Kornum JB, et al. - Whether an elevated erythrocyte sedimentation rate (ESR) is a marker of occult cancer, was investigated by examining cancer incidence and prognosis in patients with a first-time hospital contact for elevated ESR during 1980 to 2013, by linking Danish medical databases and with median follow-up of 4.9 years. Among 18,540 patients, 3,926 cancers were reported during the follow-up. General population and matched population comparisons without elevated ESR were used. Researchers reported a risk of 8.5% for any cancer diagnosed during the first year following the contact for elevated ESR. In addition, these subjects had a markedly elevated overall 1-year cancer incidence, which was even more than 3-fold elevated for most hematologic cancers and for cancers of the peritoneum and connective tissue in the abdominal wall, kidney, and adrenal glands. An increased risk of developing especially hematologic cancers was observed after the first year. Overall, elevated ESR was identified as a strong marker of undiagnosed cancer and was related to poorer survival.