Understanding Neoplasms and Cancer Cell Growth

Neoplasm

• Neoplasms can develop when a cell is injured or has a faulty mechanism for replication, cell proliferation, or differentiation.
• Neoplasms are also called cancers or tumors.
• Tumors are new growths of neoplasms.
• Tumors are not always cancerous.
• Tumors can be classified as malignant or benign.
• Oncology studies tumors and their treatments.

Cancer Cell

• Cancer begins as a mutation gone wrong.
• Cancer is also referred to as a tumor
• Normal cells find a home, stay there, grow old, and die.
• Cells detect environmental cues.
• Genes are what tell the cells what to become, also known as differentiation.
• Old or unneeded cells proceed through apoptosis.
• Cancer cells de-differentiate and become a stem cell, which can become any type of cell later on.

Alterations in Cell Growth and Replication

• Neoplasms lack normal controls and regulations.
• Cancer can start in one organ.
• Prostate cancer is most common in men.
• Breast cancer is most common in women.
• Lung cancer is the leading cause of death in both men and women.
• Cancer can spread from one site to another.

Carcinogenesis

• Carcinogenesis is cancer development.
• Carcinogenesis contains different phases:
• Initiation is introduction of the agent
• Promotion is initiation of uncontrolled growth
• Transformation happens during the malignancy
• Progression is when permanent malignant changes occur

Tumor Classification and Nomenclature

• Classification begins with identifying the tissue and organ of origin.
• Classification also examines the extent of distribution to other sites.
• Classification looks at the microscopic appearance of the tumor.
• Classification can include genetic changes.
• Tumors are classified into two types: benign and malignant.

Nomenclature of Tumors

• Benign tumors are named with the suffix "-oma," such as adenoma and fibroma.
• Malignant tumors include:
• Carcinoma, which has epithelial origin, such as adenocarcinoma.
• Sarcoma, which has mesenchymal origin, such as fibrosarcoma.

Benign VS Malignant Tumors

• Benign tumors grow slowly, are well-defined and encapsulated, non-invasive, well-differentiated, have a low mitotic index, and do not metastasize.
• Malignant tumors grow rapidly, are not encapsulated, are invasive, poorly differentiated, have a high mitotic index, and can spread distantly through metastasis.

Invasion and Metastasis

• Invasion is the local spread of the malignant neoplasm.
• Metastasis is the transfer of cells from a malignant tumor to an unconnected organ or part.
• Invasion occurs by infiltration or destruction of adjacent tissue.
• Metastasis occurs through the circulatory or lymphatic system.
• Invasion is a type of local spreading that only invades nearby tissues.
• Metastasis leads to the invasion of tissue in distinct locations.
• Invasion is less threatening.
• Metastasis is a life-threatening event.

Who Gets Cancer

• Cancer is the second leading cause of death.
• The overall mortality rate of cancer is 50%.
• Some cancers always result in fatality, while others are just a nuisance.
• Epithelial cancers outnumber all other cancers 6 to 1 but are curable.
• The least common cancers generally lead to the highest fatalities.
• Cancers are challenging because causes, behaviors, and treatments vary greatly.
• There are approximately 37 trillion cells, of 200 types, in humans.
• The variables related to the frequency and significance of cancer are:
• Site of development, such as organ.
• Gender.
• Age, particularly genetic damage.
• The top 10 causes of death in the USA are:
• Heart Diseases: 631,636
• Cancer: 559,888
• Stroke: 137,119
• Accidents: 121,599
• Chronic Breathing and Lung Disease: 124,583
• Alzheimer's 72,432
• Diabetes: 72449
• Influenza and Lung Infections: 56,326
• Kidney Diseases: 45,344
• Sepsis: 34,234
• Common Sites of Metastasis can include:
• Breast: Axillary lymph nodes, lung, liver, bone, brain
• Colorectal: Liver, lung peritoneum
• Lung: Liver, brain, bone
• Ovarian: Peritoneum, diaphragm, liver, lung
• Prostate: Bone
• Testicular: Lungs, liver

Cancer Screening

• Breast cancer screenings include mammograms and self-breast exams.
• Cervical cancer screenings include Papanicolaou (Pap) tests.
• Endometrium cancer screenings include endometrial biopsies.
• Prostate cancer screenings include Prostate Specific Antigen (PSA) tests and digital rectal exams.
• Colon cancer screenings include colonoscopies.

Clinical Manifestations

• Clinical manifestations of cancer are:
• Change in bowel or bladder habits.
• A sore that does not heal
• Unusual bleeding or discharge.
• Thickening or lump in the breast or elsewhere.
• Indigestion or difficulty swallowing.
• Obvious change in a wart or mole.
• Nagging cough or hoarseness.
• Paraneoplastic Syndrome: Symptoms caused by biologic substances such as hormones, or immune response triggered by the tumor.

Complications

• Complications of cancer include:
• Anemia
• Bone density loss
• Cachexia
• Cardiac and pulmonary damage
• Fatigue
• Gastrointestinal issues
• Hair loss and skin problems
• Infection
• Infertility
• Leukopenia
• Thrombocytopenia
• Lymphedema
• Pain

Diagnosis

• Methods of diagnosing cancer include:
• Biopsy, such as needle aspiration, endoscopy, laparoscopy, or excision.
• Tumor markers, or antigens on the surface of tumor cells, are used for screening, diagnosing, monitoring, treatment, and establishing remission.
• Miscellaneous procedures, for example, X-rays, CT scans, endoscopies, ultrasonography, MRI, and PET scans.
• Malignant cancer cells are classified based on the degree of differentiation (grading) and extent of the disease (staging).
• Grading done on a scale by pathologists.
• Staging TNM evaluates the tumor size, nodal involvement, and metastatic progress.

Classification

• Staging-TNM: looks at Tumor size, Nodal number/involvement, and Metastasis (the spread of disease)
• Grading in relation to histology is on a scale of I, II, III, and IV
• As the number increases, the tumor is less differentiated.

Stage and Grade of Cancer

• Staging of cancer is the progression or spread in the body.
• Grading is the cell differentiation and rate of growth, observed by microscopy.

TNM Staging System

• Key factors in theN staging system:
• Tumor size
• Nodule involvement
• Metastatic progress
• Stages: Tis, T1, T2, T3, T4

Treatment

• Treatments for cancer include:
• Chemotherapy
• Radiation
• Surgery
• The goals are:
• Curative, which is to eradicate the disease.
• Palliative, which is to treat symptoms.
• Prophylactic, which is to prevent the disease.

Prognosis

• Remission is a period when the cancer has responded to treatment and is under control.