Background: To assess the prognostic capability of the maximum standardized uptake values (SUV max ) measured in the primary tumor and axillary lymph nodes (ALNs) by pretreatment fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography and analyze outcomes according to the molecular breast cancer subtypes.Methods: The databases were systematically searched using keywords for breast cancer, positron emission tomography/ computed tomography, and SUV max ; the extracted studies reported at least 1 form of survival data, event-free survival (EFS) and overall survival. Comparative analyses of the pooled hazard ratios (HRs) for EFS and overall survival were performed to assess their correlations with SUV max . The pooled HR was estimated using random-effects model according to the results of heterogeneity.Results: Thirteen eligible studies comprising 3040 patients with breast cancer were included. The pooled HRs of high SUV max in the primary tumor and ALN were 3.01 (95% CI 1.83-4.97, P < .00001; I2 = 82%) and 3.72 (95% CI 1.15-12.01; I2 = 92%; P = .03), respectively. Patients with higher SUV max demonstrated a poorer survival prognosis. Furthermore, comparative analyses according to the molecular subtypes demonstrated that the SUV max in the primary tumor or ALN can be a predictive parameter in patients with the luminal subtype disease. Subtype analysis results indicated a significant association of the luminal group, with a HR of 2.65 (95% CI 1.31-5.37; I2 = 27%; P = .007).Conclusions: SUV max from pretreatment is a significant prognostic factor for EFS in patients with breast cancer. Despite several limitations, correlation with molecular subtype (luminal type) was demonstrated. Further large-scale studies are required to investigate the precise prognostic capability of SUV max .Abbreviations: 18 F-FDG PET/CT = fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography, ALN = axillary lymph node, EFS = event-free survival, ER = estrogen receptor, HER2 = human epidermal growth factor receptor 2, HR = hazard ratios, MFS = metastasis-free survival, OS = overall survival, SUV max = maximum standardized uptake values.

<b><i>Purpose:</i></b> The <i>BRCA1/2</i> gene is the most well-known and studied gene associated with hereditary breast cancer. <i>BRCA1/2</i> genetic testing is widely performed in high-risk patients of hereditary breast cancer in Korea. This study aimed to investigate the clinicopathological characteristics of <i>BRCA1/2</i> mutation-positive breast cancer patients. <b><i>Methods:</i></b> The clinical data of 188 Korean breast cancer patients who underwent genetic testing of <i>BRCA1/2</i> mutation between March 2015 and February 2020 at Pusan National University Yangsan Hospital were retrospectively reviewed. The characteristics of breast cancer according to the expression of <i>BRCA1</i> and <i>BRCA2</i> mutations were analyzed using the Health Insurance Review and Assessment Service guideline criteria and other clinicopathological factors. <b><i>Results:</i></b> The factor associated with <i>BRCA1/2</i> gene expression was cancer stage, and mutation expression was significantly decreased in stage I compared to stage 0 (<i>p</i> = 0.033; odds ratio [OR], 0.169; 95% confidence interval [CI], 0.033–0.867), and there was a tendency to increase in stage II (<i>p</i> = 0.780; OR, 1.150; 95% CI, 0.432–3.064). <i>BRCA1</i> was significantly associated with triple-negative breast cancer (TNBC) (<i>p</i> = 0.004; OR, 5.887; 95% CI, 1.778–19.498). Gene expression of <i>BRCA2</i> was significantly reduced under 40 years of age (<i>p</i> = 0.040; OR, 0.198; 95% CI, 0.042–0.930). There was no difference in disease-free survival (<i>p</i> = 0.900) and overall survival (<i>p</i> = 0.733) between the <i>BRCA1/2</i> mutation-positive and -negative groups. <b><i>Conclusion:</i></b> In this study, the clinicopathological characteristics of breast cancer patients with <i>BRCA1/2</i> gene mutations were identified. <i>BRCA1</i> gene expression was highly correlated with TNBC. <i>BRCA1/2</i> mutation did not have a poor prognosis regarding recurrence and death.

<b><i>Introduction:</i></b> Pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) is associated with improvement in survival outcomes. This study evaluated the pCR in patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer after NAC. <b><i>Methods:</i></b> We evaluated 417 patients who were diagnosed with invasive breast cancer and treated with NAC followed by curative surgery between January 2007 and December 2020 and analyzed the pCR for HR-positive and HER2-negative breast cancer. <b><i>Results:</i></b> The median age at the time of surgery was 45.4 years, and 9.1% of patients (38 of 417) with HR-positive/HER2-negative status had pCR. Among patients with HR-positive/HER2-negative breast cancer, patients with single HR-positivity had a 20.2% pCR rate, and patients with double HR-positivity had a 4.4% pCR rate. Patients with a high Ki-67 index exhibited a higher pCR rate than those with a lower Ki-67 index (14.5% vs. 3.2%). Patients with single HR-positive and high Ki-67 values exhibited a significantly higher pCR rate than those with double HR-positive and low Ki-67 values (27.8% vs. 2.1%; <i>p</i> &#x3c; 0.001). <b><i>Conclusion:</i></b> NAC could improve prognosis in patients with HR-positive/HER2-negative breast cancer with a single HR-positive and high Ki-67 values.

BACKGROUND Metaplastic breast cancer (MBC) is a rare subtype of breast cancer. They constitute less than 1% of breast cancer cases and are much rarer in males. There are few reports of MBC because of its rarity. MBC, an aggressive type of cancer, is refractory to common treatment modalities of breast cancer and has a poor prognosis. CASE SUMMARY We report a case of MBC in a 78-year-old man. He visited our clinic with a palpable mass on the left breast with no masses in the axillary areas. He had previously undergone robot-assisted laparoscopic radical prostatectomy for prostate cancer, but there was no family history of malignancy. The breast mass was visible on ultrasonography, mammography, and magnetic resonance imaging, and chest computed tomography revealed a lung mass in the posterior basal segment of the right lower lobe. The patient was diagnosed with metaplastic carcinoma on core needle biopsy with lung metastasis. Total mastectomy with sentinel lymph node biopsy and video-assisted segmentectomy of the right lung was performed. However, multiple metastases appeared 3 mo after surgery in the brain, chest, and abdomen, and the patient died 5 mo after the initial diagnosis. CONCLUSION MBC is an aggressive and extremely rare breast cancer type. Further case reports are needed to determine the optimal treatment.