It is important to have an accurate diagnosis of cancer, know which type of cancer, and the extent to which it has spread within the patient. 

There are multiple diagnostic tests and imaging procedures that help the doctor and patient on the future course of cancer treatment. At times, the patient may have cancer-like symptoms but does not have cancer. 


Takeaways of Cancer Tests and Screening

  • Confirm the presence or absence of cancer
  • look for  the spread of cancer
  • Plan on the line of treatment to eliminate cancer
  • Evaluate the progress or effectiveness of the treatment
  • Re-testing using a fresh sample to confirm the results or doubts on the quality of sample used earlier.
  • Specialized tests to check for newer modalities of treatment.


Today, an extensive range of tests used in cancer detection are  

  • Laboratory tests
  • Imaging for cancer diagnosis
  • Genetic testing
  • Endoscopy examination
  • Tumor biopsies

Laboratory tests

Laboratory tests such as Complete blood count (CBC), urine test and analysis, and other special blood tests involve using chemicals to evaluate the body fluids and tissues for chemical components such as hormones, lipids, proteins, electrolytes, enzymes, blood sugar, etc. Blood and urine samples are used for laboratory testing. Also, there are highly specialized tests available for more accurate diagnosis, if required.These include the tumor markers that are mainly used for following up of cases after completing treatment. There are other blood tests called liquid biopsies or circulating tumor cells what are sometimes used.

Imaging for Cancer Diagnosis

Imaging is yet another valuable testing resource for getting an internal view of the patient’s body. Imaging such as ultrasound scan, CT scan, MRI scan, PET CT and others help detect the location and presence of tumor or spread of cancer within the body. It also helps the doctor to judge the effect of the cancer treatment. At times, these tests are also done during surgery or a biopsy procedure.

Today, most cancer doctors or oncologists suggest any or some of these tests –

  • X-rays
  • Ultrasound
  • Mammography
  • Computed tomography (CT) scan
  • Magnetic resonance imaging (MRI) scan
  • PET CT scan

Uses and Advantages of Imaging tests-

  • Imaging tests are useful for patients who have yet to be detected with cancer or are in the early stages of cancer and may or may not display cancer symptoms.
  • Imaging tests help locate the mass or lump, or tumor in the patient’s body in case of visible symptoms that may or may not be related to cancer.
  • These tests also help in deciding whether a biopsy is required or not.
  • Imaging help in finding the stage of cancer the patient is suffering from and deciding the treatment protocol regarding radiation, chemotherapy, and cancer medication.
  • Imaging tests are done to check the remission of cancer
  • Imaging tests are done during the cancer treatment to ascertain the progress, reduction in the size of the tumor, and future treatment approach.

Imaging tests are done only on the advice of the treating oncologist and interpret the image’s findings. A radiologist gives an accurate analysis of the imaging tests and for deciding the possible treatment approach.


Endoscopy is a minimally invasive procedure through which the doctor inserts a long thin tube through the mouth or the anus within the body. Through the tube, the doctor can view, observe, and perform imaging or surgery of internal organs or tissues. Endoscopy is a basic test for diagnosing diseases affecting the digestive tract. There are various types of endoscopies, such as

  • Colonoscopy – This endoscopy allows the doctor to view the colon and the entire large intestine and detect colorectal cancer.
  • Sigmoidoscopy – This endoscopy allows the doctor to examine the sigmoid colon in greater detail. The sigmoid colon is checked for polyps, abnormal cells, ulcers, and even cancer. It is possible to get tissue samples for further checking and the presence of abnormalities.
  • Endoscopic retrograde cholangiopancreatography (ERCP) – This type of endoscopy focuses on inspecting the pancreatic and bile ducts for evaluating conditions such as the presence of stones, tumors, or lesions in the bile or the pancreas area and for checking jaundice conditions.
  • Cystoscopy:This endoscopy is also called cystourethroscopy. It helps in detecting abnormal urinary bladder conditions and growths in this region. Also, the doctor can decide to proceed with a biopsy or not.
  • Esophagogastroduodenoscopy – This endoscopy is also known as OGD or upper endoscopy and is considered a preliminary check for esophagus and stomach cancer. The doctor can get an inner view of the inner sections of the stomach, esophagus, and small intestine. The doctor can also remove the tissue samples for a biopsy if necessary.

Genetic testing

As the name suggests, genetic testing detects mutations or changes in genes, chromosomes, or proteins. Genetic testing is done for specific cancers such as breast cancer, colon cancer, ovarian cancer, thyroid cancer, prostate cancer, sarcoma, melanoma, etc. Genetic testing can help predict the risk of getting cancer, passing the cancer risk to the future generation, and the path forward in maintaining good health. The newer tests called Somatic Genetic Tests are used to determine which cancer treatment would work best for a given cancer.

Biopsy for Cancer Detection

Biopsy involves removing small part of tissue or cell from the affected area in the patient’s body for further testing. The doctor will determine whether the tumor is cancerous or non-cancerous, i.e., inflamed or infected. The you could hear various terms like 

  • Skin biopsy
  • Punch biopsy
  • Excisional biopsy
  • Bone Marrow biopsy
  • Endoscopic biopsy
  • Shave biopsy

However, the purpose of these remains the same, to reach a diagnosis.