Abstract P3-04-03: A seven-gene profile predicting benefit of postmastectomy radiotherapy independently of nodal status in high risk breast cancer

Accuracy of a multidisciplinary team-led discussion in predicting postmastectomy radiotherapy

INTRODUCTION

Immediate breast reconstruction (IBR) is performed increasingly following mastectomy for breast cancer. The literature suggests higher reconstructive failure and poorer cosmesis in the subgroup of patients receiving postmastectomy radiotherapy (PMRT) following IBR. We set out to determine the accuracy of a multidisciplinary team (MDT) discussion in predicting PMRT.

METHODS

Preoperative MDT discussions were recorded prospectively over a 12-month period (from February 2011) in a symptomatic breast unit. The estimated need for PMRT was stratified into 'PMRT not required', 'PMRT possibly required', 'PMRT probably required' and 'PMRT required' groups.

RESULTS

Of 156 referrals included in the study, 76 patients (49%) underwent mastectomy: 61 simple mastectomy, 10 skin sparing mastectomy (SSM) and delayed-immediate breast reconstruction, 3 SSM and implant-based IBR, and 2 mastectomy IBR with an autologous flap. The IBR rate was therefore 19.7%. The proportion of patients who received PMRT was 14% (3/21) in the 'PMRT not required', 30% (7/23) in the 'PMRT possibly required', 65% (9/14) in the 'PMRT probably required' and 94% (17/18) in the 'PMRT required' groups. Assigning a linear numerical score (1-4) to these groups (higher score representing greater likelihood of receiving PMRT), the predicted need for PMRT correlated with the proportion of patients who ultimately received PMRT (linear regression r(2)=0.98, p=0.01).

CONCLUSIONS

This study has examined the factors influencing MDT discussions regarding IBR, demonstrating that the MDT is reasonably accurate at predicting need for PMRT. Whether such accuracy is clinically adequate and/or reproducible across units is debatable.