Montefiore News Releases
Step Count Predicts Outcomes in Lung Cancer
- January 13, 2020
By Pam Harrison | January 13, 2020
Step counts from wearable devices appeared to predict prognosis in a small study that analyzed data from patients with locally advanced non-small cell lung cancer (NSCLC).
How active patients were and — more importantly — how inactive they were before receiving chemoradiation showed an association with how well they tolerated and responded to treatment, and was also associated with both progression-free and overall survival.
In contrast, performance status — which has long been considered an important clinical variable in predicting clinical outcomes — did not influence either progression-free survival (PFS) or overall survival (OS) in the same study.
"Baseline activity level measured using wearable devices may help identify patients with NSCLC who are fit for concurrent chemoradiation therapy and can predict clinical outcomes in this setting," the study authors, led by Nitin Ohri, MD, of Albert Einstein College of Medicine in New York City, conclude.
They also suggest that, for patients entering the final stages of their disease, physical activity metrics could help oncologists decide when aggressive treatment might do more harm than good.
The study was published in the November 15 issue of of the International Journal of Radiation Oncology Biology Physics.
"I consider step counts to be a new vital sign for cancer treatment," said Ohri in a press statement.
"We found that tracking our patients' activity levels prior to treatment could give clinicians data with powerful implications," he added. However, he was a little more circumspect in comments made directly to Medscape Medical News. "We don't yet have enough data for clinicians to base cancer treatment decisions on activity metrics," he wrote in an email.
"In contrast, we already feel confident that activity data can be used to augment the supportive care provided during cancer treatment, and if a patient's activity level declines dramatically during therapy, that change needs to spark some conversations," he added.
Prior research carried out by Ohri and colleagues showed that patients who suddenly become less active during treatment are significantly more likely to require hospitalization within the next few days.
Study Details: The analysis involved a total of 50 patients who had undergone continuous activity monitoring with a commercial fitness tracker (Garmin Vivofit) in one of three prospective clinical trials.
The majority (80%) of patients had stage 3 NSCLC while the remaining patients had inoperable stage 2 disease or limited metastatic disease in the brain that was treated radically before patients received chemoradiation. Nine of these 50 patients (18%) received adjuvant durvalumab (Imfinzi, AstraZeneca).
Using data from a median of 17 days, step count averages were calculated for each subject. Data was subsequently collected between the time patients received their step count device until after they had completed their first week of radiation therapy.
The median baseline step count average was 5354 steps (range 3425-8196 steps), the team reports.
Categorized by their baseline step count, 18% of the group was judged to be highly active, 46% were moderately active, and 36% were inactive.
The team found that half of patients who were qualified as inactive by their step count measure had to be hospitalized during the course of their radiation treatment compared with only 9% of those were moderately or highly active (P = .004). In contrast, performance status did not predict hospitalization risk, the authors add.
Moreover, only 67% of inactive patients were able to complete their treatment course without delaying treatment for over 1 week compared with 97% of patients who were moderately or highly active (P = .006). The median duration of follow-up for surviving patients was 17.2 months. For the overall cohort, the median PFS was 11.6 months and the median OS was 27.4 months.
"Baseline activity level was a statistically significant predictor of PFS…at an adjusted hazard ratio = 8.66 for inactive subjects (P < .001)," Ohri and colleagues point out. For example, only about 10% of inactive patients were alive and without disease progression after 18 months compared with approximately 60% of those who were more active (P < .001), they note. At the same time point, 45% of inactive patients were still alive compared with over 75% of those who were more active (P = .003). The team is currently concluding a randomized trial in which they are trying to increase patients' step counts through the help of personalized daily step count goals as they go through chemoradiation therapy
What Mechanism Is Involved?
What explains the link between inactivity and poor cancer outcomes? This is now being examined, Ohri commented. One obvious explanation may simply be that patients who are inactive because of difficult cancer symptoms may be unable to complete treatment as scheduled, undermining the efficacy of that treatment, he suggested.
Another hypothesis might be that being physically inactive promotes inflammation — a hallmark of cancer — and that can promote disease progression, he also suggested. Whatever the underlying mechanism, Ohri and colleagues expect that activity metrics will also prove useful in other cancer types. The study was supported by a Paul Calabresi K12 Career Development Award for Clinical Oncology and a grant from the Radiation Oncology Institute. Ohri has disclosed no relevant financial relationships.