# Adherence to oral antineoplastic therapy among patients with advanced or metastatic non-small cell lung cancer: a noninterventional, prospective study

## TL;DR

This study found that most patients with advanced lung cancer adhere well to oral cancer treatments, and nonadherence is linked to worse outcomes.

## Contribution

The study provides new evidence on adherence rates and their impact on survival in patients with non-small cell lung cancer receiving oral antineoplastic therapy.

## Key findings

- 85.3% of patients adhered to oral antineoplastic therapy with adherence >80%.
- Nonadherent patients had significantly shorter progression-free survival compared to adherent patients.
- Nonadherence was the only factor associated with progression-free survival in multivariate analysis.

## Abstract

We aimed to evaluate adherence to oral antineoplastic therapy (OAT) in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) and its potential relationship with several clinical outcomes.

Observational, prospective, multicenter study performed by 6 hospital pharmacists in Spain. The primary outcome was the proportion of treatment adherence as evaluated by pill reconciliation during the 3-month active follow-up period. Those with an adherence > 80% were categorized as adherent. We performed multivariate Cox regression analyses to explore the factors associated with progression-free survival.

From December 2019 to November 2022, we recruited 95 evaluable patients. Most of the patients received osimertinib (n = 45, 45.3%) or a first- or second-generation tyrosine kinase inhibitor (n = 23, 34.8%). Eighty-one patients showed greater than 80% adherence (85.3%, 95% CI 78.1% to 92.4%), as evaluated based on pill reconciliation; the mean (SD) adherence to OAT was 94.7% (11.4). According to the univariate analysis, the time to progression from study entry was significantly shorter among patients who were nonadherent than among those who were adherent (median 6.5 months vs. not reached, log-rank test p = 0.006; hazard ratio [HR] 2.619, 95% confidence interval [CI] 1.240–5.532). In the multivariate Cox regression analysis, nonadherence was the single factor associated with progression-free survival.

Consistent with previous evidence in this setting, our results suggest that adherence to oral antineoplastic treatment among patients with NSCLC is high. Whether this high rate of adherence translates to better clinical outcomes should be further evaluated in larger samples.

The online version contains supplementary material available at 10.1007/s00432-025-06264-0.