A Brief Introduction of Antineoplastic Agents and their Effects on Malignancy
This Article has been written by Anubhav Chaurasia and Poornima Sharma
Cancer is a wide and Broad term. also known by other names like Carcinoma, Malignancy, Neoplasms, Tumor.
Key Cancer Facts:
- Cancer is a 2nd leading cause of death worldwide, accounting for nearly 10 million deaths in 2020, or nearly one in six deaths.
- The most common cancers are breast, lung, colon and rectum and prostate cancers (Leukemia, Non-Hodgkin Lymphoma are also lethal ones)
- Around one-third of deaths from cancer are due to tobacco use(22% of cancer deaths), high body mass index, alcohol consumption, low fruit and vegetable intake, and lack of physical activity.
- Cancer-causing infections, such as human papillomavirus (HPV) and hepatitis, are responsible for approximately 30% of cancer cases in low- and lower-middle-income countries.
- Many cancers can be cured if detected early and treated effectively.
- The total annual economic cost of cancer is estimated at US$1.16 trillion.
INTRODUCTION
Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms new cells as you need them, replacing old cells that die. Sometimes this process goes wrong. New cells grow even when you don’t need them, (loss of Contact Inhibition Property Among Cells) and old cells don’t die when they should. These extra cells can form a mass called a tumor; it is a uncontrolled, abnormal growth which forms a lump the following statement is true among all the Cancer except leukaemia (cancer of the blood).
If left untreated, tumours can grow and spread into the surrounding normal tissue, or to other parts of the body via the bloodstream and lymphatic systems, and can affect the digestive, nervous and circulatory systems or release hormones that may affect body function.
These changes are the result of the interaction between a person’s genetic factors and some external agents, including:
- physical carcinogens, such as ultraviolet and ionizing radiation;
- chemical carcinogens, such as asbestos, components of tobacco smoke, alcohol, aflatoxin (a food contaminant), and arsenic (a drinking water contaminant); and
- biological carcinogens, such as infections from certain viruses, bacteria, or parasites.
- Cell growth and division absent the proper signals
- Continuous growth and division even given contrary signals
- Avoidance of programmed cell death
- Limitless number of cell divisions
- Promoting blood vessel construction
- Invasion of tissue and formation of metastases
Video Summary; LINK (Source — Wikipedia)
Cancer tumours can be divided into three groups: benign, malignant or precancerous
Benign tumours are not cancerous and rarely threaten life. They tend to grow quite slowly, do not spread to other parts of the body and are usually made up of cells quite similar to normal or healthy cells. They will only cause a problem if they grow very large, becoming uncomfortable or press on other organs — for example a brain tumour inside the skull.
Malignant tumours are faster growing than benign tumours and have the ability to spread and destroy neighbouring tissue. Cells of malignant tumours can break off from the main (primary) tumour and spread to other parts of the body through a process known as metastasis. Upon invading healthy tissue at the new site they continue to divide and grow. These secondary sites are known as metastases and the condition is referred to as metastatic cancer.
Precancerous (or premalignant) describes the condition involving abnormal cells which may (or is likely to) develop into cancer.
Signs and symptoms of cancer
There are over 200 different types of cancer that can cause many different signs and symptoms. Sometimes symptoms affect specific areas of the body, such as our tummy or skin. But signs can also be more general, and include weight loss, tiredness (fatigue) or unexplained pain.
Some possible signs of cancer, like a lump, are better known than others. But this doesn’t mean they’re more important or more likely to be cancer. It is important to get any possible symptom of cancer checked out. Cancer can be difficult to diagnose and can be considered a “Great Imitator”
Local symptoms
Local symptoms may occur due to the mass of the tumor or its ulceration. For example, mass effects from lung cancer can block the bronchus resulting in cough or pneumonia; esophageal cancer can cause narrowing of the esophagus, making it difficult or painful to swallow; and colorectal cancer may lead to narrowing or blockages in the bowel, affecting bowel habits. Masses in breasts or testicles may produce observable lumps. Ulceration can cause bleeding that can lead to symptoms such as coughing up blood (lung cancer), anemia or rectal bleeding (colon cancer), blood in the urine (bladder cancer), or abnormal vaginal bleeding (endometrial or cervical cancer). Although localized pain may occur in advanced cancer, the initial tumor is usually painless. Some cancers can cause a buildup of fluid within the chest or abdomen.
Systemic symptoms
Systemic symptoms may occur due to the body’s response to the cancer. This may include fatigue, unintentional weight loss, or skin changes. Some cancers can cause a systemic inflammatory state that leads to ongoing muscle loss and weakness, known as cachexia
Some cancers, such as Hodgkin’s disease, leukemias, and liver or kidney cancers, can cause a persistent fever.
Some systemic symptoms of cancer are caused by hormones or other molecules produced by the tumor, known as paraneoplastic syndromes. Common paraneoplastic syndromes include hypercalcemia, which can cause altered mental state, constipation and dehydration, or hyponatremia, which can also cause altered mental status, vomiting, headaches, or seizures.
Metastasis
Metastasis is the spread of cancer to other locations in the body. The dispersed tumors are called metastatic tumors, while the original is called the primary tumor. Almost all cancers can metastasize. Most cancer deaths are due to cancer that has metastasized.
Metastasis is common in the late stages of cancer and it can occur via the blood or the lymphatic system or both. The typical steps in metastasis are local invasion, intravasation into the blood or lymph, circulation through the body, extravasation into the new tissue, proliferation and angiogenesis. Different types of cancers tend to metastasize to particular organs, but overall the most common places for metastases to occur are the lungs, liver, brain, and the bones.
Pathophysiology
The pathophysiology of cancer includes the physical and hormonal changes associated with cancer and paraneoplastic syndrome. A group of diseases associated with abnormal cell growth is termed cancer. The genes associated with the development of cancer include oncogenes and tumor suppressor genes.
the pathophysiology of cancer includes the physical and hormonal changes associated with cancer and paraneoplastic syndrome. In general, cancer occurs in four main stages. The pathological stage of cancer is determined through biopsy (removal of small body tissue for laboratory examination) where the cancerous cells are compared to normal cells. The four main stages of cancer are:
- Stage 1 — Cancer is normally localized in a small area
- Stage 2 — The size of the cancer increases
- Stage 3 — The size of cancer becomes larger and starts spreading to some parts of the body including lymph nodes
- Stage 4 — Cancer has grown and has spread to most parts of the body
Diagnosis
Most cancers are initially recognized either because of the appearance of signs or symptoms or through screening Neither of these leads to a definitive diagnosis, which requires the examination of a tissue sample by a pathologist. People with suspected cancer are investigated with medical tests. These commonly include blood tests, X-rays, (contrast) CT scans and endoscopy.
The tissue diagnosis from the biopsy indicates the type of cell that is proliferating, its histological grade, genetic abnormalities and other features. Together, this information is useful to evaluate the prognosis and to choose the best treatment.
Cancer Diagnosis
It Includes diagnosis of a comprehensive physical test. also includes subsequent examinations:
- Blood tests.
- Imaging tests.
- Biopsies.
- Blood tests
Blood tests for cancer may contain:
Complete blood count (CBC): A CBC examination measures and calculates your blood cells.
Tumor markers: Tumor markers are essences that cancer cells discharge or that your normal cells discharge in response to cancer cells.
Blood protein tests: Healthcare providers use a method known as electrophoresis to estimate immunoglobulins. Your immune system responds to specific cancers by releasing immunoglobulins.
Circulating tumor cell tests: Cancerous tumors may free cells. Tracking tumor cells assists healthcare providers to observe cancer action.
Imaging tests
Imaging tests may include:
Computed tomography (CT) scan: CT scans inspect for cancerous tumors area and impact on your organs and bones.
X-rays: X-rays use safe quantities of radiation to make pictures of your bones and soft tissues.
Positron emission test (PET) scan: PET scans create pictures of your organs and tissues at work. Healthcare providers may use this examination to see early signs of cancer.
Ultrasound: An ultrasound uses high-intensity sound waves that display designs inside of your body.
Magnetic resonance imaging (MRI): MRIs use a big magnet, radio waves, and a computer to produce pictures of your organs and further structures inside of your body.
Iodine meta-iodobenzylguanidine (MIGB): This nuclear imaging examination assists to see cancer, involving carcinoid tumors and neuroblastoma.
Biopsies
A biopsy is a method healthcare providers do to receive tissue, cells, fluid, or growths that they’ll study under a microscope. There are several types of biopsies:
Needle biopsy: This examination may be known as a fine syringe aspiration or fine syringe biopsy. Healthcare providers use a delicate hollow syringe and needle to remove fluid, cells, or tissue from suspicious lumps. Syringe biopsies are frequently done to assist diagnose thyroid cancer, breast cancer, or cancer in your lymph nodes.
Skin biopsy: Healthcare providers extract a little piece of your skin to analyze skin cancer.
Bone marrow biopsy: Healthcare providers extract a little piece of bone marrow so they can inspect the specimen for signs of the condition, involving cancer in your bone marrow.
Endoscopic or laparoscopic biopsy: These biopsies utilize an endoscope or laparoscope to notice the inside of your body. With both of these techniques, a little cut is created in your skin and a tool is inserted. An )endoscope is a light, flexible pipe with a camera on the tip, along with a cutting instrument to extract your sample. A laparoscope is a just various scope.
Excisional or incisional biopsy: For these open biopsies, a surgeon or doctor cuts into your body and either the whole tumor is extracted (excisional biopsy) or a portion of the tumor is extracted (incisional biopsy) to inspect or treat it.
Perioperative biopsy: This examination may be known as a frozen section biopsy. This biopsy is accomplished while you’re having another method. Your tissue will be extracted and inspected right away. Outcomes will arrive soon after the method, so if you require treatment, it can begin instantly.
Types of Cancer (Classification)
Following are some types of cancer
- Carcinoma
- Sarcoma
- Leukemia
- Lymphoma
- Multiple Myeloma
- Melanoma
- Brain and Spinal Cord Tumors
Further Types of Tumors
- Germ Cell Tumors
- Neuroendocrine Tumors
- Carcinoid Tumors
Cancers are usually named using -carcinoma, -sarcoma or -blastoma as a suffix, with the Latin or Greek word for the organ or tissue of origin as the root. For example, cancers of the liver parenchyma arising from malignant epithelial cells is called hepatocarcinoma, while a malignancy arising from primitive liver precursor cells is called a hepatoblastoma and a cancer arising from fat cells is called a liposarcoma. For some common cancers, the English organ name is used. For example, the most common type of breast cancer is called ductal carcinoma of the breast. Here, the adjective ductal refers to the appearance of cancer under the microscope, which suggests that it has originated in the milk ducts.
Cancer Treatment
Cancer treatments may be used as:
- Primary treatment. The goal of a primary treatment is to completely remove the cancer from your body or kill all the cancer cells.
- Any cancer treatment can be used as a primary treatment, but the most common primary cancer treatment for the most common types of cancer is surgery. If your cancer is particularly sensitive to radiation therapy or chemotherapy, you may receive one of those therapies as your primary treatment.
- Adjuvant treatment. The goal of adjuvant therapy is to kill any cancer cells that may remain after primary treatment in order to reduce the chance that the cancer will recur.
- Any cancer treatment can be used as an adjuvant therapy. Common adjuvant therapies include chemotherapy, radiation therapy and hormone therapy.
- Neoadjuvant therapy is similar, but treatments are used before the primary treatment in order to make the primary treatment easier or more effective.
- Palliative treatment. Palliative treatments may help relieve side effects of treatment or signs and symptoms caused by cancer itself. Surgery, radiation, chemotherapy and hormone therapy can all be used to relieve symptoms. Other medications may relieve symptoms such as pain and shortness of breath.
- Palliative treatment can be used at the same time as other treatments intended to cure your cancer.
Other Cancer treatment options include:
- Surgery. The goal of surgery is to remove the cancer or as much of the cancer as possible.
- Chemotherapy. Chemotherapy uses drugs to kill cancer cells.
- Radiation therapy. Radiation therapy uses high-powered energy beams, such as X-rays or protons, to kill cancer cells. Radiation treatment can come from a machine outside your body (external beam radiation), or it can be placed inside your body (brachytherapy).
- Bone marrow transplant. Your bone marrow is the material inside your bones that makes blood cells from blood stem cells. A bone marrow transplant, also knowns as a stem cell transplant, can use your own bone marrow stem cells or those from a donor.
- A bone marrow transplant allows your doctor to use higher doses of chemotherapy to treat your cancer. It may also be used to replace diseased bone marrow.
- Immunotherapy. Immunotherapy, also known as biological therapy, uses your body’s immune system to fight cancer. Cancer can survive unchecked in your body because your immune system doesn’t recognize it as an intruder. Immunotherapy can help your immune system “see” the cancer and attack it.
- Hormone therapy. Some types of cancer are fueled by your body’s hormones. Examples include breast cancer and prostate cancer. Removing those hormones from the body or blocking their effects may cause the cancer cells to stop growing.
- Targeted drug therapy. Targeted drug treatment focuses on specific abnormalities within cancer cells that allow them to survive.
- Cryoablation. This treatment kills cancer cells with cold. During cryoablation, a thin, wandlike needle (cryoprobe) is inserted through your skin and directly into the cancerous tumor. A gas is pumped into the cryoprobe in order to freeze the tissue. Then the tissue is allowed to thaw. The freezing and thawing process is repeated several times during the same treatment session in order to kill the cancer cells.
- Radiofrequency ablation. This treatment uses electrical energy to heat cancer cells, causing them to die. During radiofrequency ablation, a doctor guides a thin needle through the skin or through an incision and into the cancer tissue. High-frequency energy passes through the needle and causes the surrounding tissue to heat up, killing the nearby cells.
- Clinical trials. Clinical trials are studies to investigate new ways of treating cancer. Thousands of cancer clinical trials are underway.
INDIVIDUAL CANCER DRUGS ( ANTINEOPLASTIC AGENTS )
Following are the class which used as anticancer agents ( antineoplastic agents )
Underlying mechanisms and drug intervention strategies for the tumour microenvironment
Cancer occurs in a complex tissue environment, and its progression depends largely on the tumour microenvironment (TME). The TME has a highly complex and comprehensive system accompanied by dynamic changes and special biological characteristics, such as hypoxia, nutrient deficiency, inflammation, immunosuppression and cytokine production. In addition, a large number of cancer-associated biomolecules and signalling pathways are involved in the above bioprocesses.
Other Relevant Options are:
Organoids as clinically relevant models to tailor precision medicine in cancer treatment
CRISPR-Cas9 system, the next generation in cancer therapy and target discovery
NEW APPROACH
Multiparametric-magnetic resonance imaging (mp-MRI), for instance, can uncover the jumble of blood vessels in a new prostate tumor. That close-up view can help doctors decide the best treatment.
Fluorescence lifetime imaging (FLI) is used to help women with breast cancer. A scan tells your doctor if you have proteins that are helping your cancer cells grow. If you do, they can prescribe treatment that may block the growth.
CAR T Cells: Drugs called immune checkpoint inhibitors, for instance, are already in broad use to treat people with many types of cancer, including melanoma, lung, kidney, bladder, and lymphoma.
But another form of immunotherapy, called CAR T-cell therapy, has also generated substantial excitement among researchers and oncologists. Although CAR T-cell therapies are not as widely used as immune checkpoint inhibitors, they have shown the same ability to eradicate very advanced leukemias and lymphomas and to keep the cancer at bay for many yearsExit Disclaimer. ; NATIONAL CANCER INSTITUTE
FDA APPROVED CART -T CELL THERAPY:
Serious side effects of CART-T cell therapy : Other possible serious side effects of CAR T-cell therapy can include:
- Allergic reactions during the infusion
- Abnormal levels of minerals in the blood, such as low potassium, sodium, or phosphorous levels
- A weakened immune system, with an increased risk of serious infections
- Low blood cell counts, which can increase the risk of infections, fatigue, and bruising or bleeding
IN CONCLUSION;
The latest advances in cancer treatment have created a whole new outlook on how to treat cancer. These advances have developed from a deeper understanding of the molecular basis of cancer. Some of the earlier treatments are still valuable however they have some drawbacks. For example, surgery and radiation are effective but they only treat one local area of the cancer. Chemotherapy can treat cancer cells that are spread all over the body but they have extremely toxic side effects. All of these treatments are still in use today and will probably be in use for a while although they will not be the only kind of treatments.
~ ANUBHAV CHAURASIA and POORNIMA SHARMA
