Early Changes of the Standardized Uptake Values (SUVmax) Predict the Efficacy of Everolimus-Exemestane in Patients with Hormone Receptor-Positive Metastatic Breast Cancer

Quantitative SSTR-PET/CT: a potential tool for predicting everolimus response in neuroendoctine tumour patients

BACKGROUND

This study aimed to assess 68Ga-DOTA-TATE (-TOC) PET/CT quantitative parameters in monitoring and predicting everolimus response in neuroendocrine tumor (NET) patients with hepatic metastases (NELM).

PATIENTS AND METHODS

This retrospective analysis included 29 patients with 62 target lesions undergoing everolimus treatment and pre-therapy, and follow-up 68Ga-DOTA-TATE (-TOC) PET/CT scans. Response evaluation utilized progression-free survival (PFS) categorized as responders (R; PFS > 6 months) and non-responders (NR; PFS ≤ 6 months). Lesion size and density, along with maximum and median standardize uptake value (SUV) in target lesions, liver, and spleen were assessed. Tumor-to-spleen (T/S) and tumor-to-liver (T/L) ratios were calculated, including the tumor-to-spleen (T/S) ratio and tumor-to-liver (T/L) ratio (using SUVmax/SUVmax, SUVmax/SUVmean, and SUVmean/SUVmean).

RESULTS

PET/CT scans were acquired 19 days (interquartile range [IQR] 69 days) pre-treatment and 127 days (IQR 74 days) post-starting everolimus. The overall median PFS was 264 days (95% CI: 134-394 days). R exhibited significant decreases in Tmax/Lmax and Tmean/Lmax ratios compared to NR (p = 0.01). In univariate Cox regression, Tmean/Lmax ratio was the sole prognostic parameter associated with PFS (HR 0.5, 95% CI 0.28-0.92, p = 0.03). Percentage changes in T/L and T/S ratios were significant predictors of PFS, with the highest area under curve (AUC) for the percentage change of Tmean/Lmax (AUC = 0.73). An optimal threshold of < 2.5% identified patients with longer PFS (p = 0.003). No other imaging or clinical parameters were predictive of PFS.

CONCLUSIONS

This study highlights the potential of quantitative SSTR-PET/CT in predicting and monitoring everolimus response in NET patients. Liver metastasis-to-liver parenchyma ratios outperformed size-based criteria, and Tmean/Lmax ratio may serve as a prognostic marker for PFS, warranting larger cohort investigation.

Innovations in Positron Emission Tomography and State of the Art in the Evaluation of Breast Cancer Treatment Response

The advent of hybrid Positron Emission Tomography/Computed Tomography (PET/CT) and PET/Magnetic Resonance Imaging (MRI) scanners resulted in an increased clinical relevance of nuclear medicine in oncology. The use of [18F]-Fluorodeoxyglucose ([18F]FDG) has also made it possible to study tumors (including breast cancer) from not only a dimensional perspective but also from a metabolic point of view. In particular, the use of [18F]FDG PET allowed early confirmation of the efficacy or failure of therapy. The purpose of this review was to assess the literature concerning the response to various therapies for different subtypes of breast cancer through PET. We start by summarizing studies that investigate the validation of PET/CT for the assessment of the response to therapy in breast cancer; then, we present studies that compare PET imaging (including PET devices dedicated to the breast) with CT and MRI, focusing on the identification of the most useful parameters obtainable from PET/CT. We also focus on novel non-FDG radiotracers, as they allow for the acquisition of information on specific aspects of the new therapies.

Quantitative SSTR-PET/CT for predicting response and survival outcomes in patients with pancreatic neuroendocrine tumors receiving CAPTEM

BACKGROUND

This study aimed to evaluate the predictive and monitoring role of somatostatin receptor (SSTR) positron emission tomography-computed tomography (PET/CT) and clinical parameters in patients with neuroendocrine liver metastases (NELM) from pancreatic neuroendocrine tumors (pNET) receiving capecitabine and temozolomide (CAPTEM).

PATIENTS AND METHODS

This retrospective study included twenty-two patients with pNET and NELM receiving CAPTEM who underwent pre- and post-therapeutic 68Ga-DOTATATE/-TOC PET/CT. Imaging (including standardized uptake value [SUV] of target lesions [NELM and pNET], normal spleen and liver) and clinical (Chromogranin A [CgA], Ki-67) parameters were assessed. Treatment outcome was evaluated as response according to RECIST 1.1, progression free survival (PFS) and overall survival (OS).

RESULTS

The median PFS (mPFS) was 7 months. Responders had a significantly longer mPFS compared to non-responders (10 vs. 4 months p = 0.022). Median OS (mOS) was 33 months (mOS: responders = 80 months, non-responders = 24 months p = 0.182). Baseline imaging showed higher SUV in responders, including absolute SUV, tumor-to-spleen (T/S), and tumor-to-liver (T/L) ratios (p < 0.02). All SUV parameters changed only in the responders during follow-up. Univariable Cox regression analysis identified baseline Tmax/Smean ratio and percentage change in size of pNETs as significant factors associated with PFS. A baseline Tmax/Smean ratio < 1.5 was associated with a shorter mPFS (10 vs. 4 months, (p < 0.05)). Prognostic factors for OS included age, percentage change in CgA and in T/S ratios in univariable Cox regression.

CONCLUSIONS

SSTR-PET/CT can be useful for predicting response and survival outcomes in pNET patients receiving CAPTEM: Higher baseline SUV values, particularly Tmax/Smean ratios of liver metastases were associated with better response and prolonged PFS.

Biomarkers of everolimus efficacy in breast cancer therapy

OBJECTIVE

Everolimus is an inhibitor of serine/ threonine kinase mTOR. The drug is approved for the treatment of metastatic ER positive, HER2 negative breast cancers and benefits a subset of patients with these breast cancers in combination with hormonal therapies. Despite extensive efforts, no additional predictive biomarkers to guide therapeutic decisions for everolimus have been introduced in clinical practice.

DATA SOURCES

This paper discusses predictive biomarkers for everolimus efficacy in breast cancer. A search of the medline and web of science databases was performed using the words "everolimus" and "biomarkers". References of retrieved articles were manually scanned for additional relevant articles.

DATA SUMMARY

Everolimus benefits a subset of patients with metastatic ER positive, HER2 negative breast cancers in combination with hormonal therapies. Despite extensive efforts no additional predictive biomarkers to guide therapeutic decisions for everolimus therapy have been confirmed for use in clinical practice. However, promising biomarker leads for everolimus efficacy in breast cancer have been suggested and include expression of proteins in the mTOR pathway in ER positive, HER2 negative breast cancers. In HER2 positive cancers PIK3CA mutations, and PTEN expression loss are prognostic. Other clinical predictive biomarkers with more limited data include characteristics derived from whole genome sequencing, subsets of circulating leukocytes and changes in Standardized Uptake Values (SUV) of Positron Emission Tomography (PET) scans.

CONCLUSIONS

Putative predictive biomarkers for everolimus efficacy in breast cancer patients, both genomic and clinical, deserve further study and could lead to a better selection of responsive patients.

Combined everolimus and endocrine therapy in advanced HR-positive, HER2-negative Chinese breast cancer patients: a retrospective study

Background

Everolimus (EVE) is an inhibitor of the mammalian target of rapamycin (mTOR) pathway, and it is approved for the treatment of advanced breast cancer (ABC). However, there is still little real-world data on using EVE in Chinese breast cancer patients. We retrospectively analyzed real-world data to determine the factors affecting EVE treatment efficacy and patient outcomes.

Methods

We retrospectively collected the treatment information of ABC patients treated with EVE from 2013 to 2020 in Zhejiang Cancer Hospital. Kaplan-Meier analysis and Cox regression methods were used to calculate and compare the progression-free survival (PFS), and identify the factors associated with EVE treatment efficacy.

Results

The study finally enrolled 84 patients meeting the requirement; the median PFS in all 84 patients was 6.87 months. Multivariate analysis showed that liver metastasis [hazard ratio, 1.69; 95% confidence interval (CI), 1.00–2.84; P=0.049], and brain metastasis (hazard ratio, 2.65; 95% CI, 1.07–6.58; P=0.036) were independent risk factors. Subgroup analyses demonstrated EVE + fulvestrant (FUL) was not superior to EVE + aromatase inhibitors (AIs) for PFS (5.77 vs. 7.97 months, P=0.0735). Furthermore, it showed EVE + AI was superior to EVE + FUL in some subgroups: postmenopausal group (hazard ratio, 0.50; 95% CI, 0.26–0.98); without bone metastasis group (hazard ratio, 0.22; 95% CI, 0.06–0.80); visceral disease group (hazard ratio, 0.37; 95% CI, 0.20–0.69).

Conclusions

EVE combined with endocrine therapy is an effective treatment option for Chinese patients with hormone-receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2−) breast cancer, although EVE + FUL was not superior to EVE + AI. Liver metastasis and brain metastasis were independent risk factors for successful EVE + endocrine therapy.

Establishment of Prognostic Nomograms for Predicting the Survival of HR-Positive, HER2-Negative Metastatic Breast Cancer Patients Treated with Everolimus

BACKGROUND

There are no clinically available prognostic models for patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer treated with everolimus. We aimed to develop a tool to predict the progression-free survival (PFS) and overall survival (OS) of these patients and to identify optimal candidates who would benefit from everolimus-based treatment in this heterogeneous patient population.

METHODS

The clinical data of patients with HR+, HER2- metastatic breast cancer receiving everolimus between May 2012 and January 2018 at Sun Yat-sen University Cancer Center were retrospectively retrieved. Based on potential prognostic factors derived from multivariate Cox analysis, we established predictive nomogram models for PFS and OS and evaluated their predictive values by means of the concordance index (C-index). Calibration curves were used to estimate the consistency between the actual observations and the nomogram-predicted probabilities.

RESULTS

A total of 116 patients with HR+, HER2- metastatic breast cancer were enrolled in this study. Three independent prognostic factors, including the line of everolimus in the metastatic setting, everolimus clinical benefit rate and number of liver metastatic lesions, were identified from the multivariate Cox analysis. Prognostic models for individual survival prediction were established and graphically presented as nomograms. The C-index was 0.738 (95% confidence interval [CI]: 0.710-0.767) for the PFS nomogram and 0.752 (95% CI: 0.717-0.788) for the OS nomogram, which showed favourable discrimination. The calibration curves for the probabilities of 6-, 9-, and 12-month PFS and 1-, 2-, and 3-year OS suggested satisfactory consistency between the actual observations and the predicted probabilities.

CONCLUSION

We constructed convenient nomogram models for patients with HR+, HER2- metastatic breast cancer to individually predict their potential benefits from everolimus in the metastatic setting. The models showed good performance in terms of accuracy, discrimination capacity and clinical application value.