Saxony registry study finds no prolongation of post-diagnostic treatment intervals during the early COVID-19 pandemic

A retrospective registry-based study of 3,216 adults with oral squamous cell carcinoma diagnosed in Saxony found no prolongation of the evaluated post-diagnostic treatment intervals during the early COVID-19 pandemic compared with the pre-pandemic period. Differences in initial Union for International Cancer Control stage and in selected treatment intervals were statistically significant but weak, while an exploratory year-by-year analysis showed non-linear temporal patterns.

Researchers analyzed anonymized records from the Saxony Cancer Registry for patients diagnosed between 1 January 2018 and 5 August 2024. Patients were assigned to a pre-pandemic period before March 2020, an early pandemic period from March 2020 through September 2021, and a later pandemic period after September 2021. September 2021 was used as a pragmatic transition point to distinguish the initial disruption period from a later phase in which healthcare services were adapting to continued circulation of SARS-CoV-2; it did not mark the end of the pandemic.

The cohort included 1,051 patients diagnosed before March 2020, 829 diagnosed during the early pandemic period and 1,336 diagnosed afterward. Patients were 28 to 98 years old, with a mean age of 66.14 years. Men represented 69.4% of the cohort and had a mean age of 64.10 years at diagnosis, while women represented 30.6% and had a mean age of 70.77 years. Initial UICC stage was available for 3,101 patients, and the number evaluable for treatment intervals varied because each interval required the relevant dates to be documented.

The median interval from diagnosis to the first multidisciplinary tumor board was 17 days before the pandemic, 15 days during the early pandemic period and 15 days in the later period. Among 688 patients who underwent surgery without subsequent radiotherapy, the median interval from tumor board to surgery was 12 days, 8 days and 13 days across the same periods. For 582 patients who underwent surgery followed by radiotherapy, the corresponding medians were 14, 11 and 13 days. Global tests identified differences among the periods, and all significant pairwise treatment-interval effects were weak.

Initial UICC stage also differed among the three predefined periods. Stage IV disease accounted for 46.0% of patients with available staging data before the pandemic, 36.5% during the early pandemic period and 39.3% in the later period. The association between period and stage was weak, with a Cramér’s V of 0.065, and no significant difference was found between the two pandemic periods in the adjusted pairwise comparison. The stage distribution therefore did not provide evidence of a consistent shift toward more advanced disease during the early pandemic period.

The exploratory analysis by year of diagnosis confirmed that the temporal patterns were not linear. The proportion of stage IV disease fell from 48.1% in 2018 to 36.2% in 2020, rose to 42.1% in 2022 and declined to 35.5% in 2023. The median diagnosis-to-tumor-board interval fell from 20 days in 2018 to 15 days in both 2020 and 2021, rose to 18 days in 2022 and fell to 14 days in 2023. For surgery with subsequent radiotherapy, annual medians ranged from 9 to 15 days, with a significant global difference; only the 2019-to-2020 comparison remained significant after adjustment. The interval for surgery without subsequent radiotherapy did not differ significantly by year.

These results are consistent with broader reports of heterogeneous pandemic-related changes in oral and head and neck cancer care. A German oral cancer cohort reported a longer treatment delay and higher pathological T classification in the first pandemic year, whereas a German multicenter study found no clear increase in tumor stage and reported a trend toward shorter time to intervention during lockdown. The Saxony findings add regional registry evidence, but the retrospective design and weak effect sizes mean that the observed differences cannot be attributed to the pandemic itself.

The study also examined only the period after diagnosis. The registry data did not include symptom onset, first contact with a healthcare professional or the interval between initial presentation and histological diagnosis. Consequently, the absence of longer post-diagnostic intervals does not exclude disruption earlier in the diagnostic pathway, including reduced use of screening, preventive examinations and dental visits during the pandemic.

Several limitations further constrain interpretation. Only two complete pre-pandemic years were available, and 2024 data ended on 5 August, potentially leaving later treatment steps incompletely documented. Alternative period cut-offs could change group composition, while the registry cohort may not be directly generalizable to other German states or healthcare systems. Missing treatment dates may also have introduced selection bias through complete-case analysis. The findings therefore describe temporal associations in documented post-diagnostic care, not evidence that COVID-19 either improved or harmed oral cancer care.

Subject of Research: Temporal variation in UICC stage and post-diagnostic treatment intervals for oral squamous cell carcinoma in Saxony during the COVID-19 pandemic

Article Title: Temporal variation in initial UICC stage and post-diagnostic treatment intervals in patients with oral squamous cell carcinoma in Saxony before and during the COVID-19 pandemic

Article References: Stach, G., Lauer, G., Farahzadi, S., Schröder, T. A., & Buckova, M. (2026). Temporal variation in initial UICC stage and post-diagnostic treatment intervals in patients with oral squamous cell carcinoma in Saxony before and during the COVID-19 pandemic. Frontiers in Oncology, 16, Article 1770029. https://doi.org/10.3389/fonc.2026.1770029

Image Credits: AI Generated

DOI: 10.3389/fonc.2026.1770029

Keywords: oral squamous cell carcinoma, COVID-19 pandemic, cancer registry, UICC stage, treatment intervals, Saxony, tumor board, head and neck cancer, Temporal, variation, initial, UICC