Conservative surgery and radiotherapy for stage I/II breast cancer using lung density correction: 10-year and 15-year results

Journal Article · Fri Apr 01 04:00:00 EST 2005 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2004.08.004· OSTI ID:20696163

Pierce, Lori J ^[1]; Griffith, Kent A ^[2]; Hayman, James A ^[1]; Douglas, Kathye R ^[1]; Lichter, Allen S ^[1]

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1. Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, MI (United States)
2. University of Michigan Cancer Center Biostatistics Core, Ann Arbor, MI (United States)

Purpose: Radiotherapy (RT) planning for breast cancer using lung density correction improves dose homogeneity. Its use obviates the need for a medial wedge, thus reducing scatter to the opposite breast. Although lung density correction is used at many centers in planning for early-stage breast cancer, long-term results of local control and survival have not been reported. Since 1984, we have used lung density correction for dose calculations at the University of Michigan. We now present our 10-year and 15-year results. Methods and Materials: The records of 867 patients with Stage I/II breast cancer treated with breast-conserving surgery and RT with or without systemic therapy were reviewed. Tangential fields delivering 45-50 Gy to the whole breast calculated using lung density correction were used. A boost was added in 96.8% of patients for a total median dose of 61.8 Gy. Results: With a median follow-up of 6.6 years (range, 0.2-18.9 years), 5-, 10-, and 15-year actuarial rates of in-breast tumor recurrence as only first failure were 2.2%, 3.6%, and 5.4%, respectively. With surgical salvage, the 15-year cumulative rate of local control was 99.7%. Factors that significantly predicted for increased rate of local recurrence in multivariate analysis were age {<=} 35 years, hazard ratio 4.8 (95% confidence interval [CI], 1.6-13.9) p = 0.004; negative progesterone receptor status, hazard ratio 6.8 (95% CI, 2.3-20.3) p = < 0.001; negative estrogen receptor status, hazard ratio 4.0 (95% CI, 1.5-11.1) p = 0.007; and lack of adjuvant tamoxifen therapy, hazard ratio 7.7 (95% CI, 1.7-33.3) p = 0.008. Relapse-free survival rates at 5, 10, and 15 years were 84.6%, 70.8%, and 55.9%, respectively; breast cancer-specific survival rates were 94.4%, 90.5%, and 86.9%, respectively; and corresponding estimates for overall survival were 89.7%, 75.7%, and 61.3%. Conclusions: Use of lung density correction was associated with high rates of local control, relapse-free survival, breast cancer-specific survival, and overall survival compared with other reported series of breast-conserving surgery and RT in early-stage disease. These results will serve as a benchmark against which newer radiation delivery strategies such as intensity-modulated RT and partial breast RT can be compared.

• OSTI ID: 20696163
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 5 Vol. 61; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CARCINOMAS
ESTROGENS
LUNGS
MAMMARY GLANDS
PATIENTS
PROGESTERONE
RADIATION DOSES
RADIOTHERAPY
RECEPTORS
SURGERY
TAMOXIFEN