Low locoregional recurrence rate among node-negative breast cancer patients with tumors 5 cm or larger treated by mastectomy, with or without adjuvant systemic therapy and without radiotherapy: results from five national surgical adjuvant breast and bowel project randomized clinical trials.
OBJECTIVE
Lymph node (LN) -negative breast cancer tumors > or = 5 cm occur infrequently, and their optimal management is not well defined. In this study, we assess patterns of locoregional failure (LRF) in LN-negative patients who underwent mastectomy, either with or without adjuvant chemotherapy or hormonal therapy and without postmastectomy radiation therapy (PMRT).


METHODS
Of 8,878 breast cancer patients enrolled onto National Surgical Adjuvant Breast and Bowel Project B-13, B-14, B-19, B-20, and B-23 node-negative trials, 313 had tumors that were 5 cm or larger (median, 5.5 cm; range, 5.0 to 15.5 cm) at pathology and were treated by mastectomy. Median follow-up time was 15.1 years. Therapy included adjuvant chemotherapy in 34.2% of patients; tamoxifen in 21.1%; chemotherapy plus tamoxifen in 19.2%; and no systemic therapy in 25.5%.


RESULTS
Twenty-eight patients experienced LRF. The overall 10-year cumulative incidences of isolated LRF, LRF with and without distant failure (DF), and DF alone as first event were 7.1%, 10.0%, and 23.6%, respectively. Cumulative incidences for isolated LRF as first event for patients with tumors of 5 cm or more than 5 cm were 7.0% and 7.2%, respectively (P = .9). For patients who underwent no systemic treatment, chemotherapy alone, tamoxifen alone, or chemotherapy plus tamoxifen, the incidences were 12.6%, 5.6%, 4.6%, and 5.3%, respectively (P = .2). The majority of failures occurred on the chest wall (24 of 28 patients). Multivariate analysis did not identify significant prognostic factors for LRF.


CONCLUSIONS
In patients with LN-negative tumors > or = 5 cm who are treated by mastectomy with or without adjuvant systemic therapy and no PMRT, LRF as first event remains low. PMRT should not be routinely used for these patients.
Taghian
Alphonse G
AG
National Surgical Adjuvant Breast and Bowel Project Operations and Biostatistical Centers, Graduate School of Public Health, University of Pittsburgh, PA, USA. ataghian@partners.org
Jeong
Jong-Hyeon
JH
Mamounas
Eleftherios P
EP
Parda
David S
DS
Deutsch
Melvin
M
Costantino
Joseph P
JP
Wolmark
Norman
N
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D015994:Incidence; D008408:Mastectomy; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology* / Q000517:prevention & control; D018714:Radiotherapy, Adjuvant; D016032:Randomized Controlled Trials as Topic; D014481:United States / Q000453:epidemiology