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Background: Accurate intraoperative pathologic examination of sentinel lymph nodes (SLNs) has been an important tool that can reduce the need for reoperations in patients with SLN-positive breast cancer. The objective of the current study was to determine the accuracy of intraoperative frozen section (IFS) of SLNs during breast cancer surgery., Methods: The authors retrospectively reviewed the records of 326 patients with breast cancer who underwent IF analysis of SLNs at a single institution. Then, they conducted a meta-analysis that included 47 published studies of IFS of SLNs in patients with breast cancer., Results: Hematoxylin and eosin (H&E) staining revealed metastasis in SLNs in 99 patients (30.4%), including 61 patients with macrometastasis (MAM) (>2 mm) (the MAM group) and 38 patients with micrometastasis (Mi) or isolated tumor cell (ITC) deposits (the Mi/ITC group). The overall sensitivity of the institutional series was 60.6% (60 of 99 patients), and overall specificity was 100% (227 of 227 true negatives). The sensitivity of IFS was significantly lower in the Mi/ITC group (28.9%) than in the MAM group (80.3%; P < .0001). According to the meta-analysis of published studies and data from the author's institution (47 studies, for a total of 13,062 patients who underwent SLN dissection with IFS of SLNs), the mean sensitivity was 73%, and the mean specificity was 100%. The mean sensitivity was 94% for the MAM group and 40% for the Mi/ITC group., Conclusions: IFS of SLNs was more reliable for detecting MAM than for detecting Mi/ITC deposits. It lacked sufficient accuracy to rule out Mi/ITC deposits., (Copyright © 2010 American Cancer Society.)

Nonsentinel lymph nodes (SLNs) are commonly removed at the time of selective sentinel lymphadenectomy (SSL). Their predictive value for the rest of the nodal basin is unknown. A retrospective review of 436 breast cancer patients who underwent SSL between 12/97 and 04/03 at a single institution. One-hundred nineteen patients had non-SLNs removed at SSL; eight were positive (6.7%). Positive non-SLNs predicted that SLNs would also be positive (p = 0.008). There was no difference in rates of additional positive nodes found on completion axillary node dissection between the non-SLN and SLN positive patients (p = 0.62). After adjustment for covariates, the presence of positive non-SLNs was not associated with poorer disease free survival (p = 0.24), time to systemic recurrence (p = 0.57), or overall survival (p = 0.70). Positive non-SLNs removed during SSL are not a significant risk factor for additional positive nodes on completion axillary nodal dissection (CALND) or for worse survival than positive SLNs.

Background: No consensus exists about the number of sentinel lymph nodes (SLNs) that should be removed based on radioactivity counts in breast cancer, although the "10% rule" is often used. We hypothesized that the node with the highest radioactivity would have the strongest probability of being a positive SLN, and we sought to determine the lowest radioactive count of a node harboring cancer., Study Design: We retrospectively studied 332 breast cancer patients who underwent lymphoscintigraphy by injection of technetium 99m-labeled thiosulfate colloid and sentinel lymphadenectomy (SL) between 1997 and 2006, with intraoperative determination of radioactive counts of nodes by a gamma probe. All SLNs were examined by permanent sections consisting of at least 3 levels of 40- to 100-mum intervals for hematoxylin and eosin evaluation, with or without immunohistochemical staining for cytokeratins., Results: Seventy-four percent of patients had more than 1 SLN removed (mean 2.8 per patient); 23.5% had SLN metastasis. Of the node-positive patients, the hottest SLN was positive in 85.9% (67 of 78). Five of the 78 patients (6.4%) with positive nodes had counts less than 10% of those of the hottest node. The lowest radioactive count of a positive SLN was 4.2% of that of the hottest node. Lymphatic mapping based on the 10% rule could greatly improve the false-negative rates compared with removing only the hottest SLN (14.1% versus 6.4%)., Conclusions: Most positive SLNs had the highest radioactivity. Our institutional experience indicates that to obtain an acceptable false-negative rate, nodes should be removed until the 10% rule is met.

Sentinel lymph node biopsy (SLNB) has become an acceptable alternative to complete axillary dissection to determine whether breast cancer has spread to axillary lymph nodes. Yet the best method for pathologic examination of the sentinel lymph node (SLN) remains controversial. For years there has been speculation that micrometastases in axillary lymph nodes were clinically insignificant and thus lymph nodes did not require sectioning at close intervals. Yet essentially all studies, including a recent large prospective study, have found a significantly poorer prognosis associated even with metastases less than 2 mm in size-the most common definition of micrometastasis-suggesting that such small metastases cannot be safely overlooked. The use of immunohistochemistry (IHC) to detect keratin proteins will reveal metastatic breast carcinoma in about 18% of axillary lymph nodes that appear negative on routine stains. The preponderance of evidence to date suggests a significantly poorer prognosis in patients with such occult metastases, although data from large prospective studies are lacking. Molecular techniques such as polymerase chain reaction (PCR) offer even more sensitive methods for detecting occult metastasis in SLNs, although false positives are a particular problem in techniques that do not permit morphologic correlation, and for now they remain a research tool. Intraoperative examination of the SLN permits a completion axillary dissection to be performed during the same procedure if metastatic tumor is found; however, intraoperative techniques such as cytologic examination and frozen section lack sensitivity, and can result in loss of up to 50% of the SLN tissue. A proposal for optimal pathologic examination of the SLN is offered based on the above data.

Selective sentinel lymphadenectomy (SSL) is rapidly becoming the standard of care in the surgical management of patients with early breast cancer. Sentinel lymph node macrometastasis has been well documented in the literature to have a higher risk of nonsentinel node tumor involvement when compared to micrometastasis. The aim of our study was to determine the primary tumor characteristics associated with sentinel node macrometastasis that will allow us to preoperatively determine this subgroup of patients at risk. This study was a retrospective review of 644 patients who underwent successful SSL as part of their surgical treatment of breast cancer at the University of California San Francisco Carol Franc Buck Breast Care Center from November 1997 to August 2003. All patients underwent preoperative lymphoscintigraphy followed by wide excision or mastectomy and sentinel lymphadenectomy with or without axillary lymph node dissection. One hundred twenty-two patients had positive sentinel nodes on histology. Micrometastasis was present in 43 of these patients and macrometastasis in the remaining 79. Statistical analysis showed that a tumor size greater than 15 mm, poor tubule formation by the tumor cells, and lymphovascular invasion were significantly associated with sentinel node macrometastasis. A high mitotic count showed a trend but was not significant in our study. Patients with a tumor size greater than 15 mm, poor tubule formation, and lymphovascular invasion are at risk of having sentinel node macrometastasis. These patients can be identified preoperatively based on imaging and biopsy criteria, allowing the option of selective intraoperative pathologic evaluation of the sentinel node and immediate completion axillary dissection as necessary.

Background: Routine axillary lymph node dissection (ALND) after selective sentinel lymphadenectomy (SSL) in the treatment of breast cancer remains controversial. We sought to determine the need for routine ALND by exploring the relationship between sentinel lymph node (SLN) and non-SLN (NSLN) status. We also report our experience with disease relapse in the era of SSL and attempt to correlate this with SLN tumor burden., Methods: This was a retrospective study of 390 patients with invasive breast cancer treated at a single institution who underwent successful SSL from November 1997 to November 2002., Results: Of the 390 patients, 115 received both SSL and ALND. The percentage of additional positive NSLNs in the SLN-positive group (34.2%) was significantly higher than in the SLN-negative group (5.1%; P = .0004). The SLN macrometastasis group had a significantly higher rate of positive NSLNs (39.7%) compared with the SLN-negative group (5.1%; P = .0001). Sixteen patients developed recurrences during follow-up, including 6.1% of SLN-positive and 3.3% of SLN-negative patients. Among the SLN macrometastasis group, 8.7% had recurrence, compared with 2.2% of SLN micrometastases over a median follow-up period of 31.1 months. One regional failure developed out of 38 SLN-positive patients who did not undergo ALND., Conclusions: ALND is recommended for patients with SLN macrometastasis because of a significantly higher incidence of positive NSLNs. Higher recurrence rates are also seen in these patients. However, the role of routine ALND in patients with a low SLN tumor burden remains to be further determined by prospective randomized trials.

Selective sentinel lymphadenectomy (SSL) has replaced axillary lymph node dissection (ALND) for many patients with early breast cancer and negative sentinel lymph nodes (SLNs). Yet many patients with a positive SLN are undergoing unnecessary ALND, as no further disease is found in the axilla. The aim of our study was to determine factors associated with additional positive lymph nodes in the axilla in patients who have a positive SLN. This was a retrospective study of patients undergoing SSL with ALND as part of their treatment for breast cancer at a single institution from November 1997 to August 2003. Only patients with one or more positive SLNs were selected for this study. There were 86 patients who fit our study criteria. Of these, 38% had further positive lymph nodes upon ALND. More than one positive SLN and a ratio of positive SLNs to total SLNs of greater than 0.5 were found to be predictors for additional axillary nodal involvement in both univariate and multivariate analyses. The number of positive SLNs and the ratio of positive SLNs to total SLNs is an indication of total tumor burden in the sentinel nodes and may be a reflection of the propensity of the tumor for further lymphatic invasion in the axillary basin.

Background: The propensity for spindle cell melanoma to metastasize to the lymph node is relatively low despite its relative thick depth. To date, there are no published reports on the sentinel lymph node (SLN) status in patients diagnosed with spindle cell melanoma and desmoplastic malignant melanoma (DMM)., Objective: Our purpose was to report our experience on the SLN status in spindle cell melanoma and DMM., Methods: We undertook a retrospective database and medical record review from Oct 21, 1993 to Sept 29, 1999. At the University of California at San Francisco Melanoma Center, patients with tumor thickness greater than 1 mm or less than 1 mm with high-risk features are managed with preoperative lymphoscintigraphy, selective SLN dissection, and wide excision., Results: Of 29 patients diagnosed with spindle cell melanoma and DMM, 28 had negative SLNs and are free of disease except for one patient who experienced splenic, bony, and brain metastases. The mean follow-up in this population was 16.5 and 11 months, respectively., Conclusion: Our preliminary findings show that SLNs from patients diagnosed with spindle cell melanoma and DMM only rarely harbor micrometastasis despite their relative thickness. A larger number of cases from multicenter databases may further define the true biology of SLNs in this melanoma variant.

The development of the sentinel lymph node concept has had a revolutionary effect on the way radical cancer surgery is viewed. The selective excision of the sentinel node alone has been proposed as an alternative to complete regional lymphadenectomy. This article addresses the sentinel lymph node hypothesis and the role of pathologic analysis, radiation safety, intraoperative and postoperative assessment, pathologic analysis in prognosis, and polymerase chain reaction-based studies.

Although the role of axillary lymph node dissection is controversial with respect to survival benefits, its role as a staging procedure has been well established since nodal involvement is the most reliable prognostic indicator for patients with breast cancer. Selective sentinel lymph node (SLN) dissection is gaining acceptance as a useful staging procedure because it is minimally invasive and spares approximately 70-80% of the patients a more extensive axillary lymph node dissection. The evolving techniques for selective SLN dissection using blue dye and radiotracer methods are reviewed in this article. Based on the classic definition of the breast lymphatic drainage and recently published articles addressing the issue of peritumoral and intradermal injections, a possible new and simplified approach using intradermal injection may identify the axillary SLN more quickly and reliably. This article emphasizes the importance of a multidisciplinary approach in the identification of SLNs by preoperative lymphoscintigraphy performed by expert nuclear medicine physicians, the intraoperative mapping and harvesting of SLNs by well trained surgeons and the meticulous examination of SLNs by experienced pathologists. Therefore, to achieve the highest rate of accuracy regarding SLN status, it is imperative that a multidisciplinary team with close communication and cooperation be formed. The clinical significance of SLNs will be determined by results from follow-up and clinical trials.