If you think you may be at risk for cancer, you should discuss this concern with doctor. You may want to ask about reducing your risk and about a schedule for checkups. Over time, several factors may act together to cause normal cells to become cancerous.
The most well-known ways to protect you from various cancer types, are the following:

• Avoid smoking areas and quit smoking.
• It is best to avoid the midday sun (from mid-morning to late afternoon) whenever possible. You also should protect yourself from UV radiation reflected by sand, water, snow, and ice. UV radiation can penetrate light clothing, windshields, and windows.
• Wear long sleeves, long pants, a hat with a wide brim, and sunglasses with lenses that absorb UV.
• You should talk with your doctor or dentist about the need for each x-ray. You should also ask about shields to protect parts of the body that are not in the picture.
• Follow instructions and safety tips to avoid or reduce contact with harmful substances both at work and at home. Although the risk is highest for workers with years of exposure, it makes sense to be careful at home when handling pesticides, used engine oil, paint, solvents, and other chemicals.
• Do not have unprotected sex or share needles. You can get an HPV infection by having sex with someone who is infected. You can get hepatitis B, hepatitis C, or HIV infection from having unprotected sex or sharing needles with someone who is infected.
• If you think you may be at risk for HIV or hepatitis infection, ask your doctor about being tested. These infections may not cause symptoms, but blood tests can show whether the virus is present. If so, the doctor may suggest treatment. Also, the doctor can tell you how to avoid infecting other people.
• A woman considering menopausal hormone therapy should discuss the possible risks and benefits with her doctor.
• If you think you may have a pattern of a certain type of cancer in your family, you may want to talk to your doctor. Your doctor may suggest ways to try to reduce your risk of cancer. Your doctor also may suggest exams that can detect cancer early.
• Doctors advise people who drink to do so in moderation. Drinking in moderation means no more than one drink per day for women and no more than two drinks per day for men.
• Eat well: A healthy diet includes plenty of foods that are high in fiber, vitamins, and minerals. This includes whole-grain breads and cereals and 5 to 9 servings of fruits and vegetables every day. Also, a healthy diet means limiting foods high in fat (such as butter, whole milk, fried foods, and red meat).
• Be active and maintain a healthy weight: Physical activity can help control your weight and reduce body fat. Most scientists agree that it is a good idea for an adult to have moderate physical activity (such as brisk walking) for at least 30 minutes on 5 or more days each week.

----------------------------------------------------------------------------------------------------------                                                  ROLE OF SCREENING IN  CANCER (SUMMARY).
   
Screening is the process of early diagnosis of a disease ie  identifiication of disease or risk factor in its  pre  symptomatic or preclinical stage. Concept of screening developed way back in 1940.
 
Impact of screening on human health slowly progressed, from obvious changes in the vital statistics such as the decline in incidence of syphilis, to less obvious changes such as the decline in mortality of cancer of the cervix, to finally more subtle changes, such as the impact  of  mammographic screening on breast cancer mortality.
 
Methods of evaluation had therefore to adapt, evolving from simple surveys to case-control studies, cross sectional studies, population based studies and now randomized  controlled trials.
 
A report by the National Cancer Policy Board and the Institute of Medicine, estimated that a 19% decline in the rate at which new cancers occur and a 29% decline in the rate of cancer deaths could be achieved by 2015 through changes in behavior and greater dissemination of proven technologies, including cancer screening.
 
 ADVANTAGE OF SCREENING
 

• Improved  prognosis for those with screen-detected cancers.
• The possibility of less radical treatment
• The optimal outcome is a reduction in cancer mortality.

 
  IDEAL SCREENING TEST
 

1.         High sensitivity,
2.         High specificity,
3.         low cost, and
4.         little inconvenience and discomfort to the screening population.

 
        IDEAL CANCER FOR SCREE
 

•                 Substantial morbidity and mortality,
•           High prevalence in a detectable preclinical stage ,and
•           Possibility of effective and improved treatment because of early detection.

 
 
 ASSESSMEN OF SCREENING PROGRAM
 
In assessing effectiveness of screening technologies, the RANDAMIZED CONTROLE TRIALS (RCT) has been the gold standard. It is the most powerful methodology for demonstrating the value of screening in comparison to an unscreened group.  RCTs minimize biases inherent in other designs, especially lead time, length bias, selection bias, and  over diagnosis .
   
 DRAWBACKS OF SCREENING
 
Physical, economic, and  psychological consequences of false-positives and false-negatives,
The potential for over diagnosis
 
SCREENING FOR CANCER CERVIX
 Cervical cancer is one of the leading cancer as well as leading cause of cancer   deaths among women in developing countries.
 
Pap (papinocolaou) smear ,is the screening method of choice in developed   countries.
Since the  implmentation of pap smear screening program in 1949, the  incidence rate of invasive cervical cancer has decreased from more than 30 per 100,000 women to less than 5,and the mortality rate has decreased from 12 to about 3 per 100,000.These excellent results have been obtained through a combination of a population based program with a central registry.
 
CURRENT RECOMMENDATIOS FOR SCREENING CANCER CERVIX ARE
 
Screening should start approximately 3 years after the onset of sexual activity ,and  the interval is variable from 1 to 3 years.
More than one-half of invasive cervical cancers occur in women who have never been screened, or at least not within the previous 5 years.
 ALTERNATIVE METHODS FOR CANCER CERVIX SCREENING
      Unaided visual inspection ,
      Cervicography,
      Visual inspection after application of acetic acid (VIA),
      VIA with magnification,and
      Human papilloma virus  (HPV)DNA testing
 
Currently,an IARC funded cross-sectional study is being conducted in 4 Indian locations (Mumbai, Calcutta,  Jaipur and  Trivandrum) to evaluate the test  charecterstics of various screening methods on a large sample of 30,000 women. The sensitivity and specificity of pap smear, HPV DNA testing ,and VIA are simultaneously evaluated. Results of this study are awaited .
 
SCREENING FOR BREAST CANCER
 
Breast cancer is one of the most significant health concerns in the United States.
It is the most commonly diagnosed cancer in women and the second leading cause of cancer death in women.
 
The risk of being diagnosed with breast cancer increases with age.
 
      Screening significantly contributed to the 23.5 percent decline in breast cancer mortality from 1990 to 2000.
 
National Cancer Institute has an online tool (http://www.cancer.gov/bcrisktool).
 
 Another tool is available at               http://www.breastcancerprevention.org/raf_source.asp.
 
CURRENT RECOMMENDATIOS FOR SCREENING BREST CANCER ARE
 
For women 40 years and older who are at  average risk, most major health organizations endorse mammographic screening every one to two years, and every year after age 50 as long as the woman is healthy.
 
The clinical breast examination may also be important, because up to 10 percent of breast cancers may be clinically evident while being silent  mammography. For those with breast cancer genetic mutations, mammography should begin at age 25, or at an age 10 years younger than the youngest case diagnosed in the family.
 
SCREENING FOR LUNG CANCER
 
Lung cancer is the major cause of cancer-   related mortality in both men and women in industrialised countries and causes   more deaths than colorectal, breast and    prostate cancer combined.

CURRENT RECOMMENDATIOS FOR SCREENING LUNG CANCER ARE
 
American Cancer Society, 2001  Recommends against routine screening of asymptomatic persons. Individuals interested in early detection should be encouraged to participate In trials.
American College of Chest Physicians, 2003  Recommends that individuals should only be screened in the context of well-designed clinical trials.
US Preventive Services Task Force, 2005  Evidence is insufficient to recommend for or against screening asymptomatic persons for lung cancer.
              
CONCLUSIONS FOR ROLE OF SCREENING IN  CANCER
 
Medical screening has existed for about 60 years, and has a very rich history.
The preclinical identification of disease has been a major component of modern medicine and public health.
Screening has contributed to some of  major successes of modern medicine .
 
                                                                                     DR SHASHIKANT SAINI
                                                                         CONSULTANT SURGICAL ONCOLOGY
                                                                                           BMCHRC
 
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