Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Cancer. 2012 Feb 1;118(3):603-11. doi: 10.1002/cncr.26293. Epub 2011 Jun 30.
The benefit of adding radiation therapy after excision of ductal carcinoma in situ (DCIS) is widely debated. Randomized clinical trials are underpowered to delineate long-term outcomes after radiation.
The authors of this report constructed a Markov decision model to simulate the clinical course of DCIS in a woman aged 60 years who received treatment with either of 2 breast-conserving strategies: excision alone or excision plus radiation therapy. Sensitivity analyses were used to study the influence of risk of local recurrence, likelihood of invasive disease at recurrence, surgical choice at recurrence, and patient age at diagnosis on treatment outcomes.
The addition of radiation therapy was associated with slight improvements in invasive disease-free and overall survival. However, radiation therapy decreased the chance of having both breasts intact over a patient's lifetime. Radiation therapy improved survival by 2.1 months for women who were diagnosed with DCIS at age 60 years but decreased the chance of having both breasts by 8.6% relative to excision alone. The differences in outcomes between the treatment strategies became smaller with increasing age at diagnosis. Sensitivity analyses revealed a greater benefit for radiation with an increased likelihood of invasive recurrence. The decrement in breast preservation with radiation therapy was mitigated by an increased likelihood of mastectomy at the time of recurrence or new breast cancer diagnosis.
The current analysis quantified the benefits of radiation after excision of DCIS but also revealed that radiation therapy may increase the likelihood of eventual mastectomy. Therefore, the authors concluded that patient age and preferences should be considered when making the decision to add or forgo radiation for DCIS.
在切除乳腺导管原位癌（DCIS）后加用放射治疗的益处存在广泛争议。随机临床试验在描绘放射治疗后的长期结果方面能力不足。
本报告的作者构建了一个马尔可夫决策模型，以模拟 60 岁女性 DCIS 的临床病程，该女性接受了 2 种保乳治疗策略中的任意 1 种：单纯切除术或切除术加放射治疗。敏感性分析用于研究局部复发风险、复发时浸润性疾病的可能性、复发时的手术选择以及诊断时患者年龄对治疗结果的影响。
加用放射治疗与浸润性疾病无复发和总体生存的微小改善相关。然而，放射治疗降低了患者一生中双侧乳房完整的机会。放射治疗使 60 岁诊断为 DCIS 的女性的生存延长了 2.1 个月，但与单纯切除术相比，双侧乳房完整的机会降低了 8.6%。随着诊断时年龄的增加，治疗策略之间的结果差异变小。敏感性分析显示，在浸润性复发可能性增加的情况下，放射治疗的获益更大。放射治疗对乳房保存的影响减少，可通过增加复发或新发乳腺癌时行乳房切除术的可能性来缓解。
目前的分析量化了切除 DCIS 后放射治疗的益处，但也表明放射治疗可能增加最终行乳房切除术的可能性。因此，作者得出结论，在决定是否对 DCIS 加用或放弃放射治疗时，应考虑患者年龄和偏好。
