What is the diagnosis and treatment for radial scar (RS) of the breast?

From the Guidelines

Radial scars in the breast are benign lesions that require careful evaluation due to their association with breast cancer, and the standard approach involves surgical excision of the lesion, particularly for larger radial scars or those with atypical features on biopsy, as recommended by the most recent guidelines 1. When a radial scar is detected on imaging, a biopsy is generally recommended to rule out malignancy, as approximately 10-20% of radial scars may harbor cancerous cells. The diagnosis of radial scars typically involves imaging studies such as mammography and ultrasound, which can show stellate or star-shaped abnormalities that mimic cancer.

Key Considerations

• The size and features of the radial scar are important factors in determining the treatment approach, with larger radial scars (greater than 1 cm) or those with atypical features on biopsy typically requiring surgical excision 1.
• For smaller, uncomplicated radial scars with no atypia on core needle biopsy, close imaging follow-up may be considered as an alternative to surgery in select cases, as recommended by the NCCN guidelines 1.
• After diagnosis and treatment, patients should continue routine breast cancer screening according to age-appropriate guidelines, as radial scars are associated with an increased risk of future breast cancer development 1.

Treatment Options

• Surgical excision of the lesion is the standard approach for larger radial scars or those with atypical features on biopsy.
• Close imaging follow-up may be considered for smaller, uncomplicated radial scars with no atypia on core needle biopsy.
• Routine breast cancer screening is recommended after diagnosis and treatment, according to age-appropriate guidelines.

Importance of Radial Scars

• Radial scars are benign lesions that can mimic cancer on imaging, and their importance lies in their potential association with concurrent malignancy and their status as a risk factor for future breast cancer development 1.
• The diagnosis and treatment of radial scars require careful evaluation and consideration of the individual patient's risk factors and medical history.

From the Research

Diagnosis of Radial Scar (RS) of the Breast

• Radial scar (RS) is a low-risk breast lesion that can be associated with or mimic malignancy 2.
• RS can be diagnosed using imaging-guided needle biopsy, with mammography and sonography being commonly used modalities 3, 4.
• The diagnosis of RS can be challenging, and the use of vacuum-assistance and larger biopsy needles, along with obtaining a higher number of samples, can help reduce the rate of upgrades and lower surgical excision rates 2.

Treatment of Radial Scar (RS) of the Breast

• The management guidelines for patients with RS without atypia on core needle biopsy (CNB) remain controversial 2.
• Surgical excision is often recommended for patients with RS identified on CNB, especially for those with atypical proliferative lesions (APLs) or a history of breast cancer 5, 6.
• However, recent studies suggest that conservative follow-up with imaging rather than surgical excisions may be more appropriate for patients with only RS on biopsy, especially for patients with mammotome CNBs 6.
• Close imaging surveillance is an acceptable alternative to surgical excision in patients with RS without atypia, as the upgrade rate to malignancy is low 2.
• The mammographic and sonographic features of a lesion diagnosed as a radial scar at percutaneous imaging-guided biopsy do not predict which lesions will have associated malignancy at surgery, and therefore, all patients with a percutaneous diagnosis of a radial scar should undergo surgical excision regardless of mammographic and sonographic appearances 4.

Upgrade Rates and Malignancy Risk

• The upgrade rate of RS without atypia to malignancy is low, ranging from 1% to 8% in different studies 2, 4.
• The presence of atypia and malignancy in RS is associated with a higher risk of breast cancer, and the incidence of atypia and malignancy can be as high as 24.8% and 22.4%, respectively 5.
• The use of preoperative core biopsy evaluation can help identify patients with a higher risk of malignancy and permit one-stage surgical therapy in those with B5 diagnoses 5.