Vujovic O, Perera F, Dar A R, Stitt L, Yu E, Voruganti S M, Truong P T
Department of Radiation Oncology, London Regional Cancer Centre, Ontario, Canada.
Int J Radiat Oncol Biol Phys. 1998 Mar 1;40(4):869-74. doi: 10.1016/s0360-3016(97)00922-x.
This retrospective review was conducted to determine if delay in the start of radiotherapy after definitive breast surgery had any detrimental effect on local recurrence or disease-free survival in node-negative breast cancer patients.
A total of 568 patients with T1-T2, N0 breast cancer were treated with breast-conserving surgery and breast irradiation, without adjuvant systemic therapy between January 1, 1985 and December 31, 1992, at the London Regional Cancer Centre. Adjuvant breast irradiation consisted either of 50 Gy in 25 fractions or 40 Gy in 15 or 16 fractions, followed by a boost of 10 Gy or 12.5 Gy to the lumpectomy site. The time intervals from definitive breast surgery to breast irradiation used for analysis were 0-8 weeks (201 patients), > 8-12 weeks (235 patients), > 1216 weeks (91 patients), and > 16 weeks (41 patients). The time intervals of 0-12 weeks (436 patients) and > 12 weeks (132 patients) were also analyzed. Kaplan-Meier estimates of time to local recurrence and disease-free survival rates were calculated. The association between surgery-radiotherapy interval, age (< or = 40, > 40 years), tumor size (< or = 2, > 2cm), Scharf-Bloom-Richardson (SBR) grade, resection margins, lymphatic vessel invasion, extensive intraductal component, and local recurrence and disease-free survival were investigated using Cox regression techniques.
Median follow-up was 63.5 months. Patients in all 4 time intervals were similar in terms of age and pathologic features. There was no statistically significant difference between the 4 groups in local recurrence or disease-free survival with surgery-radiotherapy interval (p = 0.189 and p = 0.413, respectively). The 5-year freedom from local relapse was 95.4%. The crude local recurrence rate was 6.9% (7.8% for 436 patients treated within 12 weeks (median follow-up 67 months) and 3.8% for 132 patients treated > 12 weeks from surgery (median follow-up 52 months). In a stepwise multivariable Cox regression model for disease-free survival, allowing for entry of known risk factors, tumour size (p < 0.001), grade (p < 0.001), and age (p = 0.048) entered the model, but the surgery-radiotherapy interval did not enter the model.
This retrospective study suggests that delay in start of breast irradiation beyond 12 and up to 16 weeks does not increase the risk of recurrence in node-negative breast cancer patients. The certainty of these results are limited by the retrospective nature of this analysis and the lack of information concerning the late local failure rate.
进行这项回顾性研究以确定在确诊为乳腺癌的手术之后延迟开始放疗是否会对淋巴结阴性乳腺癌患者的局部复发或无病生存期产生任何不利影响。
1985年1月1日至1992年12月31日期间，共有568例T1 - T2、N0期乳腺癌患者在伦敦地区癌症中心接受了保乳手术和乳腺照射，未接受辅助性全身治疗。辅助性乳腺照射包括25次分割照射50 Gy或15或16次分割照射40 Gy，随后对肿块切除部位追加10 Gy或12.5 Gy的照射剂量。用于分析的从确诊乳腺癌手术到乳腺照射的时间间隔分别为0 - 8周（201例患者）、> 8 - 12周（235例患者）、> 12 - 16周（91例患者）以及> 16周（41例患者）。还分析了0 - 12周（436例患者）和> 12周（132例患者）的时间间隔。计算了局部复发时间和无病生存率的Kaplan - Meier估计值。使用Cox回归技术研究了手术 - 放疗间隔、年龄（≤40岁、> 40岁）、肿瘤大小（≤2 cm、> 2 cm）、Scharf - Bloom - Richardson（SBR）分级、手术切缘、淋巴管浸润、广泛导管内成分与局部复发和无病生存期之间的关联。
中位随访时间为63.5个月。所有4个时间间隔组的患者在年龄和病理特征方面相似。4组在局部复发或无病生存期方面，手术 - 放疗间隔无统计学显著差异（分别为p = 0.189和p = 0.413）。5年局部无复发生存率为95.4%。粗局部复发率为6.9%（12周内接受治疗的436例患者为7.8%，中位随访67个月；手术12周后接受治疗的132例患者为3.8%，中位随访52个月）。在一个用于无病生存期的逐步多变量Cox回归模型中，纳入已知风险因素后，肿瘤大小（p < 0.001）、分级（p < 0.001）和年龄（p = 0.048）进入模型，但手术 - 放疗间隔未进入模型。
这项回顾性研究表明，在淋巴结阴性乳腺癌患者中，延迟至12周以上直至16周开始乳腺照射不会增加复发风险。这些结果的确定性受到该分析的回顾性性质以及缺乏关于晚期局部失败率信息的限制。
