What is Cancer? Diagnosis and Treatment Methods

Cancer is a disease that results from the uncontrolled multiplication and growth of cells in any organ or tissue of the body. It is named according to the tissue in which it occurs. More than 200 types have been identified. The most common and fatal types of cancer are lung, stomach, liver, colon, and breast cancer. If cancer spreads from its original site to other organs and tissues, this is called metastasis.

Cancer cells can continue to multiply without stopping. Normally, the immune system captures and destroys abnormal cells. However, cancer cells can evade the immune system. Unlike normal body cells, cancer cells do not undergo the usual cell death.

What causes cancer?

The primary factor in the formation of cancer is the alteration of the genetic structure, or DNA, due to congenital or acquired factors. If there are individuals with cancer in your family, your risk of developing cancer is higher. However, exposure to radiation, toxic substances, certain viruses, and non-cancerous diseases you have may also lead to cancer. Generally, the factors that contribute to the development of cancer include:

• Age
• Carcinogenic substances (Aflatoxin, arsenic, asbestos, benzene, beryllium, cadmium, coal tar, respirable silica, formaldehyde, chromium, inhalation of coal smoke, nickel, radon, passive cigarette smoke, soot, sulfuric acid)
• Chronic inflammation
• Poor nutrition
• Hormones
• Weak immune system
• Obesity
• Radiation
• Tobacco

How does cancer develop?

Types of cancer

Cancers are classified based on the organs they originate from (lung, breast, brain) or the type of cells they arise from. The main types of cancer are as follows:

• Carcinoma: This is the most common type of cancer. They originate from epithelial cells that line both the inside and outside of the body. Major subtypes include adenocarcinoma, basal cell carcinoma, squamous cell carcinoma, and transitional cell carcinoma.
• Sarcoma: Sarcomas are cancers that develop in muscles, fat, blood vessels, lymph vessels, and connective tissue (such as tendons and ligaments), as well as in bones and soft tissues. Osteosarcoma is the most common type of bone cancer. Examples of soft tissue cancers include leiomyosarcoma and Kaposi sarcoma.
• Leukemia: This type of cancer originates from the bone marrow and results from the abnormal proliferation of blood cells. It can arise from different blood components and can be acute or chronic.
• Lymphoma: Our immune system contains T and B lymphocytes. The cancer that arises from these cells is called lymphoma. In lymphoma, cancerous tissue develops in lymph nodes and lymph channels. It is divided into Hodgkin lymphoma and non-Hodgkin lymphoma, with different treatments and prognoses for these two types.
• Multiple Myeloma: This type of cancer originates from plasma cells, which are immune system cells. It begins in the bone marrow and affects various bones in the body.
• Melanoma: This type of cancer arises from skin cells known as melanocytes.
• Germ Cell Tumors: These tumors originate from male and female reproductive cells.
• Neuroendocrine Tumors: These tumors consist of hormone-secreting cells that secrete hormones uncontrollably.
• Carcinoid Tumors: These tumors primarily arise from the digestive system and cause carcinoid syndrome by leading to serotonin secretion.

After looking at the general types of cancer, let’s examine the types of cancer based on the organ or tissue from which they originate. You can click on the following links to obtain more detailed information about specific types of cancer:

• Lung cancer
• Cervical cancer
• Nasopharyngeal cancer
• Kidney cancer
• Brain tumors
• Skin cancers
• Colon cancer
• Bone tumors
• Liver cancer
• Larynx-Throat cancer
• Leukemias
• Lymphoma
• Bladder cancer
• Breast cancer
• Stomach cancer
• Multiple myeloma
• Spinal cord and spine tumors
• Prostate cancer
• Cervical cancer
• Head and neck cancers
• Thyroid cancer
• Testicular cancer
• Ovarian cancer

What are the possible symptoms of cancer?

• Unexplained weight loss
• Blood in urine or stool
• A lump in the breast
• A lump in any part of the body
• Cough, chest pain, shortness of breath
• Coughing up blood
• Unexplained, persistent diarrhea or constipation
• Stomach or rectal pain
• Blood in cough
• Changes in the color of moles, crusting, or growth
• Abnormal vaginal or rectal bleeding
• Abdominal pain
• Prolonged and unexplained fever
• Bone pain
• Paleness
• Weakness

Cancer Diagnosis and Treatment

If you or someone close to you has one or more of the cancer symptoms listed above, and they persist, you should see a doctor immediately. The doctor will first take a medical history from the patient. They will inquire about complaints, medical history, genetic background, and lifestyle habits. Then, they will attempt to diagnose the disease using laboratory tests and imaging methods. If a tumor is detected, a biopsy will be requested. The main laboratory and imaging tests include:

• Blood tests
• Urine tests
• Blood in stool
• Tumor markers
• Hormones
• Computed tomography (CT)
• Magnetic resonance imaging (MRI)
• Nuclear scans
• Bone scintigraphy
• PET-CT
• Ultrasound
• X-ray
• Biopsy
• Gastroscopy
• Colonoscopy
• Bronchoscopy
• Hysteroscopy
• Mammography

If cancer is detected after the tests, the next step is to check for metastasis. Based on this, cancer staging is performed. Medical oncologists carry out cancer treatment. Radiotherapy treatment is planned by radiation oncologists and nuclear medicine specialists. Cancer treatment may involve surgical operation, radiotherapy, and chemotherapy. If cancer has caused associated diseases, their treatment will also be addressed.

How is cancer staging performed?

• Location of the primary tumor
• Size of the tumor
• Lymph node involvement
• Presence and number of metastases
• The above indicators determine the course of the disease, survival rates, and mortality rates. Survival is higher in cancers that are caught early and can be surgically removed. Palliative care is provided to ensure the comfort of terminal cancer patients and to improve their quality of life.

What are the plants and foods that are beneficial for cancer?

Frequently Asked Questions:

• What causes cancer?
  There are many factors identified as causes of cancer. Radiation, poor diet, certain bacteria and viruses, toxic substances, and tobacco are some of these. However, not every individual exposed to a carcinogen will develop cancer. Here, genetic makeup and the immune system play a decisive role.
• How is cancer detected?
• If you notice an unusual change in your body that does not go away, you should see a doctor. Some of these symptoms may include unexplained rapid weight loss, fatigue, loss of appetite, abdominal and chest pain, blood in stool, urine, or vagina, blood in sputum, jaundice, paleness, a growing lump anywhere on the body, bone pain, abdominal pain, headaches, constipation, and stomach pain.
• How is cancer screening performed?
  Some types of cancer are incidentally detected during screenings. For example, women over 40 are advised to have a mammogram and breast ultrasound once a year for screening purposes. Colonoscopy and gastroscopy screenings are recommended after the age of 50. Periodic checks of tumor markers in the blood can also be beneficial. Individuals with a family history of cancer should have regular screenings.
• Does stress cause cancer?
  Stress can lead to various physical health problems; however, its relationship with cancer has not been proven. Actions taken due to excessive stress, such as smoking and alcohol consumption, can lead to cancer.
• At what stage does cancer cause death?
  The survival time varies for each type of cancer. Some types can spread very quickly even if caught early, leading to a high mortality rate. The determining factor for cancer-related deaths is not only the type of cancer but also how quickly it metastasizes. Generally, stage 4 is considered the most advanced stage.
• How long can one live if cancer spreads to the bones?
  Studies have shown that bone metastasis in cancers other than breast cancer indicates a poor prognosis.
• Does every tumor carry a risk of cancer?
  Not every tumor carries a risk of cancer. Benign tumors only cause a mass effect and do not spread. Additionally, tumors are categorized as benign or malignant based on the type of cancer cells.
• What is metastasis?
  Metastasis is the spread of a tumor from its original organ to other organs and lymph nodes.
• What cancer is caused by EBV?
  The EBV virus can cause lymphoma and also plays a role in nasopharyngeal cancers.
• Does the EBV virus cause cancer?
  The EBV virus is commonly found in children and may not show symptoms. In adults, it can cause febrile illnesses and is known as mononucleosis. Most EBV patients do not develop cancer, and it is not possible to predict who will develop cancer.
• Does the EBV virus recur?
  Chronic EBV carriers may experience recurring flare-ups, which typically have a severe course.
• Is the EBV virus contagious?
  The EBV virus is found in saliva and can be transmitted through hugging, kissing, or sharing personal items. Children can be silent carriers.