Use of aromatase inhibitors as first- and second-line medical therapy in patients with endometrial adenocarcinoma: a retrospective study

Our current understanding of the biological impact of endometrial cancer mtDNA genome mutations and their potential use as a biomarker

Endometrial cancer (EC) is a devastating and common disease affecting women's health. The NCI Surveillance, Epidemiology, and End Results Program predicted that there would be >66,000 new cases in the United States and >13,000 deaths from EC in 2023, and EC is the sixth most common cancer among women worldwide. Regulation of mitochondrial metabolism plays a role in tumorigenesis. In proliferating cancer cells, mitochondria provide the necessary building blocks for biosynthesis of amino acids, lipids, nucleotides, and glucose. One mechanism causing altered mitochondrial activity is mitochondrial DNA (mtDNA) mutation. The polyploid human mtDNA genome is a circular double-stranded molecule essential to vertebrate life that harbors genes critical for oxidative phosphorylation plus mitochondrial-derived peptide genes. Cancer cells display aerobic glycolysis, known as the Warburg effect, which arises from the needs of fast-dividing cells and is characterized by increased glucose uptake and conversion of glucose to lactate. Solid tumors often contain at least one mtDNA substitution. Furthermore, it is common for cancer cells to harbor mixtures of wild-type and mutant mtDNA genotypes, known as heteroplasmy. Considering the increase in cancer cell energy demand, the presence of functionally relevant carcinogenesis-inducing or environment-adapting mtDNA mutations in cancer seems plausible. We review 279 EC tumor-specific mtDNA single nucleotide variants from 111 individuals from different studies. Many transition mutations indicative of error-prone DNA polymerase γ replication and C to U deamination events were present. We examine the spectrum of mutations and their heteroplasmy and discuss the potential biological impact of recurrent, non-synonymous, insertion, and deletion mutations. Lastly, we explore current EC treatments, exploiting cancer cell mitochondria for therapy and the prospect of using mtDNA variants as an EC biomarker.

Current Evidence-Based Systemic Therapy for Advanced and Recurrent Endometrial Cancer

Endometrial cancer (EC) is the most common gynecologic malignancy, with worldwide increasing incidence and disease-associated mortality. Although most patients with EC are diagnosed with early-stage disease, systemic treatment options for patients with advanced or recurrent EC have historically been limited. EC-focused clinical trials and the ensuing therapeutic landscape have expanded since The Cancer Genome Atlas (TCGA) identified 4 distinct EC subgroups associated with differential survival. This endeavor revolutionized our understanding of the genomic characterization of EC as well as molecular drivers of this heterogeneous malignancy, leading to precision oncology approaches to therapeutics and advancement in treatment options. This review describes the current status of and recent advancements in therapeutic options for patients with advanced and recurrent EC. The NCCN Guidelines for Uterine Neoplasms provide detailed recommendations regarding the diagnosis, workup, and management of EC.

Uterine Neoplasms, Version 1.2023, NCCN Clinical Practice Guidelines in Oncology

Adenocarcinoma of the endometrium (also known as endometrial cancer, or more broadly as uterine cancer or carcinoma of the uterine corpus) is the most common malignancy of the female genital tract in the United States. It is estimated that 65,950 new uterine cancer cases will have occurred in 2022, with 12,550 deaths resulting from the disease. Endometrial carcinoma includes pure endometrioid cancer and carcinomas with high-risk endometrial histology (including uterine serous carcinoma, clear cell carcinoma, carcinosarcoma [also known as malignant mixed Müllerian tumor], and undifferentiated/dedifferentiated carcinoma). Stromal or mesenchymal sarcomas are uncommon subtypes accounting for approximately 3% of all uterine cancers. This selection from the NCCN Guidelines for Uterine Neoplasms focuses on the diagnosis, staging, and management of pure endometrioid carcinoma. The complete version of the NCCN Guidelines for Uterine Neoplasms is available online at NCCN.org.

Contemporary Use of Hormonal Therapy in Endometrial Cancer: a Literature Review

OPINION STATEMENT

Most endometrial cancers are estrogen receptor and progesterone receptor positive. Hormonal therapy in endometrial cancer is best used in patients with low-grade disease and hormone receptor positivity. Though not standard of care, hormonal treatment can be considered in endometrial cancer treatment in both the early-stage upfront setting for patients who are not surgical candidates and in advanced and recurrent endometrial cancer. In patients who desire fertility preservation or who are not surgical candidates, levonorgestrel intrauterine device and oral progesterone are preferred treatment options. In patients with advanced and metastatic disease, there is no standard-of-care second-line treatment, and hormonal treatment is a widely accepted option for low-grade disease. Beyond progesterone, selective estrogen receptor modulators, aromatase inhibitors, gonadotropin-releasing hormone agonists, and fulvestrant are hormonal treatment options. New therapies, such as MTOR inhibitors and CDK 4/6 inhibitors, have been extensively studied in breast cancer and are shown to be useful in conjunction with hormonal therapies particularly when there is suspected resistance to anti-estrogen treatment. Hormonal therapies also tend to be better tolerated than chemotherapy agents, making them a desirable option particularly in patients with lower performance status. Results from ongoing clinical trials will hopefully help shed light on the use of combination treatment in patients with hormone receptor-positive, low-grade metastatic, and recurrent endometrial cancer.

The Use of Targeted Agents in the Treatment of Gynecologic Cancers

OPINION STATEMENT

Patients with advanced and recurrent ovarian, uterine, and cervical cancers have limited efficacious treatment options and poor outcomes. The development of agents that target DNA repair mechanisms, angiogenesis, immune checkpoints, and hormone receptor expression provides additional options for these patients. Many available targeted therapies have limited efficacy as single agents, so clinical trials investigating combination therapies as well as continued identification and validation of predictive biomarkers are critical. Many novel small molecule therapies, antibody drug conjugates, and therapeutic vaccines are also in development. This review will focus on recent evidence supporting the use of clinically available targeted therapies for gynecologic cancer.

Local estrogen metabolism (intracrinology) in endometrial cancer: A systematic review

Endometrial cancer (EC) is the most common malignancy of the female gynaecological tract and increased exposure to estrogens is a risk factor. EC cells are able to produce estrogens locally using precursors like, among others, adrenal steroids present in the serum. This is referred to as local estrogen metabolism (or intracrinology) and consists of a complex network of multiple enzymes. Particular relevant to the final generation of active estrogens in endometrial cells are: steroid sulfatase (STS), estrogen sulfotransferase (SULT1E1), aromatase (CYP19A1), 17β-hydroxysteroid dehydrogenase (HSD17B) type 1 and type 2. During the last decades, a plethora of studies explored the level of these enzymes in EC but contrasting data were reported, which generated vigorous debate and controversies. Several reviews attempted at clarifying some of the debated issues, but published reviews are based on investigator-defined bibliography selection and not on systematic analysis. Therefore, we performed a systematic review of the literature reporting about the level of STS, SULT1E1, CYP19A1, HSD17B1 and HSD17B2 in EC. Additional intracrine enzymes and networks (e.g., HSD17Bs other than types 1 and 2, aldo-keto reductases, progesterone and androgen metabolism) were non-systematically reviewed as well.

Preliminary clinical application of an aromatase inhibitor and a gonadotropin-releasing hormone agonist combination for inoperable endometrial cancer patients with comorbidities: case report and literature review

Background: Endometrial cancer (EC) occurs most commonly after menopause. A proportion of patients present with advanced age and comorbidities, and become ineligible for surgery. The optimal treatment strategy of these patients remains a clinical challenge. Aromatase inhibitor (AI) combined with Gonadotropin-releasing hormone agonist (GnRH-a) possesses profound effect in suppressing the estrogen level, has become a valid treatment in the breast cancer. However, the combined use of an AI and a GnRH-a in EC has rarely been studied. Case presentation: Herein, we report the combination of an AI and a GnRH-a in the treatment of three patients with advanced age or comorbidities who were ineligible for surgery. The disease remained stable for two years in patients who received the combination treatment as an initial approach without any adverse effects. Moreover, an AI combined with a GnRH-a also effective as salvage treatment of recurrent patients. Further, we provide a brief review of the literature. Conclusion: The combination of an AI and a GnRH-a presents satisfactory therapeutic effect and provides an optimal option for inoperable EC patients.

Clinical Behavior and Treatment of Endometrial Cancer

Endometrial cancer is the most common gynecologic malignancy diagnosed in women in the developed nations. It affects a disproportionate number of reproductive-aged women. While the overall prognosis is good compared to other cancers affecting women, the pathogenesis and clinical behavior of endometrial cancer are heterogeneous. The risk factors associated with the type I and type II endometrial cancers and their pathogenesis will be discussed, as well as the evaluation and primary treatment of women with endometrial cancer. The chapter will also focus on risk stratification for recurrence after surgery and role of adjuvant treatments. Finally, the treatment of recurrent endometrial cancer will be presented.

Molecular targeted therapy in gynaecologic malignancies: primer for radiologists

The identification of characteristic genetic alteration in gynaecological malignancies has opened the door for molecular targeted therapy. The purpose of this review is to provide a primer for the radiologist on these agents with emphasis on the role of imaging in treatment response assessment and drug toxicities. The use of targeted therapy in gynaecological malignancies will likely increase in the future and make the role of the radiologist critical in response assessment and detection of toxicities.

Aromatase inhibitors, tamoxifen, and endometrial cancer in breast cancer survivors

BACKGROUND

The risks of both endometrial cancer and postmenopausal breast cancer are increased by obesity and higher endogenous estrogen levels. Although aromatase inhibitors reduce breast cancer incidence, their influence on endometrial cancer is uncertain.

METHODS

The authors investigated this issue in a cohort of 17,064 women who were diagnosed with hormone receptor-positive breast cancer in an integrated group practice health plan. Information on demographics, comorbidities, and the receipt of adjuvant endocrine therapy was available from electronic medical records and pharmacy records, respectively. Endometrial cancer information was obtained from the health plan's Surveillance, Epidemiology, and End Results-affiliated tumor registry, and rates were compared across endocrine therapy groups (aromatase inhibitor, n = 5303; tamoxifen, n = 5155; switchers: both [n = 3787] or none [n = 2819]) using multivariable adjusted Cox proportional-hazards models.

RESULTS

Endometrial cancer incidence was a statistically significant 48% lower in the aromatase inhibitor group versus the tamoxifen group (hazard ratio, 0.52; 95% confidence interval, 0.31-0.87; P = .01). Endometrial cancer incidence was 29% lower in the aromatase inhibitor group versus the no endocrine therapy group (hazard ratio, 0.71; 95% confidence interval, 0.37-1.35; P = .30) and 33% lower in the aromatase inhibitor group versus the tamoxifen group (hazard ratio, 0.67; 95% confidence interval, 0.42-1.06; P = .08), but neither difference was statistically significant. Associations were stronger among those with good drug adherence.

CONCLUSIONS

In a community-based, integrated health plan setting, endometrial cancer incidence was lower in women who were receiving an aromatase inhibitor compared with those who were receiving tamoxifen. In addition, aromatase inhibitors may mitigate the incidence of tamoxifen-associated endometrial cancer. Although there were somewhat fewer endometrial cancers in the aromatase inhibitor group versus the no endocrine therapy group, further studies are needed for the definitive assessment of this potential association.