Three-year survival follow-up of patients with gastrointestinal cancer treated during the COVID-19 pandemic in Spain: data from the PANDORA-TTD20 study.

Introduction: The initial SARS-CoV-2 pandemic wave in Spain in 2020 precipitated significant paradigm shifts in gastrointestinal oncology patient management. This study captures the "Zeitgeist" of this period by analyzing adaptive strategies, treatment modifications, and survival outcomes, leveraging a 3-year follow-up perspective to extract insights from this unprecedented experience.

Methods: We conducted a multicenter, retrospective cohort study utilizing the RETUD-TTD registry, encompassing 703 patients across 19 Spanish centers in April 2020. We evaluated alterations in clinical practice, therapeutic approaches, coronavirus disease 2019 (COVID-19)-related impacts, and patient survival. A Bayesian hierarchical model was employed to identify potential regional-specific frailties.

Results: The peak of the pandemic in April 2020 catalyzed substantial shifts in oncological care delivery. Outpatient consultations decreased by 13%, with a notable selection bias toward cases with more favorable prognostic indicators. Multidisciplinary tumor board discussions were significantly curtailed (eg, mean monthly colorectal cancer cases discussed was reduced from 40 to 23), compromising qualitative care measures. This occurred concurrently with an average of over 3 oncologists per center on medical leave. Contrary to initial concerns, the healthcare system demonstrated remarkable resilience. The majority of patients received standard-of-care therapies with regulatory approval, albeit with regimen modifications in 15% of cases. These adaptations included extended dosing intervals, dose intensity modulations, and transitions to oral formulations while maintaining unexpectedly stable long-term survival outcomes. The Bayesian frailty model detected minimal unmeasured prognostic factors related to geographic location, and the type of pandemic-induced adaptation did not significantly impact survival. The model revealed that coronavirus disease 2019's impact was less pronounced than other core prognostic variables.

Conclusions: The decentralized Spanish healthcare system exhibited substantial robustness in managing pre-pandemic diagnosed gastrointestinal malignancies, despite asymmetrical, and occasionally severe organizational disruptions. The insights gleaned from this experience could inform future crisis preparedness strategies and optimize care provision during subsequent public health emergencies.