Breast conservation: long-term results from Westmead Hospital

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Breast conservation surgery (CS) is a viable alternative to mastectomy for early-stage breast cancer.
• Long-term outcomes and toxicity of CS combined with radiation therapy (CS+RT) require continued evaluation.

Purpose of the Study:

• To review the long-term outcomes and toxicity of conservative surgery and radiation therapy (CS+RT) for early-stage breast cancer.
• To assess local recurrence rates, distant relapse, and treatment-related side effects.

Main Methods:

• A cohort of 438 patients with Union Internationale Contre le Cancer (UICC) stage I or II breast cancer were treated with CS+RT between 1979 and 1989.
• Treatments included varying degrees of breast surgery, axillary dissection in 68% of patients, and postoperative whole breast irradiation with or without boosts.
• Adjuvant chemotherapy was administered to 10% of patients.

Main Results:

• The median follow-up was 84 months. The 5-year and 10-year actuarial local recurrence rates were 6% and 10%, respectively.
• Younger patients (≤34 years) had a higher 5-year local recurrence rate (13%) compared to older patients (5%, P=0.04).
• Five-year freedom from distant relapse was 83%. Reported side effects included rib fractures (2%), pneumonitis (3%), fat necrosis/fibrosis (4%), and arm edema (7%).

Conclusions:

• CS+RT for UICC stage I or II breast cancer yields low local recurrence rates, with age at diagnosis being a significant factor.
• Radiation dose and boost technique did not influence local recurrence rates.
• CS+RT is confirmed as a safe and effective alternative to mastectomy for operable breast cancer.