**Core Concept**
Phyllodes tumors are rare, fibroepithelial tumors of the breast that can be benign, borderline, or malignant. The treatment of phyllodes tumors depends on their histological subtype, size, and margin status. Surgical excision is the primary treatment, and the management of these tumors can be challenging due to their potential for local recurrence.

**Why the Correct Answer is Right**
The correct answer is not a treatment for phyllodes tumors. Phyllodes tumors are typically managed with surgical excision, which may involve wide local excision or mastectomy, depending on the tumor size and margin status. The goal of surgical excision is to remove the tumor with a margin of normal tissue to prevent local recurrence.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because surgical excision is a treatment for phyllodes tumors. Surgical excision is the primary treatment for phyllodes tumors, and it may involve wide local excision or mastectomy, depending on the tumor size and margin status.
* **Option B:** This option is incorrect because radiation therapy may be used as an adjunct to surgery for phyllodes tumors, but it is not the primary treatment. Radiation therapy may be used to reduce the risk of local recurrence, especially in cases where the tumor has positive margins.
* **Option C:** This option is incorrect because chemotherapy may be used in the management of malignant phyllodes tumors, but it is not a treatment for phyllodes tumors in general. Chemotherapy may be used in cases where the tumor has metastasized or is unresectable.
* **Option D:** This option is incorrect because hormonal therapy is not a treatment for phyllodes tumors. Phyllodes tumors are not hormone-dependent tumors, and hormonal therapy is not typically used in their management.

**Clinical Pearl / High-Yield Fact**
Phyllodes tumors can be challenging to manage due to their potential for local recurrence. The risk of local recurrence is higher in cases where the tumor has positive margins, and the use of radiation therapy or chemotherapy may be considered in these cases to reduce the risk of recurrence.

**Correct Answer:** A.