Lung cancer has emerged as the leading killer of men and women stricken with invasive cancer, affecting husbands and wives, friends and neighbors, and causing suffering for many families.
This disease is difficult to detect in its early stages, and treatments for lung cancer in its later stages provide a poor prognosis: Those with stage IV non-small cell lung cancer—the most common type—have an estimated 1 percent survival rate five years after diagnosis.
The major cause of lung cancer in men and women is mainly due to cigarette smoking. Currently about 90% of all lung cancers are related to smoking. Radon gas, pollution, toxins, and other factors contribute to the remaining 10%.
Signs and Symptoms:
Unfortunately, lung cancers often have either no early symptoms or nonspecific early symptoms that people often dismiss.
List of Lung Cancer Symptoms
- Cough (chronic, recurrent)
- Weight loss
- Shortness of breath or wheezing
- Coughing up phlegm that contains blood
- Chest pain
- Paraneoplastic symptoms: Lung cancers frequently are accompanied by symptoms that result from production of hormone-like substances by the tumor cells. These paraneoplastic syndromes occur most commonly with SCLC but may be seen with any tumor type. A common paraneoplastic syndrome associated with SCLC is the production of a hormone called adrenocorticotrophic hormone (ACTH) by the cancer cells, leading to oversecretion of the hormone cortisol by the adrenal glands (Cushing’s syndrome). The most frequent paraneoplastic syndrome seen with NSCLC is the production of a substance similar to parathyroid hormone, resulting in elevated levels of calcium in the bloodstream.
Screening for lung cancer is usually accomplished using three methods.
A physical exam will look for signs of wheezing, shortness of breath, cough, pain and other possible signs of lung cancer. Depending on the advancement of the cancer, other early signs of lung cancer symptoms may include a lack of sweating, dilated neck veins, face swelling, excessively constricted pupils, and other signs. The physical exam will also include the patient’s history of smoking and a chest X-ray.
SPUTUM CYTOLOGY EXAM
A sputum cytology exam involves a microscopic examination of a patient’s mucus (sputum).
SPIRAL CT EXAM
This method of CT scanning builds a detailed image of the body’s internal workings. Inside a spiral CT machine, detailed images are taken of the relevant parts of the patient’s body. Those images are then linked to an X-ray machine to create 3D images of the patient’s internal organs. These images may reveal potentially cancerous tumors.
At best, the screening methods find about 30% of lung cancers leaving the bulk (about 70%) cancers of lung undetected.
TYPES OF LUNG CANCER:
There are only two major types of lung cancers: small cell lung cancer and non-small cell lung cancers. Less than 5% of lung cancer tumors will take the form of a carcinoid tumor, while other cancerous tumors are even more rare, including adenoid cystic carcinomas, lymphomas, and sarcomas. Although cancer from another part of the body may spread to the lungs, these are not categorized as lung cancer.
- Adenocarcinomas are the most commonly seen type of NSCLC in the U.S. and comprise up to 50% of NSCLC. While adenocarcinomas are associated with smoking like other lung cancers, this type is observed as well in nonsmokers who develop lung cancer. Most adenocarcinomas arise in the outer, or peripheral, areas of the lungs.
- Bronchioloalveolar carcinoma is a subtype of adenocarcinoma that frequently develops at multiple sites in the lungs and spreads along the preexisting alveolar walls.
- Squamous cell carcinomas were formerly more common than adenocarcinomas; at present, they account for about 30% of NSCLC. Also known as epidermoid carcinomas, squamous cell cancers arise most frequently in the central chest area in the bronchi.
- Large cell carcinomas, sometimes referred to as undifferentiated carcinomas, are the least common type of NSCLC.
- Mixtures of different types of NSCLC also are seen.
DIAGNOSIS & STAGING PROCEDURES:.
- Bone scans are used to create images of bones on a computer screen or on film. Doctors may order a bone scan to determine whether a lung cancer has metastasized to the bones. In a bone scan, a small amount of radioactive material is injected into the bloodstream and collects in the bones, especially in abnormal areas such as those involved by metastatic tumors. The radioactive material is detected by a scanner, and the image of the bones is recorded on a special film for permanent viewing.
- Sputum cytology: The diagnosis of lung cancer always requires confirmation of malignant cells by a pathologist, even when symptoms and X-ray studies are suspicious for lung cancer. The simplest method to establish the diagnosis is the examination of sputum under a microscope. If a tumor is centrally located and has invaded the airways, this procedure, known as a sputum cytology examination, may allow visualization of tumor cells for diagnosis. This is the most risk-free and inexpensive tissue diagnostic procedure, but its value is limited since tumor cells will not always be present in sputum even if a cancer is present. Also, noncancerous cells may occasionally undergo changes in reaction to inflammation or injury that makes them look like cancer cells.
Bronchoscopy: Examination of the airways by bronchoscopy (visualizing the airways through a thin, fiberoptic probe inserted through the nose or mouth) may reveal areas of tumor that can be sampled (biopsied) for diagnosis by a pathologist.
Needle biopsy: Fine-needle aspiration (FNA) through the skin, most commonly performed with radiological imaging for guidance, may be useful in retrieving cells for diagnosis from tumor nodules in the lungs. Needle biopsies are particularly useful when the lung tumor is peripherally located in the lung and not accessible to sampling by bronchoscopy.
Blood tests: While routine blood tests alone cannot diagnose lung cancer, they may reveal biochemical or metabolic abnormalities in the body that accompany cancer. For example, elevated levels of calcium or of the enzyme alkaline phosphatase may accompany cancer that is metastatic to the bones. Likewise, elevated levels of certain enzymes normally present within liver cells, including aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT), signal liver damage, possibly through the presence of tumor metastatic to the liver.
Molecular Testing: testing may be done to look for mutations or abnormalities in the epithelial growth factor receptor (EGFR) and the anaplastic lymphoma kinase (ALK) genes. Other genes that may be mutated include MAPK and PIK3. Specific therapies are available that may be administered to patients whose tumors have these alterations in their genes.
Early stage (stage 0 or even some stage I) cancer treatment of non-small cell lung cancer may benefit from surgery. Part or all of a lung segment that contains the cancer may be removed; in some individuals, this may result in a cure. However, many patients still undergo chemotherapy, radiation therapy or both to kill any cancer cells not removed by surgery. Because small cell lung cancers are almost never diagnosed early, surgery (and other treatments) may prolong life but rarely, if ever, result in a cure.
After a diagnosis of lung cancer, it is not unusual to feel depressed and upset. However, research is ongoing and it is possible to survive and extend your life with treatment. Even with the diagnosis, there is evidence that people who develop a healthy lifestyle and stop smoking do better than those who do not change.
Radiation: Radiation therapy may be employed as a treatment for both NSCLC and SCLC. Radiation therapy uses high-energy X-rays or other types of radiation to kill dividing cancer cells. Radiation therapy may be given as curative therapy, palliative therapy (using lower doses of radiation than with curative therapy), or as adjuvant therapy in combination with surgery or chemotherapy. The radiation is either delivered externally, by using a machine that directs radiation toward the cancer, or internally through placement of radioactive substances in sealed containers within the area of the body where the tumor is localized. Brachytherapy is a term used to describe the use of a small pellet of radioactive material placed directly into the cancer or into the airway next to the cancer. This is usually done through a bronchoscope. Radiation therapy can be given if a person refuses surgery, if a tumor has spread to areas such as the lymph nodes or trachea making surgical removal impossible, or if a person has other conditions that make them too ill to undergo major surgery. Radiation therapy generally only shrinks a tumor or limits its growth when given as a sole therapy, yet in 10%-15% of people it leads to long-term remission and palliation of the cancer.
Chemotherapy: Both NSCLC and SCLC may be treated with chemotherapy. Chemotherapy refers to the administration of drugs that stop the growth of cancer cells by killing them or preventing them from dividing. Chemotherapy may be given alone, as an adjuvant to surgical therapy, or in combination with radiotherapy. While a number of chemotherapeutic drugs have been developed, the class of drugs known as the platinum-based drugs have been the most effective in treatment of lung cancers.
Chemotherapy is the treatment of choice for most SCLC, since these tumors are generally widespread in the body when they are diagnosed. Only half of people who have SCLC survive for four months without chemotherapy. With chemotherapy, their survival time is increased up to four- to fivefold. Chemotherapy alone is not particularly effective in treating NSCLC, but when NSCLC has metastasized, it can prolong survival in many cases.