Lung Adenocarcinoma

Symptoms, Diagnosis, and Advances in Cancer Treatment

Mature woman being examined by doctor
Lung adenocarcinoma is the most common type of lung cancer in women. BSIP/UIG/Universal Images Group/Getty Images

Lung adenocarcinoma is a form of non-small cell lung cancer, the most common type of lung cancer. Non-small cell lung cancers account for 80 percent of lung malignancies, and of these, roughly 50 percent are adenocarcinomas.

Adenocarcinoma is today the most common form of lung cancer in women, Asians, and people under 45. Confoundingly, it can strike individuals who smoke and who have never smoked.

While the rate has been decreasing in men and leveling off in women, the numbers continue to rise in young, nonsmoking women, and we're not entirely sure why. It is largely believed that genetics, secondhand smoke, and exposure to radon in the home are all contributing factors.

Symptoms

Lung adenocarcinomas usually begin in tissues near the outer portion of the lungs and may be there for a long time before symptoms appear. When they finally appear, the signs are often less obvious than other forms of lung cancer, manifesting with a chronic cough and bloody sputum only in later, more advanced stages.

Because of this, some of the more generalized, early symptoms (such as fatigue, shortness of breath, or upper back and chest pain) may be missed or attributed to other causes. As a result, diagnoses are often late, particularly among young people and non-smokers who may have never considered cancer as a threat.

Diagnosis

Lung cancer is often first detected when abnormalities are seen on an X-ray, usually in the form of a poorly defined shadow. While distressing, the finding at least offers the opportunity for early diagnosis. In as many 25 percent of lung cancer cases, a chest X-ray will not detect any irregularities and return a perfectly "normal" diagnosis.

If cancer is suspected, other, more sensitive diagnostics may be used, including:

Sputum cytology, in which a sample of coughed up saliva and mucus are evaluated, may also be used but is considered less useful in diagnosing early cancer.

Depending upon the results, your doctor may want to obtain a sample of lung tissue to confirm the diagnosis. In addition to more invasive lung tissue biopsies, a newer blood test called a liquid biopsy may be able to detect small-cell cancers with specific genetic footprints.

Genetic Profiling

One of the more exciting advances has been the use of genetic testing to profile cancer cells. By doing so, doctors can select treatments able to target those specific genetic variants. This targeted approach is far less generalized than earlier generation treatments which broadly attacked both healthy and unhealthy cells, resulting in severe and even intolerable side effects.

Current guidelines recommend that all persons with advanced or metastatic lung adenocarcinoma be genetically tested to profile their specific cancer.

Stages

Once a cancer diagnosis is confirmed, the doctor will stage the disease based on a series of standard tests. The aim of staging is to determine how advanced the cancer is, whether it has spread, and what, if any, other tissues may be involved. Staging helps direct treatment in a more appropriate manner, neither undertreating a malignancy or overtreating in and causing more harm than good.

The four stages are classified as follow:

  • Stage 1 is when the cancer is localized and has not spread to any lymph nodes.
  • Stage 2 is when the cancer has spread to lymph nodes, the lining of the lungs, or the major passageways of the lungs.
  • Stage 3 is when the cancer has spread to nearby tissue.
  • Stage 4 is when the cancer has spread (metastasized) to farther reaches of the body.

Treatment Options

Depending upon the stage of disease, treatment may include one or a combination of the following:

  • Surgery may be offered in the early stages, either alone or accompanied by chemotherapy (usually in those whose tests are inconclusive as to whether the cancer has spread).
  • Chemotherapy may be used alone, in conjunction with radiation therapy, or following surgery.
  • Targeted therapies are medications designed to attack specific genetic mutation. They work by recognizing specific proteins on cancer cells and blocking the cell's ability to replicate. Options include Tarceva (erlotinib), Iressa (gefitinib), Gilotrif (afatinib), Xalkori (crizotinib), and Zykadia (ceritinib).
  • Radiation therapy may be used either to treat cancer or to control symptoms in those with metastatic cancer. A more targeted form of treatment, known as stereotactic body radiotherapy (SBRT), may be used for smaller cancers which surgery cannot reach.
  • Immunotherapy is a form of treatment which aims to harness the body's immune system to fight cancer. Current options include Opdivo (nivolumab) and Keytruda (pembrolizumab).

A Word From Verywell

Because the early symptoms of lung adenocarcinoma are often difficult to spot, the average five-year survival rate is only around 18 percent. For those diagnosed in the early stages, the outlook is far more promising, more than doubling survival rate to 31 percent.

What this highlights is the need for greater awareness about the nonspecific or atypical symptoms of lung cancer. On their own, the symptom may be easy to miss. Together, they may trigger a red flag that can lead to both early diagnosis and earlier, more effective treatment.

Sources:

American Cancer Society. "Lung Cancer (Non-Small Cell.) Non-Small Cell Lung Cancer Survival Rates by Stage." Atlanta, Georgia; updated May 16, 2016.

Dacic, S. "Molecular genetic testing for lung adenocarcinomas: a practical approach to clinically relevant mutations and translocations." Journal of Clinical Pathology. 2013; 66(10):870-874.

DiBardino, D.; Saqi, A.; Elvin, J.; et al. " Yield and Clinical Utility of Next-Generation Sequencing in Selected Patients With Lung Adenocarcinoma."Clinical Lung Cancer. 2016; 17(6):517-522.e3.

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.

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