Sentinel lymph nodes

Negative sentinel lymph node accurately predicts negative status of pelvic lymph nodes in uterine cervix carcinoma

OBJECTIVE

The significance of negative sentinel lymph nodes (SLN) is important in the staging and treatment of melanoma and a few other cancers, but is controversial in uterine cervix carcinoma. Our study was aimed at correlating the SLN status in cervical carcinoma with non-sentinel lymph nodes (non-SLN), in a uniform and well controlled population.

METHODS

This study includes 36 patients with stage I and IIA cervical carcinoma and bilaterally negative SLN on final pathology. SLN were identified using blue dye and radioisotopic techniques. Frozen section examination was performed for all SLN; the rest of the tissue was formalin fixed and paraffin embedded. The protocol used for SLN was also applied for non-SLN. For each block, six 4-micro m thick sections were cut at 40 micro m intervals and stained with H and E; an additional section taken between the 3rd and 4th levels was imunostained using AE1/AE3 cytokeratin.

RESULTS

The mean age for the study population was 39 years (range 25-76); the number of SLN ranged from 2 to 6 (mean 2.7) and the non-SLN from 8 to 49 (mean 23) per case. No metastasis was found in any SLN and non-SLN by step sections and IHC.

CONCLUSION

Our study demonstrates that bilaterally negative SLN on final pathology accurately predict the absence of metastases in non-SLN in cervical carcinoma. If confirmed by larger trials, these results may influence the clinical management of early cervical cancer.

Sentinel lymph node biopsy is not accurate in predicting lymph node status for patients with cervical carcinoma

BACKGROUND

The authors evaluated the accuracy of sentinel lymph node biopsy in predicting lymph node status for patients with early cervical carcinoma. In particular, the authors set out to determine the false-negative rate associated with sentinel lymph node biopsy in this setting.

METHODS

Twenty-nine consecutive patients with early cervical carcinoma who were treated with pelvic laparoscopic lymphadenectomy and radical surgery underwent sentinel lymph node biopsy following lymphatic mapping with patent blue dye. All sentinel and nonsentinel lymph nodes were evaluated for micrometastases via multilevel sectioning followed by immunohistochemical staining.

RESULTS

At least one sentinel lymph node was identified for each patient. On routine pathologic evaluation, 3 patients (10%) were found to have positive lymph nodes. Among the remaining 26 patients, multilevel sectioning in conjunction with immunohistochemical analysis identified 5 patients (19%) who had micrometastases in the pelvic lymph nodes. Two of these five patients had micrometastases in a sentinel lymph node; however, the more notable finding was that the other three patients had micrometastases in nonsentinel pelvic lymph nodes despite having negative findings on sentinel lymph node biopsy. Thus, the negative predictive value of sentinel lymph node biopsy in the current study was 87.5%.

CONCLUSIONS

Multilevel sectioning followed by cytokeratin immunohistochemistry may identify additional patients who have lymph node micrometastases; in the current study, this technique identified cases in which micrometastases were present in nonsentinel lymph nodes even when sentinel lymph nodes were found to be negative for disease on biopsy. This high false-negative rate associated with sentinel lymph node biopsy, raises questions regarding the validity of the sentinel lymph node concept in cervical carcinoma.