A woman with a 3 cm, biopsy-proven, node-negative invasive breast carcinoma wants to keep her breast, and the surgeon confirms the lesion can be removed with clear margins. The tumor board also wants the lowest achievable local recurrence while the breast is preserved. Which treatment plan best delivers breast conservation, clear margins, and the lowest local recurrence?

Breast-conserving surgery followed by whole-breast radiation meets your preference to retain the breast, uses the surgeon’s assessment that clear margins are achievable, and provides strong local control. Radiation after lumpectomy substantially reduces recurrence in the treated breast; among the breast-preserving approaches described here, whole-breast treatment is the established choice when the aim is to minimize local recurrence. Therapeutic mastectomy can provide excellent local control, but it removes the breast and therefore does not meet the breast-conservation goal. Partial-breast irradiation is a standard alternative for carefully selected patients, but a 3 cm tumor exceeds the usual size limit in many guideline-based eligibility criteria, so that approach does not fit this case. Omitting radiation in favor of endocrine therapy can be reasonable for selected older patients with small, favorable hormone-receptor-positive cancers, but this case does not establish those eligibility features, and omission does not meet the goal of the lowest local recurrence. Exam caveat: “lowest” is relative, and the appropriate radiation approach depends on individual risk and current guidance. Practical check: confirm final pathology, including margin status, tumor size, nodal status, and receptor profile, then review radiation planning with the multidisciplinary team.