Letter to the Editor Concerning the Article From Cai et al. Focusing on Coronavirus Disease 2019 Impact on Lung Cancer Resection, Published in June 2020

To the Editor:

We read with great interest the article by Cai et al.¹ focusing on the impact of coronavirus disease 2019 (COVID-19) on lung cancer resection. Among the 139 patients they operated on, they focused on seven patients who were positive for COVID-19. The authors reported three deaths (42.8%) related to COVID-19 infection, leading them to conclude that “lung resection surgery might be a risk factor for death in patients with COVID-19.” This conclusion seems hasty. First, the authors focused on a very small sample that prevents drawing any conclusions. Furthermore, the main comorbidities reported by the authors could have led to the death of the patients regardless of their COVID-19 status. In particular, a cardiac contribution to death cannot be ruled out in a patient with a coronary artery disease. In addition, no detailed information was provided for the patient with interstitial lung disease. Hence, one can wonder whether the death was caused by pulmonary fibrosis, which is known to place patients at higher risk of pulmonary decompensation after lung surgery. Finally, even though the forced expiratory volume in 1 second is given in liters and not in percentage predicted, one can speculate that patient 7 with a forced expiratory volume in 1 second of 1.39 liters had very poor pulmonary function and was at higher risk of postoperative pulmonary complications. In line, the diffusing capacity of the lungs for carbon monoxide, which is known to be an independent prognostic factor of outcomes after lung surgery, was not provided for any patient, preventing proper evaluation of the pulmonary function of these patients.

To support their conclusion, the authors cited the publication by Liang et al.,² a study of 18 patients, concluding an increased risk of death or intensive care unit admission in the case of cancer (OR: 5.4 [95% confidence interval: 1.8–16.2]), highlighting a higher risk in the case of lung cancer. Because 13 of the 18 patients with cancer had a history of surgery, surgery was pointed out as a harmful tool in the therapeutic arsenal of cancer. However, this publication had few limitations. First, in the cohort of patients positive for COVID-19, the percentage of patients harboring cancer (approximately 1%) and the proportion of those with lung cancer (0.3%) were low, preventing drawing of any conclusions. Moreover, half of the patients with cancer had a disease course superior to 4 years, which may have probably led to the inclusion of cured cancers.

The authors concluded a higher risk of severe events in patients with cancer owing to the immunosuppressive state. However, accumulated evidence has revealed that the development of cancer is usually associated with overexpressed immunosuppressive cytokines, suppressed induction of proinflammatory danger signals, impaired dendritic cell maturation, and enhanced functional immunosuppressive leukocyte populations, which are contradictory to the events believed to result in severe events in patients with COVID-19.³

In conclusion, there are, so far, not enough robust data in the literature to conclude on the harmful effect of lung cancer surgery in patients positive for COVID-19. Large studies are, therefore, more than necessary to continue offering the best care to patients with lung cancer.