RESUMO
BACKGROUND: Recent trials have provided robust evidence demonstrating that endocrine therapy with/without targeted therapy, such as cyclin-dependent kinase 4/6 inhibitors or mTOR (mammalian target of rapamycin) inhibitors, effectively halts disease progression in hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer. We investigated the survival impact of local treatment of metastases as a first-line treatment after metastasis in HR-positive and HER2-negative breast cancer patients with a very low metastatic volume. MATERIALS AND METHODS: From a retrospectively constructed database for three institutes, we identified HR-positive and HER2-negative breast cancer patients with recurrent distant oligometastatic disease after initially curative treatment. De novo stage 4 patients were excluded, and only those with recurrent metastatic disease were included. Oligometastatic disease was defined as follows: (1) ≤2 metastatic lesions in a single organ, (2) a maximal diameter ≤3 cm, and (3) organ involvement, including the lung, liver, adrenal gland, bone, or distant lymph nodes. Local treatment comprised surgery or radiotherapy. Progression-free survival (PFS) and overall survival (OS) were investigated. RESULTS: Forty-nine patients were included; 33 underwent local treatment. Of these 33 patients, 5 underwent surgical resection and 27 received radiotherapy. One patient underwent both surgical resection and radiotherapy. Median PFS was significantly longer among the patients with local treatment than among the patients without local treatment (30.0 vs. 18.0 months, p = 0.049). In multivariate analysis, local treatment was shown to prolong PFS. However, median OS after metastasis did not differ with regard to local treatment (72.3 vs. 91.0 months, p = 0.272). CONCLUSION: We showed that local treatment could positively affect disease progression in HR-positive and HER2-negative oligometastatic breast cancer.
RESUMO
BACKGROUND: We investigated the relationship between 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET-CT) standardized uptake value (SUV) and 21-gene recurrence score (RS) in estrogen receptor (ER)-positive/HER2-negative breast cancer. MATERIALS AND METHODS: One hundred sixty-seven patients were identified among those who underwent preoperative 18F-FDG-PET-CT and had RS. Maximum SUV was obtained from 18F-FDG-PET-CT; the cut-off point was 4. RESULTS: The continuous RS and SUV correlated positively (Pearson's R = 0.555; P < 0.001). An inverse correlation was found between progesterone receptor (PR) expression by reverse transcriptase-polymerase chain reaction, and SUV (Pearson's R = -0.408; P < 0.001). Good agreement between dichotomized RS (<26 vs. ≥26) and SUV (<4 vs. ≥4) was observed in 137 of 167 patients (82.0%; 95% confidence interval [CI], 76.2-87.9). Among patients with low SUV, 114 of 115 (99.1% [95% CI, 97.4-100.0]) had tumors with lower RS (<26). Although 23 of 52 women (44.2% [95% CI, 30.7-57.7]) with high SUV had higher RS (≥26), all 13 women with high RS (≥31) had high-SUV tumors. Most cases with disagreements between SUV and RS (n = 30) were classified as high SUV/lower RS (n = 29). The discordant group had higher grade or elevated Ki67 expression (≥20%) compared with the low SUV/lower RS group (n = 109), but higher PR expression compared with the high SUV/higher RS group (n = 23). Multiple logistic regression analysis showed that high SUV were associated with higher RS (≥26). CONCLUSIONS: SUV, as a biologic parameter represented using a continuous variable, was found to associate with RS in ER-positive, HER2-negative breast cancer. Further studies may reveal the biology underlying the discordance between the markers.