The Relationship between Cancer and Smoking

The 1982 United States Surgeon General's report stated that "Cigarette smoking is the major single cause of cancer mortality in the United States." (1) This statement is as true today as it was then. Tobacco smoke contains over 4,000 chemical compounds. More than 60 of these are known or suspected to cause cancer. For example, about 90,000 men die of lung cancer each year in the U.S. About 78,700 lung cancer deaths among men are caused by smoking. This means that the smoking causes about 90% of lung cancer deaths among men (2). Statistics also shows that 80% of all lung cancer deaths in women are caused by smoking (2).
Lung cancer is not the only type of cancer that is linked with smoking. Cigarette smoking accounts for at least 30% of all cancer deaths. It is linked with an increased risk of the following cancers: lung, larynx (voice box), oral cavity (mouth, tongue, and lips), pharynx (throat), esophagus (tube connecting the throat to the stomach), stomach, pancreas, cervix, kidney, bladder, acute myeloid leukemia (3).
The effect of smoking on each type of cancer is different. For example, smoking greatly increases the risk of getting and of dying from cancers of the lungs and larynx (voice box). It has a smaller effect on cancer of the cervix.
Lung cancer is the leading cause of cancer death in both men and women, and is one of the hardest cancers to treat. It claims more than 150,000 lives each year (3). Smoking is responsible for almost 9 out of 10 lung cancer deaths. It increases the risk of getting lung cancer by the factors of 23 and 12 in men and women respectively (2). Lung cancer kills more people than cancers of the breast, prostate, colon and pancreas combined. There are tens of millions of current, former and secondhand smokers in the United States, all of whom are at high risk for lung cancer (3).
Former smoker or ex-smoker means someone who has smoked more than 100 cigarettes over his or her lifetime but does not now smoke every day or some days (2). Even decades after quit¬ting, the risk of lung cancer in former smokers is increased by the factors of 9 and 5 in men and women respectively (2). It has been shown that the risk of lung cancer in ex-smokers never returns to the rate seen in persons who have never smoked.
Even if a person never smoked he or she might have been exposed to secondhand smoke. It is a mixture of 2 forms of smoke that come from burning tobacco: sidestream smoke (smoke that comes from the end of a lighted cigarette, pipe, or cigar) and mainstream smoke (smoke that is exhaled by a smoker) (4).
Secondhand smoke is classified as a "known human carcinogen" (cancer-causing agent) by the U.S. Environmental Protection Agency (EPA), the U.S. National Toxicology Program, and the International Agency for Research on Cancer (IARC), a branch of the World Health Organization (5).
Scientific evidence indicates that there is no safe amount of secondhand smoke. Breathing even a little secondhand smoke is harmful to your health. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the preeminent U.S. standard-setting body on ventilation issues, has concluded that ventilation technology cannot be relied on to completely control health risks from secondhand smoke exposure (5).
Non-smokers who breathe in secondhand smoke take in nicotine and other toxic chemicals just like smokers do. Secondhand smoke causes lung cancer in adults who don’t smoke. In the United States alone, each year it is responsible for about 3,400 lung cancer deaths in non-smoking adults (5). Breathing in secondhand smoke increases your chances of getting lung cancer by 20 percent to 30 percent. Moreover, concentrations of many cancer-causing and toxic chemicals are potentially higher in secondhand smoke than in the smoke inhaled by smokers.
Although no current screening guidelines for the lung cancer are established, the American Cancer Society recommends that people who are at increased risk for lung cancer, such as smokers, former smokers, or secondhand smokers, be aware of their lung cancer risk. They should talk to their doctors about their chances of getting lung cancer and the lung cancer screening (3).
Currently, when lung cancer is detected, the disease has already spread outside the lung in more than half of all cases. Most people with early lung cancer do not have any symptoms, so only a small number of lung cancers are found at an early stage. When lung cancer is found early, it is often because of tests that were being done for something else. Screening is the use of tests or exams to find a disease like cancer in people who don't have any symptoms. Because lung cancer often spreads beyond the lungs before it causes symptoms, a good screening test to find lung cancer early could save many lives (3). This means part of your health care should focus on related screening and preventive measures to help you stay as healthy as possible.
Several testing options could be available for pro-active people who are at increased risk for lung cancer:

Chest x-ray is the first test your doctor will do to look for any spots on the lungs. It is a plain x-ray of your chest. Studies have shown that this kind of screening does not find many lung cancers early enough to improve a person's chance for a cure (3, 6).
CT scan (computed tomography): A CT (or CAT) scan is a special kind of x-ray. Instead of taking just one picture, the CT scanner takes many pictures as it moves around you. A computer then combines these pictures into a picture of a slice of your body. Spiral CT can pick up tumors well under 1 centimeter in size, while chest x-rays detect tumors about one to two centimeters (0.4 to 0.8 inches) in size (3, 6).
MRI scan (magnetic resonance imaging): Like CT scans, MRI scans give detailed pictures of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. MRI scans take longer than x-rays -- often up to an hour. MRI scans are useful in finding lung cancer that has spread to the brain or spinal cord (6).
PET scan (positron emission tomography): PET scans use a form of sugar that contains a radioactive atom. Cancer cells in the body absorb large amounts of the sugar. A special camera can then spot the radioactivity. This test can show whether the cancer has spread to the lymph nodes. PET scans are also useful when the doctor thinks the cancer has spread, but doesn't know where (6).
Tests of tissues and cells, such as lung biopsy or sputum cytology, can be used to follow up on imaging tests to be sure that something seen on an imaging test is really lung cancer. These tests are also used to decide the exact type of lung cancer and how far it may have spread (3, 6).
Screening blood tests are offered from the private sector to meet the needs of pro-active people who are at increased risk for lung cancer. It is up to the individual to be aware of their lung cancer risk by determining whether she/he belongs to one or more risk groups such as smokers, former smokers, or secondhand smokers and talk to his/her doctor to determine if screening tests should be implemented. If the health care provider does not cover screening tests which are preferred by the patient, other options are available from the private sector to address these needs at the patient’s own cost.
This article is brought to you by GenWay Biotech Inc. GenWay offers a cancer assessment aimed to detect 20 different types of cancer in the early stages under the brand name You Test You™.
References:
1. U.S. Department of Health and Human Services. The Health Consequences of Smoking – Cancer: A Report of the Surgeon General. Atlanta, GA: U.S, 1982
2. American Cancer Society (ACS), Smoking and Cancer Mortality Table: http://www.cancer.org/docroot/PED/content/PED_10_2X_Smoking_and_Cancer_Mortality_Table.asp
3. American Cancer Society (ACS), Detailed Guide: Lung Cancer.
4. U.S. Department of Health and Human Services. The Health Consequences of Smoking: A Report of the Surgeon General. Atlanta, GA, 2004.
5. U.S. Department of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. Atlanta, GA, 2007
6. American Cancer Society (ACS), Detailed Guide: Lung Cancer - How Is Lung Cancer Diagnosed?

Understanding The Role of the U.S. Preventive Services Task Force (USPSTF)

In November 2009, the U.S. Preventive Services Task Force (USPSTF) published new guidelines for breast cancer screening by mammograms which sparked controversy on a vital topic to cancer organizations worldwide, the importance of early cancer detection. These new guidelines are a significant shift from those issued in 2002, which at that time, recommended women ages 40 and older to have an annual mammogram. The new recommended ages by the USPSTF to screen women for breast cancer is now 50 and older, leading to many questions on why such a change in policy is necessary.
Immediately after this recommendation from the USPSTF, a statement from Otis W. Brawley, M.D., chief medical official of The American Cancer Society, stated, “The American Cancer Society continues to recommend annual screening using mammography and clinical breast examination for all women beginning at age 40….reasonable experts can look at the same data and reach different conclusions….the Society’s panel found convincing evidence that screening with mammography reduces breast cancer mortality in women ages 40-74…. With its new recommendations, the USPSTF is essentially telling women that mammography at age 40 to 49 saves lives; just not enough of them… The most recent data show us that approximately 17 percent of breast cancer deaths occurred in women who were diagnosed in their 40s.” According to the American Cancer Society’s cancer statistics, this 17% represents approximately 7,000 lives, which will be left at risk once these breast cancer screening policy changes take effect.
Additional support for breast cancer screening comes from researchers at the University of London, which conducted two studies looking into the risks and benefits of breast cancer screening. The first study predicted the number of women who would have died from breast cancer in Britain without screening. The second study evaluated the number of deaths among 80,000 Swedish women with access to screening programs. The results published in the Journal of Medical Screening showed that for every 28 breast cancer diagnoses between 2 and 2.5 lives were saved. The results from the Swedish study indicated that for every 350 women screened for 10 years for breast cancer, one life would be saved. This research, along with hundreds of other publications, indicates an opportunity for saving lives from further development and implementation of cancer screening.
As stated on the Agency for Healthcare Research and Quality’s website (www.ahrq.gov), the USPSTF mission is “to improve the safety, quality, efficiency, and effectiveness of health care for all Americans.” The recommendations of the USPSTF are considered to be the “gold standard” for clinical preventive services, and are followed by almost every major primary care and federal agency associated with health care. USPSTF recommendations are used in undergraduate and post-graduate medical and nursing education as a key reference for teaching preventive care.
So what is the reasoning behind the USPSTF’s breast cancer screening recommendation? False positives can lead to psychological distress, unnecessary imaging tests and biopsies in women without cancer, and inconvenience due to false-positive screening results. Radiation exposure, although a minor concern from mammograms, is also a consideration. The USPSTF recommends that physicians be required to consider additional factors, such as an individual’s personal risk of having cancer, before conducting screening procedures such as mammograms.
It is up to the individual and his/her doctor to determine if screening tests will be implemented. If the health care provider does not cover screening tests which are preferred by the patient, other options are available from the private sector to address these needs at the patient’s own cost.
This article is brought to you by GenWay Biotech Inc. GenWay offers a cancer assessment aimed to detect 20 different types of cancer in the early stages under the brand name You Test You™. To learn more, please visit the website www.youtestyou.com.

References:
1. Agency for Healthcare Research and Quality, Rockville, MD
2. American Cancer Society (ACS) American Cancer Society Responds to Changes to USPSTF Mammography Guidelines. http://www.cancer.org/docroot/MED/content/MED_2_1x_American_Cancer_Society_Responds_to_Changes_to_USPSTF_Mammography_Guidelines.asp
3. American Cancer Society (ACS) Cancer Statistics 2009. http://www.cancer.org/docroot/PRO/content/PRO_1_1_Cancer_Statistics_2009_Presentation.asp
4. Duffy, S., McCann, J., Godward, S., Gabe, R., Warwick, J. “Some issues in screening for breast and other cancers.” Journal of Medical Screening. 2006; 13(Suppl1): S28-S34
5. U.S. Preventive Services Task Force. Screening for breast cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2009;151:716-26, W-236. [PMID: 19920272]

The Need of Early Detection to Fight Cancer

The Importance of Early Detection to Fight Cancer

This blog starts off a serious of articles called Fighting Cancer with Early Detection and is brought to you by GenWay Biotech Incorporated. Our mission is to provide our readers with important facts and figures to enable patients to make better health decisions. This article is not written by a doctor, and it should not be used in place of your physician’s recommendation. You may wish to use the information provided in this article to facilitate a discussion with your physician. To learn more about GenWay Biotech’s cancer assessment, visit the website www.youtestyou.com.

The impact of cancer in the United States in undeniable. Cancer directly affects about one in three women and one in two men in the U.S (1), with more than 560,000 dyeing (2, 3) from it each year. It is widely known that the best chance to reduce these fatality numbers is through early detection. There are two major components of early detection of cancer: screening and education to promote early diagnosis.

Regular use of established screening tests can prevent the development of cancer. Either through identification and removal or treatment abnormalities, screening tests can improve survival and decrease mortality by detecting cancer at an early stage when treatment is more effective. It is important to note that screening refers to testing in individuals who have no symptoms for a particular disease) (4). This makes sense because in many cases symptoms are not present before cancer is diagnosed.

Early detection of cancer through regular screening has been shown to reduce the number of deaths from cancers of the colon and rectum, breast, and uterine cervix. For instance, in addition to detecting cancer early, regular screening can, in many cases, prevent colorectal cancer altogether. This is because some polyps, or growths, can be found and removed before they have the chance to turn into cancer (4).

Survival rates improve dramatically when cancer is diagnosed early and the disease is confined to the organ of origin. The relative 5-year survival rate for colorectal cancer when diagnosed at an early stage before it has spread is about 90%. But only about 4 out of 10 colorectal cancers are found at that early stage. Once the cancer has spread to nearby organs or lymph nodes, the 5-year relative survival rate goes down, and if cancer has spread to distant organs (like the liver or lung) the rate is about 11% (4).

A standard 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed; it includes people with colorectal cancer who may die of other causes, such as heart disease. Five-year relative survival rates are adjusted for patients dying of other diseases, so they reflect the chances of not dying specifically from colorectal cancer. (ACS)

Another striking example is the fact that nine out of 10 women can survive breast cancer simply by detecting it early. Prognosis of a breast cancer depends largely upon its stage and grade at diagnosis, 5-year survival rates ranging from 84% in women diagnosed with Stage 1 disease to 18% in women with Stage 4 disease.

Education to promote early diagnosis should encompass the increased awareness of new screening tests and possible warning signs of cancer, among physicians, nurses and other health care providers as well as among the general public. People without symptoms or special risks need to be aware of these screening methodologies and to be sure they are communicated to the physician.

National organizations such as American Cancer Society (ACS), National Cancer Institute (NCI), American Society of Clinical Oncology (ASCO) and American Academy of Family Physicians (AAFP) are dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives, and diminishing suffering from cancer through research, education, advocacy, and service. A table below represents the generally accepted screening methods based on cancer type for your reference.

This vlog is brought to you by GenWay Biotech Incorporated. Our company strongly believes in the importance of early cancer detection and we commercialize cancer assessment aimed to detect cancer in the early stages under the brand name You Test You™. To learn more please visit the website www.youtestyou.com.

References:

1. Horner MJ, Ries LAG, Krapcho M, Neyman N, Aminou R, Howlader N, Altekruse SF, Feuer EJ, Huang L, Mariotto A, Miller BA, Lewis DR, Eisner MP, Stinchcomb DG, Edwards BK (eds). SEER Cancer Statistics Review, 1975-2006, National Cancer Institute. Bethesda, MD, http://seer.cancer.gov/csr/1975_2006/, based on November 2008 SEER data submission, posted to the SEER web site, 2009.

2. U.S. Cancer Statistics Working Group. United States Cancer Statistics: 2004 Incidence and Mortality. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute, 2007.

3. American Cancer Society. Cancer Facts & Figures 2009. Atlanta: American Cancer Society, 2009.

4. American Cancer Society. Cancer Prevention and Early Detection Facts and Figures 2009. American Cancer Society, 2009.