Prediction of Recurrence by Preoperative Intratumoral FDG Uptake Heterogeneity in Endometrioid Endometrial Cancer

Predicting recurrence and metastasis risk of endometrial carcinoma via prognostic signatures identified from multi-omics data

Objectives

Endometrial carcinoma (EC) is one of the three major gynecological malignancies, in which 15% - 20% patients will have recurrence and metastasis. Though there are many studies on the prognosis on this cancer, the performances of existing models evaluating the risk of its recurrence and metastasis are yet to be improved. In addition, a comprehensive multi-omics analyses on the prognostic signatures of EC are on demand. In this study, we aimed to construct a relatively stable and reliable model for predicting recurrence and metastasis of EC. This will help determine the risk level of patients and choose appropriate adjuvant therapy, thereby avoiding improper treatment, and improving the prognosis of patients.

Methods

The mRNA, microRNA (miRNA), long non-coding RNA (lncRNA), copy number variation (CNV) data and clinical information of patients with EC were downloaded from The Cancer Genome Atlas (TCGA). Differential expression analyses were performed between the recurrence or metastasis group and the non-recurrence/metastasis group. Then, we screened potential prognostic markers from the four kinds of omics data respectively and established prediction models using three classifiers.

Results

We achieved differential expressed mRNAs, lncRNAs, miRNAs and CNVs between the two groups. According to feature selection scores by the random forest algorithm, 275 CNV features, 50 lncRNA features, 150 miRNA features and 150 mRNA features were selected, respectively. And the prediction model constructed by the features of lncRNA data using random forest method showed the best performance, with an area under the curve of 0.763, and an accuracy of 0.819 under 10-fold cross-validation.

Conclusion

We developed a computational model using omics information, which is able to predicting recurrence and metastasis risk of EC accurately.

Endometrial cancer

Although endometrial cancer management remains challenging, a deeper understanding of the genetic diversity as well as the drivers of the various pathogenic states of this disease has led to development of divergent management approaches in an effort to improve therapeutic precision in this complex malignancy. This comprehensive review provides an update on the epidemiology, pathophysiology, diagnosis and molecular classification, recent advancements in disease management, as well as important patient quality-of-life considerations and emerging developments in the rapidly evolving therapeutic landscape of endometrial cancers.

SUV95th as a Reliable Alternative to SUVmax for Determining Renal Uptake in [68Ga] PSMA PET/CT

PURPOSE

Widely used in clinical practice, the maximum standardized uptake value (SUV_max) is a statistical index highly prone to physical and biological variations, which can lead to unpredictable errors. This study has a methodological aim: to identify a more robust SUV-based index representing the tracer accumulation. In particular, the new metric was tested to confirm the potential of mannitol to reduce renal uptake Ga-68 prostate-specific membrane antigen ([₆₈Ga]PSMA).

PROCEDURES

To this aim, our previously published work, proving the efficacy of mannitol, was considered as a background study. Renal SUV_max was calculated in nine patients undergoing [⁶⁸Ga]PSMA positron emission tomography (PET)/X-ray computed tomography (CT) at baseline (b-PET/CT) and at follow-up after intravenous infusion of 500 ml of 10 % mannitol (m-PET/CT). SUV values of kidney volumes were extracted by a new 3D segmentation method. A new parameter, the median computed on the upper 10% of the SUV distribution (SUV_95th), was introduced to better characterize the tracer accumulation. A comparison between SUV_max and SUV_95th was also performed. Kruskal-Wallis test was used to assess the statistical significance of the differences in SUV_95th between b-PET/CT and m-PET/CT.

RESULTS

SUV_95th not only confirmed the efficacy of mannitol as demonstrated in the previous study but improved the separability of b-PET/CT and m-PET/CT examinations, overturning SUV_max findings in two cases. The outcomes of the Kruskal-Wallis test computed for each kidney proved that differences between b-PET/CT and m-PET/CT SUV_95th values were significant (p value < 0.001).

CONCLUSIONS

Our findings indicate that SUV_95th is a more robust index to assess high uptake level, representing a reliable alternative to SUV_max. Independently from the segmentation method, the superiority of SUV_95th and its easy computation could make its clinical impact decisive. The results obtained with SUV_95th, more representative of tracer uptake than those with SUV_max suggest, in our opinion, that mannitol infusion could be used to reduce the adsorbed dose to the kidneys during [⁶⁸Ga]PSMA PET/CT and Lu-177 or Ac-225 therapy. Our future goal will be confirming this effect in a larger cohort of patients, also verifying the role of SUV_95th in the evaluation of tumor response to therapy.

An integrated prediction model of recurrence in endometrial endometrioid cancers

Objectives: Endometrial cancer incidence and mortality are rising in the US. Disease recurrence has been shown to have a significant impact on mortality. However, to date, there are no accurate and validated prediction models that would discriminate which individual patients are likely to recur. Reliably predicting recurrence would be of benefit for treatment decisions following surgery. We present an integrated model constructed with comprehensive clinical, pathological and molecular features designed to discriminate risk of recurrence for patients with endometrioid endometrial adenocarcinoma. Subjects and methods: A cohort of endometrioid endometrial cancer patients treated at our institution was assembled. Clinical characteristics were extracted from patient charts. Primary tumors from these patients were obtained and total tissue RNA extracted for RNA sequencing. A prediction model was designed containing both clinical characteristics and molecular profiling of the tumors. The same analysis was carried out with data derived from The Cancer Genome Atlas for replication and external validation. Results: Prediction models derived from our institutional data predicted recurrence with high accuracy as evidenced by areas under the curve approaching 1. Similar trends were observed in the analysis of TCGA data. Further, a scoring system for risk of recurrence was devised that showed specificities as high as 81% and negative predictive value as high as 90%. Lastly, we identify specific molecular characteristics of patient tumors that may contribute to the process of disease recurrence. Conclusion: By constructing a comprehensive model, we are able to reliably predict recurrence in endometrioid endometrial cancer. We devised a clinically useful scoring system and thresholds to discriminate risk of recurrence. Finally, the data presented here open a window to understanding the mechanisms of recurrence in endometrial cancer.

Clinical and prognostic value of 18F-FDG PET/CT in recurrent endometrial carcinoma

PURPOSE

Endometrial carcinoma (EC) is a cancer with a good overall prognosis, except in cases of recurrent or advanced EC. The aim of this study was to assess the diagnostic performance, the prognostic value and the impact on therapeutic management of ¹⁸F-FDG PET/CT in suspected recurrent EC.

MATERIALS AND METHODS

We retrospectively evaluated 157 patients with histologically proven EC and restaging ¹⁸F-FDG PET/CT for suspected recurrence. The PET images were analyzed visually and semi-quantitatively by measuring SUVmax, MTV and TLG. A combination of clinical/imaging follow-up and/or histopathology was taken as reference standard. Progression-free survival (PFS) and overall survival (OS) were computed using Kaplan-Meier curves.

RESULTS

Seventy-nine patients had positive ¹⁸F-FDG PET/CT showing the presence of at least one hypermetabolic lesion consistent with recurrence, while the remaining 78 were negative. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ¹⁸F-FDG PET/CT were 96%, 99%, 99%, 96%, 97%, respectively, and were higher compared to conventional imaging: 97%, 62%, 72%, 96%, 80%. After a mean follow-up of 39months, relapse/progression occurred in 58 patients and death in 37 with an average time of 22.1 and 27.6months, respectively. A positive ¹⁸F-FDG PET/CT and advanced FIGO stage were significantly associated with shorter PFS and OS. PET/CT results had a significant impact on therapeutic approach in 33 patients: avoiding unnecessary therapies in 28 and modifying therapy in 5.

CONCLUSIONS

¹⁸F-FDG PET/CT has a very good diagnostic performance in patients with suspected recurrent EC and has an important prognostic value in assessing PFS and OS. Moreover, PET/CT allowed for a change in treatment decision in about 20% of cases.

Prognostic predictive value of preoperative intratumoral 2-deoxy-2-(18F)fluoro-D-glucose uptake heterogeneity in patients with high-grade serous ovarian cancer

OBJECTIVE

This study aimed to explore the clinical and prognostic significance of pretreatment positron-emission tomography/computed tomography (PET/CT) parameters, especially 2-deoxy-2-(F)fluoro-D-glucose-based heterogeneity, in high-grade serous ovarian cancer (HGSC).

MATERIALS AND METHODS

We retrospectively investigated 56 patients with HGSC who underwent PET/CT before primary surgery at our hospital between January 2010 and June 2015. None of these patients received neoadjuvant chemotherapy. PET/CT parameters, including maximum and mean standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and intratumoral heterogeneity index (HI), were measured for all patients. Differences of each PET/CT parameter between primary tumors (-P) and omental metastatic lesions (-M) were compared by paired t tests. Progression-free survival (PFS) and overall survival were analyzed by the Kaplan-Meier method and log-rank tests in univariate analyses. Cox regression analyses were used for multivariate analysis.

RESULTS

SUVmean-P was higher than SUVmean-M (P=0.001). However, there were no statistical differences of SUVmax, MTV, TLG, or HI between primary and omental lesions. Chemosensitive patients tended to have higher levels of SUVmax-P (P=0.011), MTV-P (P=0.014), TLG-P (P=0.035), and HI-P (P=0.002), respectively. In univariate analyses, higher HI-P was associated with better PFS (P=0.007). However, in multivariate analysis, HI-P was not an independent predictor of PFS (P=0.581). Neither HI-P nor HI-M was the prognostic predictor for overall survival (P=0.078 and 0.063, respectively).

CONCLUSION

2-Deoxy-2-(F)fluoro-D-glucose-based heterogeneity appears to be a predictive and prognostic factor for patients with HGSC. Parameters of primary tumors have predominant value compared with omental metastatic lesions.

FDG-PET Assessment of Other Gynecologic Cancers

PET and PET/computed tomography play a role in the staging, monitoring of response to therapy, and surveillance for cervical and ovarian cancers. Currently, it is also an integral part of the assessment of patients with endometrial cancer and other gynecologic malignancies, such as vaginal and vulvar cancers and uterine sarcomas. In this article, we discuss in detail and highlight the potential role of PET and PET/computed tomography in evaluating these gynecologic malignancies using illustrative cases with relevant imaging findings.

The role of FDG-PET/CT in gynecologic imaging: an updated guide to interpretation and challenges

All women, during their lifetime, are at risk of developing some form of gynecologic malignancy. The role of FDG-PET/CT has become more established in the management of gynecologic malignancies in the last decade. In this article, we will review the role of FDG-PET/CT in endometrial, cervical, ovarian, and vaginal cancer, by highlighting its strengths and limitations. While the role in initial or pre-operative staging for FDG-PET/CT is controversial, it allows noninvasive detection of equivocal or distant metastases, may alter stage and prognosis, and can guide or help eliminate unnecessary interventions that may not be beneficial. FDG-PET/CT is a useful adjunct to traditional staging with MR and CT.

Preoperative [18F]FDG PET/CT tumour heterogeneity index in patients with uterine leiomyosarcoma: a multicentre retrospective study

PURPOSE

We investigated the prognostic value of the tumour heterogeneity index determined on preoperative [¹⁸F]FDG PET/CT in patients with uterine leiomyosarcoma (LMS).

METHODS

We retrospectively reviewed patients with uterine LMS who underwent preoperative [¹⁸F]FDG PET/CT scans at three tertiary referral hospitals. The PET/CT parameters maximum standardized uptake value of the primary tumour (SUV_max), metabolic tumour volume (MTV) and total lesion glycolysis were assessed. The negative values of the MTV linear regression slope (nMLRS) according to the SUV thresholds of 2.5 and 3.0 were determined as the tumour heterogeneity index. The value of PET/CT-derived parameters in predicting progression-free survival (PFS) and overall survival (OS) were determined in regression analyses.

RESULTS

Clinicopathological and PET/CT data from 16 patients were reviewed. The median postsurgical follow-up was 21 months (range 4-82 months), and 12 patients (75.0%) experienced recurrence. Tumour size (P = 0.017), SUV_max (P = 0.019), MTV (P = 0.016) and nMLRS (P = 0.008) were significant prognostic factors for recurrence. MTV (P = 0.048) and nMLRS (P = 0.045) were significant prognostic factors for patient survival. nMLRS was correlated with clinicopathological parameters including tumour size (Pearson's correlation coefficient γ = 0.825, P < 0.001) and lymph node metastasis (γ = 0.721, P = 0.004). Patient groups categorized according to the nMLRS cut-off value showed significant differences in PFS (P = 0.033) and OS (P = 0.044).

CONCLUSION

The preoperative tumour heterogeneity index obtained using the MTV linear regression slope may be a novel and useful prognostic marker in uterine LMS.

Molecular Imaging and Precision Medicine in Uterine and Ovarian Cancers

Gynecologic cancer is a heterogeneous group of diseases both functionally and morphologically. Today, PET coupled with computed tomography (PET/CT) or PET/MR imaging play a central role in the precision medicine algorithm of patients with gynecologic malignancy. In particular, PET/CT and PET/MR imaging are molecular imaging techniques that not only are useful tools for initial staging and restaging but provide anatomofunctional insight and can serve as predictive and prognostic biomarkers of response in patients with gynecologic malignancy.