Cancer

Oncology Concepts

• Cancer is the leading cause of death worldwide, although rates are lower in developing countries due to infrastructure limitations in early cancer detection and treatment.
• Cancer most frequently affects males and females, with the highest incidence in the prostate, breast, and lung.
• The majority of cancer diagnoses are in individuals over 55.
• Cancer presentation can range from acute and severe to chronic.
• Cancer involves malignant, unregulated cell transformation in a specific body system.

Basic Cancer Information

• Cancer affects all ages, with 78% of diagnoses occurring in individuals over 55.
• Common types of cancer globally include lung, breast, colorectal, stomach, and prostate cancers.
• Carcinogens can cause various patterns of cancer, including internal factors like DNA destruction, and external factors like exposure to environmental substances.
• Cancers with slow proliferation and early detection have better survival rates. Cancers without early symptoms may progress to an advanced stage before detection.

Vocabulary

• Carcinogenesis: the initiation and promotion of cancer.
• Contact inhibition: normal cells stop growing when they touch other cells.
• Apoptosis: normal cell cycle ending with programmed cell death.
• Anchorage dependence: cells' growth is reliant on typical tissue structures and environments.
• Dysplasia: uncontrolled/deranged growth resulting in varying cell size, shape, and organization. This is often a precursor to cancer.

Basic Cancer Continued

• The most common cancer risk factor is exposure to carcinogens. Exposure alone is unlikely to directly trigger cancer.
• Multiple factors including environmental, hormonal, lifestyle, infectious diseases, medications, immune status, and nutritional factors influence cancer development.
• Advanced age and genetic predisposition are also factors in cancer development.

Neoplasia and Anaplasia

• Neoplasia: uncontrolled cell proliferation.
• Anaplasia: when a cell loses its expected structure and function.
• Cancer cells expand locally into malignant tumors and have a propensity to spread (metastasis).
• Cancer spread (metastasis) patterns can be predictable, such as in prostate cancer (spread to nearby structures). Colorectal cancer often metastasizes to the liver.

Risk Factors

• The most common risk factor for cancer is exposure to carcinogens.
• Carcinogens alone are not necessarily direct triggers for cancer.
• Environmental, hormonal, lifestyle factors, infectious diseases, medications, immune status and nutrition all influence cancer development.
• Advanced age and genetic predisposition also contribute to cancer risk.

Cancer Continued

• Primary tumor: the original cancerous site.
• Secondary tumor: location of metastasis.

Types and Staging

• Solid tumors originate from specific body organs.
• Hematological tumors arise from cells in the hematopoietic or secondary immune systems. Examples are leukemia and lymphoma.
• Staging uses the TNM system (T = tumor size, N = lymph node involvement, M = presence of metastasis)

CA Staging Continued

• Cancer staging progresses through stages I-IV, demonstrating increasing tumor size, spread, and invasion of nearby tissues. Stage IV indicates metastatic spread (to other locations).

Presentation

• CAUTION signs can signal possible cancer. (C= changes in bowel or bladder; A= sores; U= unusual bleeding; T= thickened areas; I= indigestion; O= changes in appearance of warts or moles; N= cough).
• Constitutional signs could include unusual fatigue, significant weight loss, unexplained fever, or night sweats.
• Signs and symptoms specific to certain cancer types may help in diagnosis (location of primary tumor or metastasis).

Prevention

• Primary prevention: modifying risk factors, immunizations, and chemoprevention (drugs that slow/prevent cancer).
• Secondary prevention: non-invasive screenings to detect cancer early (e.g., colonoscopies, mammograms).
• Tertiary prevention: managing cancer-related morbidity and mortality.

Modifying Risk of Cancer

• Limiting exposure to carcinogens.
• Immunization (targeting viruses that cause some cancers).
• Chemoprevention (using certain chemotherapy drugs to prevent cancer in high-risk individuals).
• Early detection and treatment (finding cancer early).

Tissues and Bone

• Cancer can affect tissues and bones.

Skin Cancer

• Skin cancer presents in two main forms (basal and non-squamous).
• Skin cancer pathophysiology usually arises from UV-ray damage.
• Different types of skin cancer include: actinic keratosis, squamous cell carcinoma, basal cell carcinoma, and melanoma.
• Malignant melanoma is the most dangerous type of skin cancer, originating from melanocytes.

Details are more than skin deep

• Actinic keratosis can evolve into squamous cell carcinoma (starting as scaly lesions, progressing to crusted/bleeding plaques).
• Squamous cell carcinoma involves squamous cells, is associated with prolonged exposure to UV rays and can invade surrounding tissue and frequently metastasize
• Basal cell carcinoma starts in the basement membrane and tends to damage tissue around it. These frequently re-occur
• Malignant melanoma is the most life-threatening type, but high survival if detected early

ABCDE of melanoma

• Characteristic signs for recognizing melanoma:
• Asymmetry: Uneven shape
• Border irregularity: Jagged/unsmooth edges
• Color variation: Different colors within the lesion
• Diameter: Larger than 6 mm (1/4 inch)
• Evolving: Change in size/color/shape over time

Treatments

• Treatment of non-melanomas depends on tumor size and location.
• Malignant melanoma treatment includes removal and biopsy, and prognosis is based on the presence or absence of metastasis.
• Complications from cancer treatment include cosmetic, financial, and emotional difficulties

Examples of Skin Cancers

• Images of different skin cancer types (actinic keratosis, squamous cell carcinoma, basal cell carcinoma).

Bone Cancer and Fractures

• Bone cancers can be benign or malignant.
• Primary or secondary bone cancers occur in different age groups.
• Symptoms of bone cancer include pain, limping, swelling, redness, decreased range of motion, fractures, and elevated calcium levels.

Leukemia

• Leukemia is a type of blood cancer characterized by uncontrolled WBC production (leukocytosis)
• It can be acute or chronic, originating from either myeloid or lymphoid stem cells.
• Tumors are made up of blast cells (immature WBCs) which replace mature cells in bone marrow.

Leukemia continued

• Leukemia causes symptoms such as swollen/painful lymph nodes, low-grade fevers, and reduced neutrophils(neutropenia). This condition is characterized by a drop in the levels of neutrophils, the most abundant type of white blood cell involved in the initial phases of the immune response.
• Diagnosis is aided with CBC, and bone marrow biopsy.
• Treatment includes using systemic chemotherapy/radiation to aim for remission (returning to normal blood cell production).
• Cure is often possible with bone marrow/stem cell transplants.

Lymphomas

• Lymphomas are cancers of the lymphatic system.
• Hodgkin's lymphoma and non-Hodgkin's lymphoma are two main types.
• Hodgkin's lymphoma has a better survival rate than non-Hodgkin's lymphoma.
• Symptoms include pain-free lymph node swelling (commonly in neck, underarm, groin). Other symptoms may include fever, fatigue, weight loss, and night sweats.
• Diagnosis often involves medical history, physical exam, and procedures like CT and PET scans.
• Lymphomas are commonly treated with chemotherapy and/or radiation but some cases are surgically treated.

Endocrine System

• The endocrine system includes the thyroid glands.
• Common types of thyroid cancer include papillary, follicular, medullary, and anaplastic varieties.
• Thyroid abnormalities such as nodules can be detected by ultrasound and biopsy.
• Treatments for these often include surgery and/or radiation therapy, and in some cases, lifelong hormone replacement.

Gastrointestinal System

• Contains cancers associated with the esophageal, stomach and colorectal tracts.
• Details vary per system.

Hepatic and Pancreatic System

• Liver cancer risk is elevated in individuals with a history of alcohol use, chronic liver disease (e.g., Hepatitis B or C), and/or those whose age has progressed beyond 65.
• Liver cancer typically is detected only when the Liver has enlarged.
• Symptoms can include pain, swelling, jaundice, and fatigue.
• Diagnosis often involves radiological techniques (imaging) and tests.
• Treatment can include surgical removal or liver transplant in cases where the cancer has been detected early enough.
• Pancreatic cancer diagnosis and treatment are similar, but usually associated with a very low survival rate unless discovered at very early stages (as some studies show a mortality rate approaching 23% within a 1 year period and below 5% after 5 years in patients in remission ).

Reproductive Cancers

• Breast Cancer

Epidemiology

• Breast cancer risk increases with age, and early menarche/late menopause increases risk
• Genetic mutations are linked to some breast cancers (5-10%).
• Pathophysiology involves abnormal and uncontrolled cell growth that invade neighboring tissue and spreads through lymphatic systems

Clinical Manifestations

• New mass or lump (may feel hard and painless); changes in the shape/appearance of the nipple or breast tissue
• Diagnostic tests: mammography, ultrasound, MRI, and biopsy.
• Lab tests: CBC (complete blood count), platelets, and liver function tests.

Management

• Diagnostic tests: mammography, ultrasound, MRI, and biopsy
• Lab tests: CBC, platelets, and liver function tests,
• surgery: lumpectomy/mastectomy/preoperative neoadjuvant chemotherapy
• Breast conservation therapy (lumpectomy) or total mastectomy (radical)
• Treatment for in situ lesions: lobular carcinoma in situ (LCIS)
• Treatment for intermediate or advanced: preoperative neoadjuvant chemotherapy,
• Treatment for recurrence/metastasis: chemotherapy if not initially operable.

Ovarian Cancer

• Epidemiology: common in post-menopausal women and highest incidence is found between ages 55-65. Early diagnosis has a high survival rate in many cases (often above 88%).
• Pathophysiology: Cell growth is abnormal and uncontrolled, spreading through lymph and blood systems

Clinical Manifestations

• Bloating, pelvic pain, abdominal pain, early satiety, and urinary frequency
• Management: No recommended screening tests, CA125 marker (blood test), and surgery (tumor staging and removal). Chemotherapy follows.

Uterine Cancer

• Epidemiology: Most common gynecological cancer in the U.S., occurring in post-menopausal women and highest incidence between ages 55-65.
• Pathophysiology: Uncontrolled cell growth; invasion through lymphatic and blood systems.
• Clinical Manifestations: Post-menopausal vaginal bleeding, or heavy/irregular bleeding in pre-menopausal women.
• Management: biopsies, ultrasound, surgical removal of uterus, fallopian tubes, and ovaries, chemotherapy.

Cervical Cancer

• Epidemiology: 13th most common cancer in women, highest incidence in women age 50-79, often those who have not had routine Pap smears in 5 years.
• HPV associated (nearly 100% of cases)
• Pathophysiology: slow developing disease, related to early cervical dysplasia.
• Clinical Manifestations: No symptoms or vaginal bleeding in advanced stages. Most cases with visible dysplasia are readily detected during a routine exam.
• Management: Prevention is critical, and this can be aided by adequate routine Pap smears. Chemoradiation is routine in women with higher stages of disease following radical surgery.

Prostate Cancer

• Epidemiology: Cause of 9% of cancer-related deaths in males, and most common cancer in men.
• Pathophysiology: Slow-growing cancer; may metastasize to lymph nodes, lungs, and other organs.
• Localized cancers may be cured.
• Clinical Manifestations: Difficulty urinating, weak urine stream.
• Management: PSA test, treatment options for early detection may include radiation, cryotherapy, ablative hormone therapy, chemotherapy, or surgery.
• Radical prostatectomy may be used to treat localized cancer.

Testicular Cancer

• Epidemiology: Good survival after treatment, common between 15-35 years of age.
• Pathophysiology: Localized or metastasized cancer affecting lymph nodes in the back of the abdomen.
• Clinical Manifestations: painless mass; hard/swelling/possible pain in the scrotum.
• Treatment: physical assessment, ultrasound, lab work (blood and urine tests), surgery (for seminomas, often followed by radiation/chemotherapy), nonseminomas frequently don't respond well to radiation.