Thyroid Metastases from Triple-Negative Breast Cancer with High PD-L1 Expression - A Rare Presentation

Abstract

Thyroid metastases secondary to triple-negative breast cancer are sporadic. Diagnosis usually requires fine needle aspiration biopsy (FNAB) and immunohistochemistry. There are no treatment guidelines for this type of cancer, and to date, reports of chemotherapy combined with immunotherapy in thyroid metastases are very rare. Here, we first report the effectiveness of anti-PD-1 inhibitor in combination with chemotherapy for the treatment of metastatic thyroid cancer secondary to advanced triple-negative breast cancer with high expression of programmed cell death ligand 1 (PD-L1). Following six cycles of albumin paclitaxel (400mg d1/21 days) plus PD-1 antibody inhibitor (Sindilizumab 200mg d1/21 days), the patient experienced significant relief of neck swelling and obstructive feeding, both the thyroid metastases and the right breast lesion regressed completely following six cycles of treatment. Chemotherapy combined with immunotherapy may provide a new direction for unresectable advanced thyroid metastases.

Keywords: albumin paclitaxel; anti-PD-1 inhibitor; effectiveness; thyroid metastases; triple-negative breast cancer.

Figure 1

(A) HE staining of the thyroid mass showed invasive ductal carcinoma of mammary origin. (B) IHC examination revealed the thyroid mass was positive for PD-L1.(C) Breast MR showed a right breast nodule (red arrow), BI-RADS category 4 (1.1cm x 0.8cm x 0.8cm). (D) CT of the neck, chest and abdomen showed primary breast cancer with thyroid metastases (red arrow meant metastatic lesion).

Figure 2

(A) HE staining of the right breast mass showed invasive carcinoma of the breast. (B) IHC examination revealed the right breast mass was positive for PD-L1. (C) Breast MR showed a significantly enlarged right breast mass (1.6cm x 1.2cm x 1.1cm) (red arrow) after 3 cycles of TE regimen chemotherapy. (D) CT scan of the neck, chest and abdomen showed significantly enlarged metastases (red arrow) in the thyroid gland after 3 cycles of TE regimen chemotherapy. (E) CT showed thyroid metastases regressed completely following 6 cycles of albumin paclitaxel plus PD-1 antibody. (F) MR showed right breast lesion regressed completely following 6 cycles of albumin paclitaxel plus PD-1 antibody.