Prognostic value of metabolic activity of the psoas muscle evaluated by preoperative 18F-FDG PET-CT in breast cancer: a retrospective cross-sectional study

Background This study aimed to evaluate the potential of metabolic activity of the psoas muscle measured by 18F-fluorodeoxyglucose positron emission tomography-computed tomography to predict treatment outcomes in patients with resectable breast cancer. Methods The medical records of 288 patients who had undergone surgical resection for stages I–III invasive ductal carcinoma of the breast between January 2014 and December 2014 in Pusan National University Hospital were reviewed. The standardized uptake values (SUVs) of the bilateral psoas muscle were normalized using the mean SUV of the liver. SUVRmax was calculated as the ratio of the maximum SUV of the average bilateral psoas muscle to the mean SUV of the liver. SUVRmean was calculated as the ratio of the mean SUV of the bilateral psoas muscle to the mean SUV of the liver. Results Univariate analyses identified a higher T stage, higher N stage, estrogen receptor negativity, progesterone receptor negativity, human epidermal growth factor receptor 2 positivity, triple-negative breast cancer, mastectomy (rather than breast-conserving surgery), SUVRmean > 0.464, and SUVRmax > 0.565 as significant adverse factors for disease-free survival (DFS). Multivariate Cox regression analysis revealed that N3 stage (hazard ratio [HR] = 5.347, P = 0.031) was an independent factor for recurrence. An SUVRmax > 0.565 (HR = 4.987, P = 0.050) seemed to have a correlation with shorter DFS. Conclusions A higher SUVRmax of the psoas muscle, which could be a surrogate marker of insulin resistance, showed strong potential as an independent prognostic factor for recurrence in patients with resectable breast cancer.

Prognostic Value of Metabolic Activity of the Psoas Muscle Evaluated By Preoperative 18 F- FDG PET-CT in Breast Cancer: A Retrospective Cross-Sectional Study

Background: This study aimed to evaluate the potential of metabolic activity of the psoas muscle measured by 18F-fluorodeoxyglucose positron emission tomography-computed tomography to predict treatment outcomes in patients with resectable breast cancer.Methods: The medical records of 288 patients who had undergone surgical resection for stages I–III invasive ductal carcinoma of the breast between January 2014 and December 2014 in Pusan National University Hospital were reviewed. The standardized uptake values (SUVs) of the bilateral psoas muscle were normalized using the mean SUV of the liver. SUVRmax was calculated as the ratio of the maximum SUV of the average bilateral psoas muscle to the mean SUV of the liver. SUVRmean was calculated as the ratio of the averaged bilateral psoas muscle to the mean SUV of the liver.Results: Univariate analyses identified a higher T stage, higher N stage, estrogen receptor negativity, progesterone receptor negativity, human epidermal growth factor receptor 2 positivity, triple-negative breast cancer, mastectomy (rather than breast-conserving surgery), SUVRmean > 0.464, and SUVRmax > 0.565 as significant adverse factors for progression-free survival (PFS). Multivariate Cox regression analysis revealed that N3 stage (hazard ratio [HR] = 5.347, P = 0.031) was an independent factor for recurrence. An SUVRmax > 0.565 (HR = 4.987, P = 0.050) seemed to have a correlation with shorter PFS.Conclusions: A higher SUVRmax of the psoas muscle, which could be a surrogate marker of insulin resistance, showed strong potential as an independent prognostic factor for recurrence in patients with resectable breast cancer.

Prognostic and predictive impact of stroma cells defined by PDGFRb expression in early breast cancer: results from the randomized SweBCG91RT trial

Purpose Predictive biomarkers are needed to aid the individualization of radiotherapy (RT) in breast cancer. Cancer-associated fibroblasts have been implicated in tumor radioresistance and can be identified by platelet-derived growth factor receptor-beta (PDGFRb). This study aims to analyze how PDGFRb expression affects RT benefit in a large randomized RT trial. Methods PDGFRb was assessed by immunohistochemistry on tissue microarrays from 989 tumors of the SweBCG91RT trial, which enrolled lymph node-negative, stage I/IIA breast cancer patients randomized to RT after breast-conserving surgery. Outcomes were analyzed at 10 years for ipsilateral breast tumor recurrence (IBTR) and any recurrence and 15 years for breast cancer specific death (BCSD). Results PDGFRb expression correlated with estrogen receptor negativity and younger age. An increased risk for any recurrence was noted in univariable analysis for the medium (HR 1.58, CI 95% 1.11–2.23, p = 0.011) or PDGFRb high group (1.49, 1.06–2.10, p = 0.021) compared to the low group. No differences in IBTR or BCSD risk were detected. RT benefit regarding IBTR risk was significant in the PDGFRb low (0.29, 0.12–0.67, p = 0.004) and medium (0.31, 0.16–0.59, p < 0.001) groups but not the PDGFRb high group (0.64, 0.36–1.11, p = 0.110) in multivariable analysis. Likewise, risk reduction for any recurrence was less pronounced in the PDGFRb high group. No significant interaction between RT and PDGFRb-score could be detected. Conclusion A higher PDGFRb-score conferred an increased risk of any recurrence, which partly can be explained by its association with estrogen receptor negativity and young age. Reduced RT benefit was noted among patients with high PDGFRb, however without significant interaction.

Clinicopathological values of PD-L1 expression in HER2-positive breast cancer

Several ongoing clinical trials are investigating the use of immuno-targeting therapy with programmed cell death protein-1 and programmed death-ligand 1 (PD-L1) inhibitors for triple-negative breast cancer. However, the role of PD-L1 expression in HER2-positive breast cancer remains unclear. We investigated the clinicopathological utility of PD-L1 expression in HER2-positive breast cancer. Cohort A included 248 patients with invasive breast cancer (all subtypes). Cohort B included 126 HER2-positive patients who received neoadjuvant chemotherapy (NAC) concomitant with trastuzumab. The relationship of PD-L1 expression on the cancer cells with clinicopathological factors including pathological complete response (pCR) and prognosis was investigated. In cohort A, 8.1% patients were PD-L1-positive; PD-L1 positivity showed a correlation with high degree of tumor-infiltrating lymphocytes (TILs), estrogen receptor negativity, progesterone receptor negativity, and high histological grade. In cohort B, 17.5% patients were PD-L1-positive; PD-L1 positivity showed a significant correlation with high degree of TILs and high abundance of CD8-positive TILs. The pCR rates were related to TILs and PD-L1 expression. Among PD-L1-negative patients, high CD8-positive TILs were associated with significantly better prognosis. In conclusion, 17.5% of HER2-positive type patients were PD-L1-positive. PD-L1 expression was associated with response to NAC with trastuzumab in patients with HER2-positive breast cancer.

The prognostic significance of wild-type isocitrate dehydrogenase 2 (IDH2) in breast cancer

Background Lymphovascular invasion (LVI) is a prerequisite step in breast cancer (BC) metastasis. We have previously identified wild-type isocitrate dehydrogenase 2 (IDH2) as a key putative driver of LVI. Thus, we explored the prognostic significance of IDH2 at transcriptome and protein expression levels in pre-invasive and invasive disease. Methods Utlising tissue microarrays from a large well annotated BC cohort including ductal carcinoma in situ and invasive breast cancer (IBC), IDH2 was assessed at the transcriptomic and proteomic level. The associations between clinicopathological factors including LVI status, prognosis and the expression of IDH2 were evaluated. Results In pure DCIS and IBC, high IDH2 protein expression was associated with features of aggressiveness including high nuclear grade, larger size, comedo necrosis and hormonal receptor negativity and LVI, higher grade, larger tumour size, high NPI, HER2 positivity, and hormonal receptor negativity, respectively. High expression of IDH2 either in mRNA or in protein levels was associated with poor patient’s outcome in both DCIS and IBC. Multivariate analysis revealed that IDH2 protein expression was an independent risk factor for shorter BC specific-survival. Conclusion Further functional studies to decipher the role of IDH2 and its mechanism of action as a driver of BC progression and LVI are warranted.