Lecture 8: Oncology

Question 1

Differentiation

Answer 1

• process by which normal cells undergo physical and structural changes during development to form different body tissues
• when a tumor has completely lost identity with the parent tissue, it is considered to be undifferentiated (anaplastic)
• the less differentiated a tumor becomes, the more it metastasizes and the prognosis declines

Question 2

Dysplasia

Answer 2

-adult cell that varies from its normal size, shape, or organization

Question 3

Metaplasia

Answer 3

• adult cell changes from one type to another (early dysplasia)
• reversible and benign

Question 4

Hyperplasia

Answer 4

-increase in number of cells in tissues

Question 5

Tumors

Answer 5

• aka neoplasms
• abnormal growths of new tissue that serve no useful purpose and may harm host organism by competing for vital blood supply and nutrients
• primary tumor arises from cells that are normally local
• secondary tumor arises from cell that have metastasized from another part in the body
• carcinoma in situ: pre-invasive epithelial tumors of glandular or squamous cell origin; not broken through basement membranes of squamous cells and occur in cervix, skin, oral cavity, esophagus, bronchus, and breast

Question 6

Classifications of a Neoplasm

Answer 6

• cell type, tissue of origin, degree of differentiation, anatomic site, or whether it is benign or malignant
• a benign growth is considered harmless and does not spread or invade other tissues; can become large enough to distend, compress, or obstruct normal tissues and to impairing normal body functions
• tumors are classified by cell type and named according to tissue from which they came: 5 major classifications-epithelial, connective and muscle, nerve, lymphoid, hematopoietic
• from epithelial tissue=carcinoma
• from glandular tissue-adenocarcinoma
• from connective tissue and muscle=sarcoma
• from brain or spinal cord tissue=gliomas but are named for cell involved and are often benign
• from lymphoid tissues=lymphoma
• from pigment cells=melanomas
• from plasma cells=myelomas
• from hematopoietic tissues=leukemias, multiple myeloma, myelodysplasia, and myeloproliferative syndromes

Question 7

Staging and Grading

Answer 7

• staging is process of describing extent of disease at time of diagnosis from 0-IV
• TNM classification scheme: most often used for solid tumors
• primary tumor (T) rated from 0-4
• regional lymph nodes (N) involvement ranked 0-4
• metastasis (M) is rated 0 if there is none and 1 if present
• numbers are used with each component to denote extent of involvement
• grading classifies degree of malignancy and differentiation of malignant cells…
• low grade closely resemble normal cells (tend to remain localized, may not be an issue, tends to take a while to be found
• high grade are poorly differentiated cells, highly metastasized

Question 8

Incidence

Answer 8

• steady downward trends have been attributed to improved vigilance among Americans who are benefiting from early screening and advances in Rx, as well as smoking less, improving diets, and exercising more
• most commonly diagnosed cancers: lung, breast, and colorectal
• most prevalent in world is breast cancer
• lung cancer accounts for most deaths worldwide
• cancer is second leading cause of death in US
• overall incidence has declined in last decade by 1.1% annually with 1.4% decline in death rates

Question 9

Etiology

Answer 9

• causative agents subdivided: endogenous (genetic) and exogenous (environmental or external)
• most cancers develop as result of multiple environmental, viral and genetic agents working together
• cancers showing a familial pattern are prostate, breast, ovarian, and colon cancers
• 50% of all cancers caused by one or more of nearly 500 different cancer causing agents…
• etiologic agents capable of initiating malignant transformation of cell are called carcinogens
• chemical agents and physical agents may cause cancer after close and prolonged contact
• some drugs are carcinogenic
• hormones have been linked to tumor development and growth
• excessive alcohol consumption

Question 10

Risk Factors

Answer 10

• advancing age
• lifestyle
• alcohol consumption
• sexual and reproductive behaviors
• hormonal exposure for women
• geographic location and environmental variables
• ethnicity
• precancerous lesions
• stress

Question 11

Advancing Age (over 50)

Answer 11

• one of most significant risk factors
• median age for all cancer is 70
• telomeres are c’somal structures located at ends of chromosomes: in normal cells telomere shortens each time a cell divides, cell dies when telomere becomes so short it can no longer divide, telomerase keeps normally dividing cell healthy by rebuilding telomeres and shuts down when cells are mature but in cancer cells it keeps rebuilding; telomerase is active in up to 85% of all human cancers
• people 65 and older have risk of cancer development much greater than younger persons

Question 12

Lifestyle

Answer 12

• tobacco use is carcinogenic: most important cause of cancer, lung cancer is now leading cancer-causing death in both genders, cigarette smoking is related to nearly 90% of all lung cancers
• diet and nutrition: healthy diet is thought to detoxify carcinogens; intake of cured, pickled, smoked, salted, and preserved food has been conclusively linked to stomach cancer; intake of fresh fruits and vegetables and fiber has been shown to reduce cancer risks

Question 13

Alcohol Consumption

Answer 13

• linked to increased rates of cancer of mouth, pharynx, larynx, esophagus, and liver
• it can also increase circulating levels of estrogens

Question 14

Sexual and Reproductive Behaviors

Answer 14

• linked to risk of developing various cancers
• cervical cancer related to age of first sexual intercourse, number, and type of STD and number of sexual partners
• pregnancy and childbearing seem to be protective against cancers of endometrium, ovary, and breast
• prolonged lactation may also have significant impact in reduction of breast cancer risk

Question 15

Hormonal Exposure for Women

Answer 15

-prolonged use of estrogen hormone replacement therapy for relief of menopause has been linked with increased rates of breast cancer

Question 16

Geographic Location and Environmental Variables

Answer 16

• colon cancer more prevalent in urban than rural areas but in rural areas skin cancer is more common
• people living in rural areas are less likely to use preventive screening services or to exercise regularly
• availability of specialty care is also contributing factor for rural areas

Question 17

Ethnicity

Answer 17

• incidence and mortality from cancer is 10% higher in African Americans compared to caucasians
• attributed to preventable risk factors, such as absence of early screening, delayed diagnosis, smoking and diet
• black american men have world’s highest rate of prostate cancer

Question 18

Precancerous Lesions

Answer 18

• precancerous and some benign tumors may undergo transformation later into cancerous lesions and tumors
• common ones are pigmented moles, polyps of colon and stomach

Question 19

Stress

Answer 19

• strong link between stress and cancer

- chronic stress can cause hormonal or immunological changes which can lead to growth and proliferation of cancer cells

Question 20

Pathogenesis

Answer 20

• very close association of development of cancer and overproduction of enzyme called telomerase
• current theory of oncogenesis: small segments of genetic DNA called oncogenes…
• also called cancer-causing genes or proto- oncogenes, have ability to transform normal cells into malignant cells independently or incorporated with a virus
• oncogenes force a cell to grow and are hyperactivated versions of normal cellular growth-promoting genes
• regulatory genes called anti-oncogenes now called tumor suppressor genes, that have opposite effect of oncogenes
• tumor biochemistry and pathogenesis…
• carcinogenesis is process by which a normal cell undergoes malignant transformation

Question 21

Invasion and Metastases

Answer 21

• uncontrolled growth: cancer cell first develops from mutation in single cell and grows without control
• malignant tumors have ability to metastasize or spread from primary sites to other locations in body: occurs when cells break away from primary tumor, travel via blood or lymphatic system and become trapped in capillaries of organs; they infiltrate organ tissue and grow into new tumor deposits
• cancer can spread to adjacent structures and penetrate body cavities
• 5 most common sites of metastasis: lymph nodes, liver, lung, bone, and brain

Question 22

Mechanisms of Metastasis

Answer 22

• more likely to occur via veins rather than arteries
• key factor to cancer cure is to eradicate metastases already present at diagnosis
• blood vessels from surrounding tissue grow into solid tumor=tumor angiogenesis: complex but 2 cytokines have been identified as primary stimulators of vascular proliferation-vascular endothelial growth factor (VEGF) and fibroblast growth factor
• tumors generally lack well-formed lymphatic network, so communication of tumor cells with lymphatic channels occurs only at tumor periphery and not within tumor mass

Question 23

Clinical Manifestations of Metastasis

Answer 23

-metastatic spread usually occurs 3-5 years after initial diagnosis and Rx of malignancy (or 15-20 years with a low grade lesion)

Question 24

Clinical Manifestations: Pulmonary System

Answer 24

• pulmonary metastases are most common of all metastatic tumors-one of larges capillary beds in human body
• dry, persistent cough is often first symptom of pulmonary metastases
• first organ to filter–>picks up all the bad things

Question 25

Clinical Manifestations: Hepatic System

Answer 25

• liver metastases are among most ominous signs of advanced cancer
• primary metastatic site for tumors of stomach, colorectum, and pancreas

Question 26

Clinical Manifestations: Skeletal System

Answer 26

• largest proportion of cancer cases metastasize first to bone, often with poor prognosis
• bone metastases may be osteolytic (decrease in bone density) type or osteoblastic (increase in bone density)
• axial skeleton most commonly involved
• primary symptom associated is pain: deep and worsened with activity; pathologic fractures may occur in up to one half of people and sometimes one of the first signs of a malignant process

Question 27

Clinical Manifestations: CNS-Brain

Answer 27

• lung carcinomas account for ~1/2 of all metastatic brain lesions (lung cancer is most common primary tumor to metastasize to brain)
• life threatening and emotionally debilitation
• therapist can use same strategies known for people with TBI
• primary tumors of CNS rarely metastasize outside CNS

Question 28

Clinical Manifestations: CNS-Spinal Cord

Answer 28

• metastatic involvement of vertebrae may result in spinal cord compression, fracture, and fragility of one or more vertebral bodies
• neurologic symptoms include gradual onset of distal weakness, sensory changes, including numbness, paresthesia, and coldness

Question 29

Diagnosis of Metastasis

Answer 29

-metastases usually reproduce cellular structure of primary growth well enough to enable a pathologist to determine site of primary tumor

Question 30

Cancer Recurrenc

Answer 30

• disease-free survival describes time between diagnosis and recurrence or relapse
• recurrence may be local, regional, disseminated, or a combination of these
• most important predictors of recurrent cancer are the stage at the time of initial therapy and histologic findings

Question 31

Clinical Manifestations: Local and Systemic Effects

Answer 31

• most cancers in their earliest stages are asymptomatic, but if detected early, can be cured or successfully treated
• as cancer progresses, nausea, vomiting, retching (NVR) are common and are accompanied by anorexia and weight loss
• cancer related anorexia/cachexia (CAC-loss of body mass that can’t be reversed nutritionally) is a complex phenomenon in which metabolic abnormalities, proinflammatory cytokines, circulating tumor-derived catabolic factors, decreased food intake, and other unknown factor contribute
• later rapid growth of tumor encroaches on healthy tissue
• secondary infections frequently occur as result of hosts decreased immunity and can lead to death

Question 32

Clinical Manifestations: Cancer Pain

Answer 32

• most common symptoms of cancer is pain
• common cause is metastasis of cancer to bone
• noninvasive physical agents such as cryotherapy, thermotherapy, electrical stimulation, immobilization, exercise, massage, biofeedback, and relaxation techniques may be effective in pain management
• much debate exists about safety and efficacy of massage for therapy especially anyone with lymphedema or at risk for developing lymphedema (direct pressure over tumor is discouraged)

Question 33

Clinical Manifestations: Cancer-Related Fatigue

Answer 33

• distressing, persistent, and subjective sense of tiredness or exhaustion related to cancer or cancer treatment
• not proportional to recent activity and usually interferes with ADLs

Question 34

Clinical Manifestations: Paraneoplastic Syndromes

Answer 34

• when tumors produce signs and symptoms at a site distant from tumor or its metastasized sites
• in some cases malignant cells acquire new cellular functions uncharacteristic of originating tissue: involve hormone production and biochemically active substances
• most common cancer associated with paraneoplastic syndromes is small cell cancer of lung, which can produce adrenocorticotropic hormone (ACTH) in amounts sufficient to cause cushing’s syndrome
• clinical manifestations: musculoskeletal, neurologic, rheumatologic

Question 35

Medical Management: Prevention

Answer 35

• first: means to provide appropriate information
• second: mechanisms or systems must exist for providing people with access to state of the art preventative services and treatment
• third: mechanism for maintaining continued research and for fostering new research
• primary prevention: screening-reduction or elimination of modifiable risk factors; chemoprevention-use of agents to inhibit and reverse cancer, has focused on diet-derived agents; research focused on cancer vaccine
• secondary prevention: preventing morbidity and mortality uses early detection and prompt treatment
• tertiary prevention: focuses on managing symptoms, limiting complications, and preventing disability

Question 36

Diagnosis: History and Physical Examination

Answer 36

• radiography, endoscopy, isotope scan, CT scan, mammography, MRI, and biopsy
• biopsy of tissue samples is single most important diagnostic method for study of tumors
• sentinel lymph node biopsy (SLN), blue dye injected around cancerous tumor and first node or nodes it reaches is identified as sentinel or sentinels: then these are removed and analyzed
• tumor markers, substances produced and secreted by tumor cells, may be found in blood serum

Question 37

Treatment

Answer 37

• curative, with intent to cure or palliative, provides symptomatic relief but does not cure
• curative cancer treatment includes surgery, radiation, chemotherapy, biotherapy, angiogenesis therapy, hormonal therapy
• palliative treatment may include radiation, chemotherapy, PT, biofeedback, medications, acupuncture, chiropractic care, alternative medicine, and hospice care
• palliative treatment of NVR may incorporate both pharmacologic and nonpharmacologic approaches
• hospice care may help person achieve as full of a life as possible, with minimal pain, discomfort and restriction, focusing on death as a natural end to life

Question 38

Major Treatment Modalities

Answer 38

• surgery used often in combination with other therapies
• radiation therapy: used to destroy dividing cancer cells by destroying hydrogen bonds between DNA strands within cancer cells; generally normal cells recover from radiation faster than malignant cells-damaged cancer cells cannot self-repair
• chemotherapy includes wide array of chemical agents to destroy cancer cells-drugs can be given orally, subcutaneously, intramuscularly, by IV, intrathecally (into a body cavity such as the thoracic, abdominal or pelvic cavity-through the sheath of a structure, such as through sheath of spinal cord into subarachnoid space, and by arterial infusion
• antiangiogenic therapy: angiostatin cuts off tumor’s blood supply
• hormonal therapy is used for certain types of cancer that have been shown to be affected by specific hormones

Question 39

Prognosis

Answer 39

• influenced by type of cancer, stage, and grade of disease at diagnosis, availability of effective treatment, and response to treatment
• cancer survival statistics are usually reported as 5-year survival rate: relative 5-year survival rate of 65% is seen for cancer
• lower survival rate in African American men for most cancer classifications and has been noted-limited access to health care limited knowledge of benefits of early diagnosis and treatment, and greater exposure to carcinogens
• modified Barthel Index: comprised of 10 ADLs-half of those individuals who lose 10 or more points per week die within 2 weeks and 3/4 are dead at 3 weeks
• 50% of all cases without declines in scores survive for 2+ months

Question 40

Exercise for Person with Cancer: Screening and Assessment

Answer 40

-history should include conditions not related to cancer, current physical condition, condition before disease onset, age, CARES (cancer rehabilitation evaluation system)

Question 41

Exercise for Person with Cancer: Monitoring Vital Signs

Answer 41

• exercise intensity determined by training HR may be difficult to use
• exercise intensity can be guided by HR ranges based on oxygen consumption or MET levels or BORG RPE
• always monitor oxygen saturation with pulse oximetry and monitor arrhythmia, pulse rate, breathing frequencies, and BP throughout treatment session

Question 42

Exercise for Person with Cancer: Exercise During and After Chemotherapy

Answer 42

• monitor hematologic values
• individuals undergoing chemotherapy or radiation therapy should not exercise within 2 hours of treatment
• some oncology settings have own guidelines that may be more liberal

Question 43

Exercise for Person with Cancer: Prescriptive Exercise

Answer 43

• 15-30 minute sessions 3-5 days per week
• exercise intensity should be prescribed at 60-80% of MHR or just below anaerobic threshold depending on person’s ability to exercise
• perceived exertion 11-14
• high-rep, low-weight circuit programs recommended that do not exceed a rate of perceived exertion of 14
• people who ambulate less than 50% of the time or who are confined to a bed and those who fatigue with mild exertion may not be candidates for aerobic exercise
• ROM and gentle resistive work until tolerance of activity improves
• energy-conservation techniques and work simplification may be necessary
• scheduled during periods when person has highest level of energy

Question 44

Childhood Cancer

Answer 44

• incidence and overview: cancer is second leading cause of death among children between 1 and 14; cancers that occur in children vary greatly from those seen in adults
• types: most common pediatric malignancies are leukemia, non-hodgkin’s lymphoma, hodgkin’s disease, and primary CNS tumors; acute lymphoblastic leukemia (ALL) most common-accounts for 1/3 or all pediatric cancers

Question 45

Lung Cancer

Answer 45

• remains most common cause of cancer death in men and women
• responsible for 31% of all cancer deaths in men and 26% in women
• most commonly results from repeated tissue trauma from inhalation of irritants or carcinogens
• almost all start in epithelium of lungs
• about 85% are non-small-cell types: adenocarcinoma, squamous cell, large-cell undifferentiated (more likely to metastasize)
• CM: cough, hoarseness, wheezing, dyspnea, hemoptysis, chest pain, weight loss, dysphagia, weakness
• medical management: diagnosis: chest x-ray, sputum analysis, bronchoscopy, needle biopsy for tumors, CT scan
• tx: sx, radiation, chemotherapy