The impact of COVID-19 on head and neck cancer in Northern Ireland - a population-based study

This study examined the impact of the COVID-19 pandemic on presentation, referrals, diagnoses, stage distribution, primary treatment, and survival for Head and Neck Cancer (HNC) patients in Northern Ireland (NI) by analysing population-based patient level data collected during 2016-2023.

Individual-level data for all patients diagnosed with HNC available on the regional Cancer Patient Pathway System (CaPPs) during the period 2016-2023 was accessed to examine the number of cancers diagnosed, referrals, diagnosis, stage at diagnosis, and first treatment. Northern Ireland Cancer Registry (NICR) data up to 2021 was used to estimate the proportion of patients managed by the regional Multidisciplinary Team (MDT) and provide additional key characteristics and survival information. Data on activity in primary dental care (2016-2023) was accessed from the Northern Ireland Statistics and Research Agency (NISRA). Four time-periods were compared: pre-pandemic (PP: January 2016-March 2020), initial pandemic (IP: April 2020-March 2021), initial recovery (IR: April 2021-March 2022) and pandemic recovery (PR: April 2022-May 2023).

Adult dental examinations in primary care dental services decreased by 78%, from a yearly average of 965,000 during the PP period to 218,000 during the IP period. The number of HNC patients assessed at the MDT did not change significantly over the period 2016-2023 (P > 0.05) from an annual average of 322 in the PP period; 302 in the IP period; 315 in the IR period and 342 in RP. Although there was an increased proportion of late-stage HNCs (III and IV) in the IP period, this was only significant for the oral cancer subsite (51.7% PP versus 67.1% IP), with recovery in the following periods. There was a decrease in the number of HNC patients receiving surgery as first treatment, and conversely an increase in radiotherapy, across the four time periods. The number of patients undergoing surgery as first treatment type decreased from PP (136) to IP periods (119) and failed to recover to pre-pandemic levels (117 in PR). Short-term (2-year) observed and net survival was not significantly different for HNC patients diagnosed pre-pandemic compared to periods thereafter (IP, IR, RP). The largest decrease in 2-year net survival was found for oral cancer, from 64.7% (PP) to 57.3% (IR), which approached significance (P = 0.06).

The COVID-19 pandemic had wide-ranging impacts on HNC in Northern Ireland with substantially fewer examinations provided in primary dental care; reduced HNC incidence in the IP period; higher proportions of late-stage disease (statistically significant in oral cavity only); fewer surgical treatments and lower survival. These patterns approached statistical significance for oral cancers, the site most likely to be detected through dental screening.

The COVID-19 pandemic severely impacted patient access to primary care dental services throughout NI, where clinical screening for HNC is undertaken by General Dental Practitioners (GDPs) as part of a dental check-up. This study demonstrates the importance of primary dental care services in the identification and early diagnosis of HNCs.