High-grade/large lesions of DCIS require which treatment?

High-grade or large lesions of ductal carcinoma in situ (DCIS) are treated aggressively due to their increased risk of progression to invasive breast cancer. The recommended approach for such lesions often involves a mastectomy, which is the removal of the entire breast, to ensure complete clearance of the disease, particularly in cases where the lesions are extensive or poorly differentiated.

Alongside mastectomy, radiation therapy is generally advised post-surgery to reduce the risk of local recurrence. High-grade DCIS has a higher recurrence rate compared to lower-grade forms, making it crucial to implement a comprehensive treatment strategy that combines surgical removal with adjunctive therapies like radiation.

While local excision may be sufficient for smaller or low-grade lesions, it is not typically adequate for high-grade DCIS due to the potential for undetected invasive components. Observation alone is inadequate in this scenario, given the higher risk associated with high-grade lesions. Radiation therapy alone is also ineffective unless combined with surgical intervention in high-grade cases, as it does not address the primary tumor effectively. Thus, the combination of mastectomy and irradiation represents the most effective treatment for high-grade or large lesions of DCIS.