Question

Screening in general for cancer has been proven to save lives for each type of cancer.

True or False?

And please provide explanations, thanks!

Answer 1

Screening in general for cancer has been proven to save lives for each type of cancer. This statement is undeniably FALSE.

This can be explained through Length Bias and Over diagnosis in Cancer Screening .Length bias means that screening will likely detect slow- progressing cancers more than the fast-progressing cancers .It is important here to remember that slow-progressing cancers can stay in the body for a longer time without the development of any symptoms. The frequency of detection in case of slow-progressing will obviously higher since their pre-clinical period will be longer.

This over-detection leads to over-diagnosis of cancers. A slow-progressing cancer/tumor which was never to grow into a malignant one is detected through screening and is counted as a case of cancer, which it is not.

In-addition, screening programs never seem to save significant lives since overall mortality encompassing all the causes of deaths of screened individuals are not taken. In many cases, screening can cause harm to normal patients since screening procedures involves toxic and invasive methods which can lead to hospitalization and even death. If these cases are counted, then screening may not save a significant number of lives and would be completely ineffective.