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

Sachdeva, A.; Nagpal, S.; Grzeda, M.; Russell, B.; Petkar, I.; Qureshi, A.; Van Hemelrijck, M.; Ross, P.; Harris, V.; Owczarczyk, K.

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.