How are cancer statistics compiled? Who counts them?

I'm suspicious of cancer mortality statistics published by the government. What is a "survivor"? What is a "death?" Do people really die of one thing? What if they die from the treatment? Does early detection really alter the DATE of death or just the length of the period until death?

How are cancer statistics compiled? Who counts them?
As a cancer registrar it is my job to report all of this information to the government for the hospitals I work for. We stage the cancer, tell them what tests and treatment the patient had, if they were cancer free, alive or dead, etc. etc. We give them everything. It is required by law in every state of the United States. Each state gives the data to Washington DC and they give it to The World Health Organization as do all the countries that make up the United Nations. Researchers all over the world use this data and the government publishes the statistics.





The statistics are based on survival rates (how long the person lives) from the date of diagnosis and can be subcategorized by race, age, gender and stage at diagnosis.





No, people do not usually die of one thing. However, you can tell if early detection makes a difference if people with a stage 4 colon cancer live for a year after diagnosis and people with a stage 1 live for 10 years or more.





If someone dies and they were not cancer free at the time it is contributed to the cancer. If they were cancer free it is not.
Reply:Hi Neil. Your questions are valid and important, but not easy to answer.





First, for the latest cancer statistics use Pubmed to read this paper: CA Cancer J Clin. 2008 Mar-Apr;58(2):71-96. "Cancer statistics, 2008".





Cancer treatment is generally not very effective. The "war on cancer" has led to a dramatic increase in our understanding of the biochemical changes involved in carcinogenesis, but progress in treating most cancers has not been as rewarding.





Because of this poor treatment track record, cancer is the only disease that has a 'phony' definition of cure. A cancer is considered 'cured' if the patient survives 5 years after diagnosis. No other disease is considered cured if the patient survives 5 years after diagnosis!





I believe most cancer statistics (aside from the 5 year survival 'game') are legitimate (within the limitations of data collection). However, there are factors that are driven by scientific progress that can artificially 'change' cancer stats. A good example is the so-called "Will Roger's Phenomenon" (You can read many articles on this issue and cancer by going to Pubmed).





Will Rogers one said: "When the Oakies leave Oklahoma and move to California, they raise the average intelligence of both states!" So, how can this be true? It would be true if the intelligence of the Oakies is mid-way between those in California and the people they left behind in Oklahoma (Californians being dumber than Okies and remaing Oklahomans being smarter).





The Will Rogers Phenomena in Cancer has recently lead to 'improved' cancer survival statistics without any actual changes in cancer survival. Just 10-15 years ago, science could only seperate many cancers into 'early' or 'advanced' stages at the time of diagnosis. However, recent scientific advancements have enabled the identification of a third, intermediate, stage at diagnosis.





Generally, the new 'middle stage' of cancer severity was lumped into the 'early stage' groups. Now, it gets lumped into the 'advanced stage' groups. This results in better survival stats for both groups! - the Will Rogers Phenomenon!





Hope this wasn't too complex to be helpful.





Best wishes and good luck.





p.s. a few years ago my mother died from breast cancer. She survived more than 6 years after her initial diagnosis, so she went into the statistics as a 'cure'. Her funeral suggests otherwise.