Certain tests can help to detect certain types of cancer before symptoms arise. It is referred to as screening. The primary objectives of cancer screening are to decrease the number of cancer fatalities or completely eradicate cancer death rates and new cases from arising.

Screening tests for several cancer includes:

Imaging Tests:

Imaging tests helps to take images of the inside of your body, which can be used to detect cancer and its extent of spread, and to help determine the cancer treatment.

• Computed tomography (CT) scan: A CT scan can help detect cancer and tumor shape and size. It uses a pencil-thin beam of rays to create a series of pictures taken from different angles.
• Magnetic resonance imaging (MRI) scan: MRI scans find cancer in the body and the signs of its spread. It helps doctors plan the type of cancer treatment for the patient, like surgery or radiation. MRI uses strong magnets to produce the images and creates images of even soft tissue parts of the body which are hard to see using other imaging tests.
• Breast MRI: The routine detection of breast cancer does not include an MRI. However, it might be beneficial for women who have dense breasts and are at a higher risk of developing breast cancer or when a lump is found during breast cancer.
• X-rays and other radiographic tests: In this procedure, a controlled beam of radiation is sent to the body, which looks for cancer in various parts of the body, including bones, organs, and tissues. X-rays are typically painless and fast. Dense tissues block most radiation, but soft tissues block less. Tumors are generally denser than the tissue surrounding them and appear lighter shades of grey in the image.
• Mammography: A specific kind of x-ray called mammography is used to view the breast. Mammography scans can reveal breast cancers or other abnormalities in the breast. These images are called mammograms.
• Nuclear medicine scans (bone scans, PET scans, Thyroid scans, MUGA scans, gallium scans): Liquid substances called radionuclides, also called tracers, are used that release low levels of radiation. It helps in finding the tumors and its spread in the body to determine the stage of cancer. They may also be used to evaluate if treatment is working.
• Ultrasound: This technique helps look for tumors in certain body areas that don't show up well on x-rays. It is also used in the biopsy. This machine gives off high-frequency sound waves that enter the body and creates images called sonograms. The sound waves create echoes while they bounce off organs and tissues. These echoes are converted to real-time pictures that show organs and even the flow of blood through blood vessels that can be viewed on a computer screen. This method of screening helps to identify and differentiate fluid-filled cysts from solid tumors since they make different echo patterns.

Endoscopy Procedures:

• Bronchoscopy: Bronchoscopy look at an abnormal area seen on an imaging test. It is fitted with a transducer on its tip (a microphone-like instrument) which is sent down into the airways to look at nearby lymph nodes and other structures. The transducer gives off sound waves and picks up the echoes bounced by the organs and structures which are converted into an image on a computer screen. If suspicious areas such as enlarged lymph nodes are seen, a hollow needle can be passed through the bronchoscope and guided into these areas to obtain a biopsy. If suspicious or enlarged lymph nodes are detected, a hollow needle can be passed through the bronchoscope to obtain a biopsy.
• Colonoscopy: During this surgery, the doctor will put a colonoscope, a flexible, illuminated tube, into the rectum. Colonoscopy can show irritated and swollen tissue, ulcers, polyps, and cancer.
• Cystoscopy: In this procedure cystoscope, a thin tube with a light and a small camera at the end is put in through the urethra. Cystoscopy helps in finding out early signs of cancer, infection or any bleeding in the urinary tract.
• Laparoscopy: It is a surgical procedure where in a fibre-optic instrument is inserted through the abdominal wall. It helps to diagnose a wide range of conditions developed inside the abdomen or pelvis. Laparoscopy can also be used to remove damaged organ, or removing a tissue sample for biopsy.
• Laryngoscopy: Laryngoscopy is used to examine larynx (voice box), as well as nearby structures like the back of the throat. It is also used to remove small growths (tumors or polyps) on the vocal cords. ➢ Mediastinoscopy: Organs between the lungs and nearby lymph nodes can be examined by mediastinoscopy. It is also used in detecting the stage of cancer.
• Thoracoscopy: Thoracoscopy is a procedure used to examine the space inside the chest and for abnormal area seen on an imaging test such as a chest x-ray or CT scan. It also can be used to take biopsy samples of lymph nodes, abnormal tissues of the lung and the chest wall.
• Endoscopy: An endoscopy is a procedure used to look at the inner lining of the upper digestive tract which includes the stomach, oesophagus and duodenum. Biopsy samples of upper digestive tract can be taken by this procedure to examine for cancer.

Biopsy:

Tissue or cell samples can be taken from almost any part of the body where the tumor is detected. Some types of biopsies remove an entire organ while the other types of biopsies remove tumor samples using a thin needle or through an endoscope (a flexible lighted tube that’s put into the body). Both the procedures are done by the doctor and is sent to a laboratory for analysis.

Cytology Tests:

A cytology test is used to examine cells and body fluids.

There are two types:

• Exfoliative Cytology: Cells from the organ or tissue are scraped or brushed for testing from the surface of the tissue. Examples of exfoliative cytology that involves brushing and scrapping are:
  • Pap smear
  • Cells from gastrointestinal tract
  • Samples of skin and mucus
  • Sputum from the secretions of lung
  • Urine sample

• Intervention cytology: In this procedure, the sample cells are obtained by piercing the body. Fine needle aspiration is the most common type of intervention cytology. Some of the areas where the fine needle aspiration is performed are:
  • Cysts (Fluid-filled lumps) under your skin.
  • Solid lumps under your skin.
  • Lymph nodes.
  • Pericardial fluid, which is the fluid in the sac around your heart.
  • Pleural fluid, from the space around the lungs
  • Cerebrospinal fluid, from the space around the brain and spinal cord
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