RESUMEN
Background: The COVID-19 pandemic has created challenges in the diagnosis and management of colorectal cancer (CRC). It was proposed in regional Northern Australia that the distance to services could further impact cancer outcomes, leading to delayed diagnosis. The authors compared the outcomes of patients prior and during the pandemic; with a focus on whether patients were presenting in the emergency setting with more advanced disease. The distance to treatment was also analysed to see if there was any impact to the management of patients with colorectal cancer. Methods: A retrospective analysis of 444 patients who underwent treatment for colorectal cancer over two time periods was examined. Time period 1 (prior to COVID-19); March 2017-July 2019 and time period 2 (during COVID-19); March 2020-July 2022. Only patients with colorectal adenocarcinoma were included if they were primarily treated at a hospital in northern Australia; those with benign pathologies or recurrent disease were also excluded. Data was collected in terms of treatment and outcomes and compared between the two groups. A separate analysis of whether locality affected outcomes and referral times was also performed. Results: In the time period prior to COVID-19, 174 patients' required invasive management, while in the second time period during COVID-19, there were 188 patients managed surgically or endoscopically. Of the patients managed prior to COVID-19 17/174 (9.8%) patients required emergency interventions, during COVID-19 this number increased to 37/188 (19.7%). This difference was deemed to be statistically significant (P =0.008). No substantial difference in cancer staging at presentation was found between the two groups. There was an increase in complication rate found during COVID-19 34.6 vs 25.5% prior to COVID-19 (P=0.046). During COVID-19, the median time between General Practitioner (primary care physician) referral and colonoscopy was actually lower than prior to covid 26.5 vs 36 days (P=0.047). When comparing local to distant patients, we found locally based patients had lower rates of neoadjuvant treatment 18.9 vs 30.4% (P=0.018) and higher rates of open surgery 39.1 vs 26.5%, P =0.012. An increase in time between colonoscopy and outpatient department review (OPD) was seen in patients not from the local area 13 vs 18 days (P =0.006). Conclusion: The authors found during the COVID-19 pandemic a greater proportion of patients were presenting with colorectal cancer that required emergency intervention. This may be due to decreased presentations to general practitioners due to lockdown causing potential delays in diagnosis. The authors did not see more advanced disease in these patients presenting emergently, between the two groups. Further assessment of local patients' vs patients from distant sites, showed difference in how patients were managed but similar outcomes. Our large catchment area with distance to treatment in Northern Australia may further impact the management of colorectal cancer in the future.
RESUMEN
Phonon polaritons-light coupled to lattice vibrations-in polar van der Waals crystals are promising candidates for controlling the flow of energy on the nanoscale due to their strong field confinement, anisotropic propagation and ultra-long lifetime in the picosecond range1-5. However, the lack of tunability of their narrow and material-specific spectral range-the Reststrahlen band-severely limits their technological implementation. Here, we demonstrate that intercalation of Na atoms in the van der Waals semiconductor α-V2O5 enables a broad spectral shift of Reststrahlen bands, and that the phonon polaritons excited show ultra-low losses (lifetime of 4 ± 1 ps), similar to phonon polaritons in a non-intercalated crystal (lifetime of 6 ± 1 ps). We expect our intercalation method to be applicable to other van der Waals crystals, opening the door for the use of phonon polaritons in broad spectral bands in the mid-infrared domain.
