Chu Quyen D, Zhou Meijiao, Medeiros Kaelen L, Peddi Prakash, Wu Xiao Cheng
Department of Surgery, Louisiana State University Health Sciences Center in Shreveport, Shreveport, Louisiana, LA, U.S.A.
Feist-Weiller Cancer Center, Shreveport, LA, U.S.A.
Anticancer Res. 2017 Oct;37(10):5585-5594. doi: 10.21873/anticanres.11992.
The Cancer and Leukemia Group B (CALGB) 9343 trial demonstrated that adjuvant radiation therapy (RT) can be omitted in women 70 years or older, with small (≤2 cm), negative lymph nodes, estrogen receptor (ER)-positive breast cancer. We examined whether RT usage following the CALGB publication had decreased over time and evaluated sociodemographic and clinical factors associated with RT omission.
From the National Cancer Data Base, we analyzed a cohort of 120,308 women aged 70 years or older with stage I, ER-positive breast cancer who underwent lumpectomy. Patients were classified into two groups based on the time of CALGB 9343 publication: (i) pre-CALGB (up to 2004), and (ii) post-CALGB (2005-2012). Clinicopathological and sociodemographic variables were compared between pre- and post-CALGB groups. Chi-square and multivariable logistic regression were employed, with the omission of adjuvant RT as the primary outcome in the regression analysis.
Radiation therapy usage decreased by 4.1% after CALGB publication (on average 71.6% pre-CALGB vs. 67.5% post-CALGB; p<0.0001). Almost one-third of women aged ≥85 years received RT in the post-CALGB group. In a multivariable model, the variables significantly associated with increased odds for omission of RT in the post-CALGB group were: advanced age, African-American, increased great circle distance, therapy under academic research program, residents of East South-Central region, living in a rural population <2,500 not adjacent to a metropolitan area, low income level, Medicaid recipients, high comorbidity index, small tumor, well-differentiated histology, residual tumor, and lack of receipt of chemotherapy and anti-hormonal therapy.
During the study period, the CALGB trial publication had a minimal impact on the rate of adjuvant RT use among elderly women with small, ER-positive breast cancers. Significant variation in RT usage existed across sociodemographic strata.
癌症与白血病B组（CALGB）9343试验表明，对于年龄70岁及以上、淋巴结阴性且肿瘤较小（≤2 cm）、雌激素受体（ER）阳性的乳腺癌女性患者，可以省略辅助放疗（RT）。我们研究了CALGB发表后放疗的使用是否随时间减少，并评估了与省略放疗相关的社会人口统计学和临床因素。
从国家癌症数据库中，我们分析了120308例年龄70岁及以上、I期ER阳性乳腺癌且接受保乳手术的女性队列。根据CALGB 9343发表时间将患者分为两组：（i）CALGB发表前（至2004年），以及（ii）CALGB发表后（2005 - 2012年）。比较CALGB发表前后两组的临床病理和社会人口统计学变量。采用卡方检验和多变量逻辑回归，回归分析中以省略辅助放疗作为主要结局。
CALGB发表后放疗使用率下降了4.1%（CALGB发表前平均为71.6%，CALGB发表后为67.5%；p<0.0001）。在CALGB发表后的组中，近三分之一的85岁及以上女性接受了放疗。在多变量模型中，与CALGB发表后组中放疗省略几率增加显著相关的变量包括：高龄、非裔美国人、大圆距离增加、学术研究项目下的治疗、东南中地区居民、居住在人口<2500且不毗邻大都市地区的农村人口、低收入水平、医疗补助接受者、高合并症指数、小肿瘤、高分化组织学、残留肿瘤以及未接受化疗和抗激素治疗。
在研究期间，CALGB试验的发表对老年小肿瘤、ER阳性乳腺癌女性辅助放疗的使用率影响极小。社会人口统计学各阶层的放疗使用存在显著差异。
