The last point is the key to the whole debate–is there such a thing as indolent lung cancer? Many clinicians will say “no” categorically, and “all lung cancers are aggressive”. But this statement is made before our detection tool (chest X-ray and sputem cytology…think big fat crayon) has been replaced with spiral CT (think scanning electron microscope). The point is that noone knows until enough evidence has been collected.

Give “Should I been screened for cancer…probably not” by Gilbert Welch, M.D., a read. Very compelling. Three points:

(1) length bias: suppose you have a population of sticks floating down the river. You wish to know the average size of the sticks, so you begin pulling sticks out as they pass. You compute the sample mean. It turns out that your answer is noticably larger than the true population mean. Why? Because you’re more likely to pick longer sticks!!!
Whats this have to do with cancer screening? Think about it.

(2) Lead time bias:
Lets try to understand “early detection saves lives” a little more precisely.
Imagine two identical copies of a hypothetical person (same biology same disease history same everything), named Joe and Moe. Joe gets detected by SCT at age x. Moe gets detected by a less sensitive means (either normal chest x-ray or just walks in with an achey lung), at age y, y > x. Both men are treated, but both die of lung cancer..the fist at age T_1 and the second at age T_2. Now, the fairest comparison of the benefit due to SCT is to compare T_2 – y (Moe’s survival past Moe’s detection) to T_1 – y (Joe’s survival past the time he would have been detected in the absence of SCT screening.

The Henschke study essentially compared
T_2 – y to T_1 – x, which is exagerating the benefit due to screening by the ‘lead time’.

(3) All that glitters is not a Gold standard:
The iron clad answer to the question “do I have cancer” is presumably, the results from the pathology lab. Imagine a graph of “reliability” versus “Sensitivity of screening instrument”
As the instrument becomes more and more sensitive, the tumors and biopsy speciments sent off to the pathology lab become more and more ambiguous and difficult to read, so that the reliability of the findings from the pathology lab deteriorate. This has been verified by two (well designed) studies (Welch’s book).

Sorry for the long diatribe, but maybe this answers your question.
By the way, the mantra “early detection saves lives” doesn’t apply to every other organ as you mention. It has only been demonstrated via randomized controlled trial in the case of breast cancer (the HIP study) with efficacious results for women over 50…but even that conclusion is still controversial because of possible flaws in the study design (not quite on the level of the flaws discussed above).

As a 9 year lung cancer survivor as a result of CT screening, I am truly amazed at your attitude. Why is it that people like you think that all of the rules for other cancers don’t apply to lung cancer. If the ACS and the medical communication believe “early detection saves lives” why doesn’t that apply to lung cancer. It applies for every other one: breast, rectal, prostrate, ovarion, pancreatic, etc. Please enlighten me as to why I should be dead.

- Survivor

Its debatable whether this belief actaully holds in a number of neoplasms