Chest CT Screening Lowers Lung Cancer Mortality in Japan

Low-dose chest CT screening may result in lower lung cancer mortality in the community four to eight years after the screening introduction, according to findings of a Japanese study in the journal Lung Cancer.

Researchers undertook a 14-year analysis of lung cancer mortality among residents of Hitachi City, Japan, where nearly 40 percent of the inhabitants, aged 50 to 69, were estimated to have participated in at least one screening test between 1998 and 2009. The cancer mortality data were obtained from a regional cancer registry and the standardized mortality ratio (SMR) of lung cancer was calculated for each five-year period between 1995 and 2009 (1995 to 1999, 2000 to 2004, and 2005 to 2009.

The results showed that age-specific lung cancer mortality rates in the community among both men and women, between ages 50 and 79, were lower in 2004 to 2009 than in earlier years - after the implementation of a lung CT screening program.

When the screening program was introduced and during the early years, SMR was about the same, with mortality rates comparable to the national level. But after 2005, the lung cancer mortality rate fell by 24 percent.

“[The] results suggest that wide implementation of low-dose chest CT screening may decrease lung cancer mortality in the community four to eight years after introduction of the screening,” the authors concluded.

U.S. studies, including that of the National Cancer Institute published last year, have shown screening with CT can reduce the risk of dying from lung cancer. Community-based screening programs are gaining traction.