The standard management for early-stage endometrial cancer involves surgery with hysterectomy, salpingectomy with or without oophorectomy, and staging lymph node sampling. Surgery serves as both a therapeutic and diagnostic intervention because surgical pathology results are in turn used to predict the likelihood of relapse and guide adjuvant therapy decisions. However, in some cases, surgical intervention is not feasible or desired, particularly if fertility preservation is a goal. Fortunately, there are nonsurgical options that are associated with favorable outcomes to offer these patients.
Endometrial cancer is associated with obesity attributable to causative mechanisms that promote endometrial hyperplasia, cellular proliferation, and heightened hormonal and growth factor signaling. Not only does obesity drive the development of endometrial cancer, but it also complicates the treatment of the disease. For example, endometrial cancer staging surgery is less successfully completed through a minimally invasive route as body mass index increases, primarily because of limitations in surgical exposure.1 In fact, obesity can prevent surgery from being offered through any route. In addition to body habitus, determination of inoperability is also significantly influenced by the presence of coronary artery disease, hypertension, and diabetes.2 Given that these comorbidities are more commonly experienced by women who are overweight, obesity creates a perfect storm of causative and complicating factors for optimal treatment.
Dr. Emma C. Rossi
While surgeons may determine the candidacy of patients for hysterectomy, patients themselves also drive this decision-making, particularly in the case of young patients who desire fertility preservation. Approximately 10% of patients with endometrial cancer are premenopausal, a number that is increasing over time. These women may have experienced infertility prior to their diagnosis, yet still strongly desire the attempt to conceive, particularly if they have suffered from anovulatory menstrual cycles or polycystic ovarian disease. Women with Lynch syndrome are at a higher risk for developing their cancer in premenopausal years. Therefore, it is critical that gynecologic oncologists consider nonsurgical remedies for these women and understand their potential for success.
Certain criteria should be met for women undergoing nonsurgical management of endometrial cancer, particularly if chosen electively for fertility preservation. Diagnosis should be obtained with a curettage specimen (rather than a pipelle) to optimize the accuracy of establishing tumor grade and to “debulk” the endometrial tissue. Pretreatment imaging is necessary to rule out distant metastatic disease. MRI is particularly helpful in approximating the depth of myometrial invasion of the malignancy and is recommended for patients desiring fertility preservation. Patients who have an endometrial cancer that is deeply invasive into the myometrium are poor candidates for fertility preservation and have a higher risk for metastatic disease, particularly to lymph nodes, and treatment decisions (such as surgery, or, if inoperable, radiation which treats nodal basins) should be considered for these women.
Hormonal therapy has long been identified as a highly effective systemic therapy for endometrial cancers, particularly those that are low grade and express estrogen and progesterone receptors. Progesterone can be administered orally in preparations such as megestrol or medroxyprogesterone or “locally” with levonorgestrel-releasing intrauterine devices. Oral preparations are straightforward, typically low-cost agents. Likelihood of success is 50%-75%. However, the systemic side effects of these agents, which include increased venous thromboembolism risk and appetite stimulation, are particularly problematic in this population. Therefore, many providers prefer to place progestin-releasing intrauterine devices to “bypass” these side effects, avoid issues with adherence to dosing, and provide some preventative endometrial coverage after resolution of the cancer. Recent trials have observed elimination of endometrial cancer on repeat sampling in 67%-76% of cases.3-5 This strategy may be more successful when it is paired with the addition of GnRH agonists.4
When hormonal therapy is chosen for primary endometrial cancer treatment, it is typically monitored for efficacy with repeat endometrial samplings, most commonly with pipelle biopsies to avoid displacement of an intrauterine device, though repeat D&C may be more effective in achieving a complete pathologic response to treatment. Most providers recommend resampling the endometrium at 3-month intervals until resolution of the malignancy has been documented, and thereafter if any new bleeding events develop. For women who have demonstrated resolution of carcinoma on repeat sampling, data are lacking to guide decision-making regarding resumption of conception efforts, ongoing surveillance, and completion hysterectomy after they finish childbearing. If malignancy continues to be identified after 6 months of hormonal therapy, consideration should be made of a more definitive treatment (such as surgery, if feasible, or radiation if not). Continued hormonal therapy can also be considered, as delayed responses remain common even 1 year after starting therapy.6 If hormonal therapy is prolonged for persistent disease, repeat MRI is recommended at 6 months to document lack of progression.
Radiation, preferably with both intracavitary and external beam treatment, is the most definitive intervention for inoperable early-stage endometrial cancer. Unfortunately, fertility is not preserved with this approach. However, for patients with high-grade tumors that are less likely to express hormone receptors or respond to hormonal therapies, this may be the only treatment option available. Typical treatment courses include 5 weeks of external beam radiation treatments, focused on treating the pelvis as a whole, including occult metastases not identified on imaging. Optimal therapy also includes placement of intracavitary radiation implants, such as Heymans capsules, to concentrate the dose at the uterine fundus, while minimizing toxicity to the adjacent bladder and bowel structures. While definitive radiation is considered inferior to a primary surgical effort, disease-specific survival can be observed in more than 80% of patients treated this way.7
While surgery remains the standard intervention for women with early-stage endometrial cancer, hormonal therapy or radiation remain viable options with high rates of success for women who are not surgical candidates or who desire fertility preservation.
Dr. Rossi is assistant professor in the division of gynecologic oncology at the University of North Carolina at Chapel Hill.
References
1. Walker JL et al. J Clin Oncol. 2009;27(32):5331-6.
2. Ertel M et al. Ann Surg Oncol. 2021;28(13):8987-95.
3. Janda M et al. Gynecol Oncol. 2021;161(1):143-51.
4. Novikova OV et al. Gynecol Oncol. 2021;161(1):152-9.
5. Westin SN et al. Am J Obstet Gynecol. 2021;224(2):191.e1-15.
6. Cho A et al. Gynecol Oncol. 2021;160(2):413-17.
7. Dutta SW et al. Brachytherapy. 2017;16(3):526-33.