Sensitivity and negative predictive value for sentinel lymph node biopsy in women with early-stage cervical cancer

Abstract

Objective The role of sentinel lymph node (SLN) biopsy alone for staging of early-stage cervical cancer remains controversial. We aimed to determine the validity of this technique in women with early-stage cervical cancer. Methods We retrospectively reviewed women with early-stage cervical cancer who underwent SLN mapping followed by complete pelvic lymphadenectomy as part of initial surgical management from August 1997 through October 2015. All modes of surgical approach were included. Lymphatic mapping was performed using blue dye, technetium-99m sulfur colloid (Tc-99), and/or indocyanine green (ICG). We determined SLN detection rates, sensitivity and negative predictive value. Results One hundred eighty-eight patients were included, and 35 (19%) had lymph node metastases. At least one SLN was identified in 170 patients (90%), and bilateral SLNs were identified in 117 patients (62%). The majority of SLNs (83%) were found in the pelvis. There was no difference in detection rates between mapping agents, surgical approach, patients with and without prior conization or between patients with tumors < 2 cm and ≥ 2 cm. The detection rate for bilateral SLNs was significantly lower in women with body mass index (BMI) > 30 kg/m2 than in women with lower BMI (p=0.03). Metastatic disease in sentinel nodes was detected by H&E staining in 78% of cases and required ultrastaging/immunohistochemistry in 22% of cases. Only one patient had a false-negative result, yielding a sensitivity of 96.4% (95% CI 79.8%–99.8%) and negative predictive value of 99.3% (95% CI 95.6%–100%). The false-negative rate was 3.6%. Conclusions In these women with early-stage cervical cancer, SLN biopsy had very high sensitivity and negative predictive value. We believe it is time to change the standard of care for women with early-stage cervical cancer to SLN biopsy only.

Incidence of Lymph Node Metastases in Women With Low-Risk Early Cervical Cancer (<2 cm) Without Lymph-Vascular Invasion

“…22 In fact, a number of centers have turned to a practice of sentinel lymph node mapping alone in patients undergoing surgery with early-stage cervical cancer. 23,24 One major drawback in proposing a plan in such lowrisk patients is that the LVSI status is often not known prior to the planned surgery. In this sense, 1 study observed that hysterectomy specimen had higher sensitivity and negative predictive value in comparison with cervical biopsy, conization, and loop electrosurgical procedure (LEEP) in determining LVSI.…”

Impact of micrometastasis or isolated tumor cells on recurrence and survival in patients with early cervical cancer: SENTICOL Trial

“…In patients with early-stage cervical cancer, SLN biopsy is purported to be a sensitive method for detecting lymph node involvement, especially if the SLN is detected bilaterally,1 8 with a high sensitivity and a negative predictive value of 99% 9. According to a review by Tax,10 the false-negative rate is considered very low, with a residual risk of occult metastases of 0.08% in non-sentinel lymph nodes in cases of no suspicious lymph nodes on pre-operative imaging or during surgery, and bilateral negative SLN after ultrastaging.…”

Gynaecological malignancies and sentinel lymph node mapping: an update

“…Most significantly, the rate of detection of LN metastases increases, and the false negative rate decreases when SLNs are detected bilaterally. For that reason, a side‐specific LN dissection is undertaken in patients with unilateral mapping . Additionally, there is some evidence supporting lower false negative rates by limiting the use of SLN mapping to tumours <4 cm, although the NCCN guidelines note that mapping results are optimised in tumours <2 cm .…”

“…Negative SLNs serve as surrogate markers of negative LNs along the entire path of lymphatic drainage. Validation studies that included completion lymphadenectomy report false negative rates for SLNs at all gynaecological sites of less than 5% . Clinical and pathological aspects specific to each gynaecological site are discussed below.…”