Cancer Common Tests and Procedures

"Error leads to incorrect treatment, delayed treatment, or sometimes no treatment at all"

Having the right diagnosis always helps both the patient and the doctor. The doctor is able to give the right treatment and the patient recovers earlier as well. Typically, We visit a medical practitioner or doctor when we have unusual symptoms. Most doctor understand these symptom by talking with the patient about his or her medical history and proceeds to order a few screening tests to confirm or reject their diagnosis. The case with cancer is no different and doctors around the globe conduct tests to confirm cancer.

Biopsy

For most cancers, a biopsy is the only way to make a definite diagnosis. A biopsy is the removal of a small amount of tissue for study in the lab and confirm the presence of cancerous cells.

There are many types of biopsy that are done based on the type of patient and the disease


  • Bone marrow aspiration and biopsy
  • This test is usually done to detect blood disorders and/or presence of blood cancer.These two tests are similar in nature and are ordered at the same time by the doctor.

    The human bone marrow has both a solid and a liquid part. A bone marrow aspiration removes a sample of the fluid with a needle while the bone marrow biopsy removes a small amount of solid tissue using a needle. Typical blood cancers include leukemia, lymphoma, or multiple myeloma.

    Commonly,the extraction of the tissue and fluid is using done on the lower back (i.e. the pelvic bone). The doctor usually applied anaesthesia to numb the area and takes the sample.

  • Fine needle aspiration biopsy
  • This test includes collecting a small amount of tissue using a very think hollow needle attached to a syringe. Typically this is used for a mass that can be felt through the skin (e.g. lumps on the breast etc.). This is also used with a image-guided biopsy.

  • Core Needle Biopsy
  • In a core needle biopsy uses a larger needle to remove a larger sample of tissue compared to a fine needle biopsy. The process is similar across these two biopsies.

  • Vacuum assisted Biopsy
  • Sometimes there is a need to collect a larger sample or multiple same from the same organ/site. To achieve this , a suction is used to collect a tissue sample through a specially designed needle. This helps the doctor to not insert the needle more than one time and also collect multiple or larger samples from the same biopsy site with this method.

  • Image Guided Biopsy
  • When a tumor is deep inside the body and cannot be felt by hands, this biopsy method is advised. A needle is guided to the location with the help of an imaging technique (MRI, Ultrasound etc.) to extract the tissue for tests.

    An image-guided biopsy can be done using a fine needle, core, or vacuum-assisted biopsy. The type of scan used depends on the location, amount of tissue needed, and other factors.

  • Incisional Biopsy
  • The term "incision" means to "a surgical cut made in skin or flesh" . As the name suggests, in this approach, the doctor makes a small incision in the skin to collect a sample of tissue from underneath the skin.

  • Excisional Biopsy
  • An excisional biopsy is the removal of an entire suspicious area or tumor from the body. This type of biopsy is common for a suspicious change on the skin. It is also sometimes used for a small lump under the skin when it can be easily removed. However, fine needle aspiration or a core biopsy are more common for lumps that cannot be seen or felt through the skin.

  • Shave Biopsy
  • This approach is common for skin cancers where the doctor scrapes out tissue from the surface of the skin and sends it for testing

  • Punch Biopsy
  • In the punch biopsy approach, a circular tool ("imagine an ice-cream scooping process") is inserted through the skin and a sample of the skin and tissue below it is extracted for testing.

  • Endoscopic Biopsy
  • An endoscope is a thin, lighted, flexible tube with a camera that helps doctors to view the inside of the body like bladder, abdomen, stomach for abnormality. It can also be used to take tiny samples of the tissue using forceps (which are also a part of the endoscope) Endoscopes are inserted into the body through the mouth or through a tiny surgical incision.

PET-CT Scan


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PET-CET or PET/CT stands for Positron emission tomography–computed tomography. This is a nuclear medicine technique which combines in a single machine two scanners – a a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scanner.

These two scanners capture images in a sequential manner which are then super-posed to create a single image. That helps doctor understand the metabolic and biochemical activity in the body. At the beginning of the test, the patient is given an a biologically active module called as tracer in a safe dosage which emits radioactive rays. The system detects these radioactive rays and a 3D image of tracer concentration within the body are then constructed by computer analysis.

A commonly used tracer is fludeoxyglucose (FDG),an analogue of glucose. Concentrations of tracer imaged indicate tissue metabolic activity as it corresponds to the regional glucose uptake and help explore the possibility of cancer metastasis (i.e., spreading to other sites) and other abnormalities in the body

MRI

MRI stands for Magnetic resonance imaging. It is a medical imaging technique which is used to form images of the body and also get an understanding of the physiological processes of the body. MRI is used for medical diagnosis, disease staging and follow up examinations without exposing the body to radiation. This machine operates using strong magnetic fields and radio waves to generate images of the organs in the body. The machine does not involve x-rays, which distinguishes it from computed tomography (CT machine). Even with the improvements in medical technology, MRIs are still seen as superior to CT because of the absence of X-ray component. Note: Some patients with medical implants or with other non-removable metals inside the body might be unsuitable for undergoing an MRI examination.

Ultrasound

Ultrasound is also a medical imaging technique. It is also called as sonography and ultrasonography. Working on the doppler principle, the system uses high frequency sound waves to create pictures of internal organs. Echo of sound waves bounce differently from an abnormal tissue and a healthy tissue helping the doctor to detect potential tumors and other abnormalities.

Colonoscopy

Colonoscopy is an examination of the colon. Colon is sometimes also referred to as the large intestine. The method constitutes an endoscopic examination of the colon with a camera (either a CCD camera or a fiber optic camera) which is set up on a flexible tube passed through the anus. Based on the visual diagnosis , it also provides doctor an an opportunity of biopsy or removal of suspected lesions/ulcerations/polyps as small as 1mm. The sample removed are studied to determine presence of cancer.

Mammography

Mammography is used for the early detection of breast cancer. The process uses low energy x-ray to examine the human breast for diagnosis and screening. Breast cancer is typically associated with determining the presence of characteristic masses or micro-calcification in cancerous breast tissue.

The output of a mammography test is called a Mammogram. The results of a Mammogram are often expressed in terms of the BI-RADS Assessment Category, often called a "BI-RADS score." Typically scores are on a scale from 0-6 (0 = Incomplete 1 = normal, 2 = benign, 3 = indeterminate, 4 = suspicious of malignancy, 5 = malignant 6= Known proven malignancy).

What is the advised frequency to have a Mammogram

It is advised to have mammograms at a periodic frequency to allow for an early detection of breast cancer. The below table shows the frequency at which a mammogram should be conducted by age.

Recommendations by Age Frequency
40 to 44 Women in this age bracket should have the choice to start annual breast cancer screening with mammograms (x-rays of the breast) if they wish to do so.
45 to 54 Recommended once every year
55 and older
  • Women 55 and older should switch to mammograms every 2 years, or can continue yearly screening.
  • Screening should continue as long as a woman is in good health and is expected to live 10 more years or longer.

Note:If you have a family history of Breast Cancer (mother or sister), it is recommended to start mammograms 10 years earlier than the age the relative was diagnosed.

Pap Smear Test

A Pap smear, also called a Pap test, is a screening procedure for cervical cancer among women. It tests for the presence of precancerous or cancerous cells on the cervix. The cervix is the opening of the uterus.

During the routine procedure, cells from your cervix are gently scraped away and then examined for abnormal growth.

What is the advised frequency to have a Pap Smear Test

Recommendations by Age Pap Smear Frequency
< 21 Years old, not sexually active, no known risk factor Test is typically not needed
21-29 Once every 3 years
30-65 Once every 3-5 years if your Pap smear and HPV test are negative
65 and older You may no longer need Pap smear tests; talk to your doctor to determine your needs

Overview of Biomarkers

The dictionary definition of a biomarker is " a naturally occurring molecule, gene, or characteristic by which a particular pathological or physiological process, disease, etc. can be identified. "

In other words, our body continuously secretes biological “markers” that can act as a measurable indicator a biological state or condition. Biomarkers are found in bloodstream, urine or body tissues. Changes in the level of biomarker can indicate presence of one or more types of abnormality including cancer. Tumor markers can be produced by both tumor cells and adjacent non-tumor cells in the body.

How Biomarkers help decision making

There are now drugs that help target specific biomarkers/tumor markers. Determining if the cancer is of a particular type (based on the overexpression a biomarker), the doctor can prescribe a particular treatment that is likely to be more effective than only for you.

Few Common Biomarkers





Cancer Type Biomarker
Pancreatic Cancer Elevated levels of leucine, valine (type of amino acids)
Lymphoma / Leukimia
CD20

CD30

PDGFR

FIP1L1-PDGFR alpha

PML-RAR alpha

TPMT

UGT1A1

BCR/ABL

Skin Cancer (Melanoma) BRAF
Lung Cancer
ALK

EGFR

KRAS

Gastric (Stomach/GI Cancer) HER2
Breast Cancer
ER/PR ,


HER2


  • Serum Chemistry Blood Tests
    • These tests are used to evaluate functioning of kidneys and liver. Level of minerals in the bloodstream and enzymes can be determined using this test. Abnormal Enzymes levels indicate the the spread of cancer. It should be noted that many non-cancerous conditions also cause change in enzyme levels in the body.
  • Complete blood count (CBC)
    • Complete blood count (CBC) measures the number of different types of cells, such as red blood cells and white blood cells in the bloodstream. This can act as an early indicator on the functioning of the bone marrow and determine deficiencies
  • FISH Test
  • FISH stands for Fluorescence in situ hybridization.
    This test helps doctors visualize and map the genetic material in the cells of a patient's body including specific genes or portion of genes. Changes in the genes within a cancer cell can make it to :

    • Secrete more proteins
    • Stop producing proteins for the cell
    • Produce proteins

    There are now drugs that help target specific proteins. Based on the overexpression of specific proteins,the doctor can prescribe a particular treatment that is likely to be more effective than only for you.

    E.g. If the patient has an overexpression of HER2 protein, then the drug Herceptin?Herclon(trastuzumab) is known to be more likely effective for the patient.

  • Genomic Testing
    • Genomics is the study of how the genes in a cancer cell behave. Genomic tests look at the genes in breast cancer to help determine what is causing the cancer to grow. The information from these tests can help the cancer care team understand how the cancer may behave and help guide treatment decisions.
  • Genetic Testing
    • Genetic testing looks at the genes inherited from a person’s parents. Genetic testing may be recommended if you have a family history of breast cancer

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