General information about cancer

Cancer: An In-Depth Explanation

What is Cancer?

Cancer refers to a group of more than 100 diseases, where cells in the body grow uncontrollably. This abnormal cell growth can occur anywhere in the body, forming a mass of tissue known as a tumor. While some tumors are benign (non-cancerous), others are malignant (cancerous) and can spread to other parts of the body.

Not all cancers form tumors. For example, leukemia, myeloma, and lymphoma are cancers that affect the blood, bone marrow, or lymphatic system, spreading through the body without forming a mass.

How Does Cancer Begin?

Our body is made up of cells, the building blocks of tissues and organs. In a healthy body, cells grow, divide, and die in a controlled manner, ensuring that new cells replace old or damaged ones. This process is known as cell division.

However, in cancer, mutations disrupt this regulated cell division. Instead of dying, old or damaged cells continue to grow uncontrollably, and new cells form excessively, even when they are not needed. These excess cells accumulate to form tumors. Some cancers, like leukemia, spread throughout the bloodstream without forming solid tumors.

Types of Tumors

• Benign Tumors:

• Non-cancerous, do not spread to other parts of the body, and are usually not life-threatening.

• Malignant Tumors:

• Cancerous, capable of invading surrounding tissues and spreading to other parts of the body (metastasis).

Types of Cancer

Depending on where cancer originates, it is categorized into the following types:

1. Carcinomas:

• This type begins in tissues lining internal organs or glands. It forms solid tumors and includes common cancers like breast, lung, and colon cancer.

2. Sarcomas:

• Sarcomas develop in the connective and supportive tissues, such as muscles, bones, fat, nerves, blood vessels, and cartilage.

3. Leukemia:

• Leukemia is a blood cancer that affects white blood cells and disrupts normal blood production in the bone marrow.

4. Lymphomas:

• This type affects the lymphatic system, which helps fight infections. It includes two major types: Hodgkin lymphoma and non-Hodgkin lymphoma.

How Does Cancer Spread?

Cancer can spread (metastasize) through:

• Bloodstream

• Lymphatic system

The lymph nodes are one of the first places where cancer cells spread. These small, bean-shaped structures are part of the immune system, helping the body fight infections.

Common Diagnostic Tests for Cancer

Early detection is crucial for effective treatment. Here are some common diagnostic tests used to identify cancer:

1. Barium Enema:

• This is an X-ray test used to examine the large intestine and rectum. A contrast agent called barium is inserted into the rectum to make the intestines more visible on the X-ray.

2. Biopsy:

• A small sample of tissue is removed from the suspected area and examined under a microscope. Biopsies confirm the presence of cancer. Types include:

• Needle biopsy – Uses a fine or core needle to collect tissue.

• Image-guided biopsy – Uses scans like CT or ultrasound to guide the biopsy.

• Surgical biopsy – Removes the suspected tumor through surgery.

3. Bone Scan:

• A nuclear medicine scan where a radioactive substance is injected to detect cancer in the bones. Areas affected by cancer absorb more of the substance, making them visible on the scan.

4. Colonoscopy:

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• A procedure to examine the large intestine and rectum using a flexible tube with a camera. It helps identify polyps or colorectal cancer.

5. CT Scan (Computed Tomography):

• Produces detailed 3D images of the body using X-rays. It helps determine the location and stage of cancer and can guide treatment planning.

6. MRI (Magnetic Resonance Imaging):

• Uses magnetic fields and radio waves to create detailed images without radiation exposure. It helps visualize soft tissues more clearly than a CT scan.

7. Mammogram:

• An X-ray of the breasts used to detect breast cancer. It can identify small tumors that are not felt during a physical exam.

8. Endoscopy:

• A thin tube with a light and camera is inserted into the digestive tract or other areas to examine internal tissues for abnormalities.

9. PET Scan (Positron Emission Tomography):

• This scan uses a radioactive glucose tracer to detect cancer cells, which absorb more glucose than normal cells.

10. Tumor Marker Tests:

• Measures the levels of specific proteins in the blood or urine. High levels of tumor markers may indicate cancer. Some common markers include:

• PSA (prostate cancer)

• CA 125 (ovarian cancer)

• CEA (colon cancer)

Preparing for Diagnostic Tests

Some diagnostic tests may require preparation, such as:

• Fasting before a CT or PET scan.

• Avoiding certain foods or medications before a colonoscopy.

• Wearing comfortable clothing and avoiding metal objects during MRI or X-ray scans.

Always follow the doctor’s instructions carefully to ensure accurate test results.

Cancer is a complex disease that can develop anywhere in the body. Early detection through diagnostic tests like biopsies, CT scans, and MRIs is essential for effective treatment. Cancer can spread through the blood and lymphatic systems, but early diagnosis improves the chances of successful treatment.

Advanced diagnostic tools and personalized treatment plans now offer better outcomes for patients, helping them manage the disease more effectively. Understanding the nature of cancer, its spread, and the available diagnostic tools is key to improving awareness and treatment options.

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