8.1 Introduction to Cancer and Phases of Cancer Therapy
5 min read•june 18, 2024
is a complex disease characterized by uncontrolled cell growth and division. It develops through genetic , which can be inherited or acquired through environmental factors. Understanding the process of cancer development is crucial for effective diagnosis and treatment.
Cancer therapy involves multiple phases, from diagnosis and staging to various treatment modalities. These include surgery, radiation therapy, chemotherapy, targeted therapy, and immunotherapy. Each approach plays a unique role in combating cancer, often used in combination for optimal results.
Introduction to Cancer
Process of cancer development
Top images from around the web for Process of cancer development
Cancer and the Cell Cycle | OpenStax Biology 2e View original
Is this image relevant?
Overview of Cancer | Boundless Anatomy and Physiology View original
Is this image relevant?
Frontiers | Autophagy in Viral Development and Progression of Cancer View original
Is this image relevant?
Cancer and the Cell Cycle | OpenStax Biology 2e View original
Is this image relevant?
Overview of Cancer | Boundless Anatomy and Physiology View original
Is this image relevant?
1 of 3
Top images from around the web for Process of cancer development
Cancer and the Cell Cycle | OpenStax Biology 2e View original
Is this image relevant?
Overview of Cancer | Boundless Anatomy and Physiology View original
Is this image relevant?
Frontiers | Autophagy in Viral Development and Progression of Cancer View original
Is this image relevant?
Cancer and the Cell Cycle | OpenStax Biology 2e View original
Is this image relevant?
Overview of Cancer | Boundless Anatomy and Physiology View original
Is this image relevant?
1 of 3
- Cancer develops from genetic mutations in normal cells causing uncontrolled growth and division
- Mutations can be inherited (passed down from parents) or acquired through environmental factors (exposure to carcinogens)
- Accumulation of multiple mutations over time leads to the transformation of normal cells into cancerous cells
- Key characteristics of cancer cells enable them to grow and spread uncontrollably
- Sustained proliferative signaling allows cancer cells to continuously divide and multiply
- Evasion of growth suppressors enables cancer cells to bypass normal cellular control mechanisms that limit cell division
- Resistance to cell death () allows cancer cells to survive and accumulate despite damage or stress
- of involves the formation of new blood vessels to supply oxygen and nutrients to the growing tumor
- Activation of invasion and enables cancer cells to spread from the primary tumor site to other parts of the body
- Replicative immortality allows cancer cells to divide indefinitely without undergoing senescence or cell death
Genetic vs environmental cancer factors
- Genetic factors contribute to cancer development through inherited mutations
- Inherited mutations in tumor suppressor genes (, ) increase the risk of developing certain cancers (breast, ovarian)
- Inherited mutations in proto- (, ) can lead to the activation of oncogenes and promote cancer growth
- Family history of specific cancers may indicate the presence of inherited genetic mutations that increase cancer risk
- Environmental factors play a significant role in cancer formation
- Exposure to carcinogens such as tobacco smoke, UV radiation, and asbestos can cause DNA damage and mutations
- Chronic inflammation resulting from infections (hepatitis B and C, H. pylori) can create a tumor-promoting environment
- Dietary factors like high-fat diets and low fiber intake may increase the risk of certain cancers (colon, breast)
- Lifestyle factors such as lack of physical activity and obesity can contribute to the development of various cancers
Types of cancer and features
- Carcinomas originate from epithelial cells and are the most common type of cancer
- Examples include lung, breast, colon, prostate, and skin cancers
- Carcinomas can be further classified based on the specific type of epithelial cell (squamous cell , )
- Sarcomas arise from connective tissues such as bone, cartilage, muscle, and fat
- Examples include (bone), (fat), and (smooth muscle)
- Sarcomas are relatively rare compared to carcinomas
- Leukemias originate in blood-forming tissues (bone marrow) and are characterized by the abnormal production of white blood cells
- Examples include acute myeloid () and chronic lymphocytic ()
- Leukemias can be classified based on the type of white blood cell affected (myeloid or lymphoid) and the rate of progression (acute or chronic)
- Lymphomas develop from cells of the lymphatic system, such as lymph nodes and the spleen
- Examples include Hodgkin's and non-Hodgkin's lymphoma
- Lymphomas are characterized by the abnormal growth and accumulation of lymphocytes
- Central nervous system (CNS) tumors arise from brain and spinal cord tissues
- Examples include (arise from glial cells), (arise from the meninges), and (arise from the cerebellum)
- CNS tumors can be benign (non-cancerous) or malignant (cancerous) and are classified based on the specific cell type and location
Tumor Classification and Cell Cycle
- Tumors can be classified as benign or malignant based on their growth characteristics and potential to spread
- Benign tumors are typically slow-growing, well-differentiated, and remain localized
- Malignant tumors are characterized by rapid, uncontrolled growth and the ability to invade surrounding tissues and metastasize
- The plays a crucial role in cancer development and progression
- Dysregulation of the cell cycle can lead to uncontrolled cell division and tumor formation
- mechanisms are essential for maintaining genomic stability and preventing cancer-causing mutations
- Defects in DNA repair pathways can contribute to the accumulation of genetic alterations and cancer development
Phases of Cancer Therapy
Phases of cancer therapy
- Diagnosis and staging involve identifying the type and extent of cancer to determine the appropriate treatment plan
- Diagnostic tests may include imaging (CT, MRI, PET scans), , and blood tests
- Staging assesses the size and spread of the tumor using the TNM system (Tumor size, lymph Node involvement, Metastasis)
- Surgery aims to remove the primary tumor and/or affected lymph nodes
- Surgery can be used for diagnosis (biopsy), staging (assessing the extent of cancer), and treatment (removing the tumor)
- Types of surgery include (breast cancer), prostatectomy (prostate cancer), and colectomy (colon cancer)
- Radiation therapy uses high-energy radiation to kill cancer cells and shrink tumors
- Radiation can be delivered externally (external beam radiation) or internally (brachytherapy)
- Radiation therapy can be used before, during, or after surgery to improve treatment outcomes
- Chemotherapy is a systemic treatment that uses drugs to kill rapidly dividing cancer cells throughout the body
- Chemotherapy drugs can be administered orally, intravenously, or through other routes (intrathecal, intraperitoneal)
- Chemotherapy can be used as a primary treatment or in combination with other therapies (surgery, radiation)
- Targeted therapy involves drugs designed to target specific molecules involved in cancer growth and progression
- Examples include small molecule inhibitors (tyrosine kinase inhibitors) and monoclonal antibodies ( for HER2-positive breast cancer)
- Targeted therapies are more specific than chemotherapy and may have fewer side effects
- Immunotherapy stimulates the body's immune system to fight cancer cells
- Examples include immune checkpoint inhibitors (, ) and CAR T-cell therapy
- Immunotherapy can be used alone or in combination with other treatments
- Hormone therapy is used for cancers that are sensitive to hormones, such as breast and prostate cancers
- Hormone therapy blocks the production or action of hormones to slow cancer growth
- Examples include (breast cancer) and (prostate cancer)
- Palliative care focuses on relieving symptoms and improving quality of life for patients with advanced cancer
- Palliative care can be provided at any stage of cancer treatment and may include pain management, nutritional support, and emotional support
- Hospice care is a type of palliative care provided to patients with a limited life expectancy (usually less than 6 months)
Additional Treatment Approaches
- is given after primary treatment (such as surgery) to reduce the risk of cancer recurrence
- is administered before the primary treatment to shrink tumors and improve surgical outcomes
- The goal of cancer treatment is to achieve , where there are no detectable signs of cancer and symptoms are reduced or eliminated
Key Terms to Review (64)
Adenocarcinoma: Adenocarcinoma is a type of cancer that originates from glandular epithelial cells, commonly found in organs such as the lungs, breast, prostate, and gastrointestinal tract. It is characterized by the abnormal growth and proliferation of these glandular cells, leading to the formation of a tumor.
Adenocarcinomas: Adenocarcinomas are malignant tumors that originate in glandular epithelial tissue. They are a common form of cancer found in organs such as the lungs, colon, and breast.
Adjuvant therapy: Adjuvant therapy is additional treatment given after the primary treatment to lower the risk of the cancer returning. It often involves chemotherapy, radiation therapy, hormone therapy, or targeted therapy.
Adjuvant Therapy: Adjuvant therapy refers to additional treatment given after the primary treatment for a disease, such as cancer, to enhance the effectiveness of the primary treatment and reduce the risk of recurrence or metastasis. It is commonly used in conjunction with other cancer therapies like chemotherapy, radiation, or surgery.
Allopurinol: Allopurinol is a medication used to reduce uric acid levels in the blood, commonly prescribed for conditions like gout and kidney stones. It works by inhibiting xanthine oxidase, an enzyme involved in uric acid production.
Alopecia: Alopecia is a medical condition characterized by the loss of hair from the scalp or other parts of the body. It can result from various factors including genetics, medical treatments, and underlying health conditions.
Alopecia: Alopecia is a medical term that refers to partial or complete hair loss. It can occur on the scalp or any other part of the body and can have various underlying causes, including certain medical conditions, treatments, and genetic factors.
AML: AML, or Acute Myeloid Leukemia, is a type of cancer that starts in the bone marrow and quickly progresses to the bloodstream. It is characterized by the rapid growth of abnormal white blood cells, which can crowd out healthy blood cells and impair the body's ability to fight infection, bleed, and clot properly.
Angiogenesis: Angiogenesis is the process of new blood vessel formation from pre-existing vasculature. It is a critical component in the growth and progression of solid tumors, as it provides the necessary oxygen and nutrients to support the rapidly dividing cancer cells.
Anthracyclines: Anthracyclines are a class of chemotherapeutic drugs commonly used in the treatment of various types of cancer. They work by interfering with the replication and division of rapidly growing cancer cells, making them an important component in cancer therapy.
Apoptosis: Apoptosis is the process of programmed cell death that occurs in multicellular organisms. It is a crucial mechanism for maintaining cellular health and homeostasis.
Apoptosis: Apoptosis is a form of programmed cell death that occurs in multicellular organisms. It is a tightly regulated process that plays a crucial role in various biological contexts, including immunosuppression, cancer therapy, and the development and maintenance of healthy tissues.
Benign Tumor: A benign tumor is an abnormal growth of cells that does not spread to other parts of the body or invade surrounding tissues. Unlike malignant (cancerous) tumors, benign tumors are typically non-aggressive and do not pose a life-threatening risk. They are localized and often encapsulated, meaning they have a clear boundary separating them from the surrounding healthy tissue.
Biopsy: A biopsy is a medical procedure where a small sample of tissue is taken from the body for examination and analysis. It is a crucial diagnostic tool used to identify the presence and characteristics of various medical conditions, including cancer.
BRCA1: BRCA1 is a tumor suppressor gene that plays a crucial role in DNA repair and cell cycle regulation. Mutations in the BRCA1 gene are associated with an increased risk of developing certain types of cancer, particularly breast and ovarian cancer.
BRCA2: BRCA2 is a tumor suppressor gene that plays a crucial role in the repair of DNA double-strand breaks. Mutations in the BRCA2 gene are associated with an increased risk of developing certain types of cancer, particularly breast and ovarian cancer.
Cancer: Cancer is a group of diseases characterized by uncontrolled cell growth and spread of abnormal cells. It can invade surrounding tissues and metastasize to distant body parts.
Carcinoma: Carcinoma is a type of cancer that originates in the epithelial cells, which line the internal and external surfaces of the body. It is the most common form of cancer, accounting for the majority of cancer cases worldwide. Carcinomas can develop in various organs, such as the lungs, breast, prostate, and skin, and can have a significant impact on the body's normal functions if left untreated.
Cell Cycle: The cell cycle is the series of events that a cell undergoes, from its initial formation to its division into two or more daughter cells. This cyclical process is fundamental to the growth, development, and maintenance of all living organisms.
Cisplatin: Cisplatin is a chemotherapeutic agent used in the treatment of various types of cancer. It is a platinum-based compound that interferes with DNA replication and cell division, leading to the death of rapidly dividing cancer cells. Cisplatin is a crucial component in the phases of cancer therapy, particularly in the introduction and treatment of the disease.
CLL: CLL, or Chronic Lymphocytic Leukemia, is a type of cancer that affects the lymphocytes, a type of white blood cell. It is the most common form of adult leukemia and is characterized by the slow accumulation of abnormal lymphocytes in the blood, bone marrow, and lymph nodes.
Consolidation: Consolidation is a critical phase in cancer therapy where the body's response to initial treatment is solidified and strengthened. It involves the continued administration of drugs or other interventions to eliminate any remaining cancer cells and prevent relapse, ultimately aiming to achieve a durable remission or cure.
DNA Repair: DNA repair refers to the cellular mechanisms that detect and correct various types of damage to the DNA molecule, ensuring the integrity and proper functioning of the genetic material. This process is crucial in the context of cancer and cancer therapy, as defects in DNA repair pathways can lead to the accumulation of genetic mutations and the development of cancerous cells.
Embolization: Embolization is a minimally invasive procedure used to block blood flow to cancerous tumors. It involves the injection of substances to occlude blood vessels supplying the tumor.
Febrile neutropenia: Febrile neutropenia is a serious medical condition characterized by fever and a significant reduction in neutrophil count, often occurring in patients undergoing chemotherapy. It requires prompt medical attention due to the high risk of infection.
Gliomas: Gliomas are a type of brain tumor that originates from the glial cells, which are the supportive cells in the brain. These tumors can be classified based on their aggressiveness and growth patterns, and they are an important consideration in the context of cancer introduction and cancer therapy phases.
Hematologic cancers: Hematologic cancers, also known as blood cancers, affect the blood, bone marrow, and lymphatic system. These include leukemia, lymphoma, and multiple myeloma.
Induction: Induction is a fundamental concept in cancer biology, referring to the process by which certain factors or stimuli trigger the initiation and progression of cancer development. It is a crucial aspect in understanding the phases of cancer therapy and the introduction to cancer as a disease.
Leiomyosarcoma: Leiomyosarcoma is a type of soft tissue sarcoma that originates from smooth muscle cells. It is a rare and aggressive form of cancer that can develop in various parts of the body, including the uterus, gastrointestinal tract, and retroperitoneum. Leiomyosarcomas are characterized by their ability to rapidly grow and metastasize to other organs, making them a challenging cancer to treat effectively.
Leukemia: Leukemia is a type of cancer that originates in the bone marrow and leads to an overproduction of abnormal white blood cells. These abnormal cells crowd out normal blood cells, impeding their function.
Leukemia: Leukemia is a type of cancer that affects the blood and bone marrow, characterized by the uncontrolled proliferation of abnormal white blood cells. This cancer is closely tied to the topics of immunosuppressants, biologics, monoclonal antibodies, biosimilar drugs, and the various phases of cancer therapy.
Leuprolide: Leuprolide is a synthetic hormone agonist that acts on the pituitary gland to suppress the production of testosterone and estrogen, making it a valuable therapeutic agent in the management of hormone-sensitive cancers and conditions related to hormonal imbalances.
Liposarcoma: Liposarcoma is a type of soft tissue sarcoma that originates from fat cells. It is a rare and aggressive form of cancer that can develop in any part of the body where fat tissue is present.
Lumpectomy: A lumpectomy is a surgical procedure in which a small portion of the breast, containing a cancerous tumor or abnormal growth, is removed. It is a breast-conserving surgery that aims to remove the tumor while preserving the majority of the breast tissue.
Lymphoma: Lymphoma is a type of cancer that originates in the lymphatic system, which is part of the body's immune system. It is characterized by the abnormal growth and proliferation of lymphocytes, a type of white blood cell. Lymphoma can be classified into different subtypes based on the specific type of lymphocyte involved and the rate of disease progression.
Malignant Tumor: A malignant tumor is an abnormal growth of cells that can invade and destroy surrounding tissues, and may spread to other parts of the body through the bloodstream or lymphatic system. This type of tumor is considered cancerous and can be life-threatening if not treated properly.
Medulloblastomas: Medulloblastomas are a type of highly aggressive and fast-growing brain tumor that originates in the cerebellum, the part of the brain responsible for coordinating movement and balance. These tumors are classified as a type of embryonal tumor, meaning they develop from immature or primitive cells in the central nervous system.
Melanoma: Melanoma is a type of skin cancer that develops from melanocytes, the pigment-producing cells in the skin. It is the most serious form of skin cancer due to its ability to spread to other parts of the body if not detected and treated early.
Meningiomas: Meningiomas are a type of tumor that originates from the meninges, the protective membranes surrounding the brain and spinal cord. These tumors are typically slow-growing and often benign, but can still cause significant neurological symptoms depending on their location and size.
Metastasis: Metastasis is the process by which cancer cells spread from the primary tumor site to other parts of the body, forming new tumors. It is a critical feature of cancer that distinguishes it from benign growths and is a major cause of cancer-related deaths.
Multiple myeloma: Multiple myeloma is a type of blood cancer that affects plasma cells in the bone marrow, leading to abnormal cell proliferation. It often results in bone damage, kidney dysfunction, and impaired immune response.
Mutations: Mutations are changes in the DNA sequence of a cell's genome. These alterations can affect the function of genes and may lead to cancer if they occur in certain genes involved in cell growth and division.
Neoadjuvant therapy: Neoadjuvant therapy is a preoperative treatment designed to shrink tumors before the main treatment, usually surgery. It aims to improve surgical outcomes and increase the chances of complete tumor removal.
Neoadjuvant Therapy: Neoadjuvant therapy refers to the administration of treatment, typically chemotherapy or radiation, before the primary or main treatment for a disease. It is commonly used in the context of cancer therapy to shrink a tumor prior to surgery or other definitive treatment.
Neoangiogenesis: Neoangiogenesis is the process of new blood vessel formation from pre-existing vessels, often seen in tumor growth. It is a critical mechanism by which cancerous tumors obtain nutrients and oxygen to sustain rapid proliferation.
Neoplasm: A neoplasm is an abnormal growth of cells that results in the formation of a mass or tumor. Neoplasms can be either benign, meaning they are non-cancerous and do not spread to other parts of the body, or malignant, meaning they are cancerous and have the potential to invade and destroy surrounding tissues and spread to other parts of the body.
Neutropenia: Neutropenia is a condition characterized by an abnormally low number of neutrophils, a type of white blood cell that plays a crucial role in the body's immune response. This reduction in neutrophil count can increase an individual's susceptibility to infections, making it an important consideration in the context of cancer and its treatments.
Nivolumab: Nivolumab is a monoclonal antibody that acts as an immune checkpoint inhibitor, primarily targeting the programmed cell death-1 (PD-1) receptor on T cells. It is used as a cancer immunotherapy to enhance the body's immune response against tumor cells.
Non-Hodgkin lymphoma: Non-Hodgkin lymphoma is a type of cancer that originates in the lymphatic system, specifically in the lymphocytes. It differs from Hodgkin lymphoma by the absence of Reed-Sternberg cells.
Oncogene: An oncogene is a gene that has the potential to cause cancer when mutated or expressed at high levels. Oncogenes are involved in the regulation of cell growth, division, and survival, and their dysregulation can lead to the uncontrolled proliferation of cells, a hallmark of cancer.
Oncogenes: Oncogenes are mutated forms of genes that have the potential to cause normal cells to become cancerous. They promote cell growth and proliferation, often leading to uncontrolled cell division.
Osteosarcoma: Osteosarcoma is a type of bone cancer that typically develops in the long bones of the body, most commonly in the areas around the knee and shoulder. It is characterized by the rapid growth of abnormal bone cells, leading to the formation of a malignant tumor.
P53: p53 is a tumor suppressor protein that plays a crucial role in regulating cell division, DNA repair, and programmed cell death (apoptosis). It acts as a guardian of the genome, ensuring the integrity of the genetic material and preventing the development of cancer.
Pembrolizumab: Pembrolizumab is a monoclonal antibody that acts as an immune checkpoint inhibitor, specifically targeting the programmed cell death-1 (PD-1) receptor. It is used in the treatment of various types of cancer by enhancing the body's immune response against cancer cells.
PTEN: PTEN (Phosphatase and Tensin Homolog) is a tumor suppressor gene that plays a crucial role in regulating cell growth, division, and survival. It is a key player in the control of cellular processes and its inactivation or mutation is commonly associated with the development and progression of various types of cancer.
Rasburicase: Rasburicase is an enzyme medication used to treat hyperuricemia associated with tumor lysis syndrome (TLS) in cancer patients. It catalyzes the conversion of uric acid into allantoin, which is more easily excreted by the kidneys.
Remission: Remission refers to a temporary or permanent decrease or disappearance of the signs and symptoms of a disease, especially cancer. It is a critical concept in the context of cancer therapy and the phases of cancer treatment.
Remission indicates that the cancer has responded to treatment, and the disease is under control, even if it has not been completely cured. Achieving and maintaining remission is a primary goal of cancer therapy, as it can significantly improve a patient's quality of life and prognosis.
RET: RET, or Rearranged during Transfection, is a proto-oncogene that encodes a receptor tyrosine kinase. This gene plays a crucial role in the development and progression of certain types of cancer, particularly in the context of cancer initiation and progression.
Squamous cell carcinomas: Squamous cell carcinomas are a type of skin cancer originating in the squamous cells, which make up the middle and outer layers of the skin. They are generally caused by prolonged exposure to ultraviolet (UV) radiation from sunlight or tanning beds.
Tamoxifen: Tamoxifen is a selective estrogen receptor modulator (SERM) that is primarily used in the treatment and prevention of certain types of breast cancer. It works by blocking the effects of estrogen in breast tissue, thereby inhibiting the growth and spread of hormone-sensitive cancer cells.
TNM Staging: TNM staging is a standardized system used to classify the extent and progression of cancer based on the size and spread of the primary tumor (T), the involvement of nearby lymph nodes (N), and the presence of distant metastases (M). This comprehensive staging system is crucial for determining appropriate cancer treatment and predicting patient prognosis.
Trastuzumab: Trastuzumab is a monoclonal antibody used in the treatment of certain types of breast cancer and gastric cancer. It specifically targets the HER2 protein, which is overexpressed in some cancer cells, and helps to slow or stop the growth of these cancerous cells.
Tumor lysis syndrome: Tumor lysis syndrome (TLS) is a potentially life-threatening condition caused by the rapid destruction of malignant cells, leading to the release of intracellular contents into the bloodstream. It commonly occurs after the initiation of cancer therapy.
Tumor Suppressor Gene: A tumor suppressor gene is a type of gene that normally acts to prevent the development of cancer. These genes code for proteins that regulate cell division, repair DNA errors, or initiate apoptosis (programmed cell death) in cells with irreparable DNA damage, thereby preventing uncontrolled cell growth and tumor formation.