Division of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
JAMA. 2012 May 2;307(17):1827-37. doi: 10.1001/jama.2012.3481.
Brachytherapy is a radiation treatment that uses an implanted radioactive source. In recent years, use of breast brachytherapy after lumpectomy for early breast cancer has increased substantially despite a lack of randomized trial data comparing its effectiveness with standard whole-breast irradiation (WBI). Because results of long-term randomized trials will not be reported for years, detailed analysis of clinical outcomes in a nonrandomized setting is warranted.
To compare the likelihood of breast preservation, complications, and survival for brachytherapy vs WBI among a nationwide cohort of older women with breast cancer with fee-for-service Medicare.
Retrospective population-based cohort study of 92,735 women aged 67 years or older with incident invasive breast cancer, diagnosed between 2003 and 2007 and followed up through 2008. After lumpectomy 6952 patients were treated with brachytherapy vs 85,783 with WBI.
Cumulative incidence and adjusted risk of subsequent mastectomy (an indicator of failure to preserve the breast) and death were compared using the log-rank test and proportional hazards models. Odds of postoperative infectious and noninfectious complications within 1 year were compared using the χ(2) test and logistic models. Cumulative incidences of long-term complications were compared using the log-rank test.
Five-year incidence of subsequent mastectomy was higher in women treated with brachytherapy (3.95%; 95% CI, 3.19%-4.88%) vs WBI (2.18%; 95% CI, 2.04%-2.33%; P < .001) and persisted after multivariate adjustment (hazard ratio [HR], 2.19; 95% CI, 1.84-2.61, P < .001). Brachytherapy was associated with more frequent infectious (16.20%; 95% CI, 15.34%-17.08% vs 10.33%; 95% CI, 10.13%-10.53%; P < .001; adjusted odds ratio [OR], 1.76; 1.64-1.88) and noninfectious (16.25%; 95% CI, 15.39%-17.14% vs 9.00%; 95% CI, 8.81%-9.19%; P < .001; adjusted OR, 2.03; 95% CI, 1.89-2.17) postoperative complications; and higher 5-year incidence of breast pain (14.55%, 95% CI, 13.39%-15.80% vs 11.92%; 95% CI, 11.63%-12.21%), fat necrosis (8.26%; 95% CI, 7.27-9.38 vs 4.05%; 95% CI, 3.87%-4.24%), and rib fracture (4.53%; 95% CI, 3.63%-5.64% vs 3.62%; 95% CI, 3.44%-3.82%; P ≤ .01 for all). Five-year overall survival was 87.66% (95% CI, 85.94%-89.18%) in patients treated with brachytherapy vs 87.04% (95% CI, 86.69%-87.39%) in patients treated with WBI (adjusted HR, 0.94; 95% CI, 0.84-1.05; P = .26).
In a cohort of older women with breast cancer, treatment with brachytherapy compared with WBI was associated worse with long-term breast preservation and increased complications but no difference in survival.
近距离放射治疗是一种使用植入放射性源的放射治疗方法。近年来，尽管缺乏比较其疗效与标准全乳照射（WBI）的随机临床试验数据，但早期乳腺癌保乳手术后的乳房近距离放射治疗的应用大幅增加。由于多年来不会报告长期随机试验的结果，因此有必要在非随机环境中详细分析临床结果。
在接受医疗保险付费的年龄在 67 岁或以上的患有乳腺癌的女性全国性队列中，比较近距离放射治疗与 WBI 保乳的可能性、并发症和生存情况。
对 2003 年至 2007 年间诊断并随访至 2008 年的 92735 名年龄在 67 岁或以上、患有浸润性乳腺癌的女性进行回顾性基于人群的队列研究。在乳房切除术之后，6952 名患者接受了近距离放射治疗，85783 名患者接受了 WBI。
使用对数秩检验和比例风险模型比较后续乳房切除术（保乳失败的指标）和死亡的累积发生率和调整风险。使用 χ(2)检验和逻辑模型比较术后 1 年内感染和非感染性并发症的发生概率。使用对数秩检验比较长期并发症的累积发生率。
接受近距离放射治疗的女性（3.95%；95%CI，3.19%-4.88%）的 5 年后续乳房切除术发生率高于接受 WBI 的女性（2.18%；95%CI，2.04%-2.33%；P<0.001），并且在多变量调整后仍持续存在（风险比[HR]，2.19；95%CI，1.84-2.61，P<0.001）。与 WBI 相比，近距离放射治疗更常导致感染（16.20%；95%CI，15.34%-17.08% vs 10.33%；95%CI，10.13%-10.53%；P<0.001；调整后的比值比[OR]，1.76；1.64-1.88）和非感染性（16.25%；95%CI，15.39%-17.14% vs 9.00%；95%CI，8.81%-9.19%；P<0.001；调整后的 OR，2.03；95%CI，1.89-2.17）术后并发症；5 年乳房疼痛的发生率更高（14.55%；95%CI，13.39%-15.80% vs 11.92%；95%CI，11.63%-12.21%）、脂肪坏死（8.26%；95%CI，7.27%-9.38% vs 4.05%；95%CI，3.87%-4.24%）和肋骨骨折（4.53%；95%CI，3.63%-5.64% vs 3.62%；95%CI，3.44%-3.82%；P ≤ 0.01 均为所有）。接受近距离放射治疗的患者 5 年总生存率为 87.66%（95%CI，85.94%-89.18%），接受 WBI 的患者为 87.04%（95%CI，86.69%-87.39%）（调整后的 HR，0.94；95%CI，0.84-1.05；P = 0.26）。
在年龄较大的患有乳腺癌的女性队列中，与 WBI 相比，近距离放射治疗与长期保乳效果较差、并发症增加，但生存情况无差异。
