SAN ANTONIOBreast-conserving treatment of early-stage breast cancer confers a low risk of locoregional recurrence that does not adversely affect survival, but early local recurrence increases the likelihood of metastatic disease, M.D. Anderson investigators reported at a poster session of the 22nd Annual San Antonio Breast Cancer Symposium.
Among 1,338 breast-conservation patients followed a median of 8 years, 6.8% had a locoregional recurrence. Ten-year disease-specific survival was 93% in patients who had only locoregional recurrence vs 48% in patients who had local recurrence followed by metastatic recurrence (see Table).
Overall, breast conservation is associated with a low rate of local and regional recurrence, and the patients have excellent long-term survival, said Kelly Hunt, MD, assistant professor of surgical oncology, M.D. Anderson Cancer Center. However, patients who have early recurrence are at increased risk for development of systemic recurrence, and they require close follow-up and consideration of aggressive treatment strategies.
The 1,338 patients in the cohort had 1,369 breast cancers treated by means of breast-conserving surgery between 1955 and 1994. All but 54 of the tumors were stages 0-II. In all cases, lumpectomy was the primary surgical treatment, and axillary node dissection was performed in association with 1,075 of the tumors. In 96% of cases, treatment included adjuvant breast irradiation.
During follow-up, 93 locoregional recurrences were documented, along with 162 metastatic recurrences without locoregional recurrence, and 60 cases of locoregional and metastatic recurrence.
The 5-year disease-specific survival ranged from 89% (stage III) to 100% (stage 0), and 10-year disease-specific survival ranged from 85% (stage II) to 98% (stage 0).
For patients with stage 0 disease, disease-free survival was 94% and 88% at 5 and 10 years. Stages I-III breast cancers were associated with disease-free survival of 76% to 82% at 5 years and 65% to 68% at 10 years.
A separate analysis showed favorable results with breast-conserving surgery in patients who had large primary tumors, defined as 4 cm or greater. During a median follow-up of 6.5 years, six locore-gional recurrences were documented in association with 114 large tumors.
Dr. Hunt and her colleagues did a second evaluation of the same patient population, focusing on 135 patients who had locoregional recurrences with (42 patients) or without (93 patients) systemic recurrence. Clinical characteristics and treatment strategies did not differ between the two patient groups.
Development of metastatic disease was associated with a shorter time to loco-regional recurrence, a median of 3.4 years vs 5.7 years for patients who did not have systemic recurrences (P = .003).
Systemic recurrence was associated with significantly lower survival. At 5 years, disease-specific survival was 97% in patients who had only locoregional recurrence vs 71% in those who had metastatic recurrence. Ten-year disease-specific survival was 93% with locoregional recurrence and 48% with metastatic recurrence (P < .001).