Prospective Evaluation of Dynamic Serum ProGRP for Treatment Response Monitoring in Ewing Sarcoma

Peking University People's Hospital100 enrolled

Overview

This single-center prospective observational study aims to evaluate whether longitudinal changes in serum pro-gastrin-releasing peptide (ProGRP) reflect treatment response in patients with newly diagnosed Ewing sarcoma. Serum ProGRP levels will be measured before systemic treatment, during neoadjuvant chemotherapy, before local treatment, and after local treatment. Changes in ProGRP will be compared with radiographic tumor response assessed according to RECIST version 1.1. The study will also explore the ability of early ProGRP changes to predict objective radiographic response and the association between ProGRP patterns and event-free survival. ProGRP results obtained for research purposes will not be used to guide clinical treatment decisions.

Patients with newly diagnosed, histologically confirmed Ewing sarcoma who are scheduled to initiate first-line systemic treatment at Peking University People's Hospital will be prospectively enrolled. Treatment selection, including chemotherapy, surgery, and radiotherapy, will be determined by the treating physicians according to routine clinical practice and will not be assigned by the study protocol. Peripheral blood samples will be collected before the initiation of chemotherapy (T0), after the second or third cycle of neoadjuvant chemotherapy and before the next cycle (T1), after completion of planned neoadjuvant chemotherapy and before definitive local treatment (T2), and at the first routine follow-up visit after surgery or radiotherapy (T3). If longitudinal surveillance is included in the final protocol, additional samples will be collected during routine follow-up. Serum ProGRP will be measured using an electrochemiluminescence immunoassay. Radiographic response will be assessed according to RECIST version 1.1 by two independent radiologists blinded to the ProGRP results. Disagreements will be resolved by a third reviewer. The primary analysis will evaluate the correlation between the percentage change in serum ProGRP from T0 to T2 and the percentage change in the sum of diameters of RECIST target lesions over the same period. Secondary analyses will evaluate early prediction of objective response, longitudinal ProGRP patterns, and associations with event-free survival.

Study Type

OBSERVATIONAL

Enrollment

100

Eligibility

Sex: ALLMin age: 10 YearsMax age: 60 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age 10 to 60 years. * Histologically confirmed Ewing sarcoma. * Newly diagnosed disease and scheduled to initiate first-line systemic therapy at Peking University People's Hospital. * No prior systemic chemotherapy for Ewing sarcoma and no prior radiotherapy to the primary tumor. * At least one evaluable lesion on baseline imaging; at least one measurable lesion according to RECIST version 1.1 is required for the primary outcome analysis. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2. * Estimated life expectancy greater than 3 months. * Written informed consent provided by the participant or the participant's legally authorized representative. Exclusion Criteria: * History of another malignant tumor within the previous 3 years, except for an adequately treated malignancy with a negligible risk of recurrence, as determined by the investigator. * New York Heart Association (NYHA) class III or IV heart failure. * Uncontrolled concomitant illness, including uncontrolled diabetes mellitus or an active infection. * Severe infection requiring intravenous antimicrobial treatment within 4 weeks before enrollment. * Clinically significant bleeding or a clear bleeding tendency within 3 months before enrollment. * Severe renal impairment, defined as an estimated glomerular filtration rate (eGFR) below 30 mL/min/1.73 m². * Pregnancy or breastfeeding. * Any condition that, in the investigator's judgment, may compromise participant safety, interfere with study assessments, or prevent compliance with the protocol.

Outcomes

Primary Outcomes

Correlation Between the Change in Serum ProGRP and the Change in Tumor Size

The percentage change in serum ProGRP from baseline (T0) to the pre-local-treatment assessment (T2) will be calculated as \[(ProGRP at T2 - ProGRP at T0) / ProGRP at T0\] × 100%. The percentage change in tumor size will be calculated using the sum of diameters of RECIST 1.1 target lesions over the same period. The association between the two continuous variables will be quantified using Spearman's rank correlation coefficient.

Time frame: From baseline to completion of neoadjuvant chemotherapy before definitive local treatment, approximately 4 to 6 months

Secondary Outcomes

Accuracy of Early Change in Serum ProGRP for Predicting Objective Radiographic Response

Receiver operating characteristic analysis will be used to evaluate whether the percentage change in serum ProGRP from T0 to T1 predicts objective radiographic response at T2. Objective response is defined as complete response or partial response according to RECIST version 1.1. The area under the receiver operating characteristic curve and its 95% confidence interval will be reported.

Time frame: From baseline to the pre-local-treatment assessment, approximately 4 to 6 months

Objective Response Rate Before Definitive Local Treatment

Percentage of participants achieving complete response or partial response according to RECIST version 1.1 at the T2 assessment.

Time frame: At completion of neoadjuvant chemotherapy before definitive local treatment, approximately 4 to 6 months after baseline

Longitudinal Change in Serum ProGRP

Serum ProGRP concentration in pg/mL and its percentage change from baseline will be summarized at T1, T2, and T3.

Time frame: Baseline through the first post-local-treatment follow-up visit, approximately 7 to 9 months

Event-free Survival

Event-free survival is defined as the time from initiation of first-line systemic treatment to the first occurrence of disease progression, local recurrence, a new metastatic lesion, or death from any cause. Participants without an event will be censored at the date of their last confirmed event-free assessment.

Time frame: From initiation of first-line systemic treatment through 2 years

Prospective Evaluation of Dynamic Serum ProGRP for Treatment Response Monitoring in Ewing Sarcoma

Overview

Conditions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts