Photo Credit: Liliia Bila

Survival in NSCLC improved with guideline-concordant care in lung cancer, and several factors can be addressed to reach more patients with such care.

“The measurement of adherence to clinical practice guidelines has been demonstrated to be an effective measure of healthcare disparity and equity of access for disadvantaged populations,” researchers wrote in Clinical Lung Cancer.

However, the regularity with which guideline-concordant treatment (GCT) is implemented in lung cancer care is unknown. Also unknown are the causes behind a practitioner forgoing GCT. Although believed to be positive, the effect of GCT application on survival rates has not been studied in detail, including variables such as age and specific treatment.

To address these knowledge gaps, Baki Billah, PhD, and colleagues conducted a prospective cohort study that “aimed to describe the patterns and extent of delivery of GCT to patients with newly diagnosed NSCLC [non-small cell lung cancer] and to investigate patient, clinical and hospital characteristics impacting likelihood of receiving GCT and survival.”

Cancer Stages & Disease Management

The study cohort drew data from 13,701 patient participants gathered by the Victorian Lung Cancer Registry between July 2011 and November 2021.

Most patients in the study (11,073) were diagnosed with NSCLC. Among these patients, 52% received GCT, 32.8% did not receive GCT, and 15.2% chose to forgo GCT or received no treatment. The patients who received GCT were younger, male, and were more likely to have an Eastern Cooperative Oncology Group scale (ECOG) score less than 2 compared to non-GCT patients (89.5% vs 72.8%). The GCT cohort, compared to the non-GCT cohort, was also more likely never to have smoked (15.6% vs 11.3%) and underwent lower rates of weight loss (46% vs. 52.6%).

Patients diagnosed with localized NSCLC (L-NSCLC; stage I-II) were more likely to have had GCT administered than non-GCT intervention (37.2% vs 12.4%). Patients diagnosed with metastatic NSCLC (M-NSCLC; stage IV) were more likely to have GCT administered compared to non-GCT intervention (45.7% vs 27.8%).

Patient participants who received GCT were more likely to have their case presented at a multidisciplinary meeting (MDM) than those with non-GCT intervention (72.5% vs 65.4%).

Factoring in GCT status, patients with GCT intervention diagnosed with L-NSCLC had an 18% increase in 1-year survival and a 41% increase in 5-year survival compared to those with non-GCT intervention. Patients diagnosed with locally advanced NSCLC (LA-NSCLC) who had GCT intervention had an 18% increase in 1-year survival and a 10% increase in 5-year survival compared with patients with non-GCT intervention. Patients diagnosed with M-NSCLC with GCT intervention had a 27% increase in 1-year survival and an 8% increase in 5-year survival compared with patients with non-GCT intervention.

Receipt of GCT

Increasing age was noted as a factor that significantly lowered the likelihood of a patient receiving GCT after excluding patients who died within 6 weeks of diagnosis (>80 years OR 0.20). Additional factors noted included being an active smoker (OR 0.64), being a former smoker (OR 0.70), having a respiratory comorbidity (OR 0.77), registering an ECOG score of at least 2 (OR 0.32), being diagnosed with LA-NSCLC (OR 0.30), and being diagnosed with M-NSCLC (OR 0.49). Patients who completed support care screening were likelier to receive GCT (OR 1·36).

Notably, the researchers noted that some of the impacted receipt of GCT were modifiable. These included:

• Increasing treatment of the elderly
• Smoking cessation
• Treatment in high-volume hospitals

The researchers noted several limitations of their research, including the lack of data on lifestyle factors such as physical activity, alcohol use, education, and health behaviors. They also noted that definitions of GCT continue to change as the therapeutic landscape of NSCLC changes and will need to evolve as treatments do.

“GCT is an important potential indicator of evidence-based healthcare quality and safety,” Dr. Billah and colleagues wrote. “GCT has strong construct validity as a measure of evidence-based practice, and reflects other important measures of indicator quality, being understandable, measurable, policy-relevant, reflective of the whole of system practice, and capable of confirming equity and access.”