Short telomeres lead to chromosomal instability and increased cancer risk and mortality

Telomeres are essential to preserve the integrity of the genome. Critically short telomeres lead to replicative cell senescence and chromosomal instability and may thereby increase cancer risk.

Leukocyte telomere length was measured by quantitative polymerase chain reaction in 787 participants free of cancer at baseline in 1995 from a prospective, population-based study in Italy. The follow-up period was 10 years.

Human chromosomes (grey) capped by telomeres (white). Image source: Wikipedia, public domain.

11.7% of participants developed cancer (incidence rate, 13.3 per 1000 person-years).

Short telomere length at baseline was associated with incident cancer independently of cancer risk factors (hazard ratio [HR] 1.60).

Compared with participants in the longest telomere length group, the HR for incident cancer was 2.15 in the middle length group and 3.11 in the shortest length group. Furthermore, short telomere length was associated with cancer mortality and individual cancer subtypes with a high fatality rate.

There is an inverse relationship between telomere length and both cancer incidence and mortality.

References:
Telomere Length and Risk of Incident Cancer and Cancer Mortality. Peter Willeit, MD; Johann Willeit, MD; Agnes Mayr, MD; Siegfried Weger, MD; Friedrich Oberhollenzer, MD; Anita Brandstätter, PhD; Florian Kronenberg, MD; Stefan Kiechl, MD. JAMA. 2010;304(1):69-75.

Participation in clean-up of oil spill associated with airway injury and chromosomal damage

In 2002, the oil tanker Prestige spilled more than 67 000 tons of bunker oil, heavily contaminating the coast of northwestern Spain. The study population included local fishermen who were highly exposed (n = 501) or not exposed (n = 177) to oil. They were evaluated 2 years after the spill.

Elevated markers of airway injury

Persons exposed to oil were at increased risk for lower respiratory tract symptoms (risk difference, 8.0). However, lung function did not significantly differ between the groups. Exposed participants also had higher levels of exhaled vascular endothelial growth factor (risk difference, 44.8) and basic fibroblast growth factor (risk difference, 16.0).

Human chromosomes (grey) capped by telomeres (white). Image source: Wikipedia, public domain.

Chromosomal damage

A higher proportion of exposed participants had structural chromosomal alterations (risk difference, 27.4), predominantly unbalanced alterations.

Participation in clean-up of a major oil spill was associated with persistent respiratory symptoms, elevated markers of airway injury in breath condensate, and chromosomal damage.

References:

Health Changes in Fishermen 2 Years After Clean-up of the Prestige Oil Spill. Ann Intern Med, October 19, 2010, vol. 153 no. 8 489-498.