Abstract: Objectives: This prospective multicenter cohort study aimed to describe new cancer events in nursing home residents (NHR). Materials and Methods: The study was performed in 39 nursing homes from the Armonea network in Belgium, covering 4262 nursing home beds. All NHR in these homes were prospectively followed during 1 year for occurrence of cancer events (diagnosis or clinical suspicion of a new cancer or progression of a known cancer). After training, each site's local staff identified NHR with cancer events in collaboration with the treating general practitioner (GP). NHR with cancer events were included after informed consent, and data about general health and cancer status were collected every 3 months up to 2 years. Results: In only nine NHR (median age 87 years, range 72-92), a cancer event was recorded during follow-up including five new (suspected or diagnosed) cancer events (incidence rate = 123/100.000 NHR per year) and four NHR with (suspected or diagnosed) progressive disease. In four NHR with suspected cancer, no diagnostic procedure was performed, and in five no anticancer treatment was started. Conclusion: Clinically relevant cancer events (potentially requiring diagnostic or therapeutic action) occur at a much lower frequency in NHR than expected from cancer incidence data in the general older population. Although some underreporting of cancer events cannot be excluded, this prospective study supports several previous retrospective observations that cancer events are rare in very frail older persons. Moreover, diagnostic and therapeutic actions for (suspected) cancer events are often not undertaken in this population. (C) 2019 Published by Elsevier Ltd.