BACKGROUND Axillary disease extent according to baseline [18F]fluorodeoxyglucose PET/CT combined with pathological axillary treatment response has been proposed to guide de-escalation of axillary treatment for clinically node-positive breast cancer patients treated with neoadjuvant systemic therapy. The aim of this study was to assess whether axillary disease extent according to baseline [18F]fluorodeoxyglucose PET/CT and breast cancer molecular subtype are predictors of axillary pCR. METHODS This study included clinically node-positive patients treated with neoadjuvant systemic therapy in the prospective Radioactive Iodine Seed placement in the Axilla with Sentinel lymph node biopsy ('RISAS') trial (NCT02800317) with baseline [18F]fluorodeoxyglucose PET/CT imaging available. The predictive value of axillary disease extent according to baseline [18F]fluorodeoxyglucose PET/CT and breast cancer molecular subtype to estimate axillary pCR was evaluated using logistic regression analysis. Discriminative ability is expressed using ORs with 95% confidence intervals. RESULTS Overall, 185 patients were included, with an axillary pCR rate of 29.7%. The axillary pCR rate for patients with limited versus advanced baseline axillary disease according to [18F]fluorodeoxyglucose PET/CT was 31.9% versus 26.1% respectively. Axillary disease extent was not a significant predictor of axillary pCR (OR 0.75 (95% c.i. 0.38 to 1.46) (P = 0.404)). There were significant differences in axillary pCR rates between breast cancer molecular subtypes. The lowest probability (7%) was found for hormone receptor+/human epidermal growth factor receptor 2- tumours. Using this category as a reference group, significantly increased ORs of 14.82 for hormone receptor+/human epidermal growth factor receptor 2+ tumours, 40 for hormone receptor-/human epidermal growth factor receptor 2+ tumours, and 6.91 for triple-negative tumours were found (P < 0.001). CONCLUSION Molecular subtype is a significant predictor of axillary pCR after neoadjuvant systemic therapy, whereas axillary disease extent according to baseline [18F]fluorodeoxyglucose PET/CT is not.

中文翻译：

---

根据基线 [18F] 氟脱氧葡萄糖 PET/CT 和分子亚型的疾病范围：预测乳腺癌新辅助全身治疗后腋窝治疗反应。


背景 根据基线 [18F] 氟脱氧葡萄糖 PET/CT 联合病理腋窝治疗反应的腋窝病变范围已被提出以指导接受新辅助全身治疗的临床淋巴结阳性乳腺癌患者的腋窝治疗降级。本研究的目的是评估根据基线 [18F] 氟脱氧葡萄糖 PET/CT 和乳腺癌分子亚型的腋窝病变范围是否是腋窝 pCR 的预测因子。方法 本研究包括在腋窝前哨淋巴结活检 （'RISAS'） 试验 （NCT02800317'RISAS'） 中接受新辅助全身治疗的临床淋巴结阳性患者，在基线 [18F] 氟脱氧葡萄糖 PET/CT 成像可用的情况下接受前瞻性放射性碘种子放置。使用 logistic 回归分析评估根据基线 [18F] 氟脱氧葡萄糖 PET/CT 和乳腺癌分子亚型的腋窝疾病范围对估计腋窝 pCR 的预测价值。判别能力使用具有 95% 置信区间的 OR 表示。结果 共纳入 185 例患者，腋窝 pCR 率为 29.7%。根据 [18F] 氟脱氧葡萄糖 PET/CT，局限性与晚期基线腋窝疾病患者的腋窝 pCR 率分别为 31.9% 和 26.1%。腋窝疾病范围不是腋窝 pCR 的显着预测因子 （OR 0.75 （95% ci. 0.38 至 1.46） （P = 0.404））。乳腺癌分子亚型之间的腋窝 pCR 率存在显著差异。激素受体 + /人表皮生长因子受体 2- 肿瘤的概率最低 （7%）。使用该类别作为参考组，ORs 显著增加 14。激素受体 +/人表皮生长因子受体 2+ 肿瘤 82 例，激素受体/人表皮生长因子受体 2+ 肿瘤 40 例，三阴性肿瘤 6.91 例 （P < 0.001）。结论 分子亚型是新辅助全身治疗后腋窝 pCR 的重要预测因子，而根据基线 [18F] 氟脱氧葡萄糖 PET/CT 的腋窝病变范围则不是。