256MO - Decoding the cryptic stroma: Molecular cancer associated fibroblast 1 & 4 imaging allied with mesenchymal stroma to tumor content as a radiation dose bio-predictive signature to augur the future in locally advanced esophageal cancer

Background

The multipotent cancer stem-cell differentiates into tumor cell and mesenchymal stromal cell. Depending on the favorability of the tumor microenvironment and the metabolic demand, the ratio of stromal cells to tumor cells differ in the tumor microenvironment. Our study corelates the stromal content in molecular CAF whole body imaging with stroma to tumor ratio and outcomes of locally advanced esophageal cancer patients subjected to different radiation doses with platinum-based doublet chemotherapy regimens.

Methods

54 patients with locally advanced carcinoma of esophagus fitting into definitive chemoradiation therapy protocol were prospectively included in the study after institutional ethical clearance. All patients underwent molecular CAF whole-body imaging prior to initiation of definitive chemoradiation. The SUV Maximum at the primary site were corelated with the stromal content in histopathology. A stromal content of above 50 % was quantified as high stroma. SUV uptake of more than 7 was taken as High SUV. Patients received either 50Gy or 60Gy concurrent with platinum-based doublet chemotherapy. All patients were followed up for a period of minimum 2 years and the response assessment CAF imaging done at the end of 3 months from chemoradiation. The imaging-based response rates, disease free survival and overall survival at the end of 2 years were analyzed.

Results

The local and systemic control of patients with low stromal content is better than that with high stromal content. Amongst the high stromal content, Patients who received 60Gy had better local control rates than the ones that received 50Gy. In the low stromal content irrespective of radiation dose the local control was achieved. The systemic control and overall survival of high stromal content patients appears poorer necessitating the need for further studies on adjuvant, maintenance, or metronomic chemotherapy.

Table: 256MO

Conclusions

CAF Radiological imaging and pathological stromal content quantification could be a Bio-predictive independent tool for radiation dose escalation to augur, telltale responses and survival.

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.