Breast conservation after neoadjuvant chemotherapy.
BACKGROUND
The appropriate selection criteria for breast-conserving therapy (BCT) after neoadjuvant chemotherapy are poorly defined. The purpose of the current report was to develop a prognostic index to help refine selection criteria and to serve as a general framework for clinical decision-making for patients treated by this multimodality approach.


METHODS
From a group of 340 patients treated with BCT after neoadjuvant chemotherapy, the authors previously determined 4 statistically significant predictors of ipsilateral breast tumor recurrence (IBTR) and locoregional recurrence (LRR): clinical N2 or N3 disease, residual pathologic tumor size > than 2 cm, a multifocal pattern of residual disease, and lymphovascular space invasion in the specimen. The M. D. Anderson Prognostic Index (MDAPI) was developed by assigning scores of 0 (favorable) or 1 (unfavorable) for each of these 4 variables and using the total to give an overall MDAPI score of 0-4.


RESULTS
The MDAPI stratified the 340 patients into 3 subsets with statistically different levels of risk for IBTR and LRR after neoadjuvant chemotherapy and BCT. Actuarial 5-year IBTR-free survival rates were 97%, 88%, and 82% for patients in the low (MDAPI overall score 0 or 1, n=276), intermediate (MDAPI score 2, n=43), and high (MDAPI score 3 or 4, n=12) risk groups, respectively (P<0.001). Corresponding actuarial 5-year LRR-free survival rates were 94%, 83%, and 58%, respectively (P<0.001).


CONCLUSIONS
Patients with an MDAPI score of 0 or 1, which made up 81% of the study population, had very low rates of IBTR and LRR. The MDAPI enabled the identification of a small group (4%) of patients who are at high risk for IBTR and LRR and who may benefit from alternative locoregional treatment strategies.
Chen
Allen M
AM
Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Meric-Bernstam
Funda
F
Hunt
Kelly K
KK
Thames
Howard D
HD
Outlaw
Elesyia D
ED
Strom
Eric A
EA
McNeese
Marsha D
MD
Kuerer
Henry M
HM
Ross
Merrick I
MI
Singletary
S Eva
SE
Ames
Fredrick C
FC
Feig
Barry W
BW
Sahin
Aysegul A
AA
Perkins
George H
GH
Babiera
Gildy
G
Hortobagyi
Gabriel N
GN
Buchholz
Thomas A
TA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery*; D018572:Disease-Free Survival; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D011379:Prognosis; D016896:Treatment Outcome