Wearable Activity Tracker Data Enhance Patient Assessment in Lung Cancer

Objectively measured data gathered through a wearable activity tracker can supplement Eastern Cooperative Oncology Group Performance Status (ECOG PS) data, considered subjective, to provide a more comprehensive portrait of patient status when being treated for advanced lung cancer, according to a new analysis published online today in JAMA Oncology.

The study investigators highlight that although there is widespread use of ECOG PS “to guide treatment decisions in patients with advanced lung cancer, its assessment is subjective, potentially leading to discordance among observers.” They add that data on the role of physical activity in cancer prevention and prognosis improvement remain scarce.

Lung cancer | Image Credit: steph photographies - stock.adobe.com

Their analysis encompassed 119 outpatients—enrolled from December 2021 to August 2022; median age, 72 (range, 32-88) years; 59.7% were male patients—with advanced lung cancer scheduled to receive or already receiving systemic therapy at Matsusaka Municipal Hospital in Mie, Japan. Each was followed for up to 14 days through the amuelink wearable device from Sony, with their physical activity evaluated through the sum and mean of metabolic equivalent tasks, distance walked, and steps taken for diagnostic value. ECOG PS was measured by a study investigator or physician, and the primary study end point was estimating the area under the curve (AUC) for diagnosing ECOG PS of 2 or higher using physical activity in receiver operating characteristic (ROC) analysis.

Overall, most patients had a baseline ECOG PS of 0 or 1, the device was worn for a median of 8 (95% CI, 7.2-8.8) days, and the median (IQR) survival follow-up was 13.4 (10.1-15.2) months. Fourteen patients died, and 1 was untraceable at 6 months.

For an ECOG PS of 2 or more, the best diagnostic value was seen with mean distance walked (MDW), which had a mean AUC of 0.818 (95% CI, 0.703-0.934). Metabolic equivalent tasks had the lowest diagnostic value, with a mean AUC of 0.482 (95% CI, 0.337-0.628). Step total’s AUC was 0.755 (95% CI, 0.594-0.915).

Similar results were seen for an ECOG PS of 0 or 1 and 6-month survival. MDW had the best diagnostic value, at AUCs of 0.765 (95% CI, 0.664-0.863) and 0.806 (95% CI, 0.694-0.918), respectively, and metabolic equivalent tasks again had the lowest, at AUCs of 0.593 (95% CI, 0.470-0.716) and 0.497 (95% CI, 0.302-0.692).

When overall survival (OS) outcomes were compared between higher-activity and lower-activity groups, the difference was statistically significant, with an 81% lower mortality risk for those with a higher vs a lower level of activity (HR, 0.19; 95% CI, 0.06-0.61; P < .002). There was also a statistically significant difference in OS curves between the higher- and lower-activity groups (HR, 0.17; 95% CI, 0.05-0.57; P < .001). Differences attributed to sex, age, smoking status, and ECOG PS were not considered statistically significant.

Of their findings, the study investigators noted that the results seen for MDW indicate it has potential to be a complementary prognostic indicator for patients being treated for advanced lung cancer, due to its positive correlation with ECOG PS and prognosis.

“This highlights,” they emphasized, “the statistically significant contribution of physical activity to survival prediction, irrespective of other factors.” They caution against replacing ECOG PS with measures of physical activity in patients, however, noting that their data also show a wide range of physical activity among patients with the same ECOG PS and there is potential for overestimation of results.

They concluded that physical activity has potential as an objective measure and alternative to ECOG PS, but due to the varying patient levels of activity within the same ECOG PS category, its value is best delivered in combination with ECOG PS.

Reference

Ito K, Suzuki Y, Sakaguchi T, et al. Physical activity using a wearable device as an alternative to performance status in patients with advanced lung cancer. JAMA Oncol. Published online March 28, 2024. doi:10.1001/jamaoncol.2024.0023