Which finding after modified radical mastectomy most clearly establishes an indication for postoperative radiotherapy to the chest wall and regional nodes?

• A Lymphovascular invasion on histopathology alone
• B Grade 3 histology in a tumour less than 2 cm with clear nodes
• C Positive estrogen receptor status with negative margins
• D Four or more positive axillary lymph nodes or a T3/T4 primary tumour ✓

Explanation

The accepted indications for post-mastectomy radiotherapy are T3 or T4 primary tumours, involvement of four or more axillary nodes, positive surgical margins, or gross extranodal extension. These situations carry a substantial risk of locoregional recurrence that radiotherapy reduces, with demonstrated survival benefit. Lymphovascular invasion and grade 3 histology are adverse prognostic markers but are not standalone indications, and hormone receptor positivity influences endocrine therapy rather than the radiotherapy decision.

Reference: Sabiston Textbook of Surgery, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.