Everything You Need to Know About Lung Cancer
Table of Contents
After skin cancer, lung cancer is the second most common cancer diagnosed in both men and women in the United States.
Furthermore, it is the leading cause of cancer deaths among both men and women in the United States. It accounts for 25 percent of all deaths from cancer. To put this into perspective, more men and women die each year from lung cancer than prostate, colon, ovarian, and breast cancers combined.
Signs and Symptoms
The signs and symptoms of lung cancer vary, according to the individual and how early or advanced the disease. Many individuals with early-stage lung cancer do not have any signs or symptoms. Many of the signs and symptoms of lung cancer present when the disease is in a later stage. Yet still, if the cancer has undergone spread to other parts of the body, signs and symptoms may be specific to that particular part of the body.
Signs and symptoms of lung cancer may include:
- A persistent cough that may worsen as time goes on;
- Coughing up blood;
- Shortness of breath, wheezing, and/or hoarseness;
- Loss of appetite and/or weight loss with no discernable cause;
- Chest pain;
- Recurrent respiratory infections;
- Bone pain;
- Severe headaches, and;
- Swelling of the neck and face.
By far, cigarette smoke is the primary risk factor for lung cancer. In other words, your risk of developing lung cancer is directly related to the number of cigarettes you smoke each day and the years you have smoked. Smoking cigarettes is implicated in 80 percent to 90 percent of all lung cancer deaths.
Tobacco smoke contains more than 7,000 chemicals — many of which are poisonous and known cancer-causing agents. It should also be noted that smoking cigars or pipes also increases your risk of lung cancer.
Other risk factors for lung cancer include:
- Exposure to secondhand smoke;
- Exposure to tasteless and odorless naturally occurring gas known as radon;
- Exposure to asbestos, arsenic, diesel exhaust, and some forms of silica and chromium;
- Previous radiation therapy to the chest for cancer, and;
- Family history of lung cancer.
The objective of screening programs is to detect disease in seemingly healthy individuals with no symptoms. Compared to non-smokers, smokers are 15 to 30 times more likely to be diagnosed with lung cancer or die from the disease. This underscores the need for screening programs for lung cancer, as it can detect early-stage and improve the outcomes of patients.
The United States Preventative Services Task Force recommends low dose computed tomography (LDCT) for lung cancer screening. The ideal candidate for lung cancer screening is an individual who is 55 to 80 years old with a history of heavy smoking and continues to smoke or has quit within the last 15 years.
You are a heavy smoker if you have a smoking history of greater than or equal to 30 pack-years. A pack-year is a clinical construct used to measure your lifetime exposure to tobacco. It’s calculated by multiplying the number of packs of cigarettes smoked per day by the number of years you have smoked. For example, one pack-year is the equivalent of smoking one pack, or 20 cigarettes, per day for one year. In other words, to arrive at 30 pack-years, you will have smoked one pack of cigarettes per day for 30 years or two packs for 15 years.
LDCT is a special kind of X-ray that uses a low amount of radiation to obtain detailed images of your lungs. This is key as radiation to the chest is a risk factor for lung cancer. The scan itself is quick, pain-free, and requires no special preparation. What’s more, Medicare and most private insurances will cover the initial screening scan without co-pay if you fit all the criteria detailed above.
There is no sure way to prevent lung cancer, but you can be proactive and take measures to reduce your risk of developing lung cancer.
If you have never smoked, you should not start smoking. If you are a smoker, you should quit smoking. In fact, quitting at any age can significantly reduce your risk of developing lung cancer.
This is easier said than done, but a frank discussion with your doctor should set the stage for a smoking cessation program. There is a multitude of resources that can help you quit smoking, including:
- Behavioral therapy,
- Nicotine replacement therapy, and;
- Prescription non-nicotine medications.
Other measures you can take to decrease your risk of lung cancer include:
- Avoiding secondhand smoke;
- Testing your home for radon;
- Avoiding exposures in the workplace;
- Eating a healthy diet with plenty of fruits and vegetables, and;
- Exercising for at least 30 minutes a day on most days of the week.
When to See a Doctor
You should make an appointment with your doctor if you are experiencing any of the above symptoms that may be referable to lung cancer. Also, if you fit the criteria for lung cancer screening, you should make an appointment with your doctor to discuss the risks and benefits of screening with LDCT.
Finally, if you are a smoker, a visit to your doctor can provide you with an evidence-based smoking cessation program. After all, going “cold turkey” is not for everyone, and a dedicated smoking cessation program gives you the best chances to remain smoke-free.
As discussed earlier, some lung cancers are found through screening. However, the great majority are diagnosed because they are causing worrisome signs and symptoms.
Your doctor visit will consist of a medical history to assess your risk factors and physical examination to look for any signs or symptoms of lung cancer. Your doctor may ask about:
- Your symptoms and their duration,
- The severity of your symptoms;
- What may alleviate or exacerbate your symptoms;
- Whether you have a family history of lung cancer or a personal history of cancer, and;
- Whether you have a history of lung disease.
If your doctor’s clinical suspicion remains high that you may have lung cancer, he/she will likely order imaging tests. These tests will mostly focus on the chest/lungs.
A chest X-ray may reveal a suspicious lung mass or nodule. If this is the case, your doctor may order additional imaging studies, such as computed tomography (CT), magnetic resonance imaging, positron emission tomography, and bone scans.
A CT scan of the chest can give more detailed information on the size, shape, and location of a suspicious lung tumor. It can also identify enlarged lymph nodes, which may contain cancer that has spread.
The other imaging studies mentioned above are more appropriate to investigate the extent of lung cancer. For instance, if it has spread to lymph nodes and other parts of the body.
If imaging reveals a lung tumor, your doctor will want to know definitively if this abnormality does or does not represent cancer. The only way to accomplish this is to sample lung cells — preferably from the tumor itself — so they can be viewed under a microscope.
There are several courses of action, depending on the situation, including:
- Sputum Cytology: Collection of mucus coughed up from the lungs.
- Thoracentesis: Removing fluid that has accumulated from around the lung.
- Biopsy: Sampling cells from the actual tumor.
Of these sampling procedures, a biopsy is probably the most direct and most sensitive for the diagnosis of lung cancer. A biopsy can be performed with a needle. This procedure can be done through the skin of the chest wall, CT-guided, or achieved via bronchoscopy.
There are two main types of lung cancer:
- Non-small lung cancer (NSCLC), and;
- Small cell lung cancer (SCLC).
The distinction is based upon the microscopic appearance of the tumor cells. NSCLCs account for 80 to 85 percent of all lung cancers, while SCLCs account for 10 to 15 percent.
Non-Small Lung Cancer
NSCLCs can be divided into the following three main subtypes. They are:
- Adenocarcinomas: The most common type of NSCLC. It accounts for up to 40 percent of all cases of lung cancer. It can arise from cells that would normally secrete mucus.
- Squamous Cell Carcinomas: Sometimes referred to as epidermoid carcinomas. This type originates from flat cells that line the inside of the lungs. It comprises 25 to 30 percent of all cases of lung cancer.
- Large Cell Carcinomas: Sometimes referred to as undifferentiated carcinomas. This type is fast-growing, spread quickly, and accounts for 10 to 15 percent of all lung cancers.
Less common forms of NSCLC include:
- Adenosquamous carcinoma;
- Large cell neuroendocrine carcinoma;
- Sarcomatoid carcinoma, and;
- Adenocarcinoma in situ.
Small Cell Lung Cancer
Unfortunately, SCLCs are the most aggressive and rapidly growing of all lung cancers. Consequently, almost 70 percent of individuals with SCLC have metastasis at the time of their diagnosis.
If you are diagnosed with lung cancer, the staging of the disease is one of the most important aspects. It is a primary determinant of treatment. The staging of lung cancer is primarily accomplished through imaging studies.
Stages of Non-Small Lung Cancer
If you are diagnosed with NSCLC, you may be staged as follows:
- Stage 0: Also referred to as carcinoma in situ. This is the earliest stage at which lung cancer can be detected/diagnosed.
- Stage I: The cancer is small (usually less than 5 cm), confined to one lung, and has not spread to the lymph nodes or other distant parts of the body.
- Stage II: The cancer is confined to one lung and may or may not have spread to nearby lymph nodes. However, it has not spread to other distant parts of the body.
- Stage III: The cancer has spread to the lymph nodes and other parts of the lung and surrounding tissues.
- Stage IV: The cancer has spread to distant parts of the body, such as the brain, liver, or bone.
Stages of Small Lung Cancer
If you are diagnosed with SCLC, its staging is much simpler. It has two stages:
- Limited: The cancer is confined to one side of the chest.
- Extensive: The cancer has spread throughout the lung to the opposite lung, lymph nodes on the other side of the chest, or other distant parts of the body.
If you have been recently diagnosed with lung cancer, you are preparing for treatment and may wonder what your prognosis is for this disease. Fortunately, the American Cancer Society compiles data from Surveillance, Epidemiology, and End Results (SEER) database to provide five-year relative survival rates for lung cancer. In other words, your chances of being alive five years after your diagnosis of lung cancer.
Your prognosis is primarily dependent — but not totally — on the type of lung cancer and its stage. In general, the prognosis for NSCLC is better than for SCLC.
For simplicity, the SEER database categorizes cancers as localized (stage I), regional (stages II and III), and distant (stage IV).
For NSCLC, the five-year relative survival rates are:
- Localized: 61 percent
- Regional: 35 percent
- Distant: 6 percent
- All Stages Combined: 24 percent
For SCLC, the five-year relative survival rates are:
- Localized: 27 percent
- Regional: 16 percent
- Distant: 3 percent
- All Stages Combined: 6 percent
Lung cancer, as well as its treatments, can lead to complications. Some of which may be life-threatening.
Since they typically cause no symptoms, stage 0 and I lung cancers rarely cause complications. In contrast, late-stage lung cancer can lead to complications as it spreads to distant areas of the body.
Lung cancer can cause complications, such as:
- Shortness of breath;
- Coughing up blood;
- Accumulation of fluid around the lungs;
- Local and/or widespread pain, and;
Of course, the most dreaded complications of lung cancer is metastasis, the spread to other parts of the body. As a consequence, most cancers, including lung cancer, are considered incurable once they have undergone metastasis.
Whether you have been diagnosed with NSCLC or SCLC, there are several treatment options available.
In addition to the cancer stage, your age, preferences, and overall health, along with the type and location of the tumor, are considerations when formulating a treatment plan. The people who may take part in the formulation of your treatment plan include:
- Medical oncologists;
- Radiation oncologists;
- Pulmonologists, and;
- Respiratory therapists.
Possible treatment options for lung cancer may include surgery, chemotherapy, radiation therapy, targeted therapy, and immunotherapy.
Surgery is one of the most common methods to treat lung cancer. The goal is to remove the lung cancer with a minimum of damage to healthy lung tissue. Since most cancers spread to distant parts of the body through the lymphatic system, your surgeon may also remove lymph nodes at the same time.
Your surgical options include:
- Wedge Resection: Removal of the cancerous tumor with a small rim of healthy lung tissue.
- Segmental Resection: Removal of a larger section of the lung along with the tumor, but not an entire lobe.
- Lobectomy: Removal of an entire lobe of a lung. The right lung has three lobes, while the left lung has only two lobes.
- Pneumonectomy: Removal of an entire lung since an individual can live without a lung.
Another option for the treatment of lung cancer is chemotherapy. During this process, a medical oncologist administers cycles of drugs into a vein or by mouth to kill cancer cells. It may be given:
- Before surgery to shrink a cancerous lung tumor, making it easier to remove;
- After surgery — with or without radiation therapy — to kill any residual lung cancer cells, or;
- Sometimes if the disease has spread outside of the lungs.
Examples of some chemotherapeutic agents used to treat lung cancer are cisplatin and paclitaxel (Taxol).
Possible side effects of chemotherapy include:
- Hair loss;
- Mouth sores;
- Loss of appetite, and;
- Weight loss.
Radiation therapy uses high-energy rays to eradicate cancer cells. There are two principal forms of radiation therapy: external beam and internal. It may be administered:
- As Main Treatment: If a cancerous tumor is in a precarious location not amenable to surgery.
- Before Surgery: In this case, it’s usually combined with chemotherapy. Done to shrink a cancerous tumor.
- After Surgery: Can be done with or without chemotherapy in order to kill any residual lung cancer cells.
- To Treat Metastatic Areas: To kill cancer cells in the areas the lung cancer has spread to.
Side effects of radiation therapy may include:
- Skin changes;
- Loss of appetite, and;
- Weight loss.
Targeted therapy is a relatively new development for the treatment of lung cancer. Agents work through different mechanisms to cause the death of cancer cells, such as inhibiting the formation of new blood vessels or the growth, division, or repair of lung cancer cells.
Examples of agents used for targeted therapy include bevacizumab, erlotinib, and crizotinib.
Immunotherapy is another relatively new tool in the arsenal for lung cancer treatment. It takes advantage of your own immune system to destroy cancer cells.
Examples of immunotherapy agents used to treat lung cancer include nivolumab and pembrolizumab.
Living with Lung Cancer
Lung cancer and its treatments can take a toll on your day-to-day life. If you are living with lung cancer, the following tips have the potential to make living with the disease less burdensome:
- Pay Attention to Your Breathing: Many people with lung cancer may find it difficult to breathe at times. Therefore, breathing exercises, such as belly breathing or pursed-lip breathing can be helpful.
- Be Meticulous About Your Oral Health: Some treatments for lung cancer — namely chemotherapy and radiation therapy — can make your mouth dry and affect your sense of taste. If you suffer from this ailment, at-home interventions, like sucking on ice chips, chewing sugar-free gum, or even artificial saliva, can help.
- Stay Hydrated: Drinking plenty of fluids has many benefits, including staving off dry mouth, preventing dehydration, and boosting your energy levels.
- Make Sure You Eat: Eating five to six small meals a day can help you maintain or even put on weight. This can help with symptoms such as fatigue.
Unlike some other cancers, lung cancer is highly preventable. If you quit smoking now, you will have a lower risk of developing lung cancer. Furthermore, whether you have NSCLC or SCLC, survival rates are increasing due to appropriate screening and ongoing research giving rise to refined, improved treatments.