Sentinel Nodes in Cervical Cancer

In the JCO

Sentinel node mapping is making an appearance in all of the gynecologic cancers, most notably vulvar cancer, however two recent studies have examined the technique in cervix and endometrial cancer. The current study is in IA1-IB1 cervical lesions undergoing surgical staging and management, all of who were evaluated with a SNLB and then with a full dissection. The false negative rate was 8% (2/25), which is similar to the experience in breast. The investigators also noted that if bilateral nodes were mapped, there were no false negatives, but I would apply that with some caution as it appears to be a post hoc analysis.

While the rate false negative rate is similar to breast cancer, it remains to be seen if the clinical results will be the same as breast cancer. While this is a great step in the path towards integrating this into the management of early cervical cancer, one awaits a clinical trial in which the completion dissection is not performed, with careful follow up of the results. One must also be mindful of what we are actually accomplishing by performing less extensive dissections - while there are some adverse events associated with pelvic and PA dissections, in general they are relatively rare. The benefit of less extensive nodal sampling is much clearer in vulvar and breast cancer, where the risk of morbidity due to lymphedema is correspondingly higher.

Link and Abstract:

Bilateral Negative Sentinel Nodes Accurately Predict Absence of Lymph Node Metastasis in Early Cervical Cancer: Results of the SENTICOL Study [Gynecologic Cancer]: "Purpose

Sentinel lymph node (SLN) biopsy may be used to target lymph node metastases in patients with early cervical cancer. Whether SLN biopsy only is acceptable in the staging and surgical management of early cervical cancer remains unknown. This prospective multicenter study (SENTICOL [Ganglion Sentinelle dans le Cancer du Col]) assessed the sensitivity and negative predictive value (NPV) of SLN biopsy.

Patients and Methods

Adults with cervical carcinoma who met the International Federation of Gynecology and Obstetrics criteria for stage IA1 with lymphovascular space invasion to stage IB1 underwent technetium 99 lymphoscintigraphy and Patent Blue injection followed by laparoscopic lymph node mapping, SLN removal, and lymph node dissection. Only surgeons trained in SLN biopsy in cervical carcinoma participated in the study. SLNs and nonsentinel lymph nodes underwent routine staining. Negative SLNs were subjected to ultrastaging. The reference method was pelvic and/or para-aortic lymphadenectomy with histologic examination of all nodes.

Results

One hundred forty-five patients were enrolled, and 139 were included in a modified intention-to-diagnose analysis. Intraoperative radioisotope-blue dye mapping detected at least one SLN in 136 patients (97.8%; 95% CI, 93.8% to 99.6%), 23 of whom had true-positive results and two who had false-negative results, yielding 92.0% sensitivity (23 of 25; 95% CI, 74.0% to 99.0%) and 98.2% NPV (111 of 113; 95% CI, 74.0% to 99.0%) for node metastasis detection. No false-negative results were observed in the 104 patients (76.5%) in whom SLN were identified bilaterally.

Conclusion

Combined labeling for node mapping was associated with high rates of SLN detection and with high sensitivity and NPV for metastasis detection. However, SLN biopsy was fully reliable only when SLNs were detected bilaterally.

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