Lung cancer is cancer that begins in any part of the lungs. Smoking is the number one cause of lung cancers, so in many cases, it can be prevented.
Often, there are no symptoms in early-stage lung cancer. Later, symptoms include coughing, wheezing, and weight loss. Early-stage lung cancer is easier to treat and has a better prognosis than when discovered in later stages.
Types of Lung Cancer & Frequency
There are two primary types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).
Non-small Cell Lung Cancer
NSCLC represents about 85 to 90 percent of all lung cancers, according to the American Cancer Society (ACS). Within this type are three subtypes. The prognosis and treatment are much the same. They are:
- adenocarcinoma: This type of cancer begins in cells that secrete mucus and other substances. It is usually detected in the outer areas of the lung, but tends to grow more slowly than other kinds of lung cancer. It is linked to smoking, but it’s also the most common type of lung cancer in non-smokers. Younger people and women are more likely to develop this type, which accounts for approximately 40 percent of lung cancers.
- squamous cell (epidermoid) carcinoma: This type of lung cancer starts inside the airways of the lungs and is usually discovered near a bronchus. It represents about 25 to 30 percent of lung cancer cases. Smoking is usually the cause.
- large cell (undifferentiated) carcinoma: This kind starts anywhere in the lungs and is very aggressive. About 10 to 15 percent of lung cancers are this type.
Adenosquamous carcinoma and sarcomatoid carcinoma are rare subtypes of NSCLC.
Small Cell Lung Cancer
SCLC represents 10 to 15 percent of lung cancers, and it mainly affects smokers. It gets its start in bronchi located in the center of the chest, and it tends to spread very quickly.
In addition to NSCLC and SCLC, other types of cancer can start in the lungs. Lung carcinoid tumors are slow growing and have a better prognosis. Less than 5 percent of lung tumors are of this type. Other rare types include lymphomas, sarcomas, and adenoid cystic carcinomas. Cancer that spreads from other organs to the lungs is not lung cancer.
Prevalence and Incidence
Around the world, more people get lung cancer than any other kind. According to theInternational Agency for Research on Cancer, about 1.8 million people were diagnosed with lung cancer in 2012. That’s about 13 percent of total cancer cases.
According to the National Cancer Institute (NCI), about 402,326 people in the United States were living with lung and bronchial cancer in 2011. The ACS estimates that in 2014, there will be about 224,210 new cases of lung cancer.
Rates vary within the United States, too. According to the Centers for Disease Control and Prevention (CDC), the highest levels are found in: Alabama, Arkansas, Delaware, Indiana, Kentucky, Louisiana, Maine, Mississippi, Missouri, Oklahoma, Tennessee, and West Virginia. The lowest levels occur in: Arizona, California, Colorado, District of Columbia, Hawaii, Idaho, Minnesota, Nebraska, New Mexico, South Dakota, Texas, Utah, and Wyoming.
According to the American Lung Association (ALA), in 2010, Kentucky led with the highest incidence of lung cancer. Utah had the lowest. These rates mirrored smoking prevalence rates.
According to the NCI, about 6.8 percent of us will develop lung or bronchus cancer in our lifetime.
Over the past few decades, rates of lung cancer have dropped for men and risen for women. Today, rates are similar. In 2014, it is expected that about 116,000 men and 108,210 women will be diagnosed with lung cancer.
There are some racial differences. According to theACS, black men are 20 percent more likely to get lung cancer than white men. White women are 10 percent more likely to get lung cancer than black women. The lowest incidence of lung cancer appears to be among Hispanics.
2006 Race and Lung Cancer Incidence Rate Per 100,000, according to the ALA:
|Native American/Native Alaskan||44.9|
|Asian American/Pacific Islander||38.9|
You’re more likely to develop lung cancer as you age, with an average age of 70 at diagnosis. Two out of three diagnoses are in people over age 65. The rate in people under age 45 is under 2 percent.
The single biggest cause of lung cancer is smoking. According to the ALA, male smokers are 23 times more likely to get lung cancer than their non-smoking peers. Female smokers are 13 times more likely to get lung cancer than women who never smoked.
Non-smokers who are regularly exposed to secondhand smoke have a 20 to 30 percent higher risk of developing lung cancer. Radon is linked to 10 percent of lung cancers. Occupational exposure to carcinogens causes 9 to 15 percent of cases. These include asbestos, uranium, and a fuel called coke. Outdoor air pollution is responsible for 1 to 2 percent.
In some cases, a person’s lung cancer can be linked to multiple exposures. Smokers who are exposed to radon or asbestos have a greater risk for lung cancer.
Lung cancer is the top cause of cancer deaths, accounting for 27 percent of all cancer deaths, according to the ACS. That’s more than breast, colon, and prostate cancer combined. It is estimated that in 2014, 86,930 men and 72,330 women will die of lung cancer.
The ALA puts the overall five-year survival rate is 53.5 percent when diagnosed before it spreads outside the lungs. Unfortunately, only about 15 percent are caught that early. Once it has spread to distant organs, the five-year survival rate is 3.9 percent. Fifty percent of lung cancer patients die within a year.
Lung cancer has a bigger impact on the global economy than any other form of cancer. A 2010economic report found that $88 billion was spent on breast cancer and $99 billion on colorectal cancer. Lung cancer cost the world economy $188 billion.
In the United States, it is estimated that $12.1 billion was spent on lung cancer in 2010.