The results of this comprehensive retrospective study offer intriguing insights into the potential association between COVID-19 infections and the declining incidence of lung cancers. The observed trends and temporal patterns in our study have sparked intriguing discussions on the potential association between COVID-19 infections and the declining incidence of lung cancers. While the results indicate no statistically significant reduction in lung cancer diagnoses during the COVID era, it is essential to interpret these findings cautiously and to explore plausible explanations for the observed relationship. Further investigation into the temporal patterns of lung cancer diagnoses revealed fascinating nuances. At the beginning of the COVID-19 pandemic, a severe decline in the incidence of lung cancers occurred [3]. As the pandemic progressed and healthcare systems adapted to the new challenges, a gradual but steady recovery in lung cancer diagnoses was observed [7]. The temporal association suggests a plausible influence of COVID-19 infections on lung cancer incidence, although causal relationships remain inconclusive [8, 9].
One possible explanation for the decline in lung cancer incidence during the COVID-19 pandemic could be related to the host immune response triggered by viral infection [10]. Studies have suggested that COVID-19 elicits a robust immune response involving both innate and adaptive immunity [11, 12]. This heightened immune surveillance might inadvertently target and eliminate precancerous or early-stage lung cancer cells, leading to a reduction in cancer development and progression [13]. However, further studies are required to further clarify these immunological mechanisms involved and their impact on lung cancer biology.
During the COVID-19 pandemic, widespread public health measures, such as lockdowns and social distancing, dramatically altered individuals’ lifestyles and behaviors [14]. Reduced exposure to air pollutants and second-hand smoke could potentially lead to a reduction in the incidence of lung cancers [15]. Additionally, decreased smoking rates during the pandemic could have contributed to the reduced burden of lung cancers in certain populations [16]. Long-term studies are required to assess the sustainability of these lifestyle changes and their lasting effects on lung cancer incidence beyond the pandemic period [17]. Reduced risk factors only affect lung cancer incidence with a latency of years. However, the current effect can be attributed to anxiety, healthcare facilities, seeking medical attention, and healthcare system overload.
The pandemic’s overwhelming impact on healthcare systems may have inadvertently affected lung cancer diagnosis and detection rates [18]. Delays in seeking medical attention, postponed routine screenings, and reprioritization of healthcare resources toward COVID-19 management could have resulted in missed or delayed lung cancer diagnoses [19]. While our sensitivity analyses demonstrated robustness in the findings, the potential influence of delayed diagnoses on the observed decline in lung cancer incidence cannot be overlooked [20]. Future research should investigate the long-term consequences of these healthcare disruptions and their implications for cancer outcomes.
Individuals with preexisting comorbidities, especially chronic respiratory conditions, seemed to be more vulnerable to the influence of COVID-19 on lung cancer development [21]. This suggests that the interaction between COVID-19 and lung cancers may be context-dependent, with specific risk factors influencing disease outcomes [22, 23].
While our study provides robust evidence of an association between COVID-19 infections and declining lung cancer incidence, although without statistical significance, establishing causality remains challenging in a retrospective study design. Prospective cohort studies and experimental models are needed to unravel the causal mechanisms and confirm the observed relationships.
Understanding the potential impact of COVID-19 on lung cancer incidence sheds light on novel avenues for cancer prevention and treatment. Harnessing the immune response triggered by COVID-19 to target early-stage lung cancers could pave the way for innovative immunotherapeutic approaches. Furthermore, the lifestyle changes prompted by the pandemic offer valuable insights into modifiable risk factors for lung cancers, guiding public health initiatives and educational campaigns to promote healthier behaviors.
In conclusion, our study provides compelling evidence for a potential association between COVID-19 infections and the declining incidence of lung cancers, although without statistical significance, and an increase the number of advanced lung cancer stages.
Limitations
As with any research study, our investigation into the potential association between COVID-19 infections and the declining incidence of lung cancers has several limitations that warrant careful consideration: 1. Retrospective study design: A selection bias could have arisen due to the retrospective study design. It is self-explanatory that not all confounding variables could be prevented despite all efforts. 2. Data completeness and accuracy: When collecting data from medical records, human errors may have arisen. Despite our best efforts to preprocess and validate the data, inaccuracies or missing information may affect the study’s findings. 3. Generalizability: Our study focused on a specific population in a particular location and time duration, which may limit the generalizability of the results to other regions and time periods. Variations in healthcare systems, demographics, and COVID-19 dynamics could influence the observed associations in different settings. 4. Temporal confounding: The temporal association between the COVID-19 pandemic and the decline in lung cancer incidence may not necessarily imply a causal relationship. Unmeasured confounding factors related to societal changes, healthcare utilization, and public health interventions during the pandemic could influence the observed trends. 5. Bias in diagnosis and screening: During the COVID-19 pandemic, disruptions to healthcare services and screening programs may have influenced lung cancer diagnosis rates. Reduced access to medical facilities, delayed screenings, and altered healthcare priorities could introduce biases in our data. 6. Lack of pre-COVID baseline: While our study compared lung cancer incidence before and after the emergence of COVID-19, we did not have access to a pre-pandemic baseline for comparison. A preexisting trend in lung cancer incidence could have influenced the observed changes during the pandemic. 7. Duration of study period: The duration of our study period may not capture the full extent of the pandemic’s influence on lung cancer incidence. Longer-term follow-up is necessary to assess the sustainability of the observed trends and potential rebound effects in lung cancer diagnoses. 8. Confounding lifestyle changes: Although we discussed the impact of lifestyle changes during the pandemic, isolating the direct influence of COVID-19 on lung cancer incidence from other pandemic-related lifestyle modifications is challenging. Unmeasured lifestyle factors could contribute to the observed decline in lung cancer cases.
Acknowledging these limitations is vital for interpreting the results accurately and highlighting areas for further investigation. Despite these constraints, our study contributes valuable insights into the complex interplay between COVID-19 infections and lung cancer incidence, opening avenues for future research and informed healthcare strategies.