Collecting data on cancer.

EDITOR, - Few people would disagree with S J Karp's plea for improving the collection of data on patients with cancer.1 The case Karp makes for the clinical oncology information network, however, is unconvincing. One justification claimed for the network is that three studies came to erroneous conclusions in auditing the outcomes of care because they used data for cancer registries.*RF 2-4* This is incorrect; Karp has misunderstood the studies' design. All three studies were …