Non-sentinel lymph node metastases in breast cancer patients with a positive sentinel lymph node: validation of five nomograms and development of a new predictive model.

AIMS AND BACKGROUND: Discordance of intraoperative analysis with definitive histology of the sentinel lymph node in breast cancer leads to completion axillary lymph node dissection, which only in 35-50% shows additional nodal metastases. The aim of the study was to identify individual patient risk for non-sentinel lymph node metastases by validating several statistical methods present in the recent literature and by developing a new tool with the final goal of avoiding unnecessary completion axillary lymph node dissection. METHODS: We retrospectively evaluated 593 primary breast cancer patients. Completion axillary lymph node dissection was performed in 139 with a positive sentinel lymph node. The predictive accuracy of five published nomograms (MSKCC, Tenon, Cambridge, Stanford and Gur) was measured by the area under the receiver operating characteristic curve. We then developed a new logistic regression model to compare performance. Our model was validated by the leave-one-out cross-validation method. RESULTS: In 53 cases (38%), we found at least one metastatic non-sentinel lymph node. All the selected nomograms showed values greater than the 0.70 threshold, and our model reported a value of 0.77 (confidence interval = 0.69-0.86 and error rate = 0.28) and 0.72 (confidence interval = 0.63-0.81, error rate = 0.28) after the validation. With a 5% cutoff value, sensitivity was 98% and specificity 9%, for a cutoff of 10%, 96% and 2%, respectively. CONCLUSIONS: All the nomograms were good discriminators, but the alternative developed model showed the best predictive accuracy in this Italian breast cancer sample. We still confirm that these models, very accurate in the institution of origin, require a new validation if used on other populations of patients.

Is complete axillary dissection necessary for all patients with positive findings on sentinel lymph node biopsy? Validation of a breast cancer nomogram for predicting the likelihood of a non-sentinel lymph node.

AIM AND BACKGROUND: Axillary dissection in patients positive for sentinel lymph nodes is currently under discussion in the literature, since approximately only 50% of such patients has metastases in the remaining lymph nodes. To identify patients at risk for non-sentinel lymph nodes metastases, a nomogram was developed by the Breast Service of the Memorial Sloan-Kettering Cancer Center. The aim of this study was to assess the nomogram's predictive accuracy in a population of Italian breast cancer patients in our hospital. MATERIALS AND METHODS: The system of calculation used as variables prognostic factors of breast cancer: pathologic size, tumor type and nuclear grade, lymphovascular invasion, multifocality, estrogen receptor status, method of detection of the sentinel lymph nodes metastases (frozen section, serial hematoxylin-eosin, routine hematoxylin-eosin, and immunohistochemistry), number of positive and number of negative sentinel lymph nodes. RESULTS AND CONCLUSIONS: To measure the discrimination of the nomogram, a receiver-operating characteristic curve was construed, and the area under the curve was calculated. However, the area under the curve was 0.72, a very high value considering that the limit of acceptability is 0.70-0.80. The calculation system developed by the Memorial Sloan-Kettering Cancer Center provides a predictive value on the histopathologic state of sentinel lymph nodes.

High-resolution, hand-held camera for sentinel-node detection.

BACKGROUND: The imaging probe (IP) is a high-resolution (HR), 1-in(2) field-of-view hand-held gamma camera. We used it to detect breast cancer sentinel node (SN). PATIENTS AND METHODS: We divided 120 T1 breast cancer patients, who underwent Anger camera lymphoscintigraphy (ACL), in two subgroups of 60 patients who were age, body mass index, and cancer size matched: subgroup A (SA) and B (SB). SN was detected with a common gamma probe (GP) in SA, with IP plus GP in SB. RESULTS: Surgeons removed radioactive nodes without exceeding four nodes. Eighty-two (82) SNs were taken off in SA and 105 in SB (p<0.01). Of SA, 22 of 60 patients and 36 of 60 patients of SB showed more than 1 node, and 3 of them showed 3 nodes and 1 showed 4 nodes. Thirteen (13) patients resulted N(+) (21.6%) in SA. Ten (10) patients of SA showed an invasion on the hottest nodes and 3 on the second nodes. In the SB, 18 patients (25%) showed invasion. Sixteen (16) invasions were on hot, 4 on second, and 1 on the third node. Withdrawal time of SN was 11.25+/-4.7 minutes for SA and 7.4+/-2.8 minutes for SB (p<0.025). CONCLUSIONS: SN biopsy with IP is fast and discovers more SNs and more invasions than ACL.