Prognostic Value of Primary Tumor Uptake on F-18 FDG PET/CT in Patients with Invasive Ductal Breast Cancer

Abstract

Purpose: To determine the prognostic implications of pretreatment F-18 FDG PET/CT in patients with invasive ductal breast cancer (IDC), we evaluated the relationship between FDG uptake of the primary tumor and known prognostic parameters of breast cancer. Prognostic significance of tumoral FDG uptake for the prediction of progression-free survival (PFS) was also assessed.

Materials and methods: Fifty-five female patients with IDC who underwent pretreatment F-18 FDG PET/CT were enrolled. The maximum standardized uptake value of the primary tumor (pSUVmax) was compared with clinicopathological parameters including tumor size, grade, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor2 (HER2), axillary lymph node (LN) metastasis, and stage. The prognostic value of pSUVmax for PFS was assessed using the Kaplan-Meier method.

Results: A high pSUVmax was significantly related to a higher stage of tumor size (P < 0.05), grade (P < 0.001), and stage (P < 0.001). pSUVmax was significantly higher in ER-negative tumors (P < 0.001), PR-negative tumors (P < 0.001), and positive LN metastasis (P < 0.01), but not different according to HER2 status. pSUVmax was significantly higher in patients with progression compared to patients who were disease-free (10.6 ± 5.1 vs. 4.7 ± 3.5, P < 0.001). A receiver-operating characteristic curve demonstrated a pSUVmax of 6.6 to be the optimal cutoff for predicting PFS (sensitivity; 86.7%, specificity; 82.5%). The patients with a high pSUVmax (more than 6.6) had significantly shorter PFS compared to patients with a low pSUVmax (P < 0.0001).

Conclusions: pSUVmax on pretreatment F-18 FDG PET/CT could be used as a good surrogate marker for the prediction of progression in patients with IDC.

Keywords: F-18 FDG PET/CT; Invasive ductal breast cancer; Prognosis; SUVmax.

Fig. 1

pSUVmax differences according to disease group. Mann-Whitney U-test reveals a significant difference between the disease-free group and progression group (P < 0.001). Mean values of pSUVmax (4.7 in the disease-free group and 10.6 in the progression group) are indicated with purple boxes. The error bars represent the 95% confidence interval for mean

Fig. 2

Optimal cutoff of pSUVmax for predicting progression-free survival

Fig. 3

Progression-free survival according to the pSUVmax

Fig. 4

A 71-year-old female patient diagnosed with invasive ductal breast cancer (pSUVmax 7.0, tumor size 3.6 cm, ER-, PR-, HER2+). a F-18 FDG PET/CT before cancer treatment. In the pre-treatment, a focal hypermetabolic lesion in the left breast and enlarged LNs with focal FDG uptake in the left axillary area were shown, which were histologically confirmed as malignancy in both lesions (long arrow). b In the follow-up F-18 FDG PET/CT taken after neoadjuvant chemotherapy and operation, there was no evidence of residual malignancy. c But 6 months later, a newly found hypermetabolic lesion in the right breast on the 2nd follow-up F-18 FDG PET/CT was shown and histologically confirmed as metastasis (short arrow). In addition, FDG uptake in the left internal mammary LN was shown (long dotted arrow)

Fig. 5

A 43-year-old female patient diagnosed with invasive ductal breast cancer (pSUVmax 2.9, tumor size 2.2 cm, ER+, PR+, HER2+). In initial F-18 FDG PET/CT, a mildly hypermetabolic lesion was shown (pSUVmax is lesser than 6.6) and histologically confirmed as malignancy in the right breast (long arrow). In the follow-up F-18 FDG PET/CT taken after the operation, chemotherapy, and hormonal therapy, there was no evidence of residual or recurrent malignancy