How Data on Cancer Are Collected and Used
Every state has a law requiring it to have a cancer surveillance program and collect specific information about every patient whose cancer was diagnosed by a doctor in that state.
Although most patients are not aware of the programs, doctors and hospitals are. They provide the patient data, which include the name, address, age and race of every patient, as well as information on the type of tumor and its spread. The federal government helps pay for the registries and coordinates the aggregation of state data but does not have the legal authority to collect the data itself.
Seventeen regions, covering 26 percent of the population, also provide detailed information to the National Cancer Institute, which uses the data to provide a snapshot of the nation’s cancer rates and to track cancer nationally.
This program follows patients from the time their cancers are diagnosed until the time they die, and is the way survival rates are calculated. The cancer institute program also follows patients to see whether they develop a second cancer. And the data are used to identify differences in care and outcomes among people of different racial, ethnic and socioeconomic groups.
Different state registries use their data in different ways. Some just count cancer cases and provide summary reports. Others, including the 17 regions that are part of the cancer institute’s network, do much more, investigating cancer risk factors and outcomes. They provide data to academic researchers who are doing studies and need to interview patients or need genetic information. But first, the registries review the studies for scientific merit and make sure the study has been approved by at least one ethics panel.