# University of Arizona Y chromosome cancer study

> Live situation record from CLSTR: https://clstr.news/situations/university-of-arizona-y-chromosome-cancer-study
> Updated: 2026-10-03T14:37:19.000Z. Sources: 12. Developments: 3.

Researchers at the University of Arizona Cancer Center have published findings in ‘JCI Insights’ regarding the link between mosaic loss of the Y chromosome (mLOY) and cancer risk in men.

The study, led by Dr. Dan Theodorescu, involved the analysis of over 4.3 million cell nuclei from 1,000 tissue samples across 405 men. The research suggests that mLOY creates a ‘pre-neoplastic field effect,’ establishing zones of genetic vulnerability in tissues that appear normal under microscopic examination. This pattern of chromosome loss was observed across various organs, including the bladder, colon, rectum, esophagus, pancreas, lungs, and prostate.

Subsequent details emphasize a spatial correlation, noting that Y-chromosome loss occurs more frequently in tissue located immediately adjacent to tumors. While the findings suggest mLOY could potentially serve as a biomarker for early cancer detection, researchers stated that further determination is required to establish it as a reliable clinical screening method.

Further analysis highlights that mLOY is a common genetic change in aging men; reports suggest up to 40 percent of men show identifiable loss in certain blood cells by age 70, increasing to 60 percent by age 90. To conduct their research, the team utilized fluorescent in situ hybridization to examine the presence of X and Y chromosomes within the cells, reinforcing the potential for mLOY to serve as an early warning sign for cancer risk.

## Claims

- A research team led by Dan Theodorescu from the University of Arizona Cancer Center studied 1,000 tissue samples from 405 men. (corroborated by 3 sources)
- There is a spatial relationship between the loss of the Y chromosome and proximity to cancerous tissue. (corroborated by 3 sources)
- The research team evaluated 4,327,315 cell nuclei. (corroborated by 3 sources)
- Men can lose the Y chromosome in individual body cells as they age, a phenomenon known as mosaic loss of Y (mLOY). (corroborated by 3 sources)
- The study examined tissue samples from eleven different organs or body regions, including the bladder, prostate, lung, intestine, and pancreas. (corroborated by 3 sources)

## Timeline

### 2026-10-03: University of Arizona study links Y chromosome loss to cancer risk

University of Arizona researchers have linked the gradual loss of the Y chromosome in men to an increased genetic risk for cancer development.

2 sources. https://clstr.news/cluster/university-of-arizona-study-links-y-chromosome-loss-to-cancer-risk-1

### 2026-09-25: Scientific studies reveal dual brain origins and genetic cancer markers

Recent scientific studies reveal the human brain develops from two distinct nervous systems, link Y-chromosome loss in men to cancer proximity, and suggest longevity may be influenced by parental age.

6 sources. https://clstr.news/cluster/university-of-arizona-study-links-y-chromosome-loss-to-cancer-proximity

### 2026-09-19: University of Arizona study links Y chromosome loss to cancer risk

Research from the University of Arizona suggests that the loss of the Y chromosome in men may be an early sign of cancer, creating genetically vulnerable zones in otherwise normal tissues.

4 sources. https://clstr.news/cluster/university-of-arizona-study-links-y-chromosome-loss-to-cancer-risk

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Cite as: University of Arizona Y chromosome cancer study. CLSTR, https://clstr.news/situations/university-of-arizona-y-chromosome-cancer-study