Patho Ch. 20 - Neoplasms and Cancer
Prognosis
Generally the term cure, or being considered cancer free, is defined as 5-year survival without a recurrence after cancer diagnosis and treatment. Several periods of remission without clinical signs may occur before the disease becomes terminal. Death rates for the different types of cancer vary greatly.
3 most common cancers - Women
-Breast cancer: first among women of all races -Lung cancer: second among white, black and native American women; third among asian and hispanic women -Colorectal cancer: second among asian and hispanic women; third among white, black and native American women
Treatment - Other drugs
-hormones -sex hormones -biologic response modifiers -angiogenesis inhibitor drug -analgesics
Why do patients who are going through radiation or chemotherapy treatment for cancer often lose their hair and find that their skin has become sensitive and fragile?
Cancer cells are rapidly dividing cells, and chemotherapy and radiation treatments are designed to hinder this rapid growth and destroy these masses. Unfortunately, the epithelial cells that make up the hair and skin, which also divide rapidly, are often also destroyed by chemotherapy or radiation therapy.
Pathophysiology: Warning Signs of Cancer
Health care professionals should be aware of the early indicators of malignancies, which include: -Unusual bleeding or discharge -A change in bowel or bladder habits -Change of the shape and size of a wart or mole -A sore that does not heal -Unexplained weight loss, anemia, low hemoglobin, or persistent fatigue -Persistent cough or hoarseness without apparent reason -A solid, often painless lump anywhere in or on the body
Pathophysiology: Staging of Cancer
Staging (classification) of cancer is applied at the time of diagnosis and is the basis of treatment and prognosis. Staging is based on: -Size of the primary tumor (T) -Extent of involvement of the regional lymph nodes (N) -Spread of the tumor (M), which includes invasion and metastasis
Little metastasis is seen with brain tumors because:
The patient usually dies before metastasis begins.
Explain why radiation can so effectively cause cancerous tumors.
The radiation can directly damage chromosomes, causing abnormal cellular function and reproduction. Damage to tissue itself may cause a rapid rate of mitosis. Accelerated cell division statistically results in more mutations, which may affect not only cell function but also cell reproduction.
Paraneoplastic syndromes
are additional problems associated with certain tumors, such as bronchogenic carcinoma in the lungs. tumor cells release substances that affect neurologic function or blood clotting or have hormonal effects. this syndrome may confuse the diagnosis of cancer, complicate the monitoring and treatment of the patient, and cause change in body image.
Biologic response modifiers
are agents that augement the natural immune response in the body to improve surveillance and removal of abnormal cells.
Grading
grading of tumors is based on the degree of differentiation of the malignant cells-- a grade I tumor has well-differentiated cells similar to the original cells, whereas a grade IV tumor is undifferentiated with cells varying in size and shape (anaplasia); this type of tumor is considered highly malignant and likely to progress quickly
Alopecia
hair loss
Neoplasm or tumor
is a cellular growth that is no longer responding to normal body controls. The cells continue to reproduce when there is no need for them. many neoplasms are unable to function as normal tissue cells because they consist of atypical (abnormal) or immature cells.
Carcinogenesis
is the process by which normal cells are transformed into cancer cells
A person's genetic predisposition to cancer may be revealed by the presence of:
oncogenes
Anemia
or decreased hemoglobin is a common problem resulting from anorexia and decreased food intake, chronic bleeding with iron loss, and bone marrow depression. anemia decreases the oxygen available to cells, leading to fatigue and poor tissue regeneration.
One treatment that is most effective against rapidly dividing cancer cells is:
radiation
Spread of Malignant Tumors
-Invasion -Metastasis -Seeding
Malignant Tumors - Examples
-skin cancer -ovarian cancer -brain cancer
Systemic Effects of Malignant Tumors
-weight loss and cachexia -anemia -severe fatigue -infections -bleeding -paraneoplastic syndromes
Leading causes of cancer deaths - Men
-Lung cancer: first among men of all races -Prostate cancer: second among white, black, hispanic, and native American men; fourth among asian men -Liver cancer: second among asian men -Colorectal cancer: third among men of all races
Leading causes of cancer deaths - Women
-Lung cancer: first among white, black, asian, and native American women; second among hispanic -Breast cancer: first among hispanic women and second among white, black, asian, and native American women -Colorectal cancer: third among women of all races
3 most common among Men
-Prostate cancer: first amount men of all races -Lung cancer: second among white, black, native American, and asian men; third among hispanic men -Colorectal cancer: second among hispanic; third among white, black, native American, and asian men
Ovarian Cancer
-has a poor prognosis, ranking high in mortality rate -it is a "silent tumor" -hormonal and genetic factors appear to play a role in development of this cancer. -presenting (or first) signs are vague and appear only after the tumor is well advanced and is large enough to cause pressure on the adjacent structures, such as the bladder or intestine -the first indications are usually altered bowel or bladder function or increased abdominal girth. -treatment includes surgery, radiation, and chemotherapy Ovarian cancer has a poor prognosis and a high mortality rate. -This tumor is "silent" because it is hidden in the peritoneal cavity; the first signs are vague and appear only after the tumor is well advanced. -The tumor spreads easily by the way of the lymphatic vessels and by cells along the peritoneal membranes. The accompanying illustration demonstrates the spread of ovarian cancer throughout the peritoneal cavity. -Hormonal and genetic factors appear to play a role in the development of this cancer. -Tumor markers can assist in early diagnosis and screening.
Brain Cancer
-may be benign or malignant -creates pressure inside the skull -can cause death, even if small, if they are located in the brainstem or cerebellum, where they can interfere with vital functions such as respiration. -signs: seizure or signs of pressure such as headache, drowsiness, vomiting, visual problems, or impaired motor function -malignant brain tumors do not metastasize outside the central nervous system because the primary tumor is usually fatal before metastasis begins. -treatment: surgery, radiation, or chemotherapy and may cause the loss of some additional brain tissue. -aftereffects of treatment may include loss of specific function and disability Brain tumors are masses that create pressure inside the skull. A brain tumor may be benign or malignant, but because of the pressure development in various areas of the brain, each type can be life-threatening. Some common sites of intracranial tumor occurrences are shown in the illustration. -Tumors vary histologically and may originate from neurons, Glossary glial cells, blood vessels, or connective tissue. -Early signs include seizures, headache, drowsiness, vomiting, visual problems, and impaired motor function. -Primary tumors are generally fatal before metastasis begins.
Tumor Nomenclature
-tumors are named according to a system -depending on the type of tissue in which a tumor is located, the suffix indicates malignant tumors. -the suffix "oma" alone indicates a benign tumor e.g., lipoma. ROOT: fatty tissue: lip- SUFFIX: benign: -oma EXAMPLE: lipoma: benign tumor of fatty tissue ROOT: gland tissue: adeno- SUFFIX: malignant epithelial tissue: -carcinoma EXAMPLE: adenocarcinoma: malignant tumor of epithelial lining of a gland ROOT: Fibrous tissue: fibro- SUFFIX: Malignant connective tissue: -sarcoma EXAMPLE: fibrosarcoma: malignant tumor of fibrous tissue
Benign Tumors
-usually consist of differentiated cells that reproduce at a higher than normal rate -often encapsulated and expands but does not spread -usually freely moveable on palpation. -not considered life threatening unless it is in an area such as the brain where the pressure effects can become critical CELLS: -similar to normal cells -differentiated -mitosis fairly normal GROWTH: -relatively slow -expanding mass -frequently encapsulated SPREAD: -remains localized SYSTEMIC EFFECTS: -rare LIFE-THREATENING: -only certain locations (e.g., brain)
Malignant Tumors
-usually made up of undifferentiated, nonfunctional cells that do not appear organized -cells tend to reproduce more rapidly than normal and often show abnormal mitotic figures -cells have lost cellular connections with each other, and reproduction is not inhibited in the presence of other similar cells -tumor cells infiltrate or spread into surrounding tissue and may easily metastasize or break away to spread to other organs and tissues CELLS: -varied in size and shape with large nuclei -many undifferentiated -mitosis increased and atypical GROWTH: -rapid growth -cells not adhesive, infiltrate tissue -no capsule SPREAD: -invades nearby tissues or metastasizes to distant sites through blood and lymph vessels SYSTEMIC EFFECTS: -often present LIFE-THREATENING: -yes, by tissue destruction and spread of tumors
Skin Cancer
-visible, easily diagnosed and treated -develops slowly -have the highest rate of recurrence and usually arise on the head neck or back, areas exposed to the sun and irritation. -occur frequently in individuals with fair skin and over 40 years old -basal cell carcinoma is the most common form of skin cancer Skin cancer is visible and therefore can easily be diagnosed. This type of cancer generally develops slowly, and most skin cancers—with the exception of malignant melanoma—can be treated successfully and have a good prognosis. -Basal cell carcinoma (BCC) is the most common form of skin cancer. ---The tumor appears as a small lesion that grows slowly. ---The tumor is slowly invasive in Glossary subcutaneous tissue if not recognized and treated. ---Basal cell carcinoma occurs most frequently in individuals with fair skin living in southern climates.
Treatment: Chemotherapy
Antineoplastic drugs may be used alone or in combination with surgery or radiation. Usually these drugs are given in combinations of two to four drugs at specified intervals. The drugs interfere with protein synthesis and DNA replication of the target. Side effects of chemotherapy include: -Bone marrow depression, a limiting factor for chemotherapy that necessitates blood tests before each treatment -Vomiting, which may occur during or shortly after treatment, although antiemetic drugs are helpful in decreasing nausea and vomiting -Epithelial cell damage: hair loss, breakdown of skin and mucous membranes -Damage to specific areas: fibrosis in the lungs, damage to myocardial cells
The most common form of skin cancer is:
Basal cell carcinoma
What characteristic of benign tumors is actually helpful as it keeps the spread of the tumor localized?
Benign tumors are frequently encapsulated, preventing invasion of nearby tissue or metastasis to distant sites. The encapsulated tumor may grow in size but usually won't spread to other tissue
One of the main differences between the effects of benign tumors and those of malignant tumors is:
Benign tumors rarely cause systemic effects, whereas malignant ones often do.
Tumors are named in accordance with a system based on:
Cell type or tissue Correct
Pathophysiology: Local Effects of Tumors
Local effects of tumors include pain, obstruction, tissue necrosis, and ulceration, as shown in the illustration of invasive squamous cell carcinoma on the ear. -Pain occurs when a tumor is well advanced; severity depends on the type of tumor. -Obstruction is a result of compression of a duct or passageway by a tumor. ---These may include blood and lymphatic supply. ---Obstructions can also occur in the digestive tract. ---Obstructions may result in compromised air flow in the bronchi. -Tissue necrosis and ulceration may lead to infections around the tumor.
Using your knowledge of the characteristics of ovarian cancer, explain why the mortality rate is so high.
Ovarian cancer tumors can stay hidden in the peritoneal cavity. Initial signs and symptoms are also vague and do not appear until the cancer is advanced, which does not allow for quick diagnosis and treatment. The cancer cells spread easily through the lymphatic system of the peritoneum and can invade the tissues/organs throughout.
Additional problems associated with certain tumors are referred to as:
Paraneoplastic syndromes
Etiology: Prevention
Precautions, or Glossary prophylactic measures, can be taken to reduce the risk of or even prevent cancer. These measures include: -Limiting sun/UV exposure -Regular medical and dental exams for cancer screening -Refraining from smoking -Altering the diet to: ---Increase the fiber content in the diet ---Reduce fat content ---Increase fresh fruit and vegetable intake ---Increase the amount of foods containing antioxidants -Using chemotherapy or radiation treatment after tumor surgery to help prevent cancer spread
Actions such as limiting UV exposure, refraining from smoking, and using chemotherapy after tumor surgery to help prevent metastases are classified as:
Prophylactic measures
Treatment: Radiation Therapy
Radiation, which causes mutation or alterations in the target DNA, may be used alone or in combination with other therapies. It is most effective in rapidly dividing cells, although some types of cancer are resistant to radiation. Radiation therapy may be used before surgery to shrink a tumor. Adverse effects of radiation include: -Bone marrow depression- decreased production of blood cells -Epithelial cell damage- causes damage to underlying tissue with serious physiological complications -Damage to organs- such as ovaries and testes -Nonspecific fatigue and lethargy -Mental depression
Pathophysiology: Systemic Effects of Tumors
The most common systemic or general effects of cancer include: -Weight loss and cachexia (see illustration), which occur as a result of anorexia, fatigue, pain, stress, and the increased demands of tumor cells -Anemia, or decreased hemoglobin level, which results in a decrease in the oxygen available to the cells -Severe fatigue, which may occur as a result of inflammatory changes, cachexia, anemia, psychological factors, and stress of the treatment schedule -Infections, which occur frequently because of the decline in host resistance -Bleeding, which occurs when tumor cells erode blood vessels or cause tissue ulceration -Paraneoplastic syndromes, which are additional problems associated with certain tumor cells that release substances that affect neurologic function or blood clotting or exert hormonal effects
Angiogenesis inhibitor drug
angiogenesis means new blood vessels, and as a tumor grows and spreads, so must new blood vessels. anti-angiogenesis drugs block the stimulates for endothelial cell growth by various mechanisms and therefore reduce local blood flow and starve the tumor cells.
Oncogenes
cancer causing genes
Analgesics
for pain control are an important part of therapy, particularly when cancer is advanced.
Treatment - Palliative
if the cancer is advanced. this treatment is intended to reduce the manifestations and complications related to the cancer and to prolong lief.
Treatment - Curative
if the tumor is small and localized
Metastasis
means spread to distant sites by blood or lymphatic channels. in this case the tumor cells erode into a vein or lymphatic vessel, travel through the body, and eventually lodge in a hospitable environment to reproduce and create one or more secondary tumors. only a few tumor cells survive this transfer, but it only take a few to start a new tumor.
The classification of treatment that is used when a cancer is advanced, intended to reduce the manifestation of the cancer and prolong life, is called:
palliative treatment
Nadir
point of lowest cell count, may may occur at different points in the cycle depending on the particular drug
Treatment - Prophylactic
preventative treatment used in cancers that are known to metastasize early in their development, producing secondary tumors that are too small to be detected.
Invasion
refers to local spread, in which the tumor cells grow into adjacent tissue and destroy normal cells
Situ
refers to neoplastic cells in a pre-invasive stage of cancer that may persist for months or years. this condition offers an excellent opportunity for early diagnosis of cervical cancer and certain oral cancers.
Seeding
refers to the spread of cancer cells in body fluids or along membranes, usually in body cavities. the tumor cells break away and travel easily with the movement of fluid and tissue. ex: ovarian cancer, in which the large peritoneal membrane encourages dispersion of the tumor cells throughout the peritoneal cavity.
Angiogenesis
the development of new capillaries in the tumor, thus promoting tumor development
Etiology: Carcinogenesis
the process by which normal cells are transformed into cancer cells, varies greatly with respect to time among different types of tumors. Combinations of risk factors and repeated exposure to a single risk factor each play a major role in carcinogenesis. The stages of carcinogenesis are identified as: -An initiating factor (procarcinogen) causes the first irreversible changes in the DNA. -Promoters, including hormones and environmental chemicals, cause further changes in the DNA, including less differentiation and an increased rate of mitosis in the affected cells. -Continued exposure and DNA changes result in the formation of a malignant tumor. -Changes in cell growth regulation result in cells that are capable of detaching from the tumor, thus causing metastasis.
