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 和分子亚型的疾病程度：乳腺癌新辅助全身治疗后腋窝治疗反应的预测。


背景 根据基线[18F]氟脱氧葡萄糖 PET/CT 的腋窝疾病程度结合病理腋窝治疗反应，已建议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疾病程度是否是腋窝 pCR 的预测因子。方法本研究纳入了前瞻性放射性碘粒子植入腋窝并进行前哨淋巴结活检（“RISAS”）试验（NCT02800317）中接受新辅助全身治疗的临床淋巴结阳性患者，并具有基线[18F]氟脱氧葡萄糖PET/CT成像。使用逻辑回归分析评估根据基线[18F]氟脱氧葡萄糖PET/CT和乳腺癌分子亚型估计腋窝pCR的腋窝疾病程度的预测价值。辨别能力使用具有 95% 置信区间的 OR 来表示。结果 总体而言，纳入了 185 名患者，腋窝 pCR 率为 29.7%。根据[18F]氟脱氧葡萄糖 PET/CT，有限性基线腋窝疾病患者和晚期基线腋窝疾病患者的腋窝 pCR 率分别为 31.9% 和 26.1%。腋窝疾病范围并不是腋窝 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 率存在显着差异。激素受体+/人表皮生长因子受体 2- 肿瘤的概率最低 (7%)。使用此类别作为参考组，OR 显着增加为 14。激素受体+/人表皮生长因子受体 2+ 肿瘤有 82 个，激素受体-/人表皮生长因子受体 2+ 肿瘤有 40 个，三阴性肿瘤有 6.91 个（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 得出的腋窝疾病程度则不是。