Neoplasm

A new abnormal growth or tumor

Oncology

Study of neoplasms (tumors) or cancer

Tumor parenchyma

The clonal neoplastic cancer cells of a tumor

Tumor stroma

Supportive tissue including connective tissue, blood vessels, and immune cells. Growth and evolution of the tumor dependent on the stroma.

Benign tumor

Localized, encapsulated, slow growing tumor that does not metastasize. Usually differentiated cells that reproduce at a higher rate than normal and can cause tissue damage (result of compression of adjacent structures).

Malignant tumor

Invasive, rapidly, growing tumor capable of metastasis and tissue destruction. Undifferentiated (Look nothing like normal healthy cells) and nonfunctional.

Key difference benign vs malignant

Benign stays localized while malignant invades and spreads

Typical benign naming rule

Cell type plus suffix -oma

Carcinoma

Malignant tumor arising from epithelial tissue (Most common)

Sarcoma

Malignant tumor arising from mesenchymal/connective tissue

Adenocarcinoma

Malignant epithelial tumor forming glandular structures

Teratoma

Tumor containing tissues from multiple germ layers: Ectoderm (nervous tissue and epithelial tissue), Mesoderm (muscle, connective tissue), and endoderm (digestive system and internal organs) (More rare)

Malignant tumor characteristics

Rapid growth, abnormal mitosis, lack of differentiation, invasion, metastasis, angiogenesis

Angiogenesis

Formation of new blood vessels to supply tumor growth

Loss of contact inhibition

Cancer cells continue growing despite touching neighboring cells

Common cancer warning signs

Unusual bleeding, persistent lump, chronic cough, unexplained weight loss, change in bowel or bladder habits, nonhealing sore, change in mole

Where cancer can arise: Epithelia

High occurrence (80% of cancer deaths); Carcinoma. Highest risk of exposure and high replacement rate (highly mitotic)

Where cancer can arise: Connective

Sarcomas (1% of tumors in clinics). Bone, cartilage, fat, muscle, blood vessels, or other connective/supportive tissues

Where cancer can arise: Blood forming (hematopoietic) tissues

Leukemia (starts in marrow and produces abnormal blood cells that enter the blood) and lymphoma (begin in cells of the immune system) (17% of cancer related deaths)

Where cancer can arise: Central and Peripheral Nervous System

Spinal cord and outlying nervous tissues. Neuroectodermal tumors (2.5% of cancer related deaths)

Local tumor effects

Pain, obstruction, tissue necrosis, bleeding, infection

Tumor obstruction effect

Compression of ducts vessels or airway impairing organ function

Systemic cancer effect cachexia

Severe weight loss and muscle wasting due to cancer metabolism

Systemic cancer anemia

Blood loss or nutritional deficiency reduces hemoglobin

Systemic cancer Severe fatigue

Caused by inflammatory changes, cachexia, anemia, stress of treatment schedule, and psychological factors

Effusion

Fluid buildup in body cavities due to inflammation

Systemic cancer Infections

Occur frequently as resistance declines

Systemic cancer Bleeding

Tumor cells may erode the blood vessels

Paraneoplastic syndrome

Systemic hormonal or neurologic effects caused by tumor secretions

Diagnostic tests

Routine screening, self-examination, blood tests, tumor markers, and genomic tumor assessment

Cancer screening and self-examination

Purpose is early detection and monitoring recurrence

Blood tests

Measure blood cell levels during treatment. May detect tumor markers.

Tumor markers

Substances, enzymes, antigens, or hormones produced by cancer cells detectable in blood

Genomic tumor assessment

Testing tumor DNA mutations to guide treatment

Imaging for cancer diagnosis

Xray, CT, MRI, ultrasound used to visualize tumor location

Biopsy

Removal of tissue sample for histologic confirmation of cancer

Histology vs cytology

Histology examines tissue structure while cytology examines individual cells

Most reliable cancer confirmation

Biopsy with histologic examination

How do cells invade and spread?

1. Altered cell adhesion (cadherins) 2. Change in interaction with stroma (loses anchors/integrins) 3. Altered synthesis of enzymes that break down basement membrane and stroma (Metallopeptidases); factors produced that help cells spread (scatter factor)

Invasion ability

Cancer cells break through basement membrane and then spread into surrounding tissue and lymphatic/vasculature channels. Malignant cells.

Metastasis

Spread of cancer cells to distant sites through lymph blood or body cavities

Primary tumor

Original site where cancer begins

Secondary tumor

Metastatic growth at distant location

Common metastasis route lymphatic

Spread through lymph nodes common for carcinomas

Common metastasis route blood

Spread through veins to lung liver brain or bone

Coelomic spread

Cancer spread through body cavity fluid such as ovarian cancer

Role of cadherins in cancer

Reduced adhesion allows tumor cells to detach and migrate

Role of integrins in cancer

Altered interaction with stroma allows invasion and movement

Matrix metalloproteinases

Enzymes that break down basement membrane to allow tumor spread

Carcinogenesis

Process of normal cells transforming into cancer cells

Initiation stage

First irreversible DNA mutation caused by carcinogen

Promotion stage

Hormones and environmental chemicals that cause further DNA changes that increase proliferation and reduce differentiation

Proto-oncogene

Normal gene regulating growth that can mutate into cancer promoting oncogene

Oncogene

Mutated gene increasing cell growth and division. Cell growth and survival increase; accelerates cell division; gas pedal. Gain of function mutation- increase activity or expression level of a gene product

Tumor suppressor gene

Gene that normally inhibits cell division or promotes apoptosis; brakes that protect cells from carcinogenesis. Loss of function mutation- gene product has lost partial or total activity or expression.

Loss of tumor suppressor function

Removes cell growth control and promotes cancer

Cancer risk factors genetic

Inherited mutations affecting growth regulation

Cancer risk factors viral

Oncoviruses that alter host DNA such as HPV or hepatitis B

Cancer risk factors radiation

UV rays, x rays, gamma radiation, cumulative exposure

Cancer risk factors chemicals

Asbestos, solvents, heavy metals, formaldehyde

Cancer risk factors lifestyle

Smoking, alcohol, diet, obesity, inactivity

Cancer prevention avoid tobacco

Eliminates major carcinogen exposure

Cancer prevention diet

High fiber fruits vegetables antioxidants reduce DNA damage

Cancer prevention vaccination

HPV and hepatitis B vaccines reduce cancer risk

Host defense tumor suppressor genes

Normal mechanisms that block carcinogenesis

Host defense immune system

Cell mediated immunity recognizes and destroys tumor cells

Cancer staging

Purpose is determine prognosis and treatment planning

In situ cancer

Cells remain in original layer and have not invaded

Invasive cancer

Cancer has penetrated basement membrane and spread locally

TNM staging

T describes tumor size N lymph node involvement M metastasis

Stage IV cancer

Most advanced cancer with distant metastasis

Cancer treatment options

Surgery, radiation, chemotherapy, immunotherapy, or combination therapy

Surgery for cancer

Removal of tumor and surrounding tissue

Radiation therapy

Uses ionizing radiation to damage DNA of rapidly dividing cancer cells

Radiation side effects

Bone marrow suppression, infection, fatigue, hair loss, infertility

Chemotherapy

Antineoplastic drugs that interfere with DNA replication or protein synthesis

Chemotherapy side effects

Bone marrow suppression, nausea, epithelial damage, hair loss, organ toxicity

Hormone blocking therapy

Drugs that block growth signals to hormone sensitive tumors

Biological response modifiers (BRMs)

Drugs that enhance immune response against cancer

Angiogenesis inhibitors

Drugs that prevent tumor blood vessel formation

Cancer nutrition issue

Many patients develop malnutrition due to treatment effects

Cancer metabolic demand

Tumors often have high glucose requirements

Remission

Period with no clinical signs of cancer

Five year survival

Common benchmark used to define cancer free status