Validation and update of a lymph node metastasis prediction model for breast cancer.

PURPOSE: This study aimed to validate and update a model for predicting the risk of axillary lymph node (ALN) metastasis for assisting clinical decision-making. METHODS: We included breast cancer patients diagnosed at six Dutch hospitals between 2011 and 2015 to validate the original model which includes six variables: clinical tumor size, tumor grade, estrogen receptor status, lymph node longest axis, cortical thickness and hilum status as detected by ultrasonography. Subsequently, we updated the original model using generalized linear model (GLM) tree analysis and by adjusting its intercept and slope. The area under the receiver operator characteristic curve (AUC) and calibration curve were used to assess the original and updated models. Clinical usefulness of the model was evaluated by false-negative rates (FNRs) at different cut-off points for the predictive probability. RESULTS: Data from 1416 patients were analyzed. The AUC for the original model was 0.774. Patients were classified into four risk groups by GLM analysis, for which four updated models were created. The AUC for the updated models was 0.812. The calibration curves showed that the updated model predictions were better in agreement with actual observations than the original model predictions. FNRs of the updated models were lower than the preset 10% at all cut-off points when the predictive probability was less than 12.0%. CONCLUSIONS: The original model showed good performance in the Dutch validation population. The updated models resulted in more accurate ALN metastasis prediction and could be useful preoperative tools in selecting low-risk patients for omission of axillary surgery.

Rationale for superficial injection techniques in lymphatic mapping in breast cancer patients.

One of the most avidly debated issues in lymphatic mapping is where the tracers are best deposited in patients with breast cancer. The four superficial approaches are easy to perform and have several other distinct advantages. They are based on the hypothesis that the entire breast parenchyma and the overlying skin drain to a common node in the axilla because of their common embryological origin. Evidence is presented that casts doubt upon the correctness of this assumption. Tracer administration close to the tumor site appears to be the safest approach for the time being. Excellent results can be obtained with this latter approach, despite the fact that it is technically more demanding.

What is a sentinel node and what is a false-negative sentinel node?

Morton's original definition of a sentinel node as the first lymph node to receive afferent lymphatic drainage from a primary tumor reflects the concept of stepwise spread of cancer through the lymphatic system. Several new definitions have been developed, based on surgical anatomy and on the technique that is used to find the node. The various definitions of a sentinel node are critically analyzed. Breast cancer surgeons use three different definitions of a false-negative sentinel node biopsy. The best definition appears to be based on the assumption that the procedure is truly positive if either the sentinel node or a suspicious node that is not radioactive or blue contains metastatic disease.

Lymphatic drainage patterns from the breast.

OBJECTIVES: The aim of this study was to describe the lymphatic drainage patterns from the 5 "quadrants" of the breast. SUMMARY BACKGROUND DATA: Lymphatic mapping has provided techniques to visualize and harvest sentinel nodes in various locations and has generated renewed interest in nodes outside the axilla. METHODS: Between January 1997 and June 2002, 700 sentinel node procedures were performed in patients with cN0 breast cancer. Preoperative lymphoscintigraphy was performed after injection of 99mTc-nanocolloid into the tumor in a volume of 0.2 mL and a mean dose of 107.7 MBq (2.8 mCi). Intraoperatively, the sentinel node was pursued with the aid of a gamma-ray detection probe and patent blue dye (1.0 mL, into the lesion). The patients were divided into 5 groups according to the location of the primary breast cancer. In each group, a distinction was made between palpable and nonpalpable lesions of the breast. RESULTS: Drainage to either an axillary or an extra-axillary basin was observed in 678 patients. Both palpable and nonpalpable lesions may drain toward the internal mammary chain, although the latter more frequently, regardless of the quadrant. Drainage was also observed to supraclavicular, infraclavicular, interpectoral, and intramammary sentinel nodes. CONCLUSION: In each quadrant, a breast cancer may drain to sentinel nodes in various locations. There is a distinct difference in drainage patterns between palpable and nonpalpable lesions. These findings may improve the assessment of lymphatic dissemination in invasive breast cancer.

Should the hunt for internal mammary chain sentinel nodes begin? An evaluation of 150 breast cancer patients.

BACKGROUND: The aim of this study was to determine the visualization rate, identification rate, and clinical implications of biopsy of sentinel nodes in the internal mammary chain (IMC) in patients with breast cancer. METHODS: From January 1999 to December 2002, 691 sentinel node procedures were performed. Preoperative lymphoscintigraphy was performed after injection of (99m)Tc-labeled nanocolloid into the tumor (.2 mL; 115 MBq; 3.1 mCi). The sentinel node was surgically identified with the aid of patent blue dye and a gamma ray detection probe. RESULTS: The sentinel node in the IMC could be harvested in 130 (87%) of the 150 patients in whom it was visualized on the images and contained metastases in 22 (17%) of these 130 cases. In nine patients (7%), the IMC sentinel node was tumor positive, whereas the axilla was tumor-free. Stage migration was seen in all patients with a tumor-positive IMC sentinel node (17%). There was a change of management in 38 (29%) of the 130 patients: institution or omission of radiotherapy to the IMC, adjuvant systemic therapy, or omission of an axillary lymph node dissection. CONCLUSIONS: Pursuit of IMC sentinel nodes improves the staging of patients with breast cancer and enables treatment to be better adjusted to the needs of the individual patient.

Review and evaluation of sentinel node procedures in 250 melanoma patients with a median follow-up of 6 years.

BACKGROUND: The aim of this study was to evaluate the results of sentinel node biopsy in cutaneous melanoma at our institute. METHODS: A total of 250 patients with cutaneous melanoma were studied prospectively. Preoperative lymphoscintigraphy was performed after injection of (99m)Tc-nanocolloid intradermally around the primary tumor or biopsy site (.32 mL, 65.5 MBq [1.8 mCi]). The sentinel node was surgically identified with the aid of patent blue dye and a gamma ray detection probe. The median follow-up was 72 months. RESULTS: Lymphoscintigraphic visualization was 100%, and surgical identification was 99.6%. In 60 patients (24%), 1 or more sentinel nodes were tumor positive at initial pathology evaluation. Late complications after sentinel node biopsy of the remaining 190 patients were seen in 35 patients (18%). The false-negative rate was 9%. In-transit metastases were seen in 7% of sentinel node-negative and 23% of sentinel node-positive patients. The estimated 5-year overall survival rates were 89% and 64%, respectively (P <.001). CONCLUSIONS: This study confirms that the status of the sentinel node is a strong independent prognostic factor. The false-negative rate and the incidence of in-transit metastases in sentinel node-positive patients are high and have to be weighed against the possible survival benefit of early removal of nodal metastases.

Intratumoral versus intraparenchymal injection technique for lymphoscintigraphy in breast cancer.

A 1.5-cm nonpalpable mass was detected in the upper outer quadrant of the left breast by screening mammography in a 55-year-old woman. The patient was scheduled for a sentinel node procedure, and lymphoscintigraphy was performed the day before surgery. Unintentionally, she received an intraparenchymal tracer injection 3 cm away from the malignant lesion instead of the intended intratumoral injection. Lymphoscintigraphy revealed two sentinel nodes in the axilla. A second dose of Tc-99m nanocolloid was injected the next day into the primary tumor through a catheter that had been inserted under ultrasound guidance the previous day. Once more, a lymphoscintigraphic image was obtained that showed additional sentinel nodes in two different regions outside the axilla. This observation supports the authors' contention that lymphatic watersheds exist in the breast and highlights the importance of tracer administration into or close to the tumor.

Metastatic patterns of extremity myxoid liposarcoma and their outcome.

BACKGROUND AND OBJECTIVES: Extremity myxoid liposarcomas have a unique extrapulmonary metastatic potential. We studied the metastatic pattern of extremity liposarcomas to determine what types of posttreatment imaging may be of value in the follow-up these patients. METHODS: Twenty-two patients from a total of 128 patients with primary extremity liposarcoma were treated at a tertiary care institution for subsequent metastases from January 1981 to January 2000. Median follow-up was 45 months (range: 6-270 months). Data on these patients was prospectively collected and then retrospectively analyzed for effect of metastatic pattern and treatment on outcome. RESULTS: Of these 22 patients, extrapulmonary metastases developed in 10, combined pulmonary and extrapulmonary metastases developed in 6, and isolated pulmonary metastases developed in 6. Of the 16 patients with extrapulmonary metastases, 13 were of the myxoid subtype. Of the 49 patients with extremity myxoid liposarcomas, metastases developed in 14 (29%). The most common sites of metastases among these 14 patients include: the retroperitoneum, 10 patients (71)%; intra-abdominal extra-hepatic, 7 patients (50%); spinal/paraspinal, 6 patients (43%). Only 3 of the patients are alive and disease free and all 3 of these patients are from the subgroup of 10 patients with only extra-pulmonary metastases (2 intra-abdominal and 1 retroperitoneal). CONCLUSIONS: Extremity myxoid liposarcomas have an unusually high predilection for extra-pulmonary metastases, frequently without any pulmonary metastases. After treatment of the primary tumor, these patients should be followed with periodic chest X-ray and abdominal/pelvic computed tomography (CT) scans. Any back or neurologic complaints should prompt additional imaging of the appropriate spinal area. Consideration should be given to surgical and adjuvant treatment of metastatic disease when appropriate.