Ludwig Johns Hopkins Co-director Bert Vogelstein and and Johns Hopkins colleague Cristian Tomasetti led a study exploring why cancer incidence climbs precipitously after the age of 65 but then declines in people over the age of 80. A major clue for the study came from a review of data that indicated the accumulation of mutations slows in the very old. Cristian, Bert and their colleagues analyzed cell replication rates in samples of healthy, self-renewing tissues collected during biopsies and other medical procedures from more than 300 patients in their 20s and 80s. They reported in a September paper in the Proceedings of the National Academy of Sciences that cell division rates slowed by 40% in colon tissue samples from people in their 80s compared with those in their 20s. In esophageal tissue, the division rate slowed by about 25%, by 26% in the duodenum and by 83% in tissue found near the nose. A parallel slowdown was not seen in mice, which do not experience a similar decline in cancer incidence. These results have significant implications for understanding the relationship between normal stem cells, aging and cancer.
This article appeared in the April 2020 issue of Ludwig Link. Click here to download a PDF (1 MB).