Life expectancy in stomach cancer survivors adjusted for blood-test-based frailty: insights into biological aging.

[BACKGROUND] Frailty is associated with biological aging, causing poor prognosis for cancer survivors, but has not been considered in life expectancy (LE) estimates. This study aims to estimate frailty-adjusted LE for patients aged ≥50 with stomach cancer, using routine blood tests.

[METHODS] We included 8,281 patients aged ≥50 diagnosed with stomach cancer in 2007-2018 at National Cancer Center (NCC), extracted from electronic health records. Frailty was assessed by 27 laboratory tests (FI-Lab) and classified as non-frail and frail. The impact of frailty on mortality was estimated by cause-specific Cox regression models with age as the timescale. The area under the survival curve was used to estimate the remaining LE adjusted for frailty.

[RESULTS] Frail patients (higher FI-Lab) had 1.4-fold higher risk of cancer and non-cancer mortality and shorter LE than non-frail patients (lower FI-Lab). Frailty affected 31.2% of middle-aged populations, leading to larger LE losses than in older groups. LE losses due to frailty for males at age 50 and 85 were 7.6 and 2.0 years, slightly higher than the losses in females (6.9 and 1.8 years, respectively). The mortality risk and LE loss due to frailty were largest in localized stage, at age 50: 3.9 years for males and 3.0 years for females, compared to <2 years in regional stage and 0.5 years in distant stage for both sexes.

[CONCLUSIONS] FI-Lab-defined frailty was associated with significant LE loss, particularly in male, middle-aged survivors with early-stage stomach cancer. By capturing early signs of biological aging, FI-Lab-based LE estimates may support clinical assessment and individualized survivorship care.