What Is Cancer
Cancer is a group of diseases characterized by the uncontrolled growth and division of abnormal cells in the body. These cells can form masses/tumors, invade nearby tissues, and spread to other parts of the body through the blood or lymphatic system, a process called metastasis. Cancer can begin in virtually any part of the body and behaves differently depending on where it starts and how it grows. While the word “cancer” can feel overwhelming, understanding what it is and how it works is the first step toward prevention, early detection, and informed decision-making.
How Cancer starts
categories of Cancer
Carcinoma
Carcinoma
Carcinoma
Cancers that arise from epithelial cells, which line the surfaces of the body, including skin and internal organs. They are the most common type.
• Adenocarcinoma: Originates in glandular tissues (e.g., breast, prostate, colon, pancreas, lung).
• Squamous Cell Carcinoma: Develops in squamous epithelium (e.g., skin, lung, esophagus).
• Basal
Cancers that arise from epithelial cells, which line the surfaces of the body, including skin and internal organs. They are the most common type.
• Adenocarcinoma: Originates in glandular tissues (e.g., breast, prostate, colon, pancreas, lung).
• Squamous Cell Carcinoma: Develops in squamous epithelium (e.g., skin, lung, esophagus).
• Basal Cell Carcinoma: Common skin cancer that arises in the basal layer of the epidermis.
• Transitional Cell Carcinoma: Arises in the urinary system, especially the bladder.
Sarcoma
Carcinoma
Carcinoma
Cancers that originate in connective or supportive tissues, such as bone, cartilage, muscle, and fat.
• Osteosarcoma: Bone cancer, often occurring in long bones.
• Chondrosarcoma: Arises in cartilage.
• Liposarcoma: Originates from fat tissue.
• Rhabdomyosarcoma: Affects skeletal muscle tissue.
• Angiosarcoma: Develops in the lining of blood o
Cancers that originate in connective or supportive tissues, such as bone, cartilage, muscle, and fat.
• Osteosarcoma: Bone cancer, often occurring in long bones.
• Chondrosarcoma: Arises in cartilage.
• Liposarcoma: Originates from fat tissue.
• Rhabdomyosarcoma: Affects skeletal muscle tissue.
• Angiosarcoma: Develops in the lining of blood or lymph vessels.
• Fibrosarcoma: Originates in fibrous connective tissue.
Leukemia
Carcinoma
Leukemia
Cancers of the blood-forming tissues, primarily the bone marrow, leading to abnormal white blood cell production
• Acute Lymphoblastic Leukemia (ALL): Rapid progression, affects lymphoid cells.
• Acute Myeloid Leukemia (AML): Affects myeloid cells with rapid growth.
• Chronic Lymphocytic Leukemia (CLL): Slow-growing cancer of lymphocytes.
• C
Cancers of the blood-forming tissues, primarily the bone marrow, leading to abnormal white blood cell production
• Acute Lymphoblastic Leukemia (ALL): Rapid progression, affects lymphoid cells.
• Acute Myeloid Leukemia (AML): Affects myeloid cells with rapid growth.
• Chronic Lymphocytic Leukemia (CLL): Slow-growing cancer of lymphocytes.
• Chronic Myeloid Leukemia (CML): Slow progression affecting myeloid cells..
Lymphoma
Carcinoma
Leukemia
Cancers that begin in the lymphatic system, affecting lymph nodes and lymphocytes (a type of white blood cell).
• Hodgkin Lymphoma (HL): Presence of Reed-Sternberg cells.
• Non-Hodgkin Lymphoma (NHL): A diverse group of lymphatic cancers.
Myeloma
Neuroendocrine Tumor (NET)
Melanoma
Cancer of plasma cells, a type of white blood cell that produces antibodies
.• Multiple Myeloma: Abnormal plasma cells accumulate in the bone marrow.
Melanoma
Neuroendocrine Tumor (NET)
Melanoma
Cancer that develops from melanocytes, the pigment-producing cells of the skin.
• Cutaneous Melanoma: Skin melanoma.
• Ocular Melanoma: Melanoma in the eye.
Germ Cell Tumor
Neuroendocrine Tumor (NET)
Neuroendocrine Tumor (NET)
Cancers originating from reproductive cells (sperm or egg cells).
• Testicular Cancer: Often germ cell tumors (e.g., seminoma, non-seminoma).
• Ovarian Germ Cell Tumors: Arise from egg cells.
• Extragonadal Germ Cell Tumors: Occur outside the reproductive organs.
Neuroendocrine Tumor (NET)
Neuroendocrine Tumor (NET)
Neuroendocrine Tumor (NET)
Cancers that develop in hormone-producing cells of the body.
• Carcinoid Tumors: Often found in the gastrointestinal tract or lungs.
• Pheochromocytoma: Arises in adrenal glands.
• Merkel Cell Carcinoma: Rare skin cancer.
Central Nervous System Cancer (CNS)
Central Nervous System Cancer (CNS)
Central Nervous System Cancer (CNS)
Cancers originating in the brain or spinal cord.
• Gliomas: Arise from glial cells (astrocytoma, oligodendroglioma).
• Meningiomas: Develop in the meninges (brain/spinal cord lining).
• Medulloblastoma: Common in children, develops in the cerebellum.
Blastoma
Central Nervous System Cancer (CNS)
Central Nervous System Cancer (CNS)
Cancers that arise from immature or embryonic tissue, more common in children.
• Neuroblastoma: Originates from nerve tissue, typically in adrenal glands.
• Nephroblastoma (Wilms’ Tumor): Affects the kidneys.
• Retinoblastoma: Eye cancer affecting the retina.
• Hepatoblastoma: Liver cancer in young children.
Other Rare and Mixed Cancer
Central Nervous System Cancer (CNS)
Other Rare and Mixed Cancer
Mixed Tumors: Contain multiple types of tissue (e.g., carcinosarcoma).
• Mixed Tumors: Contain multiple types of tissue (e.g., carcinosarcoma).
• Mesothelioma: Cancer of the mesothelium, commonly in the pleura (lung lining).
• Lymphoproliferative Disorders: Abnormal proliferation of lymphocytes.
• Myelodysplastic Syndromes (MDS): Abnormal bone marrow cell production.
types of Cancer
How doctors measure cancer
Why TNM Matters
-Guides the treatment plan (e.g., surgery vs chemo vs radiation)
-Helps provide insight into the prognosis
-Standardizes how doctors talk about cancer progression
-Allows comparison of results between patients and clinical studies
T = Tumor
This describes the size and local spread of the main tumor
N= Nodes
Shows if cancer has spread to nearby lymph nodes
M = Metastasis
Tells if cancer has spread to other organs
Example
T2 N1 M0
Moderate tumor size, small spread to lymph nodes, no distant spread
T4 N3 M1
Large, invasive tumor, widespread lymph involvement, cancer has spread