Abstract 107P
Background
Tumor stroma consists of a complex network of safeguards for tumor proliferation. Tumour stromal imaging using fibroblast-activated protein-tagged radionuclide provides a metabolic-radiological quantum of tumor stromal content. Tumors rich in stroma have been traditionally associated with poorer disease-free outcomes. Our study correlates between standard uptake values (SUV) in fibroblast imaging to tumor stromal ratio evaluated pathologically and the response to radiation therapy in locally advanced carcinoma rectum.
Methods
50 patients of carcinoma Rectum with all patients having undergone cancer associated Fibroblast PET CT scan prior to starting neoadjuvant chemoradiation. Tumors having SUV max > 10 were considered as High. Metabolic activity in tumor site was compared to Tumor stromal ratio and response to radiation was evaluated in histopathological report. Patients were classified into High TSR (<50% Stromal content) and Low Tumor Stroma Ratio (>50% Stromal content).
Results
7 patients who had complete pathological response all had high TSR and SUV mean 20.4. 34 patients had <50% residual disease 67% had high TSR and SUV mean 17.6 and 34% had low TSR and SUV mean of 21.44. 9 patients had >50% residual disease had 77% low TSR and high SUV mean 25.11(Range- 9.51-92.33). Patients with both Low TSR [ >50% stromal content] and SUV Max > 10 have poor pathological response compared to patients with low TSR. In the low stromal content irrespective of SUV the local control was good. Table: 107P
| High TSR | Low TSR | High SUV | Low SUV | |
| Complete response | 7(32%) | 0 | 4(15.4%) | 3(12.5%) |
| <50% Residual disease | 23(71.8%) | 11(61%) | 14(53.8%) | 20(83.3%) |
| >50% Residual disease | 2(6.2%) | 7(39%) | 8(30.8%) | 1(4.2%) |
Conclusions
High Tumor Stromal Ratio showed better complete and partial response to neoadjuvant chemoradiation in locally advanced carcinoma rectum. Tumors with high stromal content were observed to have higher SUV values in fibroblast stromal imaging and the same were also more commonly associated with suboptimal response. The need for dose escalation for the same has to be explored for better tumor control.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
144P - Integrated clinical and genomic models using machine-learning methods to predict the efficacy of paclitaxel-based chemotherapy in patients with advanced gastric cancer from K-MASTER project
Presenter: Jwa Hoon Kim
Session: Poster Display
Resources:
Abstract
145P - Tislelizumab (TIS) + chemotherapy (Chemo)/chemoradiotherapy (CRT) as neoadjuvant treatment for resectable esophageal squamous cell carcinoma (R-ESCC)
Presenter: Longqi Chen
Session: Poster Display
Resources:
Abstract
146P - Phase (ph) Ib results of bemarituzumab (BEMA) added to capecitabine/oxaliplatin (CAPOX) or S-1/oxaliplatin (SOX) with or without nivolumab (NIVO) for previously untreated advanced gastric/gastroesophageal junction cancer (G/GEJC): FORTITUDE-103 study
Presenter: Keun-Wook Lee
Session: Poster Display
Resources:
Abstract
147P - Four-year overall survival (OS) update from the phase III HIMALAYA study of tremelimumab plus durvalumab in unresectable hepatocellular carcinoma (uHCC)
Presenter: Stephen Chan
Session: Poster Display
Resources:
Abstract
148P - Safety and efficacy of atezolizumab (Atezo) + bevacizumab (Bev) in Japanese patients (pts) with unresectable hepatocellular carcinoma (uHCC): Preliminary analysis of a prospective, multicenter, observational study (ELIXIR)
Presenter: Teiji Kuzuya
Session: Poster Display
Resources:
Abstract
149P - A prospective observational study of MSI screening in unresectable chemotherapy-naïve advanced gastric cancer/gastroesophageal junction cancer: WJOG13320GPS
Presenter: Yukiya Narita
Session: Poster Display
Resources:
Abstract
150P - Anlotinib plus chemotherapy as first-line therapy for gastrointestinal tumor patients with unresectable liver metastasis: Updated results from a multi-cohort, multi-center phase II trial ALTER-G-001-cohort C
Presenter: Junwei Wu
Session: Poster Display
Resources:
Abstract
151P - Relationship between depth of response and early tumor shrinkage with overall survival in advanced pancreatic cancer
Presenter: EMIKA KUROKI
Session: Poster Display
Resources:
Abstract
152P - Interim analysis of the NAPOLEON-2 study: Safety evaluation of nanoliposomal irinotecan with fluorouracil and folinic acid for unresectable pancreatic cancer patients with prior biliary drainage
Presenter: Futa Koga
Session: Poster Display
Resources:
Abstract
153P - IMbrave150: Exploratory analyses for investigating associations between overall survival (OS) and depth of response (DpR) or duration of response (DoR) in patients (pts) with unresectable hepatocellular carcinoma (HCC)
Presenter: Masatoshi Kudo
Session: Poster Display
Resources:
Abstract