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 – OverviewLung 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, 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.
SymptomsBecause 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.
DiagnosisLung cancer is often first suspected when abnormalities are seen on an x-ray. Further evaluation may include:
- Chest CT Scan
- Sputum Cytology
- 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.
StagesLung 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
CausesSmoking 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.
TreatmentsDepending 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.
- pemetrexed (Altima) and cisplatin (Platinol).
- erlotinib (Tarceva), gefitinib (Iressa) and Xylori (crizotinib)
Molecular ProfilingOne of the most exciting recent advances in lung cancer treatment has been the discovery of genetic mutations in cancer cells, that in turn can be treated with medications that "target" those mutations. If you have been diagnosed with adenocarcinoma, talk to your doctor about genetic profiling -- tests that check for EGFR and ALK mutations. New guidelines recommend that all patients with this type of lung cancer have molecular profiling (gene testing.)
PrognosisThe 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.
CopingA 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.
Dacic, S. Molecular genetic testing for lung adenocarcinomas: a practical approach to clinically relevant mutations and translocations. Journal of Clinical Pathology. 2013 June 25. (Epub ahead of print)
Lindeman, N. et al. Molecular Testing Guideline for Selection of Lung Cancer Patients for EGFR and ALK Tyrosine Kinase Inhibitors: Guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association of Molecular Pathology. Journal of Thoracic Oncology. 2013. 8(7):823-859.
National Cancer Institute. Non-Small Cell Lung Cancer Treatment (PDQ). Health Professional Version. Updated 02/14/13. 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.