Lung Cancer Treatment Efficacy Not Directly Affected by COVID-19, Study Finds

A new analysis of patients treated for lung cancer in a French health system suggests the COVID-19 pandemic led to an initial drop in new cases but that the efficacy of most treatment modalities was not significantly affected.

The study also showed, however, that for individual patients who underwent systemic therapy, a COVID-19 diagnosis led to a higher risk of mortality. The report was published in European Journal of Cancer.

The authors wanted to understand whether the COVID-19 pandemic and associated lockdowns led to a delay in lung cancer diagnoses and poorer responses to therapy. They retrospectively analyzed electronic health records and administrative data from the Greater Paris University Hospital to compare key metrics from the years immediately before the pandemic (2018-2019) to those in 2020, when the pandemic was reshaping daily life.

Overall, the investigators found 6240 patients with lung cancer. Most underwent tumor resection (35%) or systemic anticancer therapy (33%). The rest received either best supportive care (BSC; 12%) or no treatment (20%).

When the investigators compared 2018-2019 to 2020, the first thing they found was that new diagnoses dropped dramatically—32%. However, that drop was not followed by a “catch-up” surge, suggesting that patients were not necessarily avoiding care but instead seeking care at general hospitals in order to avoid the overloaded university hospital, the authors said.

“Of note, such a decrease was no longer observed during the second lockdown,” the authors said. “This suggests that both patients and health care providers adapted differently to that situation.”

When they compared outcomes between the timeframes, they found little difference. Six-month overall survival (OS) rates for tumor resection were 98% in 2018-2019 and 97% in 2020. For patients undergoing systemic therapy, 6-month OS rates were 78% and 79%, respectively. There was a decline among patients receiving BSC, with the 20% 6-month OS rate in 2018-2019 falling to 13% in 2020. The investigators noted that advanced lung cancer is tied to poor outcomes in patients with COVID-19, which may account for the lower survival in that treatment category.

Similarly, although COVID-19 did not affect overall outcomes when comparing 2018-2019 to 2020, when the investigators looked exclusively at lung cancer diagnoses in 2020, they found patients with COVID-19 had higher mortality vs patients with cancer diagnosed in 2020 who did not have COVID-19. However, the mortality gap only reached statistical significance for patients receiving systemic therapy (HR, 2.1, 95% CI, 1.5-3.0). The mortality decrease did not reach statistical significance in patients undergoing tumor resection, and there was an insufficient number of patients receiving BSC in 2020 to conduct such an analysis.

The investigators said their study was limited by a lack of access to cause-of-death data, meaning it is not possible to know how many patients died from their cancer, from COVID-19, or from other causes.

They concluded that while the pandemic did result in a decrease in new patient referrals, those who sought treatment had largely similar outcomes to patients treated before the pandemic arrived.

“The additional mortality may have been more related to SARS-CoV-2 infection itself than to any treatment delays,” they wrote, adding that a longer follow-up period will be needed to better understand the pandemic’s full impact.

Reference

Priou S, Lamé G, Zalcman G, et al. Influence of the SARS-COV-2 outbreak on management and prognosis of new lung cancer cases, a retrospective multicenter real-life cohort study. Eur J Cancer. Published online June 26, 2022. doi:10.1016/j.ejca.2022.06.018