Radiotherapy after segmental resection of breast cancer with favorable prognostic features: 12-year follow-up results of a randomized trial.
OBJECTIVE
Postoperative breast irradiation is considered standard after breast-preserving surgery for cancer. We evaluated the efficacy of radiation therapy in the prevention of local recurrence in a patient population that had small-size breast cancer with features that suggested low biologic aggressiveness.


METHODS
Women (n = 264) older than 40 years who were treated by breast resection with > or = 1 cm of tumor-free margin and axillary nodal dissection were randomly assigned to receive or not to receive breast irradiation (cumulative dose, 50 Gy) after surgery. The tumor was required to be < or = 20 mm, node negative, progesterone receptor positive, well to moderately well differentiated and unifocal, and of low cell proliferation rate (ie, S phase fraction < or = 7% or nuclear Ki-67 expression < 10%) and had to lack an extensive intraductal component. The median follow-up time was 12.1 years after random assignment.


RESULTS
Sixteen (11.6%) and 34 (27.2%) cancers recurred locally in the radiotherapy and the control arms, respectively (P = .0013). Time to local recurrence was longer in the radiotherapy arm (hazard ratio [HR], 0.36; 95% CI, 0.20 to 0.65; P = .00071). Twenty-one patients assigned to radiotherapy and 26 assigned to control died during the follow-up. There were no differences in overall survival time (HR, 0.63; 95% CI, 0.35 to 1.12; P = .11), distant disease-free survival (P = .94), or breast cancer-specific survival (P = .56) between the radiation therapy and control groups.


CONCLUSIONS
Radiation therapy after breast resection reduces the frequency of ipsilateral breast recurrences, even among women with small-size breast cancers that have favorable histologic features and that are resected with at least a 1-cm margin. Postoperative radiotherapy did not significantly improve survival.
Holli
Kaija
K
Department of Oncology, Tampere University Hospital, Medical School, Tampere University, Teiskontie 35, 33014 Tampere, Finland. kaija.holli@uta.fi
Hietanen
Päivi
P
Saaristo
Rauni
R
Huhtala
Heini
H
Hakama
Matti
M
Joensuu
Heikki
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D016896:Treatment Outcome