Department of Radiation Oncology, The Cancer Institute of New Jersey, NY 08903, USA.
Cancer. 2011 Mar 15;117(6):1156-62. doi: 10.1002/cncr.25623. Epub 2010 Nov 29.
Recent data from Eastern Cooperative Oncology Group (ECOG) Study 5194 (E5194) prospectively defined a low-risk subset of ductal carcinoma in situ (DCIS) patients where radiation therapy was omitted after lumpectomy alone. The purpose of the study was to determine the ipsilateral breast tumor recurrence (IBTR) in DCIS patients who met the criteria of E5194 treated with lumpectomy and adjuvant whole breast radiation therapy (RT).
A total of 263 patients with DCIS were treated between 1980 and 2009 who met the enrollment criteria for E5194: 1) low to intermediate grade (LIG) with size >0.3 cm but <2.5 cm and margins >3 mm (n = 196), or 2) high grade (HG), size <1 cm and margins >3 mm (n = 67). All patients were treated with lumpectomy and whole breast RT with a boost to a median total tumor bed dose of 6400 cGy. Standard statistical analyses were performed with SAS (v. 9.2).
The average follow-up time was 6.9 years. The 5-year and 7-year IBTR for the LIG cohort in this study was 1.5% and 4.4% compared with 6.1% and 10.5% in E5194, respectively. The 5-year and 7-year IBTR for the HG cohort was 2.0% and 2.0% in this study compared with 15.3% and 18% in E5194, respectively.
Adjuvant whole breast radiation therapy reduced the rate of local recurrence by more than 70% in patients with DCIS who met the criteria of E5194 (6.1% to 1.5% in the LIG cohort and 15.3% to 2% in the HG cohort). Additional follow-up is necessary given that 70% of IBTRs occurred after 5 years.
来自东部肿瘤协作组（ECOG）研究 5194（E5194）的最新数据前瞻性地确定了一个低风险的乳腺导管原位癌（DCIS）患者亚组，这些患者在单纯乳房切除术（保乳术）后可以不接受放射治疗。本研究的目的是确定符合 E5194 标准的 DCIS 患者在接受保乳术和辅助全乳放射治疗（RT）后的同侧乳房肿瘤复发（IBTR）。
1980 年至 2009 年间，共有 263 例 DCIS 患者符合 E5194 的入组标准：1）低到中等级别（LIG），肿瘤大小>0.3cm 但<2.5cm，切缘>3mm（n=196），或 2）高级别（HG），肿瘤大小<1cm，切缘>3mm（n=67）。所有患者均接受保乳术和全乳 RT，中位总肿瘤床剂量为 6400cGy。采用 SAS（v.9.2）进行标准统计分析。
平均随访时间为 6.9 年。本研究中 LIG 队列的 5 年和 7 年 IBTR 分别为 1.5%和 4.4%，而 E5194 分别为 6.1%和 10.5%。HG 队列的 5 年和 7 年 IBTR 分别为 2.0%和 2.0%，而 E5194 分别为 15.3%和 18%。
在符合 E5194 标准的 DCIS 患者中，辅助全乳放疗使局部复发率降低了 70%以上（LIG 队列为 6.1%降至 1.5%，HG 队列为 15.3%降至 2%）。由于 70%的 IBTR 发生在 5 年后，因此需要进一步随访。
