P-265 Neoadjuvant radiotherapy for locally advanced rectal cancer during the first wave of COVID19 pandemic: Guy's cancer cohort experience

ABSTRACT

Background: The Covid-19 pandemic is a healthcare emergency with a significant impact on cancer services provision. In March 2020, our institution adopted the ESMO expert consensus guidelines for radiotherapy management of rectal cancer during the pandemic. Here we present short-term oncological outcomes of this approach compared to the same period in 2018. Methods: Patients who underwent neoadjuvant (chemo) radiotherapy for rectal cancer between 1st March 2020 and 31 May 2020 were identified from a research ethics committee (REC)-approved research database for cancer patients (Guy’s Cancer Cohort). Patient demographics and treatment characteristics were extracted and compared with a control cohort treated in the same period in 2018. The definition of local response was based on identification of downstaging on re-staging Magnetic Resonance Imaging (MRI) post neoadjuvant treatment (mrT3c/d-4 to mrT0-2 and mrT2 to mrT0-1) and classified in a binary format (response vs no response). In addition, in patients who underwent total mesorectal excision (TME), neoadjuvant rectal (NAR) score was calculated, as described previously, and classified into low (<8), intermediate (>=8<=16) and high (>16). The frequency of MRI and pathological response was compared using non-parametric Fisher exact test. Results: Thirty patients were treated in the three-month period in 2020 as compared with 21 in 2018 (43% increase). No statistically significant differences were observed in baseline tumour characteristics. The use of neoadjuvant short-course radiotherapy (SCRT) treatment increased significantly from 19% of cases in 2018 to 50% during the pandemic, which was reflected in reduced radiotherapy-related hospital footfall (median 15 appointments in 2020 vs 25 appointments in 2018). While the use of concomitant fluoropyrimidines was lower (47 vs 71%), the use of induction chemotherapy was higher (30 vs 19%) in 2020 compared to 2018, which may reflect more prevalent use of total neoadjuvant treatment. There was no difference in the proportion of MRI responders between cohorts (52% in 2020 vs 38% in 2018). In patients who underwent TME, there was no difference in the proportion of R1 resection (0 in 2020 vs 9% in 2018), median NAR scores (8 (1-30) in 2020 v 15 (range 4-50) in 2018) or NAR score categories (22% good responders, 64% intermediate and 14% non-responders during Covid-19 vs 9% good responders, 55% intermediate and 36% non-responders in 2018). Conclusions: Changes in radiotherapy treatment of rectal cancer during Covid-19 pandemic, including more frequent use of SCRT (often in combination with neoadjuvant chemotherapy), did not seem to have negatively impacted short-term oncological outcomes, as measured by MRI downstaging rates and NAR scores following TME. The effect of the pandemic on medium and long-term oncological outcomes is still awaited. Legal entity responsible for the study The author. Funding: We acknowledge funding support from King’s Health Partners Research and Development Challenge Fund and Biomedical Research Centres (BRC) at Guy's and St Thomas' NHS Foundation Trust. Disclosure All authors have declared no conflicts of interest.