Utility of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Fusion Imaging for Prediction of Metastasis to Sentinel and Nonsentinel Nodes in Patients with Clinically Node-Negative Breast Cancer.

PURPOSE: 18F-Fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) is an important diagnostic tool in breast cancer. The utility of maximum standardized uptake values (SUVmax) of primary tumors has been evaluated to predict sentinel node (SN) and non-SN metastasis in clinically node-negative (cN0) patients. PATIENTS AND METHODS: 18F-FDG PET/CT was performed on 414 cN0 patients. The following parameters were evaluated: SUVmax at 60 min (SUVmax1), SUVmax at 120 min (SUVmax2), percent change between SUVmax1 and SUVmax2 (ΔSUVmax%), SN metastasis foci maximum size (SN meta size), and ratio of metastatic SNs to total SNs or SN ratio (SNR). It was assessed whether these were risk factors for SN metastasis. The relationship between these parameters and the status of SN and/or non-SN metastasis was retrospectively explored to predict non-SN metastasis. RESULTS: All SUV parameters significantly correlated with pathological T factor (pT), nuclear grade, lymphatic invasion (Ly), and Ki-67 labeling index. On multivariate analysis, pT and Ly were independent predictive factors for SN metastasis. In SN meta-positive cases, SN meta size, SNR, and ΔSUVmax% were predictors for non-SN metastasis on univariate analyses, and the former two were independent predictors on multivariate analysis. The combination of SUVmax2 and ΔSUVmax% was an independent predictor of non-SN metastasis (P = 0.0312) and was associated with prediction of non-SN metastasis negative status with high probability (92.3%). CONCLUSIONS: In patients with cN0 breast cancer, SUV parameters of the primary tumor were correlated with pathological features. The combination of SUVmax2 and ΔSUVmax% may be useful for predicting non-SN metastasis.

Multiple metastases of human epidermal growth factor receptor 2­positive, hormone receptor­positive, pT1a pN0 breast cancer within 1 year after surgery: A case report.

Adjuvant chemotherapy is usually not considered for pT1a pN0 human epidermal growth factor receptor 2 (HER2)-positive breast cancer due to its low recurrence rate. The present report describes a case of pT1a hormone receptor-positive HER2-positive breast cancer with multiple recurrences in the axillary lymph nodes and liver within 1 year after radical surgery. A 58-year-old woman underwent left total mastectomy and sentinel lymph node biopsy for left breast cancer with pathological stage IA (pT1a pN0). The subtype corresponded to luminal B-like breast cancer with a nuclear grade of 3 and a Ki-67 labeling index of 37%. An aromatase inhibitor (letrozole) was planned to be administered for 5 years after surgery, but the patient was diagnosed with multiple liver and axillary lymph node metastases 11 months after surgery. After 1 year of chemotherapy (paclitaxel) in combination with anti-HER2 therapy (pertuzumab and trastuzumab), liver metastases resolved. A complete response of the liver lesion has been maintained 4 years after the anti-HER2 therapy initiation. The present case exhibited two poor prognostic factors: High Ki-67 labeling index and nuclear grade 3. Based on the 'Predict' tool, the present case would be expected to have a cancer-related mortality rate of 6% 10 years after surgery with adjuvant endocrine therapy. Although this value may be controversial for postoperative anti-HER2 therapy, the present case should not be considered to be a low-risk case. When the identification of high-risk pT1a pN0 HER2-positive breast cancer is possible, postoperative anti-HER2 therapy plus chemotherapy would be effective in decreasing the rate of recurrence.

Comparison between AJCC 8th prognostic stage and UICC anatomical stage in patients with primary breast cancer: a single institutional retrospective study.

BACKGROUND: The 8th edition American Joint Committee on Cancer (AJCC) proposed a prognostic stage (PS), which included not only anatomical factors, but also biological factors. We aimed to investigate the clinicopathological significance of the PS and to compare PS and anatomical stage (AS) that has been established by the Union for International Cancer Control (UICC). METHODS: Between 2002 and 2017, 800 patients were included in the study. Patients were classified using pathological UICC AS and pathological AJCC PS. The usefulness of PS in comparison with AS was validated using the Akaike information criterion (AIC) and Harrell concordance index (C-index). RESULTS: A total of 401 (50.1%) patients had pathological AS I, 324 (40.5%) had AS II, and 75 (9.4%) had AS III. Meanwhile, 535 (66.8%) had pathological PS I, 163 (20.4%) had PS II, and 102 (12.8%) had PS III. The number of AS II cases was 1.99-fold higher than that of PS II cases. For each stage, these survival curves were almost similar between AS and PS classification. Therefore, many patients to be classified into stage I and stage III were included in AS II group, while many patients to be classified into stage II were included in AS I group. To trichotomize the survival groups, PS appeared to be more specific than AS, and AIC and C-index confirmed the speculation. CONCLUSION: For the prognostication of primary breast cancer patients, AJCC PS appeared to be able to stratify the cases more appropriately than UICC AS.

Membrane mesothelin expression positivity is associated with poor clinical outcome of luminal-type breast cancer.

Mesothelin is expressed in various types of malignant tumors. The present study immunohistochemically investigated mesothelin expression and its clinicopathological significance in each subtype of breast cancer, with special reference to its cellular localization, in particular, membrane mesothelin expression. Using tissue specimens from 482 patients with breast cancer, immunohistochemistry was used to study mesothelin expression and help classify its localization as membrane or cytoplasmic expression. Mesothelin expression was detected in 77 (16.0%) cases and was the highest in triple-negative breast cancer (31/75; 41.3%), followed by human epithelial growth factor receptor type 2 type (6/33, 18.2%) and luminal type (36/374; 9.6%). Among the 482 cases, membrane mesothelin expression was detected in 73 cases and was significantly associated with a negative hormone receptor status, higher Ki-67 labeling index, nuclear grade 3 and a lower relapse-free survival rate. Cytoplasmic mesothelin expression was not significantly associated with a lower relapse-free survival rate (P=0.058). In the 343 cases of luminal type, the membrane mesothelin expression-positive group had significantly worse prognosis than the membrane mesothelin-expression-negative group (P=0.042). There was no significant difference in the relapse-free survival rate according to the membrane mesothelin expression status in the triple-negative type and other types. It was suggested that membrane mesothelin expression in luminal type breast cancer is associated with a lower rate of relapse-free survival.