SLNB and the importance of micrometastases in vulvar squamous cell carcinoma

Performance of Indocyanine Green Compared to 99mTc-Nanocolloids for Sentinel Lymph Node Detection in Early Vulvar Cancer

STUDY OBJECTIVE

The aim of this study was to evaluate the performance of indocyanine green (ICG) compared to that of the gold standard 99mtechnetium (99mTc-nanocolloids) in detecting sentinel lymph nodes (SLN) in early vulvar cancer.

MATERIAL AND METHODS

A single-center retrospective cohort study comparing SLN detection by 99mTc-nanocolloids and ICG was performed in patients presenting early vulvar cancer (T1/2), with clinically negative nodes. All SLN showing a radioactive and/or fluorescent signal were resected. The primary endpoints were the sensitivity, positive predictive value (PPV) and false negative (FN) rate of ICG in detecting SLN compared to 99mTc-nanocolloids.

RESULTS

Thirty patients were included and 99 SLN were identified in 43 groins. Compared to 99mTc-nanocolloids, ICG had a sensitivity of 80.8% (95% CI [72.6; 88.6%]), a PPV of 96.2% (95% CI [91.8; 100%]) and a FN rate of 19.1% in detecting SLN. Seventeen (17.1%) infiltrated (positive) SLN were identified out of the 99 SLN detected. Compared to 99mTc-nanocolloids, ICG showed a sensitivity of 82.3% (95% CI [73.1; 91.5%]), a PPV of 100% and a FN rate of 17.6% (3/17) in detecting infiltrated SLN.

CONCLUSION

Despite its many advantages, ICG cannot be used as the sole tracer for the detection of SLN in early vulvar cancer and should be employed in conjunction with 99mTc-nanocolloids.

[Reporting and handling of lymphonodectomy specimens in gynecologic malignancies and sentinel lymph nodes]

Die Aufarbeitung von Lymphonodektomiepräparaten gynäkologischer Malignome orientiert sich an den nationalen AWMF-Leitlinien und internationalen Empfehlungen. Die Definition von Mikrometastasen und isolierten Tumorzellen entspricht den Festlegungen der UICC(Union Internationale Contre le Cancer)/TNM(TNM-Klassifikation maligner Tumoren). Deren Nachweis soll im Befundbericht erwähnt werden sowie in die Tumorklassifikation einfließen. Alle übersandten Lymphknoten (LK) sollen untersucht werden mit vollständiger Einbettung aller LK bis 0,3 cm und Lamellierung aller größeren Lymphknoten parallel zu ihrer kurzen Achse in ca. 0,2 cm dicken Scheiben. Bestandteile des histologischen Befundberichtes sind: Zahl der befallenen LK im Verhältnis zur Zahl der entfernten/untersuchten LK entsprechend der Entnahmelokalisationen, metrische Ausdehnung der größten LK-Metastase, Fehlen/Nachweis einer extrakapsulären Ausbreitung. Zuschnitt und Einbettung von Sentinel-LK mit oder ohne Schnellschnittuntersuchung erfolgt in Analogie zu Nicht-Sentinel-LK mit Anfertigung von ca. 3 HE-gefärbten Stufenschnitten in einem Abstand von ca. 200 µm sowohl vom Gefrier- als auch Paraffinblock. Stellen sich die Sentinel-LK in der HE-Färbung negativ dar, soll ein immunhistochemisches Ultrastaging erfolgen.

Use of the Sentinel Lymph Node Technique Compared to Complete Inguino-femoral Lymph Node Removal in Patients with Invasive Vulvar Cancer in Germany

In the current S2 guidelines, the standard surgical therapy for patients with vulvar cancer also includes inguino-femoral lymphadenectomy. However, in view of the severe side-effects associated with this approach such as problems with wound healing, lymphoceles and lymphoedema, the search is on for alternative treatments that could decrease treatment-associated morbidity and improve patients' quality of life, particularly for node-negative patients. The sentinel lymph node technique is currently the gold standard in the treatment of unifocal breast cancer (clinically negative axilla), and studies on the use of this technique in the treatment of vulvar cancer are promising. To date, the diagnostic accuracy of this method in vulvar cancer has only been evaluated in a single, one-arm, non-randomised, multicentre study. In preparation for a multicentre study, in 2010 we surveyed 41 German hospitals to investigate how often they used the sentinel lymph node technique compared to inguino-femoral lymphadenectomy. The hospitals were grouped according to hospital size and number of patients treated for vulvar cancer. The decision criteria to determine the type of procedure performed were also investigated. Finally, the hospitals were asked whether they would be willing to participate in a prospective clinical study to evaluate the sentinel lymph node technique in patients with vulvar cancer. The majority of surgeons questioned (73 %) already had some experience with this technique in patients with vulvar cancer. In our survey, 27 % of hospitals carried out inguino-femoral lymphadenectomy, 10 % used the sentinel lymph node technique, and 63 % used both methods. In 24 % of hospitals, the standard procedure consisted of the sentinel lymph node technique supplemented by inguino-femoral lymphadenectomy. Only 20 % of the institutions surveyed in our study carried out sentinel lymph node biopsy alone in accordance with the criteria of the consensus recommendations. The majority of the investigated institutions were willing to participate in a randomised prospective clinical study to evaluate the effectiveness of sentinel lymph node sampling in patients with vulvar cancer.

New FIGO staging system of vulvar cancer indeed provides a better reflection of prognosis

OBJECTIVE

To find out whether the new FIGO staging system (introduced 2009) indeed leads to a more specific prediction of the survival for patients with vulvar SCC.

METHODS

A retrospective study of 269 patients with vulvar SCC from 1988 to 2009. All patients were staged according the old and revised FIGO staging system by histopathological data. Overall survival (OS) and disease specific survival (DSS) were calculated.

RESULTS

Of all 269 patients, a total number of 113 patients (42.4%) was restaged according to the new FIGO staging, mainly downstaged. In patients with negative nodes, tumor size was not predictive for OS (p = 0.475) and DSS (p = 0.915). Patients of old FIGO stage III and negative node status showed no difference in survival with the group mentioned above (OS p = 0.105 and DSS p = 0.743, respectively). An increasing number of positive lymph nodes (range 1-9) led to a decrease in survival in OS and DSS (p = 0.022 and p = 0.004 respectively). When corrected for the number of positive nodes, there was no difference in survival between patients with unilateral or bilateral lymph nodes. In patients with positive nodes, extranodal growth showed a significant worse survival compared to patients without extranodal growth (OS p < 0.001 and DSS p = 0.004).

CONCLUSION

The new FIGO staging system provides indeed a better reflection of prognosis for patients with vulvar SCC. An accurate description of clinical and histopathological data combined with information about which FIGO classification has been used is necessary to interpret the literature correctly and to keep the possibility to compare data of different studies.

The role of sentinel node biopsy in gynecological cancer: a review

PURPOSE OF REVIEW

In early-stage vulvar, cervical and endometrial cancer, lymph node status is the most important prognostic factor. Surgical treatment is aimed at removing the primary tumor and adequately staging the regional lymph nodes. As morbidity of regional lymphadenectomy is high, sentinel node biopsy is a technique with potential for adequate staging with less treatment-related morbidity. This manuscript reviews its current role in vulvar, cervical and endometrial cancer.

RECENT FINDINGS

In early-stage vulvar cancer, level 3 evidence indicates that it appears to be safe to omit inguinofemoral lymphadenectomy in case of a negative sentinel node. However, false-negative results with fatal consequences do occur and are often attributable to procedural failures. For early-stage cervical cancer, level 3 evidence points to an acceptable false-negative rate of a negative sentinel node; clinical utility and safety remain to be established. The optimal technique of the sentinel node biopsy in endometrial cancer is currently unclear.

SUMMARY

In early-stage vulvar cancer, data suggest that sentinel node biopsy could be offered as a treatment option instead of routine inguinofemoral lymphadenectomy. However, more (long-term follow-up) data are needed to further appreciate real clinical benefits. It is emphasized that the procedure should be performed by a skilled multidisciplinary team, centralized in oncology centers and preferably within the protection of clinical trials. For cervical cancer, data are promising, but routine application cannot be recommended due to lack of data on clinical utility and safety. For endometrial cancer, studies on the sentinel node biopsy are still in feasibility stage.