Purpose

We aimed to investigate whether visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area (SMA) index are predictive for efficacy and hematological toxicity in ER + HER2—metastatic breast cancer (BC) patients who received CDK 4/6 inhibitors.

Methods

This retrospective cohort study analyzed 52 patients who were treated with CDK 4/6 inhibitors between January 2018 and February 2021. The values of VAT, SAT, SMA indices and hematological parameters were noted before the start, at the third and sixth months of this treatment. The skeletal muscle area (SMA) and adipose tissue measurements were calculated at the level of the third lumbar vertebra. A SMA-index value of <40 cm²/m² was accepted as the threshold value for sarcopenia.

Results

Patients with sarcopenia had a worse progression-free survival (PFS) compared to patients without sarcopenia (19.6 vs. 9.0 months, p = 0.005). Patients with a high-VAT-index had a better PFS (20.4 vs. 9.3 months, p = 0.033). Only the baseline low-SMA- index (HR: 3.89; 95% CI: 1.35–11.25, p = 0.012) and baseline low-VAT-index (HR: 2.15; 95% CI: 1.02–4.53, p = 0.042) had significantly related to poor PFS in univariate analyses. The low-SMA-index was the only independent factor associated with poor PFS (HR: 3.99; 95% CI: 1.38–11.54, p = 0.011). No relationship was observed between body composition parameters and grade 3–4 hematological toxicity.

Conclusion

The present study supported the significance of sarcopenia and low visceral adipose tissue as potential early indicators of poor PFS in patients treated with CDK 4/6 inhibitors.

中文翻译：

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内脏肥胖和肌肉减少症作为 CDK 4/6 抑制剂治疗转移性乳腺癌患者疗效和血液学毒性的预测因子

目的

我们的目的是研究内脏脂肪组织 (VAT)、皮下脂肪组织 (SAT) 和骨骼肌面积 (SMA) 指数是否可以预测接受 CDK 4 的 ER + HER2 转移性乳腺癌 (BC) 患者的疗效和血液学毒性/6 抑制剂。

方法

这项回顾性队列研究分析了 2018 年 1 月至 2021 年 2 月期间接受 CDK 4/6 抑制剂治疗的 52 名患者。在治疗开始前、第三个月和第六个月记录了 VAT、SAT、SMA 指数和血液学参数的值。在第三腰椎水平计算骨骼肌面积（SMA）和脂肪组织测量值。^{<40 cm 2} /m ²的SMA指数值被接受为肌肉减少症的阈值。

结果

与没有肌肉减少症的患者相比，肌肉减少症患者的无进展生存期 (PFS) 更差（19.6 个月与 9.0 个月，p  = 0.005）。高 VAT 指数的患者具有更好的 PFS（20.4 个月与 9.3 个月，p  = 0.033）。仅基线低 SMA 指数（HR：3.89；95% CI：1.35–11.25，p  = 0.012）和基线低 VAT 指数（HR：2.15；95% CI：1.02–4.53，p  = 0.042）具有单变量分析中与不良 PFS 显着相关。低 SMA 指数是与不良 PFS 相关的唯一独立因素（HR：3.99；95% CI：1.38–11.54，p  = 0.011）。未观察到身体成分参数与 3-4 级血液学毒性之间的关系。

结论

本研究支持肌少症和低内脏脂肪组织作为接受 CDK 4/6 抑制剂治疗的患者 PFS 不良的潜在早期指标的重要性。