Lung Cancer

Lung Cancer

Lung cancer is a disease in which the cells of the lung tissues grow uncontrollably and form tumors. It is the leading cause of death from cancer among both men and women in the United States.

The American Cancer Society (ACS) estimated that in 1998, at least 172,000 new cases of lung cancer were diagnosed, and that lung cancer accounted for 28% of all cancer deaths, or approximately 160,000 people.

In 2002, the ACS reported that more than 150,000 Americans die from the disease every year. Only 15 percent of people with lung cancer will live five years.


Types of lung cancer

There are two kinds of lung cancers, primary and secondary. Primary lung cancer (also called adenocarcinoma) starts in the lung itself. Primary lung cancer is divided into small cell lung cancer and non-small cell lung cancer, depending on how the cells look under the microscope. Secondary lung cancer is cancer that starts somewhere else in the body (for example, the breast or colon) and spreads to the lungs.

Small cell cancer was formerly called oat cell cancer, because the cells resemble oats in their shape. About one-fourth of all lung cancers are small cell cancers. This type is a very aggressive cancer and spreads to other organs within a short time.

It generally is found in people who are heavy smokers. Non-small cell cancers account for the remaining 75% of lung cancers. They can be further subdivided into three categories.

Incidence of lung cancer

Lung cancer is rare among young adults. It usually is found in people who are 50 years of age or older, with an average age at diagnosis of 60. While the incidence of the disease is decreasing among Caucasian men, it is steadily rising among African-American men, and among both Caucasian and African-American women.

This change probably is due to the increase in the number of smokers in these groups. In 1987, lung cancer replaced breast cancer as the number one cancer killer among women.

Causes and symptoms

Lung cancer infographic

Causes

SMOKING. Tobacco smoking is the leading cause of lung cancer. Ninety percent of lung cancers can be prevented by completely giving up tobacco. Smoking marijuana cigarettes is considered yet another risk factor for cancer of the lung.

These cigarettes have a higher tar content than tobacco cigarettes. In addition, they are inhaled very deeply; as a result, the smoke is held in the lungs for a longer period of time.

EXPOSURE TO ASBESTOS AND TOXIC CHEMICALS. Repeated exposure to asbestos fibers, either at home or in the workplace, also is considered a risk factor for lung cancer. Studies show that compared to the general population, asbestos workers are seven times more likely to die from lung cancer. Asbestos workers who smoke increase their risk of developing lung cancer by 50-100 times.

Besides asbestos, mining industry workers who are exposed to coal products or radioactive substances, such as uranium, and workers exposed to chemicals, such as arsenic, vinyl chloride, mustard gas, and other carcinogens, also have a higher than average risk of contracting lung cancer.

ENVIRONMENTAL CONTAMINATION. High levels of a radioactive gas (radon) that cannot be seen or smelled pose a risk for lung cancer. This gas is produced by the breakdown of uranium, and does not present any problem outdoors.

In the basements of some houses that are built over soil containing natural uranium deposits, however, radon may accumulate and reach dangerous levels. Having one’s house inspected for the presence of radon gas when buying or renting is a good idea. Other forms of environmental pollution (e.g., auto exhaust fumes) also may slightly increase the risk of lung cancer.

In 2002, a study in the Journal of the American Medical Association (JAMA) linked for the first time long-term exposure to fine-particle air pollution to lung cancer deaths. The risk of death from lung cancer increased substantially for people living in the most heavily polluted metropolitan areas. Tiny particles from the air pollution emitted from coal-fired power plants, factories and diesel vehicles are to blame.

CHRONIC LUNG INFLAMMATION AND SCARRING. Inflammation and scar tissue sometimes are produced in the lung by diseases, such as silicosis and berylliosis, which are caused by inhalation of certain minerals, tuberculosis, and certain types of pneumonia. This scarring may increase the risk of developing lung cancer.

FAMILY HISTORY. Although the exact cause of lung cancer is not known, people with a family history of lung cancer appear to have a slightly higher risk of contracting the disease. In 2003, researchers were continuing work aimed at learning why some smokers were more susceptible to lung cancer than others.

They discovered a type of DNA repair characteristic apparent in smokers who were less likely to get lung cancer. Continued work along these lines could lead to possible screening for DNA that makes some people at higher risk for lung cancer.

Symptoms

Lung cancers tend to spread very early, and only 15% are detected in their early stages. The chances of early detection, however, can be improved by seeking medical care at once if any of the following symptoms appear:

• a cough that does not go away
• chest pain
• shortness of breath
• persistent hoarseness
• swelling of the neck and face
• significant weight loss that is not due to dieting or vigorous exercise
• fatigue and loss of appetite
• bloody or brown-colored spit or phlegm (sputum)
• unexplained fever
• recurrent lung infections, such as bronchitis or pneumonia

However, these symptoms may be caused by diseases other than lung cancer. It is vital, however, to consult a doctor to rule out the possibility that they are the first symptoms of lung cancer.

If the lung cancer has spread to other organs, the patient may have other symptoms, such as headaches, bone fractures, pain, bleeding, or blood clots. Early detection and treatment can increase the chances of a cure for some patients. For others, it can at least prolong life.

Diagnosis

Physical examination and initial tests

If the patient’s doctor suspects lung cancer, he or she will take a detailed medical history to check all the symptoms and assess the risk factors. The assessment of the patient’s medical history will be followed by a complete physical examination.

The doctor will examine the patient’s throat to rule out other possible causes of hoarseness or coughing, and listen to the patient’s breathing and the sounds made when the patient’s chest and upper back are tapped (percussed). The physical examination, however, is not conclusive.

If the doctor has reason to suspect lung cancer—particularly if the patient has a history of heavy smoking or occupational exposure to substances that are known to irritate the lungs—he or she may order a chest x ray to see if there are any masses in the lungs. Special imaging techniques, such as CT scans or MRIs, may provide more precise information about the possibility, size, shape, and location of any tumors.

A technology called spiral CT, which rotates allowing for images of the chest from all angles, can detect lung cancer when tumors are smaller than a dime. A report in 2002 said spiral CT technology could help doctors screen the population for lung cancer, but the idea of screening remains controversial.

Until clinicians and insurers receive more proof the scans produce fewer false positive (a seemingly positive result or nodule that turns out not to be a cancerous mass), widespread screening won’t occur. And in 2002, the cost of a spiral CT chest study to screen for lung cancer averaged about $400. However, researchers were recommending further trials to determine the effectiveness of the screening tool for future use.

In 2003, a new radiology technique emerged for staging lung cancer. By combining positron emission tomography (PET) with CT, or PET-CT, physicians could more accurately see the details of the tumorís progression (or regression after treatment) and to diagnose a lung tumor better.

Sputum analysis

Sputum analysis involves microscopic examination of the cells that are either coughed up from the lungs, or are collected through a special instrument called a bronchoscope. Sputum analyses can diagnose at least 30% of lung cancers, some of which do not show up even on chest x rays.

In addition, the test can help detect cancer in its very early stages, before it spreads to other regions. The sputum test does not, however, provide any information about the location of the tumor and must be followed by other tests, such as bronchoscopy, where machines can detect cancerous cells without the need to open the chest.

Lung biopsy

Lung biopsy is the most definitive diagnostic tool for cancer. It can be performed in several different ways. The doctor can perform a bronchoscopy, which involves the insertion of a slender, lighted tube, called a bronchoscope, down the patient’s throat and into the lungs. In addition to viewing the passageways of the lungs, the doctor can use the bronchoscope to obtain samples of the lung tissue.

In another procedure known as a needle biopsy, the location of the tumor first is identified using a CT scan or MRI. The doctor then inserts a needle through the chest wall and collects a sample of tissue from the tumor.

In the third procedure, known as surgical biopsy, the chest wall is opened up and a part of the tumor, or all of it, is removed. A doctor who specializes in the study of diseased tissue (a pathologist) examines the tumor samples to identify the cancer’s type and stage.

Treatment

Alternative therapies should complement conventional treatment, not replace it. Before participating in any alternative treatment programs, patients should consult their doctors concerning the appropriateness and the role of such programs in overall cancer treatment plans.

Appropriate alternative treatments can help prolong a patient’s life or at least improve quality of life, prevent recurrence of tumors, or prolong the remission period and reduce adverse reactions to chemotherapy and radiation.

The use of beta-carotene and vitamin A supplements in lung cancer patients is controversial. Vitamin A and beta-carotene were advocated as antioxidants with lung-protective effects that may decrease the risk of lung cancer.

However, recent studies suggest that betacarotene supplements may have no demonstrated effect in smokers and no effects on nonsmokers. Therefore, use of beta-carotene supplement in lung cancer patients or as preventive measure in smokers is not recommended at the present time.

However, researchers believe that patients benefit from nature’s source of beta-carotene and vitamin A. Beta-carotene in food carries all the benefits, yet does not have the harmful effects controversial high-dose supplements may carry.

The effectiveness of many of the anticancer drugs used to treat lung cancer can be reduced when patients take megadoses of antioxidants. These antioxidants in patients not undergoing chemotherapy can be helpful in protecting the body against cancer. However, taken during chemotherapy, these antioxidants protect the cancer cells from being killed by chemotherapy drugs.

Because high-dose supplementation of antioxidants can interfere with conventional chemotherapy treatment, patients should check with their physicians concerning dosage and recommended daily allowance (RDA) during chemotherapy or radiation therapy.

Dietary guidelines

The following dietary changes may help improve a patient’s quality of life, as well as boost the immune function to better fight the disease. They also may help prevent lung cancer.

• Avoiding fatty and spicy foods. A high-fat diet may be associated with increased risk of lung cancer. Also, lung cancer patients may have a hard time digesting heavy foods.
• Eating new and exciting foods. Tasty foods stimulate appetite so that patients can eat more and have the energy to fight cancer.
• Increasing consumption of fresh fruits and vegetables. They are nature’s best sources of antioxidants, as well as vitamins and minerals. Especially helpful are the yellow and orange fruits (orange, cantaloupes) and dark green vegetables. They contain high amounts of vitamin A and carotene.
• Eating more broccoli sprouts. These young sprouts are a good source of sulforaphane, a lung cancer fighting substance.
• Eating multiple (5-6) meals per day. Small meals are easier to digest.
• Establishing a regular eating time and not eating around bedtime.
• Avoiding foods containing preservatives or artificial coloring.
• Monitoring weight and intake of adequate calories and protein.

In 2002, a report in Family Practice News said that daily consumption of a soup used in Traditional Chinese Medicine helped slow the progression of non-small cell lung cancer for patients with advanced stages of the disease. The soup consisted of herbs and vegetables containing natural ingredients that boost immunity and help fight tumors.

Patients should check with their doctors and with a licensed Traditional Chine Medicine specialist for more information. The soup does not prevent or reverse the disease, but helped prolong survival for a percentage of patients in a clinical study.

Nutritional supplements

A naturopath may recommend some of the following nutritional supplements to boost the patient’s immune function and help fight tumor progression:

• Vitamins and minerals. Vitamins that are considered particularly beneficial to cancer patients include B-complex vitamins, especially vitamins B6, C, D, E, and K. Most important minerals are calcium, chromium, copper, iodine, molybdenum, germanium, selenium, tellurium, and zinc. Many of these vitamins and minerals are strong antioxidants or cofactors for antioxidant enzymes. However, patients should not take mega doses of these supplements without first consulting their doctors. Significant adverse or toxic effects may occur at high dosages, which is especially true for the minerals.
• Other nutritional supplements may help fight cancer and support the body. They include essential fatty acids (fish or flaxseed oil), flavonoids, pancreatic enzymes (to help digest foods), hormones such as DHEA, melatonin, or phytoestrogens.

Traditional Chinese medicine

Conventional treatment for leukemia is associated with significant side effects. These adverse effects (such as nausea, vomiting, and fatigue) can be reduced with Chinese herbal preparations. Patients should consult an experienced herbalist who will prescribe remedies to treat specific symptoms that are caused by conventional cancer treatments.

Juice therapy

Juice therapy may be helpful for patients with cancer. Patients should mix one part of pure juice with one part of water before drinking.

Homeopathy

There is conflicting evidence regarding the effectiveness of homeopathy in cancer treatment. Because cancer chemotherapy may suppress the body’s response to homeopathic treatment, homeopathy may not be effective during chemotherapy. Therefore, patients should wait until after chemotherapy to try this relatively safe alternative treatment.

Acupuncture

Acupunture is the use of needles on the body to stimulate or direct the meridians (channels) of energy flow in the body. Acupuncture has not been shown to have any anticancer effects. However, it is an effective treatment for nausea, and other common side effects of chemotherapy and radiation.

Other treatments

Other alternative treatments include stress reduction, meditation, yoga, t’ai chi, and the use of guided imagery A new report in 2003 showed early results for bee venomís possible antitumor effects on lung cancer. However, further, research was needed.

Allopathic treatment

Treatment for lung cancer depends on the type of cancer, its location, and its stage. Treating the cancer early is key. In 2002, researchers announced the discovery of a chromosomal region that shows the earliest genetic change in the development of lung cancer.

Eventually, this discovery could lead to earlier detection, diagnosis, prevention, and treatment of lung cancer. The most commonly used modes of treatment are surgery, radiation therapy, and chemotherapy.

Surgery

Surgery is not usually an option for small cell lung cancers, because they have likely spread beyond the lung by the time they are diagnosed. Because non-small cell lung cancers are less aggressive, however, surgery can be used to treat them.

The surgeon will decide on the type of surgery, depending on how much of the lung is affected. Surgery may be the primary method of treatment, or radiation therapy and/or chemotherapy may be used to shrink the tumor before surgery is attempted.

There are three different types of surgical operations:

• Wedge resection. This procedure involves removing a small part of the lung.
• Lobectomy. A lobectomy is the removal of one lobe of the lung. If the cancer is limited to one part of the lung, the surgeon will perform a lobectomy.
• Pneumonectomy. A pneumonectomy is the removal of an entire lung. If the surgeon feels that removal of the entire lung is the best option for curing the cancer, a pneumonectomy will be performed.

The pain that follows surgery can be relieved by medications. A more serious side effect of surgery is the patient’s increased vulnerability to bacterial and viral infections. Antibiotics, antiviral medications, and vaccines are often needed.

Radiation therapy

Radiation therapy involves the use of high-energy rays to kill cancer cells. It is used either by itself or in combination with surgery or chemotherapy. There are two types of radiation therapy treatments: external beam radiation therapy and internal (or interstitial) radiotherapy.

In external radiation therapy, the radiation is delivered from a machine positioned outside the body. Internal radiation therapy uses a small pellet of radioactive materials placed inside the body in the area of the cancer.

Radiation therapy may produce such side effects as tiredness, skin rashes, upset stomach, and diarrhea. Dry or sore throats, difficulty in swallowing, and loss of hair in the treated area are all minor side effects of radiation. These may disappear either during the course of the treatment or after the treatment is over. The side effects should be discussed with the doctor.

Chemotherapy

Chemotherapy uses anticancer medications that are either given intravenously or taken by mouth (orally). These drugs enter the bloodstream and travel to all parts of the body, killing cancer cells that have spread to different organs.

Chemotherapy is used as the primary treatment for cancers that have spread beyond the lung and cannot be removed by surgery. It also can be used in addition to surgery or radiation therapy.

Chemotherapy is tailored to each patient’s needs. Most patients are given a combination of several different drugs. Besides killing the cancer cells, these drugs also harm normal cells. Hence, the dose has to be carefully adjusted to minimize damage to normal cells.

Chemotherapy often has severe side effects, including nausea, vomiting, hair loss, anemia, weakening of the immune system, and sometimes infertility. Most of these side effects end when the treatment is over. Other medications can be given to lessen the unpleasant side effects of chemotherapy.

Expected results

If the lung cancer is detected before it has had a chance to spread to other organs, and if it is treated appropriately, at least 49% of patients can survive five years or longer after the initial diagnosis. Only 15% of lung cancers, however, are found at this early stage.

Due to improvements in surgical technique and the development of new approaches to treatment, the oneyear survival rate for lung cancer has improved considerably. As of 1998, approximately 40% of patients survive for at least a year after diagnosis, as opposed to 30% that survived 20 years ago. In 2003, 14% of people diagnosed with lung cancer were reported to be long-term survivors.

Prevention

The best way to prevent lung cancer is to not smoke or to quit smoking if one has already started. Secondhand smoke from other people’s tobacco also should be avoided when possible. In 2002, a report on the impact of cigarette smoking said that in California, decreases in smoking among residents had resulted in reduced lung cancer death rates.

Appropriate precautions should be taken when working with cancer-causing substances (carcinogens). Monitoring the diet and eating well-balanced meals that consist of whole foods, vegetables, and fruits; eliminating toxins, exercising routinely, and weight reduction; testing houses for the presence of radon gas, and removing asbestos from buildings also are useful preventive strategies.