Open Peer Review on Qeios Missing Data National Cancer Institute Source: National Cancer Institute. Missing Data. NCI Thesaurus. Code C142610. Missing data refers to required or expected data that is not present, which may be due to non-completion or corruption.Open Peer Review on Qeios Missing Data National Cancer Institute Source: National Cancer Institute. Missing Data. NCI Thesaurus. Code C142610. Missing data refers to required or expected data that is not present, which may be due to non-completion or corruption.