Prospective Study on Exemption of Tumor Bed Boost Radiotherapy for pCR Patients After Breast Conserving Surgery With Neoadjuvant Therapy

NCT ID: NCT07113613

Last Updated: 2025-08-11

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE2
• Total Enrollment: 150 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-01-01
• Study Completion Date: 2031-12-31

Brief Summary

This study is a multicenter, single-arm, phase II clinical trial, aiming to evaluate the safety and efficacy of tumor bed dose escalation radiotherapy for patients with primary breast lesions achieving pCR (ypT0) after neoadjuvant chemotherapy and breast-conserving surgery.

Detailed Description

New neoadjuvant chemotherapy (NAC) is mainly used for patients with locally advanced or those who wish to preserve their breast. It not only helps to downstage the tumor but also increases the success rate and possibility of breast-conserving treatment for patients. Moreover, NAC provides doctors with the opportunity to assess the chemotherapy response, which can be used to predict the survival of patients. Studies have shown that patients who achieve pathological complete response (PCR) after NAC and surgery have a lower local-regional recurrence rate, higher disease-free survival rate and overall survival rate. Currently, there are no treatment guidelines for this group of patients. Avoiding unnecessary tumor bed dose escalation can reduce radiotherapy toxicity and help promote the effective utilization of medical resources. This study is the first prospective single-arm study to explore the prognostic significance of NAC and breast-conserving surgery without tumor bed dose escalation for patients with pCR breast cancer. The aim is to identify the appropriate population for exemption from tumor bed dose escalation and to develop more precise adjuvant radiotherapy plans.

Conditions

Breast Cancer

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Exempted tumor bed radiotherapy group

The total breast irradiation dose was 43.5 Gy/15 fractions, with each fraction being 2.9 Gy, administered once a day, 5 times a week; the dose for the regional lymph nodes was also 43.5 Gy/15 fractions, with each fraction being 2.9 Gy, administered once a day, 5 times a week.

Group Type: EXPERIMENTAL

Exemption from additional radiotherapy on the tumor bed after surgery

Intervention Type: RADIATION

For patients who met the inclusion criteria and were enrolled, postoperative tumor bed boost radiotherapy was waived, and only whole breast and/or regional lymph node irradiation was administered.

Interventions

Exemption from additional radiotherapy on the tumor bed after surgery

For patients who met the inclusion criteria and were enrolled, postoperative tumor bed boost radiotherapy was waived, and only whole breast and/or regional lymph node irradiation was administered.

Intervention Type: RADIATION

Eligibility Criteria

Inclusion Criteria

(1) Voluntary participation, good compliance, able to cooperate with the trial observation, and having signed a written informed consent form; (2) Confirmed as invasive cancer through pathological tissue examination, and received baseline breast MR or PET/MR examination before neoadjuvant therapy; (3) Received the standard neoadjuvant treatment plan recommended by the guidelines based on molecular typing; (4) Single lesion, initially diagnosed as cT1-3N0-3a; (5) Underwent breast-conserving surgery, with negative surgical margins and a margin distance of ≥1mm, and achieved pCR of the primary breast lesion after NAC (ypT0); (6) Age 30-75 years, ECOG score 0-1; (7) Met the basic requirements for adjuvant radiotherapy, including basically normal peripheral blood count, no significant abnormalities in heart, liver, and kidney functions, and basically normal electrocardiogram; (8) Had no previous chest radiotherapy.

Exclusion Criteria

(1) Pregnant women, lactating women, or women with reproductive capacity but without contraceptive measures in place; (2) Known to carry mutated susceptibility genes for breast cancer (including BRCA-1 and BRCA-2); (3) Diagnosed with cT4, N3b-c, bilateral breast cancer, with multiple primary lesions, multicentricity or non-bulky enhancement at the primary site; (4) Not receiving the standard neoadjuvant treatment regimen recommended by guidelines, or the primary breast lesion did not achieve pCR (including ypTis) after NAC; (5) Suffering from other malignant tumors or participating in other clinical trials simultaneously; (6) Unable to start radiotherapy within 8 weeks after breast cancer surgery; (7) Diagnosed with distant metastasis through initial imaging or pathology; (8) Previous history of breast cancer, history of radiotherapy in the neck, chest or ipsilateral axilla; (9) Severe non-tumor-related medical comorbidities affecting the implementation of radiotherapy; (10) Suffering from uncontrollable neurological, mental disorders or mental impairments, with poor compliance and inability to cooperate and describe treatment responses.

• Minimum Eligible Age: 30 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

The First Affiliated Hospital with Nanjing Medical University

OTHER

Sponsor Role: lead

Responsible Party

Sun Xinchen

Director of the Radiotherapy Center

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Xinchen Sun, Doctor

Role: PRINCIPAL_INVESTIGATOR

The First Affiliated with Nanjing Medical University (Jiangsu Province People's Hospital)

Locations

The First Affiliated with Nanjing Medical University (Jiangsu Province People's Hospital)

Nanjing, Jiangsu, China

Site Status: RECRUITING

Countries

China

Central Contacts

Xinchen Sun, Doctor

Role: CONTACT

13770662828@163.com

13770662828

Facility Contacts

Xinchen Sun, Doctor

Role: primary

13770662828@163.com

86-13770662828

Other Identifiers

2024-SR-983

Identifier Type: -

Identifier Source: org_study_id