Non-Small Cell Lung Cancer Treatment & Information
There are two main types of lung cancer: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). While this document will address some common issues with both types, the focus will be on non-small cell lung cancer. Small cell lung cancer will be addressed separately.
Most lung cancers, whether NSCLC or SCLC, tend to start in the bronchi but lung cancer can originate from other locations such as trachea (wind pipe), bronchioles, or alveoli. Lung cancers are thought to start as pre-cancerous changes within the lungs and then develop into lung cancer over many years. The pre-cancerous changes occur at the cellular level so they cannot be seen by x-rays, magnetic resonance imaging (MRI), or computed tomography (CT or CAT) scans, nor will they cause symptoms.
The pre-cancerous changes may progress to cancer over time. As lung cancer develops and grows, new blood vessels form to nourish and feed the lung tumor. Eventually the tumor will grow large enough to be seen by imaging scans. The problem is that lung cancers tend to break off and move to distant organs (metastasize) and may have already done so by the time they are discovered on imaging scans. Both blood supply and even more frequently, the lymphatic system may carry tumor cells to distant organs which result in the formation of new tumors at these sites.
Non-small cell lung cancer (NSCLC) is a general term used to cover several different lung cancers; including squamous cell carcinoma, adenocarcinoma, & large cell carcinoma, which all behave similarly. They are grouped together because approaches to diagnosis, staging, prognosis, and treatment for each are similar.
Patients with non-small cell lung cancer that is resectable by surgery may be cured by surgery and/or with additional chemotherapy treatments. Local control can be done with radiation therapy in many NSCLC patients with unresectable tumor(s), but cure is seen only in a small number of patients. Non-small cell lung cancer patients with locally advanced, unresectable disease may have long-term survival with radiation therapy combined with chemotherapy. Patients with NSCLC that have advanced metastatic disease may achieve improved survival and palliation of symptoms with chemotherapy.
Once diagnosed with non-small cell lung cancer, your physician will determine the extent, or stage, of the cancer. Staging NSCLC helps to determine the proper treatment course and tests to stage the lung cancer may include magnetic resonance imaging (MRI), computed tomography (CT), positron emission testing (PET) and bone scans.
The stages of non-small cell lung cancer are:
- Stage I = Lung cancer that has invaded the underlying lung tissue but hasn't spread to the lymph nodes.
- Stage II = Lung cancer that has spread to lymph nodes or invaded the chest wall.
- Stage IIIA = Lung cancer that has spread from the lung to lymph nodes in the center of the chest.
- Stage IIIB = Lung cancer that has spread to close areas such as the heart, blood vessels, trachea and esophagus, all within the chest, or that has spread to lymph nodes in the area of the collarbone, or that has spread to the tissue that surrounds the lungs within the rib cage (pleura).
- Stage IV = Lung cancer that has spread to other parts of the body, and may include the liver, brain, or bones.
At diagnosis, patients with non-small cell lung cancer can be divided into three (3) groups that reflect both the extent of the NSCLC and the treatment(s) used. The first group of NSCLC patients has tumors that may be surgically removed (generally stage I or stage II, and some selected stage III tumors). This group of non-small cell lung cancer patients has the best prognosis, which will be affected by different cancer and host factors. Patients with resectable NSCLC with contraindications to surgery are usually candidates for curative radiation therapy. Additional combination chemotherapy may provide a survival advantage to patients with resected stage IB, stage II, or stage IIIA non-small cell lung cancer.
The second group of non-small cell lung cancer patients is those with either locally and/or regionally advanced lung cancer. Selected NSCLC patients with locally advanced tumors may benefit from combined treatments such as surgery and chemotherapy. Patients with non-small cell lung cancer which cannot be removed/treated surgically are given radiation therapy in combination with chemotherapy. Some NSCLC patients may be treated with surgery along with either preoperative or postoperative chemotherapy and/or chemoradiation therapy.
The third group of non-small cell lung cancer patients has distant metastases found at the time of diagnosis. This group of NSCLC patients can be treated with radiation therapy or chemotherapy for relief of symptoms from the lung cancer. Short-term relief of symptoms has been achieved with platinum-based chemotherapy and may also provide a survival advantage.
Many risk factors play a role not only in the formation of lung cancers but also in the prognosis of lung cancers. These risk factors include:
- Smoking – This is the single greatest risk factor for lung cancer and is most often associated with small cell lung cancer (SCLC) a much more aggressive form of lung cancer than non-small cell lung cancer (NSCLC). The number of cigarettes smoked each day and the number of years of smoking will also increase the risk. Quitting, at any age, will lower lung cancer risk.
- Secondhand Smoke – Lung cancer risk increases, even in non-smokers, exposed to secondhand smoke, especially if prolonged.
- Gender – Women, especially current or former smokers, are at greater risk for lung cancer than men who smoke(d) the same. The cause is unknown but it is thought that women may be more susceptible to cancer causing substances in tobacco and that estrogen may play roles. It is known that women who smoke inhale more than men and women are less likely to quit than men.
- Radon Gas – Radon is produced as uranium found in soil, rock & water breaks down and is then inhaled. Radon gas is tasteless, colorless & odorless and can accumulate in any building but highest levels are found in homes. All homes should be tested for radon.
- Asbestos/Chemicals – Most chemical exposures occur at work and many are known to be carcinogenic (cancer causing). All warning labels and precautions should be observed and followed. Chemical exposure can increase lung cancer risks in smokers.
- Family History – Parents, siblings, or other first relatives with lung cancer increase the risks of developing lung cancer.
- Excessive Alcohol Use – Drinking more than moderate amounts, more than 1 drink/day for women and 2 drinks/day for men may also increase lung cancer risks.Non-small cell lung cancer (NSCLC)
Despite many improvements in both diagnosis & therapy for non-small cell lung cancer, current prognosis for any patient with NSCLC is not usually good. Many studies have shown that there are additional post-diagnosis factors which negatively affect prognosis. These include:
- Presence of Respiratory/pulmonary symptoms
- Tumors larger than 3cm
- Cellular structure that is nonsquamous
- Metastases to multiple lymph nodes
- Blood vessel (vascular) invasion of tumor(s)
- Increased tumor blood vessels within the tumor itself
All non-small cell lung cancer patients are eligible for clinical trials and should consider these as a treatment option in conjunction with current treatment regimens.