Lung adenocarcinoma is a form of non-small cell lung cancer. Non-small cell lung cancers account for 80% of lung cancers, and of these, roughly 50% are adenocarcinomas.
Lung Adenocarcinoma – Overview
Lung adenocarcinomas usually begin in tissues that lie near the outer parts of the lungs, and may be present for a long time before they cause symptoms and are diagnosed. Adenocarcinoma is the most common form of lung cancer found in women, and is often found in non-smokers. It is also the most common type of lung cancer in people under the age of 45 and the most common type of lung cancer among all Asians. One subtype of lung adenocarcinoma, bronchioloalveolar carcinoma (BAC), appears to be increasing in young, non-smoking women.Lung adenocarcinoma has been increasing in recent years, whereas another form of non-small cell lung cancer, squamous cell carcinoma, has been decreasing. It is thought by some that the addition of filters to cigarettes allows smoke to be inhaled more deeply into the lungs where adenocarcinoma occurs.
Symptoms of Adenocarcinoma
Because lung adenocarcinoma often begins in the outer parts of the lungs, well-known symptoms of lung cancer such as a chronic cough and coughing up blood may be less common until later in the disease. Early symptoms of adenocarcinoma that may be overlooked may include fatigue, mild shortness of breath, or achiness in your back, shoulder, or chest.Diagnosis
Lung cancer is often first suspected when abnormalities are seen on an x-ray. Further evaluation may include:- Chest CT Scan
- Sputum Cytology
- Bronchoscopy
- PET Scan - a test designed to look for actively growing tumors
Depending upon the results, your doctor will usually want to obtain a sample of tissue to confirm the diagnosis, and will order further tests to check to see if your cancer has spread.
Your doctor may also recommend that you have tests for lung markers – genetic changes that are present in some lung adenocarcinomas. These markers may help your oncologist decide which treatments are most likely to work for you.
Stages
Lung adenocarcinoma is broken down into 4 stages:- Stage 1 – The cancer is localized within the lung and has not spread to any lymph nodes
- Stage 2 – The cancer has spread to lymph nodes or the lining of the lungs, or is in a certain area of the main bronchus
- Stage 3 – The cancer has spread to tissue near the lungs
- Stage 4 – The cancer has spread (metastasized) to another part of the body
Causes
Smoking is the most common cause of lung cancer overall, but many people diagnosed with adenocarcinoma of the lungs have never smoked. The most common cause in non-smokers is exposure to radon in the home. Lung adenocarcinoma is a multifactorial disease, meaning that several factors may work together to cause or prevent cancer.Treatments
Depending upon the stage, treatment may include surgery, chemotherapy, radiation therapy, or a combination of these. Many clinical trials are in progress looking for new ways to treat this cancer, and to help decide which treatments are most effective.Surgery
When lung adenocarcinoma is caught in the early stages, surgery may offer a chance for a cure.Chemotherapy
Chemotherapy may be used alone, in conjunction with radiation therapy, or following surgery for lung cancer. Examples of chemotherapy medications that may be used include pemetrexed (Altima) and cisplatin (Platinol).Targeted Therapies
Targeted therapies are medications that are designed to attack cancer specifically. Because they work by targeting proteins on cancer cells, or normal cells that have been “hijacked” by a tumor in its attempt to grow, they may have fewer side effects than traditional chemotherapy. Examples of targeted therapies used with adenocarcinoma include erlotinib (Tarceva) and gefitinib (Iressa)Radiation Therapy
Radiation therapy may be used to treat cancer, or to control symptoms related to the spread of cancer.
Prognosis
The 5-year survival rate for lung cancer overall is sadly only about 15%. For those diagnosed in the early stages of the disease, the prognosis is much better.Coping
A diagnosis of lung cancer is frightening and you may feel very alone. Allow your loved ones to support you. Many people have no idea how to react towards someone who is diagnosed with cancer. Letting people know specific things they can do to help may ease their anxiety, as well as fill your need for extra support at this time. Ask questions. Learn as much as you can. Consider joining a lung cancer support group either through your cancer center or online. And be true to yourself. No matter what others have experienced or recommend, only you know what is best for you.Sources:
National Cancer Institute. Non-Small Cell Lung Cancer Treatment (PDQ). Health Professional Version. Updated 02/10/12. http://www.cancer.gov/cancertopics/pdq/treatment/non-small-cell-lung/HealthProfessional
Sheth, S. Current and emerging therapies for patients with advanced non-small cell lung cancer. American Journal of Health-System Pharmacy. 2010. 67(1 Suppl 1):S9-14.
