful outcomes benefiting patients substantially giving them a healthy lease(maybe!).

So no need to freak out yet!

Determining whether you have cancer depends on various factors, including the type of cancer and how advanced it is. But, the use of blood tests in diagnosing or ruling out cancer has become a powerful tool in recent years.

Types of Blood Tests Used to Detect Cancer

So, now that we know why blood tests are used in detecting early stages of cancers let’s dive into the details about what types of blood test might be used:

CBC (Complete Blood Count)

A CBC measures many aspects related to your blood health such as white & red cell counts and growth factor which could indicate acute Myeloid Leukaemia/ Myelodysplastic Syndrome.

White cells could also signify potential fights against infections i.e. viral hepatitis / increased eosinophilia with parasitic infection triggering possibilities.

Red Cells count examines anemia during prolonged bleeding from bladder for example; while Platelet Counts are responsible for clotting factors – being low during chemotherapy cycles because these treatments tend to destroy healthy tissues as well.

Tumor Marker Tests

As mentioned earlier, tumor markers can denote higher levels than expected based on age demographics within normal ranges . detection / discovery may not solely confirm malignant diagnosis but merely reveal Inflammation/Misfunctioning basis elevated numbers found.. Consummate interpretation , therefore required before drawing any conclusions .

It’s vital to note that just because someone has elevated tumor marker levels doesn’t necessarily mean they have cancer –false-positive results occur.( We don’t want that drama !) Additionally false negatives (tumours exist yet undetected/enhanced due to patient variability) should not be ruled out outright .

Liquid Biopsy Tests

A liquid biopsy involves sampling less invasive than other biopsies — no tissue requirements here!

Through analysis of bodily fluids like urine or saliva professionals find relevant traces but mostly a sample usually drawn from peripheral veins via needles…Circulating tumor DNA (ctDNA) in plasma or non-cancerous blood-borne tumor matter provide critical information and counts number of circulating tumour cells(CTCs).

These tests can also be used to determine whether the cancer has responded to treatment, how quickly it’s spreading from cell-to-cell or if there is any sign of relapse following previous therapy.


After all that complicated jargon & vocab throwing around we sure did learn a thing or two! Let me sum up what you need to know:

  • A simple blood test can detect signs of cancer before your body starts showing symptoms
  • Non-tumor biomarkers have emerged as significant factors correlating with potential cancer spread.
  • The use of biomarker-based liquid biopsies for early detection remains an exciting field especially when other traditional methods seem very invasive.

So next time you feel sick/different than usual, don’t delay matters — consult with a medical professional who may steer you towards necessary evaluations /tests instead of waiting until things get bad–

Early detection and preventive treatments are key here. At this point – I think I’ve scared myself into getting tested just writing about it !