Cancer General Information

CANCER GENERAL INFORMATION

21.03.2024

Cancer is a group of diseases that occur as a result of abnormal and uncontrolled growth and proliferation of cells in the body. Normal cells grow and multiply in a certain order and control, in line with the needs of the body. Cancerous cells violate these regular processes of growth and death. This condition can be triggered by factors such as genetic mutations and environmental factors.

The World Health Organization (WHO) and its Agency for Research on Cancer (IARC) classify cancers into various types and subtypes. Although more than 200 types of cancer have been identified today, it is difficult to specify an exact number of "cancer types" defined by WHO. Cancer can develop in almost any organ and tissue in the body, and more than one type of cancer has been identified for each organ or tissue. The number of cancer types identified by the World Health Organization is considered an ever-changing and evolving field. It is generally known that there are hundreds of different types of cancer, and each of these types has unique characteristics, treatment methods and disease courses.

The main features of cancerous cells are:

Uncontrolled Proliferation: Cancerous cells do not comply with the growth restrictions that normal cells have and multiply uncontrollably.

Abnormal Morphology (appearance): Cancerous cells are usually abnormal in shape and size and differ from normal cells.

Damage to Tissues and Spread: Cancerous cells damage and can penetrate healthy tissues around them (invasion). They can also metastasize by spreading to other parts of the body through blood and lymphatic pathways.

WHAT ARE THE CANCER RISK FACTORS?

Genetic Factors: Some types of cancer are more common in people with a family history of cancer.

Environmental Factors: Environmental factors such as UV rays, radiation, chemicals and air pollution can increase the risk of cancer.

Life style: Smoking, excessive alcohol consumption, unhealthy diet and sedentary lifestyle increase the risk of cancer development.

Infections: Some viruses and bacteria (for example, HPV or Helicobacter pylori) can cause cancer.

Image 1: Cancer is a group of diseases caused by cells that multiply and spread uncontrollably throughout the body.

WHAT ARE THE TYPES OF CANCER?

Cancers are divided according to the tissue from which they originate:

1-Carcinomas:They are cancers arising from epithelial tissue (cells covering the inner and outer surfaces of the body). Carcinomas account for the vast majority of cancer cases. There are different subtypes.

Adenocarcinomas: These are cancers that develop in glands and secretory tissues.

Squamous Cell Carcinomas: Occur in places where flat cells are present, such as the skin, mouth, throat, lungs and cervix.

2-Sarcomas: These are cancers arising from connective tissue, bone, muscle and other supporting tissues. It is divided into two main subtypes:

Bone sarcomas: They are a type of cancer seen in bones.

Soft Tissue Sarcomas: Originate from muscles, fatty tissues, blood vessels, lymph vessels, and other soft tissues.

3-Lymphoma, leukemia and myeloma: They are cancers caused by the immune system.

Lymphoma develops from lymph nodes and other parts of the immune system. There are two main types: Hodgkin and non-Hodgkin.

Myeloma: It originates from plasma cells in the bone marrow and is characterized by the cancerization of these cells.

Leukemia: They are blood and bone marrow cancers. These types involve the production of abnormal blood cells in blood-forming tissues. Leukemias are generally divided into four main types: Acute Lymphoblastic Leukemia (ALL), Chronic Lymphocytic Leukemia (CLL), Acute Myeloid Leukemia (AML), and Chronic Myeloid Leukemia (CML).

4-Brain and Nervous System Tumors: Tumors arising from brain and other nervous system cells.

Each type of cancer requires different diagnostic and treatment approaches depending on the biological characteristics of the tissue from which it originates and the unique characteristics of the cancer.

SOME COMMON TYPES OF CANCER

Cancer can occur in different parts of the body and there are many different types. Here are some of the most common types of cancer:

Lung cancer: It is a type of cancer that occurs in the lung tissue and is often associated with smoking.

Breast Cancer: It develops in breast tissue and can occur in both women and men, but is much more common in women.

Prostate cancer: It is a type of cancer that develops in the prostate gland and is especially common in older men.

Colon and Rectum Cancer (Colorectal Cancer): It develops on the inner surface of the large intestine (colon) or rectum (last part of the intestine).

Skin cancer: It starts in skin cells and there are various types. The most common types are basal cell carcinoma and squamous cell carcinoma. Melanoma is a less common but more dangerous type of skin cancer.

Blood Cancers (Leukemia): They are types of cancer that affect blood and bone marrow cells. Leukemia is characterized by rapid proliferation of cells before they mature.

Lymphoma: It develops in the lymph nodes and other lymph tissues that are part of the lymph system. There are two main types: Hodgkin lymphoma and non-Hodgkin lymphoma.

Pancreatic Cancer: It occurs in the cells of the pancreas and is usually an aggressive type of cancer.

Cervix (cervical) cancer: It develops in the cervix, that is, in the lower part of the uterus. In most cases it is associated with human papillomavirus (HPV).

Bladder Cancer: It develops on the surface of the bladder and usually manifests itself with bleeding in the urinary tract.

Thyroid Cancer: It is a type of cancer that develops in the thyroid gland and usually responds well to treatment.

Liver Cancer: It begins in the liver cells and is often associated with chronic liver diseases or hepatitis infections.

These types of cancer develop differently in different organs and tissues in the body, and each has its own unique symptoms, diagnostic methods, and treatment options. Early diagnosis and appropriate treatment are the most important factors in the fight against cancer.

Image 2: The Latin meaning of cancer is crab. This name was given because cancer was likened to a crab in ancient times.

EARLY DIAGNOSIS AND TREATMENT OF CANCER

Early diagnosis and treatment of cancer is extremely important for many reasons:

The Importance of Early Diagnosis: Cancers diagnosed in the early stages can often be treated more successfully. Early detection means the cancer spreads less and causes less damage to the body, which increases treatment options and generally provides a better prognosis (course of the disease).

Treatment Planning: Early diagnosis allows the most effective treatment methods to be determined. Factors such as cancer type, stage, and the patient's general health status play a critical role in personalizing treatment options.

Preventing the Spread of Disease: Treatment prolongs life and improves quality of life by preventing cancer from spreading further in the body. Especially in metastatic (spread) cancers, treatment helps control the disease and relieve symptoms.

Improving Quality of Life: Cancer treatments help relieve pain and other symptoms, help patients maintain daily activities and improve their overall quality of life.

Increasing the Chances of Long-Term Survival: Effective treatment can reduce the risk of cancer-related death and increase patients' chances of long-term survival.

Psychological and Social Support: Cancer diagnosis and treatment is a process in which patients and their families need psychological and social support. Early diagnosis and curability of cancer, counseling and support services for patients and their families help patients cope with the disease.

For these reasons, cancer diagnosis and treatment not only improves the patient's health and life expectancy, but also makes significant contributions to the quality of life of them and their families. Diagnosis of cancer is usually made through laboratory tests, imaging techniques (such as MRI, CT, PET) and biopsy. Treatment methods vary depending on the type of cancer, its stage, and the patient's general health and often include surgery, chemotherapy, radiotherapy, targeted therapies, and immunotherapy. Early diagnosis is a very important factor in cancer treatment because early-stage cancers can often be treated more successfully. Therefore, regular health checks and cancer screening programs are vital.

Image 3: Cancer treatment is performed by oncology physicians. Oncology physicians are divided into different branches such as medical oncology, surgical oncology and radiation oncology.

THE IMPORTANCE OF CANCER FOR THE WORLD

The number of people diagnosed with cancer worldwide every year is quite high. According to GLOBOCAN 2020 data; Approximately 18.1 million new cancer cases were detected worldwide in 2020. 9.3 million of these cases were in men and 8.8 million in women. In the same year, the most common types of cancer included breast cancer (2.26 million cases), lung cancer (2.21 million cases), colon and rectum cancer (1.93 million cases), prostate cancer (1.41 million cases) and skin cancer (non-melanoma; 1.20 million cases). In the USA, it is estimated that 1,958,310 new cancer cases will be diagnosed in 2023 and 609,820 people will die from this disease. These data show that cancer is a global health problem and that it widely affects the communities it affects. Increasing research and awareness about cancer diagnosis and treatment is vital to control the spread of this disease and improve treatment options.