The RALC pathway was established by the NCCP in order to facilitate timely radiological and clinical assessment of individuals with clinical suspicion of having lung cancer in Ireland [3]. Unfortunately, the COVID-19 pandemic had a huge impact on healthcare services across the world, including cancer care [19,20,21]. Some of the RALC centres in Ireland were not spared [15, 16]. Early reports during the COVID-19 pandemic indicated that Irish RALC centres in Limerick and Beaumont hospitals experienced reduced number of referrals, and increased wait times for patient review at RALC. More importantly, a higher proportion of lung cancers diagnosed were stage IV, when compared to prior years [15, 16]. In contrast, our findings indicate that the COVID-19 pandemic had minimal impact on the performance and the outcome of CUH-RALC within the study timeframe. Although the numbers of referrals and reviews at our centre dropped significantly during the pandemic (period II, Fig. 1), similar to other parts of the country [15, 16], no significant change was noticed in the stages or proportions of lung cancers diagnosed pre- and during the pandemic (Fig. 3). Also, the difference seen on the lung cancer data between periods I and II could be due to the year-to-year variability. However, a significant reduction in referrals to RALC during the pandemic may have been related to fewer visits to the GP in the setting of national lockdowns, or GPs raising the threshold for referrals to the acute hospital setting to avoid patient exposure or over burdening the healthcare system during a time of crisis. Furthermore, the average wait time for RALC review did not change significantly during the pandemic (14 vs. 12 days) but significantly more patients were being seen within 10 working days (12 calendar days) of referral during the pandemic compared to before (OR 1.41, Fig. 1e). These findings suggest that the reduction in referrals during the pandemic period reduced the burden on the RALC in terms of patient volume.

Radiology is one of the key modalities of COVID-19 diagnosis [22]. During the pandemic, the radiology departments had to adapt and prioritise to maintain activity for influx of COVID-19 patients, while continue supporting non-COVID-19 patients such as cancer patients and those in emergency situations. Our results indicate that there has been a noticeable reduction in the total number of CT scans performed at RALC during the COVID-19 pandemic, consistent with reduction in the number of referrals to RALC. Interestingly, the wait times for post-referral CT scans were significantly shorter during the pandemic compared to before, suggesting that the reduction in referrals may have led to increased availability of CT scan slots. Another possibility is that there were less patients undergoing CT imaging for other general indications. In the UK, the beginning of the lockdowns resulted in reduction of referrals from GPs and secondary care to imaging services and the elimination of backlogs allowing the more essential tests to be done, which is consistent with our findings at CUH-RALC [23]. However, the long-term effect of some of the delays regarding imaging in post-COVID-19 era, particularly for cancer patients remains to be seen.

The results of this study indicate that there have been no delays in time to diagnosis, MDT meeting, or start of treatment for lung cancer patients coming through the RALC pathway in one year since the start of the pandemic (Fig. 4). The average wait time from MDT meeting to start of SACT for lung cancer patients was 51.4 days in period II which is not significantly different from the wait time before the pandemic (Fig. 4E). This wait time is consistent with ESMO recommendation of maximum eight weeks between MDT meeting and start of treatment for lung cancer patients during the pandemic [14].

Throughout the pandemic, the respiratory physicians and clinical nurse specialists at RALC also had to look after the influx of additional COVID-19 / pneumonia patients and adapt to the new challenges associated with access to diagnostic imaging services including CT, Positron Emission Tomography, bronchoscopy, and endobronchial ultrasound. However, our results indicate that they continued to prioritise RALC referrals, MDT meetings, and timely treatment commencements. In fact, shorter wait times for surgery was observed during the pandemic indicating a potential reduction in elective surgeries, or cancer-related surgeries being prioritised. Furthermore, median PFS and OS of patients diagnosed with lung cancer at CUH-RALC was similar between the periods investigated indicating no impact of the COVID-19 pandemic on the short-term cancer outcome for patients, within the study time frame. This demonstrates the successful robust, reactive, risk mitigating strategies that were implemented early by thoracic leadership to prioritise continued CT cancer detection, which prevented the potential negative consequence of the pandemic, particularly with respect to cancer-specific mortality.

The development of Rapid Access Clinic by the NCCP in 2009 has been critical for timely diagnosis and access to hospital-based treatments for cancer patients in Ireland. The results of this study show how crucial these services are particularly during a national health crisis, like the COVID-19 pandemic. However, our findings may not reflect the performance of other RALC centres in Ireland. Our analysis was limited to the two years surrounding the COVID-19 pandemic and the data on year-to year variability along with patient category of GP vs. ED/inpatient referrals were not analysed in this study. Furthermore, our follow-up period for PFS and OS was limited to 7 months; therefore, we were unable to determine the effects of the pandemic on lung cancer outcome in the long term. Although similar trends are seen in the number of referrals to the RALC centres in Cork, Limerick, and Beaumont, other confounding factors such as staffing, access to diagnostics, variations in COVID-19 local protocols, and total number of annual referrals might influence variations seen among centres during the pandemic. Ultimately, the prevention, screening, and survivorship programmes developed by the NCCP play an important role in reducing the burden of cancer in Ireland. As with this study, the quality and performance of these programmes must be routinely measured to ensure that they meet their respective recommendations and KPIs.

Strengths of this study include large patient cohort, robust statistical analysis when comparing periods, and inclusion of PFS and OS with a follow-up period. Limitations of the analysis include the size and retrospective design of the study, absence of data from other RALC centres in Ireland, lack of data for the annual period of the pandemic post this analysis, short follow-up period, and confounding factors like change in staff. Furthermore, separate analysis on GP and emergency department referrals to RALC would help clarify the impact of COVID-19 on the primary care in Ireland.

In conclusion, we have presented reassuring data surrounding the performance of our rapid access lung cancer clinic during the COVID-19 pandemic. However, we must continue to strive to improve our compliance with the NCCP KPIs by increasing efficacy of the RALC service and pathways which will ultimately improve survival outcomes over the next decade. Longer follow-up data and additional investigations would provide further insight into the full impact of the COVID-19 pandemic on outcomes of patients at risk of and diagnosed with lung cancer in Ireland and indeed globally. A national evaluation will help determine the full impact of this pandemic on lung cancer diagnosis, management, and long-term outcomes.