Breast-Conservation Therapy Associated With Better Cancer-Specific Survival Than Mastectomy in Patients With Early-Stage Invasive Ductal Carcinoma
In a study reported in JAMA Surgery, Agarwal et al compared breast cancer–specific survival rates of patients with early-stage invasive ductal carcinoma undergoing breast-conservation therapy (lumpectomy followed by radiation), mastectomy alone, or mastectomy with radiation using the SEER (Surveillance, Epidemiology, and End Results) database. They found that breast-conservation therapy was associated with significantly better disease-specific survival.
Study Details
The study involved assessment of outcomes among 132,149 patients with early-stage breast cancer, defined as tumor size ≤ 4 cm with ≤ 3 positive lymph nodes identified from the SEER database. Patients underwent breast-conservation therapy (n = 92,671; 70%), mastectomy alone (n = 34,999; 27%), or mastectomy with radiation (n = 4,479; 3%) from 1998 to 2008.
Compared with patients receiving mastectomy or mastectomy with radiation, patients receiving breast-conservation therapy were more likely to be white (84% vs 78% and 75%; P < .001 for trend), to have lower tumor grade (1 in 23% vs 16% and 9%, P < .001 for trend), to be estrogen receptor–positive (75% vs 66% and 65%; P < .001 for trend) and progesterone receptor–positive (65% vs 55% and 55%; P < .001 for trend), to have smaller tumor size (≤ 2 cm in 80% vs 64% and 46%; P < .001 for trend), and to be node-negative (80% vs 70% and 36%; P < .001 for trend). Patients receiving mastectomy with radiation were younger at diagnosis (median, 52 years vs 57 years for women receiving breast-conservation therapy and 61 years in those receiving mastectomy alone; P < .001 for trend). Median year of diagnosis was 2004 in the breast-conservation therapy group and 2003 in the other two groups (P < .001).
Improved Disease-Specific Survival
The 5-year breast cancer–specific survival rates of patients who underwent breast-conservation therapy, mastectomy alone, or mastectomy with radiation were 97%, 94%, and 90% (P < .001) and 10-year breast cancer–specific survival rates were 94%, 90%, and 83% (P < .001).
On multivariate analysis adjusting for year of diagnosis, age, race, number of positive lymph nodes, tumor size, estrogen receptor and progesterone receptor status, and tumor grade, women receiving breast-conservation therapy had significantly greater breast cancer–specific survival vs those receiving mastectomy alone (hazard ratio [HR] = 1.31, P < .001) or mastectomy with radiation (HR = 1.47, P < .001). The effect of treatment on survival was similar in a propensity analysis comparing treatment groups within sets of patients with similar likelihood for a given treatment.
The investigators concluded, “Patients who underwent [breast-conservation therapy] have a higher breast cancer–specific survival rate compared with those treated with mastectomy alone or mastectomy with radiation for early-stage invasive ductal carcinoma. Further investigation is warranted to understand what may be contributing to this effect.”
Jayant Agarwal, MD, of the University of Utah School of Medicine, is the corresponding author for the JAMA Surgery article.
The study authors reported no potential conflicts of interest.
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