Locoregional recurrence patterns after mastectomy and doxorubicin-based chemotherapy: implications for postoperative irradiation.
OBJECTIVE
The objective of this study was to determine locoregional recurrence (LRR) patterns after mastectomy and doxorubicin-based chemotherapy to define subgroups of patients who might benefit from adjuvant irradiation.


METHODS
A total of 1,031 patients were treated with mastectomy and doxorubicin-based chemotherapy without irradiation on five prospective trials. Median follow-up time was 116 months. Rates of isolated and total LRR (+/- distant metastasis) were calculated by Kaplan-Meier analysis.


RESULTS
The 10-year actuarial rates of isolated LRR were 4%, 10%, 21%, and 22% for patients with zero, one to three, four to nine, or >/= 10 involved nodes, respectively (P <.0001). Chest wall (68%) and supraclavicular nodes (41%) were the most common sites of LRR. T stage (P <.001), tumor size (P <.001), and >/= 2-mm extranodal extension (P <.001) were also predictive of LRR. Separate analysis was performed for patients with T1 or T2 primary disease and one to three involved nodes (n = 404). Those with fewer than 10 nodes examined were at increased risk of LRR compared with those with >/= 10 nodes examined (24% v 11%; P =.02). Patients with tumor size greater than 4.0 cm or extranodal extension >/= 2 mm experienced rates of isolated LRR in excess of 20%. Each of these factors continued to significantly predict for LRR in multivariate analysis by Cox logistic regression.


CONCLUSIONS
Patients with tumors >/= 4 cm or at least four involved nodes experience LRR rates in excess of 20% and should be offered adjuvant irradiation. Additionally, patients with one to three involved nodes and large tumors, extranodal extension >/= 2 mm, or inadequate axillary dissections experience high rates of LRR and may benefit from postmastectomy irradiation.
Departments of Radiation Oncology, Biomathematics, Medical Oncology, and Surgical Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX, USA.
A
A
Katz
E A
EA
Strom
T A
TA
Buchholz
H D
HD
Thames
C D
CD
Smith
A
A
Jhingran
G
G
Hortobagyi
A U
AU
Buzdar
R
R
Theriault
S E
SE
Singletary
M D
MD
McNeese
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000473:pathology / Q000628:therapy*; D003131:Combined Modality Therapy; D003657:Decision Making; D004317:Doxorubicin / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008408:Mastectomy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012307:Risk Factors; D016019:Survival Analysis
D004317:Doxorubicin