Potential Harms of Screening

Earlier detection of induced cancer harm is not that much easy to understand. Cancer screening has no or little sense as it is excellent example for unavoidable progressive diseases. Intermediate abrasions can be controlled from reaching cancer stage by screening and diagnosis. At times, diagnostic test produces side effects which lead to individual sufferings.

Cascade of screening

It is obvious screening is not a single time clinical test. It requires series of clinical steps which may end up in benefiting an individual or inducing harm. Result of screening can either result in positive benefits or negative harms.  Majority of individual shows negative result rather than positive result. If result is positive, then it is necessary to cross check whether it is true positive or false positive before opting for a diagnostic test. Diagnosis varies depending on the sensitivity degree of screening test. Individual who shows true positive result are not benefited from earlier cancer detection.

Potential harm of screening categories

Two types of potential harm of screening are

• False positive test
• Over diagnosis and Over treatment

False positive test

Due to uncertainty of cancer development, false positive screening result may occur. For instance female with abnormal mammogram is suspected to develop breast cancer. Hence follow up test should be carried out. As a result psychological stress may arise. That is female with abnormal mammogram may undergo negative biopsy after which physicians say that there is no possibility of cancer development. Such false positive screening test fractions are more compared to true positive screening tests. Specificity determines the screening results. Specificity refers to the number of individual who are not having any diseases but are suspected to have cancer. True positive screening results extend the life of an individual and are rare. Sensitivity of screening test benefits the individual. False positive result may raise psychological effects and adverse effects. This shows sensitivity and specificity are inversely proportional to each other. When sensitivity increases specificity decreases.

Over diagnosis and Over treatment

True positive result may lead to over diagnosis and over treatment. Over treatment of cancerous cells is not avoidable. As a result of this, over treatment produce side effects which long last. So to over treatment they are again subjected to treatments which add up to the lesions and inflammations. Based on this individuals are classified in to four categories.

Category 1: Screening of rapidly growing cancerous cells is no more effective. Earlier detection cannot provide any benefit.

Category 2: In spite of detection period some cancers can be easily detected. Here screening has no effect.

Category 3: Cancer which requires no screening and further treatment is not effective for the individuals who have pseudo disease. Treating Category 3 individuals may result in over treatment. This may cause potential harm to an individual. It is because it is difficult to differentiate the cancer from other such categorized diseases.

Category 4: Individual who require effective screening and further diagnosis treatment. They are benefited by this screening test.

Questions:

• What are referred as cancer survivors?
• How do weigh potential harms and benefits of screening?
• State major categories of potential harms of screening test with paradigm of cancer development.
• What is 5 year survival rate statistic calculation?
• Define pseudo disease.