The evolving role of adjuvant therapy in endometrial cancer

Efficacy and Toxicity of Adjuvant Therapies for High-Risk Endometrial Cancer in Stage I-III: A Systematic Review and Network Meta-Analysis

BACKGROUND The use of adjuvant therapy for high-risk endometrial cancer patients (HREC) in International Federation of Gynecology and Obstetrics (FIGO) stage I-III remains debatable. This network meta-analysis was conducted to compare and rank adjuvant therapies based on efficacies and toxicities to facilitate clinical decision-making and further research. MATERIAL AND METHODS We searched 3 databases - PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials - from inception to December 9, 2019. Only randomized controlled trials that compared any of these adjuvant therapies (pelvic radiotherapy, vaginal brachytherapy, chemotherapy, and chemoradiotherapy) with each other or surgery alone were included. The network meta-analysis was performed in a frequentist framework using Stata software 15.0. RESULTS Fourteen RCTs with 5872 participants were eligible. No significant difference between treatments was observed in 5-year overall survival (OS) or distant metastasis. Compared with surgery alone, adjuvant pelvic radiotherapy plus chemotherapy (pelvic RT-CT) prolonged 5-year progression-free survival (PFS) and pelvic radiotherapy (pelvic RT) (RR=0.61, 95% CI 0.39-0.96; RR=0.779, 95% CI 0.63-0.95). Compared with surgery alone, pelvic RT, the combination of pelvic RT and vaginal brachytherapy (pelvic RT-VBT), chemotherapy (CT), and pelvic RT-CT led to fewer local recurrences (RR=0.33, 95% CI 0.21-0.50; RR=0.15, 95% CI 0.03-0.74; RR=0.39, 95% CI 0.21-0.73; RR=0.17, 95% CI 0.06-0.46). Adjuvant CT was found to result in more grade III/IV late toxicities than surgery alone (RR=11.8, 95% CI 1.02-137.14). Pelvic RT-CT ranked first for OS, PFS, distant metastasis, and local recurrence. CONCLUSIONS Pelvic RT-CT is superior to other treatments for PFS and local recurrence rate, and associated related toxicities are tolerable, suggesting it may be an ideal adjuvant therapy for HREC patients.

Patterns of Failures and Clinical Outcome of Patients with Early-Stage, High-Risk, Node-Negative Endometrial Cancer Treated with Surgery Followed by Adjuvant Platinum-Based Chemotherapy and Vaginal Brachytherapy

OBJECTIVE

To assess the clinical outcome of patients with high-risk early-stage endometrial cancer and negative pelvic nodes who received adjuvant platinum-based chemotherapy plus vaginal brachytherapy (VBT).

METHODS

This investigation assessed 80 patients who underwent hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymphadenectomy for stage Ib-II, grade 2-3 endometrioid (n = 43) or stage Ia-II nonendometrioid (n = 37) endometrial cancer.

RESULTS

Five-year local control rate, 5-year disease-free survival, and 5-year overall survival were 97, 87, and 97%, respectively, for endometrioid carcinoma, and 66, 50, and 72%, respectively, for nonendometrioid carcinoma.

CONCLUSIONS

This retrospective study appears to show that adjuvant platinum-based chemotherapy plus VBT achieve very good results in endometrioid carcinoma. This combined treatment seems to be less effective in nonendometrioid carcinoma.

Does the apex optimization line matter for single-channel vaginal cylinder brachytherapy planning?

The objective of this study is to test the impact of the use of the apex optimization line for new vaginal cylinder (VC) applicators. New single channel VC applicators (Varian) that have different top thicknesses but the same diameters as the old VC applicators (2.0 cm diameter, 2.3, 2.6, 3.0, and 3.5 cm) were compared using phantom studies. Old VC applicator plans without the apex optimization line were also compared to the plans with an apex optimization line. The apex doses were monitored at 5 mm depth doses (eight points) where a prescription dose (Rx) of 6 Gy was prescribed. VC surface doses (eight points) were also analyzed. The new VC applicator plans without apex optimization line presented significantly lower 5‐mm depth doses over the Rx (on average −31 ± 7%, P < 0.00001) due to thicker VC tops (3.4 ± 1.1 mm thicker with the range of 1.2–4.4 mm) than the old VC applicators. Old VC applicator plans also showed a statistically significant reduction (P < 0.00001) due to the Ir‐192 source anisotropic effect at the apex region, but the percent reduction over the Rx was only −7 ± 9%. However, by adding the apex optimization line to the new VC applicator plans, the plans improved 5‐mm depth doses (−7 ± 9% over Rx) that were not statistically different from old VC applicator plans (P = 0.923), along with apex VC surface doses (−22 ± 10% over old VC vs −46 ± 7% without using apex optimization line). The use of the apex optimization line is important in order to avoid significant additional cold doses (−24 ± 2%) at the prescription depth (5 mm) of the apex, specifically for the new VC applicators that have thicker tops. A template‐based vaginal cylinder planning reduced the intra‐ and inter‐planner variations of manual generation of apex optimization line, along with treatment time.

Acute and late vaginal toxicity after adjuvant high-dose-rate vaginal brachytherapy in patients with intermediate risk endometrial cancer: is local therapy with hyaluronic acid of clinical benefit?

PURPOSE

The aim of the present study was to evaluate the effectiveness of hyaluronic acid (HA) in the prevention of acute and late vaginal toxicities after high-dose-rate (HDR) vaginal brachytherapy (BT).

MATERIAL AND METHODS

Between January 2011 and January 2015, we retrospectively analyzed 126 patients with endometrial cancer who underwent extrafascial hysterectomy with or without lymphadenectomy and adjuvant HDR-vaginal BT +/- adjuvant chemotherapy. The total dose prescription was 21 Gy in 3 fractions (one fraction for week). Vaginal ovules containing 5 mg of HA were given for whole duration of vaginal BT and for the two following weeks. Acute and late toxicities were evaluated according to CTCAE vs 4.02.

RESULTS

According to the revised FIGO 2009 classification, most tumors were in stage IA (30.9%) and in stage IB (57.9%). Thirty-three patients (26.2%) received adjuvant chemotherapy before vaginal BT. Five-year disease-free survival (DFS) and five-year overall survival (OS) were 88% and 93%, respectively. The most common grade 1-2 acute toxicities were vaginal inflammation (18 patients, 14.3%) and dyspareunia (7 patients, 5.5%). Two patients (1.6%) had more than one toxicity. Late toxicity occurred in 20 patients (15.9%). Grade 1-2 late toxicities were fibrosis (14 patients, 11.1%) and telangiectasias (7 patients, 5.5%). Six patients (4.8%) had more than one late toxicity. No grade 3 or higher acute or late toxicities were observed.

CONCLUSIONS

These results appear to suggest that the local therapy with HA is of clinical benefit for intermediate risk endometrial cancer patients who receive adjuvant HDR-vaginal BT after surgery. A randomized trial comparing HA treatment vs. no local treatment in this clinical setting is warranted to further evaluate the efficacy of HA in preventing vaginal BT-related vaginal toxicity.

Effect of mTOR inhibitors in nude mice with endometrial carcinoma and variable PTEN expression status

Background

The aim of this study was to investigate the sensitivity to rapamycin of endometrial cancer cells with different phosphatase and tensin homologue (PTEN) expression to understand the mechanism of resistance to mammalian target of rapamycin (mTOR) inhibitors in the treatment of endometrial cancer.

Material/Methods

Twenty specific pathogen-free female BALB/c mice received transplants of either HEC-1A (PTEN-positive) or Ishikawa (PTEN-negative) cells. Mice in the treatment group were injected intraperitoneally once a week for 4 consecutive weeks. The control group was injected weekly with phosphate buffer saline (PBS) for 4 consecutive weeks. Tumor volume, tumor mass, growth curves, and inhibition rate were measured, after which the mice were killed.

Results

Both tumor growth rate and size were slower in the treatment group than in the control group for all mice that received transplants of either HEC-1A or Ishikawa cells. The tumor inhibition rates in the treatment group were 48.1% and 67.1% in mice transplanted with HEC-1A and Ishikawa cells, respectively.

Conclusions

The inhibitory effects of rapamycin were enhanced in PTEN-negative Ishikawa tumor cells compared with PTEN-positive HEC-1A cells, which could explain the reduced effect of rapalogues in some endometrial cancer patients and help to understand the mechanism of resistance to this drug.

Antiangiogenic agents in advanced, persistent or recurrent endometrial cancer: a novel treatment option

The limited efficacy of endocrine therapy and chemotherapy has stimulated several researches aimed to detect novel molecularly target therapies for advanced, persistent or recurrent endometrial cancer. Prior attempts to block vascular endothelial growth factor (VEGF) with sunitinib, sorafenib and thalidomide have obtained disappointing results. Bevacizumab has shown a promising activity in a phase II study. The percentages of patients with progression-free survival ≥6 months were similar for endometrioid (35%) and serous carcinoma (36%), but the number of cases was too small to assess the relevance of histological type for response to bevacizumab. In a phase II study, aflibercept was administered every 2 weeks to women with recurrent or persistent disease after chemotherapy. Forty-one percent of the patients were progression-free at 6 months, but 32% of the women had been removed from study because of toxicity. The detection of activating mutations of Fibroblast Growth Factor Receptor (FGFR)-2 in primary endometrial carcinoma has generated a new avenue for the development of molecularly target agents. Dovitinib, a tyrosine kinase inhibitor targeting both VEGF receptor (VEGFR) and FGFRs, is under clinical investigation in different malignancies including endometrial cancer.

Mismatch repair status and clinical outcome in endometrial cancer: a systematic review and meta-analysis

BACKGROUND

The association between the deficiency in mismatch repair (MMR) genes and prognosis in women with endometrial cancer is unclear. Here we report a systematic review and meta-analysis exploring this association.

METHODS

We searched literature databases (MEDLINE, EMBASE, and Cochrane) from 1980 until December 2011 to identify studies evaluating the association between MMR status and clinical outcome in endometrial cancer. The main outcome measures were overall survival (OS) and disease-free survival (DFS).

RESULTS

Twenty-three studies met the inclusion criteria. The median sample size of studies was 112, 74% were retrospective case-series and 70% performed microsatellite instability (MSI) analysis to evaluate the status of MMR. Only 22% of studies used the panel of five microsatellite markers recommended by the National Cancer Institute. Seven studies used immunohistochemistry to define MMR deficiency, but only two of them determined the expression of all four MMR proteins. Overall, significant associations between MMR and outcome were observed in 32% of studies. There was marked inter-study heterogeneity for estimates of OS and DFS. Pooled analysis did not show any significant association between deficiency in MMR and worse OS (6 studies, hazard ratio [HR] 2.0, p=0.11) or DFS (4 studies, HR ratio 1.31, p=0.66).

CONCLUSION

There is no definitive evidence of a significant association between MMR status and detrimental survival in endometrial cancer.

External-beam radiotherapy and/or HDR brachytherapy in postoperative endometrial cancer patients: clinical outcomes and toxicity rates

PURPOSE

The objectives of this study were to evaluate local disease control, overall survival (OS), disease-free survival (DFS) and local relapse-free survival (LRFS) in patients with endometrial cancer undergoing adjuvant vaginal brachytherapy (VBT )± external-beam radiotherapy (EBRT).

MATERIALS AND METHODS

From September 2007 to February 2011, 40 patients with endometrial cancer were retrospectively analysed. Surgery consisted of total hysterectomy and bilateral salpingo-oophorectomy without node dissection (16 patients) or with bilateral pelvic node dissection (24 patients). The stage distribution was as follows: two IA, nine IB, 12 IC, five IIA, eight IIB, two IIIA and two IIIC. Thirty-four patients underwent EBRT and VBT. Six patients received VBT alone.

RESULTS

Median follow-up was 26 months. The 5-year OS and DFS were 96.4% and 86.9%, respectively. No local recurrence was observed. Four patients presented distant disease (three had lung metastases and one had hepatic node metastases). Acute EBRT-related toxicities were seen in 15 (38%) patients. We recorded late toxicities in 14 patients (35%). There was no evidence of grade 3-4 toxicity.

CONCLUSIONS

Adjuvant EBRT and/or VBT in patients with endometrial cancer showed good outcomes in terms of local disease control, with an acceptable toxicity profile.