DEFINITION EPIDEMIOLOGY TYPES CAUSES SIGNS AND SYMPTOMS STAGING DIAGNOSIS TREATMENT PROGNOSIS PREVENTION REFERENCES TABLE OF CONTENTS
WHAT IS LUNG CANCER? Lung cancer also known as carcinoma of the lung or pulmonary carcinoma is a malignant tumor characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung by process of metastasis into nearby tissue or other body parts.
EPIDEMIOLOGY Lung Cancer is the most common cancer. In 2008,there were1.4 million deaths worldwide and 1.61 million new cases. In the USA, lifetime risk for men is 8% and women is 6%. Lung Cancer was rare before the advent of cigarette smoking, first recognized in 1761. For every 3.5 million cigarettes smoked, 1 lung cancer death
TYPES OF LUNG CANCERS Most cancers that start in the lung, known as primary lung cancers are carcinomas that derive from epithelial cells. The main primary lung cancer types are : Small cell lung carcinoma(SCLC) and Non Small cell lung carcinoma(NSCLC).
TYPES OF LUNG CANCERS 1. Non small cell lung cancer Most common type Seen in about 85 – 90% Grows more slowly 2. Small cell lung cancer Spread more rapidly and aggressively Seen in 10 – 15% Found mostly in heavy smokers
SCLC Small cell carcinoma also known as oat cell carcinoma is a type of highly malignant cancer that commonly arises within the lungs although it can occasionally arise in other body sites such as the cervix, prostate and GI tract. As the name implies, the cells are smaller than normal cells and barely have room for cytoplasm. When associated with the lung it is sometimes called oat cell carcinoma due to the flat shape of the cell and scanty cytoplasm.
NSCLC Non small cell carcinoma is any type of epithelial lung cancer other than SCLC. As a class, NSCLC’s are usually insensitive to Chemo compared to SCLC. The most common types of NSCLC are : -Squamous cell carcinoma - Large cell carcinoma -Adenocarcinoma
WHAT CAUSES LUNG CANCER? The vast majority(80-90%) of lung cancer are due to exposure to tobacco smoke. About 10-15% of cases occur in non- smokers. These cases are often caused by a combination of genetic factors and exposure to radon gas, asbestos or other forms of air pollution including second hand smoke.
WHAT CAUSES LUNG CANCER? SMOKING: particularly of cigarettes is by far the main contributor to lung cancer. Cigarette smoke contains over 60 known carcinogens. Additionally, nicotine appears to depress the immune response to cancerous growths in exposed tissue. Smoking accounts for 80–90% of lung cancer cases PASSIVE SMOKING: the inhalation of smoke from another's smoking is a cause of lung cancer in nonsmokers. ASBESTOS: can cause a variety of lung diseases, including lung cancer. Tobacco smoking and asbestos have a synergistic effect on the formation of lung cancer.
WHAT CAUSES LUNG CANCER? AIR POLLUTION: Air pollution from vehicles, industry, and power plants can raise the likelihood of developing lung cancer in exposed individuals. Up to 1% of lung cancer deaths are attributable to breathing polluted air, and experts believe that prolonged exposure to highly polluted air can carry a risk for the development of lung cancer similar to that of passive smoking.
SIGNS AND SYMPTOMS respiratory symptoms: continuous coughing, coughing up blood(hemoptysis), wheezing and shortness of breath. systemic symptoms: weight loss, fever, clubbing of the fingernails, and fatigue. symptoms due to local compress: chest pain, bone pain, superior vena cava obstruction, difficulty swallowing.
SIGNS AND SYMPTOMS If the cancer grows in the airways, it may obstruct airflow, causing breathing difficulties. This obstruction can lead to accumulations of secretions behind the blockage and predispose to pneumonia
Paraneoplastic syndrome A paraneoplastic syndrome is a disease or symptom that is the consequence of cancer in the body but, unlike mass effect, is not due to the local presence of cancer cells but to its ability to secret hormones or hormones like substances. Some of paraneoplastic syndrome of lung cancer are: Hypercalemia - Typically associated with squamous cell lung cancer Cushing Syndrome – Associated with Small cell lung cancer SIADH – Associated with Small cell lung cancer
STAGING Lung cancer staging is an assessment of the degree of spread of the cancer from its original source. It is one of the factors affecting the prognosis and potential treatment of lung cancer. For both SCLC and NSCLC, the 2 general types of staging evaluations are clinical and surgical staging.
STAGING Clinical staging is performed prior to definitive surgery. It is based on the results of the imaging studies such as CT scans and PET scans and also the biopsy results. Surgical staging is evaluated either during or after the operation and is based on the combined results of surgical and clinical findings.
DIAGNOSIS Lung cancer may be seen on chest radiographs and computed tomography scans (CT scan) The diagnosis is confirmed by biopsy which is usually performed by bronchoscopy or CT-guidance.
TREATMENT The treatment of lung cancer depends on the stage in which the cancer has developed to. The different treatments include: 1. Surgery: the most effective surgery done is lobectomy(complete removal of the cancerous lobe). 2. Radiation therapy: side effects include fatigue, malaise(feeling unwell), skin irritation at treatment site, loss of appetite. 3. Chemotherapy
The TNM system The American Joint Committee on Cancer (AJCC) and the International Union for Cancer Control (UICC) maintain the TNM classification system as a tool for staging of different types of cancer based on certain standards. It’s reviewed every 6 to 8 years to include advances in the understanding of cancer. In the TNM system, each cancer is assigned a letter or number to describe the tumor, node, and metastases. T stands for t umor. It’s based on the size of the original (primary) tumor and whether it has grown into nearby tissues N stands for n ode. It tells whether the cancer has spread to the nearby lymph nodes M stands for m etastasis. It tells whether the cancer has spread to distant parts of the body
PROGNOSIS Treatment and longterm outcomes depend on the type of cancer, the stage(degree of spread), and the person’s overall health, measured by performance status. Overall, 16.8% of people in the United States diagnosed with lung cancer survive 5 years after diagnosis while outcomes are worse in the developing world. Worldwide, lung cancer is the most common cause of cancer related death in men and women and was responsible for 1.56 million deaths anually as of 2012.