Abstract 5773
Background
Anal Squamous Cell Carcinoma (ASCC) is radically treated by chemoradiotherapy (CRT). The use of DW-MRI as a predictive marker of outcome would enable early individualisation of treatment. We aimed to quantify the changes in mean apparent-diffusion-coefficient (ADCMean) between a DW-MRI at diagnosis and on fraction 8-10 of CRT as a biomarker for cellularity, and correlate these with outcome.
Methods
This prospective study recruited patients with ASCC between October 2014 and November 2017. DW-MRI was performed at diagnosis and after fraction 8-10 of radical CRT. A region of interest (ROI) was delineated for all primary tumours and any lymph nodes >2 cm on high-resolution T2 –weighted images and propagated to the ADC map. A pre-defined cut-off for percentage change in ADCMean (ΔADC) was set at < 20%. Complete response (CR) was assessed 3 months following completion of CRT. Routine clinical follow up data from patients were collected from NHS electronic systems.
Results
Twenty-three of 29 recruited patients underwent paired DW-MRI scans. The median (range) tumour volume was 13.6 cm3 (2.8 cm3 to 84.9 cm3). The median ΔADCMean between scans was 20.7% (95% CI: 12.7%, 34.1%). Nine of 23 (43%) patients had a change of ADCMean <20%. Two patients failed to achieve a CR, with ΔADCMean of 14.6% and 20.3%, respectively. On routine follow up, 2 further patients had relapsed, with ΔADCMean of -1.2% and 6.8%.
Conclusions
In a subset of patients, <20% ΔADCMean on DW-MRI between diagnosis and day 8-10 of CRT was observed. Four patients in the study demonstrated persistent or recurrent disease, all of whom demonstrated an ADC on or below the pre-specified cut-off. Further investigation of the predictive merit of DW-MRI change, and the optimum cut-off is needed in larger cohorts.
Clinical trial identification
NCT02145416.
Editorial acknowledgement
Legal entity responsible for the study
University of Oxford.
Funding
CRUK EPSRC Cancer Imaging Centre in Oxford, the CRUK Oxford Centre and the NIHR.M Hawkins is supported by Medical Research Council grant MC_UU_00001/2.
Disclosure
R. Muirhead: Honoraria (self), Fee for lecture: Boehringer Ingelheim. V. Goh: Research grant / Funding (self): Siemens. All other authors have declared no conflicts of interest.
Resources from the same session
4317 - Prognostic factors analysis of 343 patients with adenocarcinoma of esophagogastric junction
Presenter: Yixun Lu
Session: Poster Display session 2
Resources:
Abstract
4099 - Effects of preoperative preparation time on efficacy of neoadjuvant chemotherapy (SOX) in patients with advanced gastric cancer
Presenter: Xinxin Wang
Session: Poster Display session 2
Resources:
Abstract
3769 - The prognostic value of higher absolute lymphocyte counts for patients with surgically resected non-advanced gastric cancer
Presenter: Se Jun Park
Session: Poster Display session 2
Resources:
Abstract
1718 - Trastuzumab and pertuzumab added to neoadjuvant chemoradiotherapy in resectable HER2+ esophageal adenocarcinoma patients: an update on survival and predictive biomarkers in the TRAP study
Presenter: Charlotte Stroes
Session: Poster Display session 2
Resources:
Abstract
5403 - Interim analysis of a phase II trial of perioperative chemotherapy plus avelumab in esophagogastric and gastric adenocarcinoma
Presenter: Thierry Alcindor
Session: Poster Display session 2
Resources:
Abstract
591 - Evaluation of the introduction of primary G-CSF prophylaxis to the FLOT chemotherapy regimen.
Presenter: Kelly-Marie Crampton
Session: Poster Display session 2
Resources:
Abstract
1402 - Subgroup analyses of a randomized two-by-two factorial phase II trial comparing neoadjuvant chemotherapy with 2 and 4 courses of cisplatin/S-1 (CS) and docetaxel/cisplatin/S-1 (DCS) as neoadjuvant chemotherapy for locally advanced gastric cancer
Presenter: Tsutomu Hayashi
Session: Poster Display session 2
Resources:
Abstract
3743 - HER2 Copy Number as Predictor of Disease-Free Survival in HER2-Positive Resectable Gastric Cancer
Presenter: Zimin Liu
Session: Poster Display session 2
Resources:
Abstract
2032 - Effect of neoadjuvant chemotherapy on the Programmed Death-1 pathway in esophageal and gastric cancer
Presenter: Maria Svensson
Session: Poster Display session 2
Resources:
Abstract
4304 - A user-friendly nomogram to predict relapse-free survival (RFS) in western patients with resected gastric cancer (GC)
Presenter: Massimiliano Salati
Session: Poster Display session 2
Resources:
Abstract