Sentinel lymph node biopsy for stage II endometrial cancer: Recent utilization and outcome in the United States

Low-grade endometrioid endometrial cancer with adnexal only metastasis: Evaluation of de-escalation of adjuvant therapy

OBJECTIVE

To assess survival outcomes of stage IA3 endometrial cancer and the association of adjuvant therapy and survival.

METHODS

The National Cancer Database was retrospectively queried to examine 594 and 1455 patients with stage IA3 and IIIA1 endometrial cancer, respectively, from 2010-2015. Overall survival (OS) was examined based on adjuvant therapy: multimodal combination chemotherapy and external beam radiotherapy, chemotherapy alone, external beam radiotherapy alone, and none.

RESULTS

For stage IA3 disease, 109 (18.4%) patients did not receive adjuvant therapy. The 5-year OS rates for the no adjuvant therapy group and the combination group were 86.3% and 91.4%, respectively (adjusted-hazard ratio [aHR] 1.23, 95% confidence interval [CI] 0.70-2.18). This survival association was consistent when compared to chemotherapy alone (5-year OS rates 86.3% vs 86.3%, aHR 1.11, 95%CI 0.67-1.83). The results were similar among those who underwent nodal evaluation (5-year OS rates, 92.6%, 86.6%, and 89.4% for combination therapy, chemotherapy alone, and no adjuvant therapy), including grade 1 lesions (96.2%, 89.4%, and 100%, respectively). In grade 2 lesions, 5-year OR rates was modestly lower for no adjuvant therapy than combination therapy (89.4%, 84.0%, and 82.7% for combination, chemotherapy alone, and no adjuvant therapy, P = 0.03). For stage IIIA1 disease, omission of adjuvant therapy was associated with decreased OS compared to combination therapy (43.2% vs 73.1%, aHR 1.65, 95%CI 1.30-2.11) or chemotherapy alone (43.2% vs 67.1%, aHR 1.62, 95%CI 1.32-1.99).

CONCLUSION

The results of this investigation suggest that survival effects of adjuvant therapy differ for stage IA3 and IIIA1 diseases. Patients with stage IA3 disease have overall good prognosis regardless of adjuvant therapy particularly grade 1 lesions, partly supporting the FIGO committee suggestion for adjuvant therapy de-escalation in stage IA3 endometrial cancer.

Comparison of progression-free survival outcome of sentinel node biopsy without ultrastaging versus lymphadenectomy in endometrial cancer: a propensity-matched analysis

OBJECTIVE

We aimed to investigate the oncologic outcomes of patients with endometrial cancer who underwent sentinel lymph node (SLN) biopsy without ultrastaging compared with that of those who underwent lymphadenectomy (LND).

METHODS

Patients with endometrial cancer who underwent staging with SLN biopsy or LND during 2006 - 2021 were analyzed using propensity score matching (PSM). SLN metastasis was examined using hematoxylin and eosin staining, without ultrastaging. Progression-free survival (PFS) was compared between the two groups before and after PSM using age, histology, and stage as covariates. Clinical variables such as recurrence patterns and lymphatic complications, were assessed.

RESULTS

After excluding 213 patients who underwent validation LND with SLN biopsy, 902 were identified. The demographics of the remaining patients differed according to histology, myometrial invasion depth, and stage. Lymph node metastasis was less frequent in the SLN group than in the LND group (9.4% vs. 3.8%, p=0.004). The recurrence rates within 2 years were lower in the SLN group. The SLN group exhibited significantly superior 2-year and overall PFS than the LND group. Among patients with uterus-confined disease, overall PFS was favorable for SLN biopsy. After matching, differences in PFS were no longer observed, although the lymphocele and lymphedema rates were significantly lower in the SLN group.

CONCLUSION

In patients with endometrial cancer, SLN biopsy without ultrastaging did not compromise survival outcomes and was associated with significantly reduced lymphatic complication rates compared with LND. Therefore, SLN biopsy can be recommended for patients with endometrial cancer without definitive preoperative evidence of distant metastasis.

Sentinel lymph node sampling versus full lymphadenectomy in endometrial cancer: a SEER database analysis

OBJECTIVE

To assess the long term outcomes and prognosis of sentinel lymph node sampling compared with full lymph node dissection in endometrial cancer patients.

METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) database for information on women diagnosed with endometrial cancer from 2010 to 2019. We conducted a comparison including overall survival between patients who had undergone sentinel lymph node sampling only and patients who had undergone formal lymph node dissection. Propensity score matching was performed according to the patient's age, type of endometrial cancer, grade and stage of disease, and adjuvant therapy. Subgroup analyses were performed according to type and grade of endometrial cancer.

RESULTS

41411 endometrial cancer patients were identified through the database. After matching, 6019 patients each were included in the sentinel lymph node and lymph node dissection groups. Median (interquartile range (IQR)) follow-up time was 16 (7-31) months in both groups. One year survival rates were longer in the sentinel lymph node group compared with the lymph node dissection group (hazard ratio (HR) 1.61 (95% confidence interval (CI) 1.17 to 2.21); p=0.004). Subgroups analysis according to grade of disease showed that 1 year survival rates were longer in the sentinel lymph node group in patients with endometrioid-type grade 1-2 endometrial cancer (HR 1.70 (95% CI 1.31 to 2.56); p=0.01), while no difference in survival was found between the sentinel lymph node and lymph node dissection groups in the subgroup of patients with high grade endometrial cancer (HR 1.40 (95%CI 0.94 to 2.24); p=0.17). In patients with low grade endometrial cancer included in the sentinel lymph node group, only 7% had lymph nodes positive for malignancy compared with 17% in the high grade group.

CONCLUSION

Survival rates were not compromised in endometrial cancer patients undergoing sentinel lymph node sampling versus full lymph node dissection for all grades of disease.

Impact of sentinel lymph node assessment on the outcomes of patients with advanced endometrial cancer: A meta-analysis

BACKGROUND

Sentinel lymph node (SLN) assessment is used to treat early endometrial cancer; however, its application in advanced endometrial cancer remains controversial. Therefore, we assessed the effects of SLN assessment and lymphadenectomy (LND) on the prognosis (survival rate and primary outcome) of patients with advanced endometrial cancer.

METHODS

Pertinent studies were selected from PubMed, Embase, Web of Science, and the Cochrane Library until March 19, 2022. Relevant studies were strictly screened according to the inclusion and exclusion criteria. Data from the included studies were extracted and their quality was evaluated. Then RevMan5.4 software was used for the meta-analysis.

RESULTS

Four retrospective studies were included, which enrolled 7181 patients; 492 were treated with SLN and 6689 with LND. In terms of overall survival, there was no significant difference between the 2 groups (odds ratio = 1.14, 95% confidence interval: 0.92-1.41, I2 = 0%, P = .39).

CONCLUSIONS

SLN assessment is an alternative to LND as a treatment modality for advanced endometrial cancer.

Utilization of sentinel lymph node biopsy in the early ovarian cancer surgery

OBJECTIVE

Sentinel lymph node (SLN) biopsy has been incorporated into surgical care for many malignancies; however, the utility has not been examined in ovarian cancer. This study examined population-level trends, characteristics, and outcomes related to SLN biopsy in early stage ovarian cancer.

METHODS

This is a retrospective cohort study querying the National Cancer Institute's Surveillance, Epidemiology, and End Result Program from 2003-2018. The study population consisted of 11,512 women with stage I ovarian cancer who had adnexectomy-based surgical staging including lymph node evaluation. Exposure allocation was based on SLN biopsy use. Main outcomes measured were (i) trends and characteristics associated with SLN biopsy use, assessed by multivariable logistic regression model, and (ii) overall survival assessed with inverse provability of treatment weighting propensity score.

RESULTS

SLN biopsy was performed in less than 1% of study population. In a multivariable analysis, recent surgery (2011-2018 versus 2003-2010, odds ratio [OR] 1.64, 95% confidence interval [CI] 1.03-2.59), smaller tumor size (< 10 versus ≥ 10 cm, OR 3.07, 95% CI 1.20-7.84), and East registry area (OR 2.74, 95% CI 1.73-4.36) remained independent characteristics for SLN biopsy use. In a propensity score weighted model, 5-year overall survival rate was 90.5% for the SLN biopsy-incorporated group and 88.6% for the lymphadenectomy group (hazard ratio 0.96, 95% CI 0.53-1.73).

CONCLUSION

SLN biopsy was rarely performed for early ovarian cancer surgery during the study period with insufficient evidence to interpret the survival effect. SLN biopsy in early ovarian cancer appears to be in early development phase, warranting further study and careful evaluation to assess feasibility and oncologic outcome.

Applications and Safety of Sentinel Lymph Node Biopsy in Endometrial Cancer

Lymph node status is important in predicting the prognosis and guiding adjuvant treatment in endometrial cancer. However, previous studies showed that systematic lymphadenectomy conferred no therapeutic values in clinically early-stage endometrial cancer but might lead to substantial morbidity and impact on the quality of life of the patients. The sentinel lymph node is the first lymph node that tumor cells drain to, and sentinel lymph node biopsy has emerged as an acceptable alternative to full lymphadenectomy in both low-risk and high-risk endometrial cancer. Evidence has demonstrated a high detection rate, sensitivity and negative predictive value of sentinel lymph node biopsy. It can also reduce surgical morbidity and improve the detection of lymph node metastases compared with systematic lymphadenectomy. This review summarizes the current techniques of sentinel lymph node mapping, the applications and oncological outcomes of sentinel lymph node biopsy in low-risk and high-risk endometrial cancer, and the management of isolated tumor cells in sentinel lymph nodes. We also illustrate a revised sentinel lymph node biopsy algorithm and advocate to repeat the tracer injection and explore the presacral and paraaortic areas if sentinel lymph nodes are not found in the hemipelvis.

Sentinel lymph node biopsy in high-risk endometrial cancer: performance, outcomes, and future avenues

Endometrial cancer is the second most common gynecological malignancy worldwide, with an overall favorable prognosis. However, a subgroup of patients has a high risk of recurrence and poor prognosis. This review summarizes recently published articles that examined sentinel lymph node (SLN) biopsy in patients with high-risk endometrial cancer. We focused on the performance and outcomes of SLN biopsy, and examined potential methods for improving the management of this high-risk subset. Few studies have examined the long-term outcomes of SLN in patients with high-risk endometrial cancer. Thus, we reviewed recently published retrospective studies that have adopted statistical techniques, such as inverse probability weighting or propensity score matching, to examine the outcome of SLN biopsy compared to conventional lymphadenectomy. Potential avenues for future research to fine-tune decision making for this patient subgroup were also discussed.

Association between sentinel lymph node biopsy and micrometastasis in endometrial cancer

OBJECTIVE

Sentinel lymph node (SLN) biopsy is increasingly utilized at surgical staging for early endometrial cancer. This study examined the association between SLN biopsy and micrometastasis in endometrial cancer.

METHODS

This is a retrospective cohort study examining the National Cancer Institute's Surveillance, Epidemiology, and End Result Program. The study population was 6,414 women with T1-2 endometrial cancer who underwent primary hysterectomy and surgical nodal evaluation. Exclusion criteria included cases with isolated tumor cells. Exposure assignment was surgical nodal evaluation (SLN biopsy or lymphadenectomy). Main outcome measure was micrometastasis, assessed by inverse probability of treatment weighting propensity score in a stage-specific fashion.

RESULTS

In T1a disease (n = 4,608), SLN biopsy was performed in 1,164 (25.3%) cases. SLN biopsy was associated with a 90% increased likeliness of identifying micrometastasis compared to lymphadenectomy (1.3% versus 0.7%, odds ratio 1.90, 95% confidence interval 1.02-3.55, P = 0.040). In T1b disease (n = 1,369), 270 (19.7%) cases had SLN biopsy. The incidence of micrometastasis was significantly higher in the SLN biopsy group compared to the lymphadenectomy group (8.4% versus 5.0%, odds ratio 1.74, 95% confidence interval 1.06-2.86, P = 0.028). In T2 disease (SLN biopsy in 57 [13.0%] of 437 cases), the incidence of micrometastasis was similar between the two groups (7.9% versus 7.0%, odds ratio 0.88, 95% confidence interval 0.30-2.60, P = 0.818).

CONCLUSION

This study suggests that SLN biopsy protocol may identify more micrometastasis in the regional lymph nodes of T1 endometrial cancer. Whether national-level increase in the utilization of SLN biopsy for early endometrial cancer results in a stage-shifting to advanced disease on a population-basis warrants further investigation.

Characterizing isolated tumor cells in regional lymph nodes of early endometrial cancer

OBJECTIVE

To examine the characteristics of isolated tumor cells (ITCs) in regional lymph nodes of early-stage endometrial cancer.

METHODS

This is a retrospective cohort study examining the National Cancer Institute's Surveillance, Epidemiology, and End Result Program. The study population was 6472 women with non-metastatic, node-negative T1 endometrial cancer who underwent primary hysterectomy and surgical nodal evaluation. Multivariable binary logistic regression model was used to identify the independent characteristics for ITCs. Postoperative therapy according to ITCs status was also assessed with propensity score weighting.

RESULTS

ITCs were seen in 111 (1.7%) cases. In a multivariable analysis, ITCs were largely associated with tumor factors including deep myometrial invasion (T1b versus T1a, 4.0% versus 1.0%, adjusted-odds ratio [aOR] 3.42, P < 0.001) and larger tumor size (>4 versus ≤4 cm, 3.0% versus 1.6%, aOR 1.55, P = 0.037). Moreover, women undergoing sentinel lymph node (SLN) biopsy had a higher likelihood of identifying ITCs compared to those undergoing lymphadenectomy (LND): 2.7% for SLN alone, 3.7% for SLN/LND, and 1.2% for LND alone (aOR ranged 2.60-2.99, P < 0.001). Women who had ITCs identified were more likely to receive postoperative therapy (81.8% versus 31.7%, P < 0.001), including external beam radiotherapy (EBT) alone (25.1% versus 3.2%) and chemotherapy/EBT (16.3% versus 1.9%). Similar associations were observed in the low-risk group (stage IA, grade 1-2 endometrioid, 78.4% versus 9.2%, P < 0.001), including EBT alone (35.3% versus 0.6%).

CONCLUSION

This study suggests that a SLN protocol can identify more ITCs in the regional lymph nodes of early endometrial cancer. Deep myometrial invasion and large tumor size were associated with increased risk of ITCs. Postoperative therapy is offered more frequently in the setting of ITCs with variable treatment patterns, warranting further outcome studies and practice guidelines.

Uptake in sentinel lymph node biopsy for endometrial cancer with T3 classification

OBJECTIVE

The current clinical practice guidelines for endometrial cancer specify sentinel lymph node (SLN) biopsy to be performed in apparent uterine-confined disease. However, a recent population-based analysis found that the utilization of SLN biopsy is increasing in extra-uterine disease such as T2 classification. The objective of this study was to examine trends and outcomes related to SLN biopsy for endometrial cancer with T3 classification, another extra-uterine disease.

METHODS

A population-based retrospective cohort study was conducted to examine 7004 women with T3 endometrial cancer who underwent primary surgery between 2010 and 2018, identified in the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. Trends and characteristics related to SLN biopsy were assessed by multinomial regression analysis, and inverse probability of treatment weighting propensity score was used to assess overall survival related to SLN biopsy.

RESULTS

Nodal evaluation type included lymphadenectomy (n = 5276, 75.3%), SLN biopsy (n = 287, 4.1%), and none (n = 1441, 20.6%). The utilization of SLN biopsy increased from 0.4% to 12.9% between 2010 and 2018 (P < 0.001) that this association remained independent in multivariable analysis (adjusted-odds ratio compared to 2010-2012, 2.63 [95% confidence interval 1.57-4.42] for 2013-2015 and 10.1 [95% confidence interval 6.30-16.2] for 2016-2018). When compared to the lymphadenectomy group, the SLN biopsy group was less likely to have T3b disease (adjusted-odds ratio 0.69, 95% confidence interval 0.51-0.94) but had similar postoperative chemotherapy and radiotherapy (both, P > 0.05). In a weighted model, the 3-year overall survival rate was 66.3% for the SLN biopsy group and 64.7% for the lymphadenectomy group (hazard ratio 0.85, 95% confidence interval 0.69-1.05). Similar association was observed in subcohorts for young, old, endometrioid, non-endometrioid, T3a, T3b, and N0 cases.

CONCLUSION

Utilization of SLN biopsy in T3 endometrial cancer is increasing in the United States.

Utilization and Outcomes of Sentinel Lymph Node Biopsy for Early Endometrial Cancer

OBJECTIVE

To examine trends, characteristics, and oncologic outcomes of sentinel lymph node biopsy for early endometrial cancer.

METHODS

This observational study queried the National Cancer Institute's Surveillance, Epidemiology, and End Results Program by examining 83,139 women with endometrial cancer who underwent primary hysterectomy with nodal evaluation for T1 disease from 2003 to 2018. Primary outcome measures were the temporal trends in utilization of sentinel lymph node biopsy and patient characteristics associated with sentinel lymph node biopsy use, assessed by multivariable binary logistic regression models. Secondary outcome measure was endometrial cancer-specific mortality associated with sentinel lymph node biopsy, assessed by propensity score inverse probability of treatment weighting.

RESULTS

The utilization of sentinel lymph node biopsy increased from 0.2 to 29.7% from 2005 to 2018 (P<.001). The uptake was higher for women with endometrioid (0.3-31.6% between 2005 and 2018) compared with nonendometrioid (0.6-21.0% between 2006 and 2018) histologic subtypes (both P<.001). In a multivariable analysis, more recent year surgery, endometrioid histology, well-differentiated tumors, T1a disease, and smaller tumor size were independently associated with sentinel lymph node biopsy use (P<.05). Performance of sentinel lymph node biopsy was not associated with increased endometrial cancer-specific mortality compared with lymphadenectomy for endometrioid tumors (subdistribution hazard ratio [HR] 0.96, 95% CI 0.82-1.13) or nonendometrioid tumors (subdistribution HR 0.85, 95% CI 0.69-1.04). For low-risk endometrial cancer, the increase in sentinel lymph node biopsy resulted in a 15.3 percentage-point (1.4-fold) increase in surgical nodal evaluation by 2018 (expected vs observed rates, 37.8 vs 53.1%).

CONCLUSION

The landscape of surgical nodal evaluation is shifting from lymphadenectomy to sentinel lymph node biopsy for early endometrial cancer in the United States, with no indication of a negative effect on cancer-specific survival.

Sentinel Lymph Node Mapping in High-Grade Endometrial Cancer

Sentinel lymph node (SLN) mapping is becoming an acceptable alternative to full lymphadenectomy for evaluating lymphatic spread in clinical stage I endometrial cancer (EC). While the assessment of pelvic and para-aortic lymph nodes is part of the surgical staging of EC, there is a long-standing debate over the therapeutic value of full lymphadenectomy in this setting. Although lymphadenectomy offers critical information on lymphatic spread and prognosis, most patients will not derive oncologic benefit from this procedure as the majority of patients do not have lymph node involvement. SLN mapping offers prognostic information while simultaneously avoiding the morbidity associated with an extensive and often unnecessary lymphadenectomy. A key factor in the decision making when planning for EC surgery is the histologic subtype. Since the risk of lymphatic spread is less than 5% in low-grade EC, these patients might not benefit from lymph node assessment. Nonetheless, in high-grade EC, the risk for lymph node metastases is much higher (20–30%); therefore, it is crucial to determine the spread of disease both for determining prognosis and for tailoring the appropriate adjuvant treatment. Studies on the accuracy of SLN mapping in high-grade EC have shown a detection rate of over 90%. The available evidence supports adopting the SLN approach as an accurate method for surgical staging. However, there is a paucity of prospective data on the long-term oncologic outcome for patients undergoing SLN mapping in high-grade EC, and more trials are warranted to answer this question.