[Comparison of three models to predict non-sentinel lymph node status in breast cancer patients with metastatic sentinel lymph nodes: a retrospective study of 77 patients]

Various statistic predictive models have been developed to predict the status of the non-sentinel lymph nodes (NSLN) when the sentinel one was invaded by tumor cells in the case of breast invasive carcinoma. The objective of this study was to compare the accuracy of three of these statistic models: the MSKCC nomogram, the Tenon score and the MDA score. The study was conducted at Croix Rousse Hospital, Lyon, France.

OBJECTIVE

When sentinel lymph node is invaded by metastasis, complete lymph node dissection of the axilla can be avoided using statistic predictive models especially when talking about micrometastases and moreover about isolated tumor cells in the sentinel lymph node. Over the different existing models, we tested the three most used ones to determine the model that is most adapted to our everyday practice.

METHOD

The study population consisted of 77 women with an invasive breast cancer treated by complete axillary lymph node dissection for metastatic sentinel lymph node. Over the nine models already published, we focused on three of them due to their ease to use as well as their good preliminary results: the Memorial Sloan-Kettering Cancer Center nomogram (MSKCC), the Tenon score and the M.D Anderson score (MDA). Different criteria are used by these models, but all of them take in consideration: tumor size, multifocality, tumor type, lymphovascular invasion, hormonal receptors, number of sentinel lymph node resected, degree of sentinel lymph node invasion (i.e. macrometastasis, micrometastasis or isolated tumor cells) and histologic method used to diagnose sentinel lymph node invasion. These scores are validated depending on their false negative ratio as well as the proportion of patient selected as having a low risk of non-sentinel lymph node invasion. The major criterion for the MSKCC score is the calibration that compares the predicted likelihood of invasion and the histologically proved one.

RESULTS

The rate of non-sentinel lymph node invasion was 37.6%. The discrimination of the three models was good with an AUC of 0.74 for both MSKCC nomogram and Tenon score and of 0.72% for MDA score. MSKCC nomogram was well calibrated (P=0.23). The false negative ratio was 0 (CI 95%: 0-18.1%) for MSKCC nomogram, 16.7% (CI 95%: 8.6%-27.8%) for Tenon score and 16% (CI 95%: 6.8-31%) for MDA score. The percentage of patients considered as having a low risk of invasion of the non-sentinel lymph node was 20.5% for MSKCC nomogram, 34.7% for MDA score and 47.4% for Tenon score.

CONCLUSION

MSKCC nomogram seems to be the statistic model that is most adapted to the population we studied. To validate the Tenon and MDA score, we should have a most important population.

Keeping Data Continuous when Analyzing the Prognostic Impact of a Tumor Marker: An Example with Cathepsin D in Breast Cancer

The prognostic value of cathepsin D has been recently recognized, but as many quantitative tumor markers, its clinical use remains unclear partly because of methodological issues in defining cut-off values. Guidelines have been proposed for analyzing quantitative prognostic factors, underlining the need for keeping data continuous, instead of categorizing them. Flexible approaches, parametric and non-parametric, have been proposed in order to improve the knowledge of the functional form relating a continuous factor to the risk. We studied the prognostic value of cathepsin D in a retrospective hospital cohort of 771 patients with breast cancer, and focused our overall survival analysis, based on the Cox regression, on two flexible approaches: smoothing splines and fractional polynomials. We also determined a cut-off value from the maximum likelihood estimate of a threshold model. These different approaches complemented each other for (1) identifying the functional form relating cathepsin D to the risk, and obtaining a cut-off value and (2) optimizing the adjustment for complex covariate like age at diagnosis in the final multivariate Cox model. We found a significant increase in the death rate, reaching 70% with a doubling of the level of cathepsin D, after the threshold of 37.5 pmol mg(-1). The proper prognostic impact of this marker could be confirmed and a methodology providing appropriate ways to use markers in clinical practice was proposed.

[Complete remission after abdominal wall metastasis from uterine cervical cancer on a laparoscopic trochar site: a case report]

Abdominal wall metastasis to laparoscopic trochar sites after preoperative staging procedure is rare for uterine cervix cancer. Prognosis is unfavorable. We report a case of metastasis to a laparoscopic trochar site in a patient with a stage IIB cervical cancer with no nodal involvement who is alive four and a half years after radical surgery and radiotherapy.