In breast cancer FDG-PET/CT is used to detect recurrence or to evaluate treatment response, but discordant data are available about its role in the staging setting. Additionally, controversy remains about the prognostic role of SUVmax in breast cancer. We aimed to investigate the role of FDG-PET/CT in primary breast cancer patients to establish the effective advantage in staging and to determine the prognostic role of SUVmax.
Forty-eight patients (one bilateral) with a median age of 55 yrs (range 34-82) having newly diagnosed with biopsy proven breast cancer (ductal carcinoma=43, lobular carcinoma=6) were retrospectively included in this analysis.
Based on estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor2 (Her2) status patients were grouped in 5 categories (A=ER+ and/or PgR+, Her2-, Ki-67 <14%; B=ER+ and/or PgR+, Her2+, Ki-67 ≥14%; C=triple-negative, D= ER-, PgR-, Her2+; E=ER+ and/or PgR+, Her2-, Ki-67 ≥14%).
PET/CT was performed for all patients at diagnosis to stage disease (pre-operative=39, post-surgical=9). Qualitative and semi-quantitative analysis of PET/CT were compared to clinico-pathological features. Patients were followed with clinical/radiological assessment for a median of 691 days (155-2269 days). Disease-free survival (DFS) was also recorded. For statistics, p-value < 0.05 was considered significant. Prognostic role of PET/CT was evaluated by comparing PET/CT results to final follow-up.
Based on above mentioned categories, patients were divided in A=8, B=6, C=7, D=10, E=18 groups. PET/CT was completely negative in 13/48 cases. PET/CT identified uptake only in the primary tumor (T) in 16 patients, in lymph node(s) (N) in 3 cases, in T + N in 10 cases, T + distant metastases (M) in 1 case, T + N + M in 4 patients, and in N + M in 1 case. SUVmax was 5,5 (2,2-27), 3,6 (1,2-15,7) and 6,8 (3,8-7) for T, N and M, respectively. According to TNM classification, PET/CT was TP in 17 and 5 cases, for N and M, respectively (Table 1) and changed stage of disease (all upgraded) and management in 6/48 and 4/48 patients, respectively. Considering T, N and M a statistically difference among groups was found for N (p=0.03) while no difference was found considering final follow-up (Tables 2 and 3).
Median DSF was 426 days (36-2313). Thirty-seven patients had negative final follow-up, 10 patients had progressive disease and in the remaining 2 cases disease was present but stable.
Our results showed the potential usefulness of PET/CT to stage breast cancer, especially as regards the correct patients’ management (i.e. type of treatment) however further investigations in larger series of patients are needed to confirmed these preliminary data. Nonetheless, if our data will be confirmed treatment will be increasingly tailored by using PET/CT.