Breast conservation: long-term results from Westmead Hospital.

BACKGROUND

Breast conservation has been shown to be a safe and effective alternative to mastectomy in early-stage breast cancer. The present study reviews the long-term outcome and toxicity after treatment of early breast cancer by conservative surgery and radiation.

METHODS

Between November 1979 and December 1989, 438 patients with Union Internationale Contre le Cancer (UICC) stage I or II breast cancer were treated with conservative surgery and radiation therapy (CS+RT) at Westmead Hospital. Surgery to the breast varied from a local excision to a quadrantectomy, depending on the preference of the referring surgeon. The axilla was surgically dissected in 299 patients (68%). All patients received postoperative breast irradiation. The whole breast was irradiated to 46-54 Gy (median dose, 50 Gy) using 6 Mev photons for 5-6.5 weeks. Boosts were given at the primary tumour site in 336 patients (78%), by electron therapy (88 patients), iridium-192 (247 patients) or photons (one patient). A total of 44 patients (10%) received adjuvant chemotherapy.

RESULTS

The median follow-up period for surviving patients was 84 months (range: 56-172 months). The 5-year actuarial rate of local recurrence was 6% (312 patients at risk), and the 10-year rate was 10% (52 patients at risk). Very young patients (aged 34 years at diagnosis) had a 5-year actuarial rate of local recurrence of 13% compared to 5% for older patients (P = 0.04). Neither the total dose to the primary site nor the boost technique influenced local recurrence. The 5-year freedom from distant relapse was 83%. The side effects included rib fractures (2%), symptomatic pneumonitis (3%), fatty necrosis or fibrosis requiring surgery (4%), and moderate-severe oedema of the arm (7%).

CONCLUSIONS

The long-term data show that CS+RT for UICC stage I or II breast cancer results in low rates of local recurrence which are influenced by age at diagnosis, but not by radiation dose or boost technique. These results confirm those of other international series that CS+RT is a safe alternative to mastectomy for most women with operable breast cancer.