Treatment implications of a positive sentinel lymph node biopsy for patients with early-stage breast carcinoma

Radiation therapy and early breast cancer: current controversies

Radiation therapy (RT) is an important component of breast cancer treatment. RT reduces local recurrence and breast cancer mortality after breast conservation for all patients and for node-positive patients after a mastectomy. Short courses of RT over 3-4 weeks are generally as effective as longer courses. A patient subgroup where RT can be avoided after conservative surgery has not been consistently identified. A radiation boost reduces the risk of a recurrence in the breast but may be omitted for older patients with good prognosis tumours with clear margins. Axillary recurrences can take a long time to appear, with 35% occurring after 5 years. Leaving disease untreated in regional nodes is associated with reduced survival. Not all patients require radiation after neoadjuvant chemotherapy and a subsequent mastectomy. Modern RT equipment and techniques will further improve survival rates.

Trends in stage-specific breast cancer incidence in New South Wales, Australia: insights into the effects of 25 years of screening mammography

PURPOSE

Screening mammography aims to improve breast cancer (BC) prognosis by increasing the incidence of early-stage tumours in order to decrease the incidence of late-stage cancer, but no reports have investigated these potential effects in an Australian population. Therefore we aimed to identify temporal trends in stage-specific BC in New South Wales (NSW), Australia, between 1972 and 2012.

METHODS

An observational study of women who received a diagnosis of BC from 1972-2012 as recorded in the NSW Cancer Registry, a population-based registry with almost complete coverage and high rates of histological verification. We analysed trends in stage-specific incidence before screening and compared them to periods after screening began. Our primary group of interest was women in the target age range of 50-69 years, though trends in women outside the target age were also assessed.

RESULTS

Screening was not associated with lower incidence of late-stage BC at diagnosis. Incidence for all stages remained higher than prescreening levels. In women aged 50-69 years, the incidence of carcinoma in situ (CIS), localised and regional BC has more than doubled compared to the prescreening era, with incidence rate ratios ranging from 2.0 for regional (95% CI 1.95-2.13) to 121.8 for CIS (95% CI 82.58-179.72). Before the introduction of screening, there was a downward trend in distant metastatic BC incidence, and after the introduction of screening there was an increase (IRR 1.8; 95% CI 1.62-2.00). In women too young to screen the incidence of late-stage BC at diagnosis also increased, whereas localised disease was stable.

CONCLUSIONS

The incidence of all stages of BC has increased over the past 40 years, with the greatest rise seen during the established screening period for women aged 50-69 years. Our findings suggest that some of the expected benefits of screening may not have been realised and are consistent with overdiagnosis.

A new clinical cut-off of cytokeratin 19 mRNA copy number in sentinel lymph node better identifies patients eligible for axillary lymph node dissection in breast cancer

AIMS

Cytokeratin 19 (CK19) mRNA copy number predicts the probability of tumour load in axillary lymph nodes (ALN) and can help in decision-making regarding the axillary dissection. The purpose of this study was to define a new cut-off of CK19 mRNA copy number using the one-step nucleic acid amplification (OSNA) assay on metastatic sentinel lymph nodes (SLN) in order to identify cases at risk of having one or more positive ALN.

METHODS

1296 SLN from 1080 patients were analysed with the OSNA assay. 194 patients with positive SLN underwent ALN dissection and the mean value of CK19 copy number (320 000) of their SLN was set as initial cut-off. Receiver operative characteristics curve identify a best cut-off of 7700 (sensitivity 78%, specificity 57%). A comparison between our and the traditional cut-off (5000) was performed.

RESULTS

The cut-off of 7700 successfully identifies patients with positive ALN (p=0.001, false- negative cases: 17%). In the range between 5000 and 7700, one patient with positive ALN would not undergo axillary dissection, whereas eight patients with negative ALN would be correctly identified.

CONCLUSIONS

We suggest that the level of CK19 mRNA copy number could be the only parameter to consider in the intraoperative management of the axilla.

The impact of international guidelines on breast cancer management

SUMMARY In Europe, breast cancer is the most common type of cancer among women and has an annual incidence of 2000 new cases per 1,050,000. Over the past two decades, there has been a massive increase in breast cancer diagnosis, and the therapeutic strategies have changed with increasing knowledge. Most breast cancer programs are now integrated into either national or international cancer networks, and there has been a trend towards development of consensus conferences and guidelines. With this greater understanding and the publication of initial treatment guidelines in the latter half of the 1980s, there has been a reduction in associated mortality rates. Increased experience has led to vast changes in practice, requiring guidelines to constantly evolve with research findings. This leads one to question the concept of guidelines and their ability to be correct and up to date for the treatment of individual patients with breast cancer.

The location of small tumor deposits in the SLN predicts Non-SLN macrometastases in breast cancer patients

AIMS

The extent to which the location of micrometastases (MIC) or isolated tumor cells (ITC) in sentinel lymph nodes (SLNs) is correlated with the risk of downstream metastases is still unknown. This study examined this issue and compared the impact of MIC/ITC location with other established risk factors.

METHODS

Paraffin slides of SLNs with MIC/ITC-involvement obtained from 68 breast cancer patients were evaluated for MIC/ITC location, lesion size, and various SLN morphologic features. These parameters, together with demographic data and primary tumor characteristics, were analyzed using univariate and multivariate analysis to determine their association with the presence of downstream macrometastases in Non-SLN.

RESULTS

Eighteen of 68 patients with MIC (n=37) or ITC (n=31) had Non-SLN metastases. After multivariate analysis, the location of MIC/ITC in the SLN (parenchyma vs. sinus/vessel) had the strongest association with the presence of Non-SLN macrometastases (p<0.0001), followed by the pT-category (p=0.008). Sixteen of 18 patients with parenchymal involvement but only 2 of 31 without parenchymal involvement had Non-SLN macrometastases. The metric size of the primary tumor and the estrogen receptor status were significantly associated only on univariate analysis (p=0.041, 0.034), whereas the correlation to the size classification for tumor cell deposits (MIC vs. ITC) was not significant (p=0.077).

CONCLUSIONS

The results indicate that lesion location is an important predictor of Non-SLN-macrometastases. This finding may simplify the decision for axillary treatment in patients with small tumor deposits in the SLN.

Validation of clinical prediction rules for a low probability of nonsentinel and extensive lymph node involvement in breast cancer patients

BACKGROUND

Two recently developed clinical prediction rules aim to anticipate the lack of nonsentinel lymph node metastases and the involvement of less than 4 lymph nodes in breast cancer patients with positive sentinel lymph nodes (SLNs).

METHODS

The University of Louisville Breast SLN Study clinical prediction rules were validated on an independent set of SLN-positive patients with tumors < or = 15 mm.

RESULTS

The data on 475 and 473 patients, respectively, were used for the validation. The areas under the receiver operating characteristic curves were similar to the originals for both predictive tools (.70 and .76). The lowest score of 1 identified 5 of 7 patients with disease limited to the SLNs and 161 of 165 as having less than 4 involved lymph nodes.

CONCLUSIONS

A subset of patients with SLN-only involvement and less than 4 metastatic lymph nodes can probably be identified by means of the Louisville clinical prediction rules, but prediction of the lack of non-SLN metastasis seems less reliable.

Localization of the Sentinel Node of the Upper Outer Breast Quadrant in the Axillary Quadrants

BACKGROUND

Sentinel node (SN) biopsy is associated with much less morbidity than axillary dissection. In patients with early breast cancer, lymphatic mapping and SN biopsy accurately stage the axillary nodes. Both currently available lymphatic mapping agents, radiocolloid and blue dye, have some limitations that may make perioperative or preoperative SN identification difficult. In such cases, exact knowledge of the topography of the axilla and the most probable location of the SN may be crucial.

METHODS

In 12 fresh female cadavers with no history of breast carcinoma, injections of patent blue dye were used to visualize the SNs in the axillary quadrants and their lymphatic collectors from the upper outer quadrant of the breast, which is the most common location of breast cancer. The axilla was divided into quadrants with regard to the intersection of the thoracoepigastric vein and the third intercostobrachial nerve.

RESULTS

All SNs were located within a circle of 2-cm radius of this intersection in the fatty tissue at the clavipectoral fascia. In most cases, the SN was located in the fatty tissue near the clavipectoral fascia in the lower ventral quadrant of the axilla (n = 14, 58%). In seven cases (29%), the SN was located in the upper ventral quadrant, in two cases (8%) in the upper dorsal quadrant, and in one case in the lower dorsal quadrant.

CONCLUSIONS

The results of this anatomical study may facilitate SN biopsy in patients with breast cancer.

Risk Factors for Non-Sentinel Lymph Node Metastases in Patients with Breast Cancer. The Outcome of a Multi-institutional Study

BACKGROUND

In this multi-institutional prospective study, we evaluated whether we could identify risk factors predictive for non-sentinel lymph node (non-SN) metastases in breast cancer patients with a positive sentinel lymph node (SN).

METHODS

In this multi-institutional study, 541 eligible breast cancer patients were included prospectively.

RESULTS

The occurrence of non-SN metastases was related to the size of the SN metastasis (P = .02), primary tumor size (P = .001), and lymphovascular invasion (P = .07). The adjusted odds ratio was 3.1 for SN micro-metastasis compared with SN isolated tumor cells, 4.0 for SN macro-metastasis versus SN isolated tumor cells, 3.1 for tumor size (>3.0 cm compared with </=3.0 cm), and 2.0 for lymphovascular invasion (yes versus no). There were no positive non-SNs when the primary tumor size was </=1.0 cm (n = 24) [95% confidence interval (95% CI) 0%-14.0%]. The proportion of positive non-SNs ranged in a prognostic logistic regression model from 9.7% (95% CI 4.0%-23.0%) for patients with SN isolated tumor cells, tumor size of 1.1-3.0 cm, and without vessel invasion, to 72.6% (95% CI 47.0%-89.0%) for patients with SN macro-metastasis, tumor size >3.0 cm, and with vessel invasion.

CONCLUSION

We identified three predictive factors for non-SN metastases in breast cancer patients with a positive SN: size of the SN metastasis; primary tumor size; and vessel invasion. We were not able to identify a specific group of patients with a positive SN in whom the risk for non-SN metastases was less than 5%.

The “Sentinel Chain”: a new concept for prediction of axillary node status in breast cancer patients

BACKGROUND AND OBJECTIVES

More than half the breast cancer patients with positive sentinel lymph nodes (SLN) do not harbor additional metastases in non-sentinel nodes (NSN). The aim of this study was to identify a subgroup of patients with positive SLNs and negative NSNs, on the basis of tumor involvement patterns in multiple radioactive nodes.

METHODS

Between 2000 and 2004, 290 patients with primary invasive breast cancer and clinically negative axillary nodes had a SLN biopsy in our breast unit. Radiotracer was identified intraoperatively in the axilla. All radioactive nodes were removed and radioactivity was measured in each node extracorporeally. Nodes were ranked according to radioactivity, constituting a "Sentinel Chain", and the histopathological status of each node was reported. The different metastatic involvement patterns of the Sentinel Chain were correlated with the metastatic status of the NSNs after axillary dissection. Information was charted in a prospective database.

RESULTS

Of 290 patients, 216 (74.5%) had multiple radioactive nodes. Ninety patients (31%) had SLN metastases. Fifty patients had multiple ranked radioactive nodes and positive SLNs. Twenty-five of these patients had a sequential involvement pattern, with tumor-bearing high radioactivity nodes, and uninvolved low-radioactivity nodes. In the 23 of these 25 patients who had axillary dissection, NSN involvement was detected in only one patient (4.3%), whereas in 24 patients with other involvement patterns of the Sentinel Chain, NSN involvement reached 54.2% (p<0.001).

CONCLUSION

Tumor-free status of NSN may be predicted using the Sentinel Chain concept in some breast cancer patients with positive SLNs.

Micrometastases in Sentinel Lymph Node in a Multicentric Study: Predictive Factors of Nonsentinel Lymph Node Involvement—Groupe Des Chirurgiens De La Federation Des Centres De Lutte Contre Le Cancer

Purpose

To determine the rate of nonsentinel lymph node (NSN) involvement at axillary lymph node dissection (ALND) and predictive factors of this involvement following detection of micrometastasis in sentinel nodes (SN).

Methods

We analyzed 700 observations of SN micrometastases with additional ALND with the characteristics of the patients, tumors, and SN.

Results

Involvement of SN was diagnosed 388 times by serial sections (55.4%) with standard hemoxylin and eosin staining (HES) and 312 times solely on immunohistochemical analysis (IHC; 44.6%). The accurate size of the micrometastases was indicated in 488 cases: 301 larger than 0.2 mm (61.7%) and 187 ≤ 0.2 mm (38.3%). Ninety-four patients (13.4%) presented an NSN involvement with only one NSN involved in 62 cases (66%). Predictive factors of NSN involvement were in univariate analysis (pT stage [P < .000], menopausal status [P = .048], T stage [P = .006], grade [P = .013], lymphovascular invasion [LVI; P = .013], histologic tumor type [P = .017], and method of micrometastasis detection, by HES or IHC [P = .015]) and in multivariate analysis (pT stage ≤ or > 20 mm [odds ratio, 2.54], micrometastases detected by HES or IHC [odds ratio,1.734], presence or absence of LVI [odds ratio, 1.706]). Micrometastasis size ≤ or greater than 0.2 mm was not predictive.

Conclusion

This study confirms the value of serial sections and the vital role played by IHC in screening for small micrometastases. Omission of additional ALND may be envisaged with minimal risk for pT1a and pT1b tumors, and pT1a-b-c tumors corresponding to tubular, colloidal, or medullar cancers.

Primary tumor characteristics predict sentinel lymph node macrometastasis in breast cancer

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.

Implications of the sentinel lymph node procedure for local and systemic adjuvant treatment

PURPOSE OF REVIEW

The objective of the sentinel lymph node procedure in breast cancer is to perform an accurate axillary staging and provide good local control, while sparing the patients the morbidity of an axillary lymph node dissection. Since its routine clinical use, questions were raised concerning the implications for local and systemic adjuvant treatment. This review provides an update of the recent literature.

RECENT FINDINGS

As a result of a more detailed histopathologic work-up of the sentinel lymph node, higher rates of lymph node metastases are detected. This leads to an upstaging of a subset of node-negative patients and an increase in the overall percentage of node-positive patients. However, the clinical implications of micrometastases and isolated tumor cells remain unclear. Furthermore, sentinel lymph nodes may be found in the internal mammary lymph node chain but the treatment of these nodes is subject of debate.

SUMMARY

Current guidelines recommend axillary lymph node dissection in patients with a positive sentinel node. The surgical removal of the internal mammary lymph node is only indicated in the context of a clinical trial. Radiation therapy of the axilla is an acceptable alternative for patients who refuse an axillary lymph node dissection (clinical trial). The value of radiotherapy to the internal mammary lymph node has never been established. Systemic treatment decisions in patients with a macrometastasis or micrometastasis in the sentinel lymph node follow the guidelines of node-positive patients, whereas in patients with isolated tumor cells only, guidelines for node-negative patients are followed. The results of ongoing clinical trials will be important for the development of further guidelines.

Ratio of Positive to Total Number of Sentinel Nodes Predicts Nonsentinel Node Status in Breast Cancer Patients

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.

EXPERIENCE OF SENTINEL NODE BIOPSY ALONE IN EARLY BREAST CANCER WITHOUT FURTHER AXILLARY DISSECTION IN PATIENTS WITH NEGATIVE SENTINEL NODE

AIMS

The aims of surgical therapy of breast cancer are loco-regional tumour control and staging. Axillary staging is still considered the single most important prognostic indicator in breast cancer. Surgical removal of axillary nodes remains the standard way to assess their involvement in most centres. The morbidity associated with axillary dissection (AD) is well recognized. In recent years sentinel node biopsy (SNB) has evolved. Multiple studies suggest it has the same accuracy as AD in axillary staging and less morbidity in early breast cancer (EBC). SNB has become the standard of practice in EBC in many parts of the world. In Australia, the preference has been to wait for the results of the Sentinel Node versus Axillary Clearance (SNAC) trial as well as other international trials before accepting SNB as a standard of care. The experience of a single surgeon with SNB alone in EBC without further completion axillary dissection (CAD) in negative sentinel node (SLN) is described in the present paper.

METHODS

An audit was done of the senior author's prospective data from the Royal Australasian College of Surgeons database. Other information was added retrospectively from case notes.

RESULTS

Between December 2000 and December 2003, 154 EBC cases (153 patients) underwent SNB alone. An average of four SLN was removed. Of these cases, 31.8% had positive SLNs (excluding 2.6% cases that had isolated tumour cells), of these, 93.9% had metastases (39.1% micro- and 60.9% macro-metastases) in axillary-SLN (ASLN) and almost all of these had CAD. ASLNs were the only positive nodes in 73.9%. Extra-ASLN retrieved in 68.8% of 34% demonstrated on lymphoscintigraphy. Of these, 12.1% were positive (6.1% micro- and macro-metastases each), all internal mammary. Mean follow up was 22.1 months. There was one local-regional-systemic and one systemic recurrence over this time.

CONCLUSION

SNB has a valid role in staging of the axilla particularly in low-risk patients. After adequate self audit, SNB offers a minimal morbidity and reliable method of axillary staging. Patients choosing SNB alone must understand that the long-term results of the randomized controlled trial are still pending for level I evidence of long-term efficacy.

The clinical significance of axillary lymph node micrometastases in breast cancer

OBJECTIVE

To evaluate the clinical significancer of axillary lymph-node micrometastases, in the era of sentinel lymph node (SLN) biopsy.

DATA SOURCES

Searches of MEDLINE (1966-2003) and an extensive manual review of journals were performed using the key search terms breast cancer, axillary lymph-node micrometastases, micrometastatic disease, and SLN biopsy.

STUDY SELECTION

All articles identified from the data sources were evaluated and all information deemed relevant was included for this review.

CONCLUSIONS

Axillary lymph-node micrometastases can be detected by serial sectioning, immunohistochemistry, or reverse transcriptase-polymerase chain reaction (RT-PCR). The presence of axillary SLN micrometastases is generally associated with a worse prognosis and is an indication for axillary lymph node dissection (ALND) and adjuvant therapy. The clinical significance of micrometastases identified by RT-PCR remains unknown and further research with longer follow-up is needed to ascertain the clinical implications of a positive result.

Breast cancer patients with pN0(i+) and pN1(mi) sentinel nodes have high rate of nonsentinel node metastases

BACKGROUND

The recent American Joint Committee on Cancer revision of the staging system for breast cancer classifies sentinel node metastases < 0.2 mm (pN0[i+]) as node negative and those > 0.2 mm but < 2 mm are designated pN1(mi). We examined the association between size of sentinel node metastases and rate of nonsentinel node metastases, specifically in the subgroup of patients with micrometastases.

STUDY DESIGN

We examined the nonsentinel nodes of 124 patients with positive sentinel nodes and correlated the likelihood of nonsentinel node involvement with the size of the metastasis in the sentinel node and primary tumor characteristics.

RESULTS

Nonsentinel node metastases were found in 19% (6 of 31) of patients with sentinel node metastases <or= 0.2 mm, 20% (6 of 30) of patients with metastases 0.2 mm to 2 mm, and 46% (29 of 63) of patients with metastases > 2 mm. Multivariate analysis found that involvement of the majority of sentinel nodes (p = 0.01) and sentinel metastases > 2 mm (p = 0.001) were significantly related to presence of metastases in nonsentinel nodes. Age, tumor size, pathology, multifocality, satellites, and lymphovascular invasion were not significantly related to nonsentinel node metastases in multivariate analysis.

CONCLUSIONS

These findings indicate that frequency of nonsentinel node metastases with sentinel node metastases <or= 0.2 mm is comparable to the frequency when sentinel metastases are > 0.2 to 2 mm. Omitting complete axillary dissection in pN1(mi) and pN0(i+) patients may leave residual disease in up to 20% of these patients.

Use and Limitations of a Nomogram Predicting the Likelihood of Non-Sentinel Node Involvement after a Positive Sentinel Node Biopsy in Breast Cancer Patients

After a positive sentinel lymph node (SLN) biopsy, some patients may be considered to have a very low risk of non-SLN involvement and could be candidates for axillary sparing. The aim of this study was to validate the nomogram created at the Memorial Sloan-Kettering Cancer Center (MSKCC) for the prediction of non-SLN involvement in an independent set of 140 patients with both positive SLNs and axillary dissection. The predicted proportions of positive non-SLNs were compared with the observed percentages of non-SLN metastasis. Although the SLN metastasis size and tumor size did influence the risk of non-SLN involvement, the correlation between the predicted and observed proportions was weaker for our patients (R: 0.84) than for the patients assessed at the MSKCC (R: 0.97). Differences were noted in the intraoperative assessment and in the final histology of the SLNs (imprints vs frozen sections and more detailed vs less detailed, respectively), and these could partly explain the lower level of the correlation. The nomogram could not be validated and was found to be of only limited use for the prediction of non-SLN involvement in patients operated on under similar, though not fully identical conditions. We therefore warn against the unvalidated use of this prediction tool.

Meta-analysis of non-sentinel node metastases associated with micrometastatic sentinel nodes in breast cancer

BACKGROUND

The need for further axillary treatment in patients with breast cancer with low-volume sentinel node (SN) involvement (micrometastases or smaller) is controversial.

METHODS

Twenty-five studies reporting on non-SN involvement associated with low-volume SN involvement were identified using Medline and a meta-analysis was performed.

RESULTS

The weighted mean estimate for the incidence of non-SN metastases after low-volume SN involvement is around 20 per cent, whereas this incidence is around 9 per cent if the SN involvement is detected by immunohistochemistry (IHC) alone. Subset analyses suggest that studies with axillary dissection after any type of SN involvement result in somewhat higher estimates than studies allowing omission of axillary clearance, as do studies with more detailed histological evaluation of the SN compared with those with a less intensive histological protocol. Higher-quality papers yield lower pooled estimates than lower-quality papers.

CONCLUSION

The risk of non-SN metastasis with a low-volume metastasis in the SN is around 10-15 per cent, depending on the method of detection of SN involvement. This should be taken into account when assessing the risk of omission of axillary dissection after a positive SN biopsy yielding micrometastatic or immunohistochemically positive SNs.

Dose-dependent biodistribution of [(99m)Tc]DTPA-mannosyl-dextran for breast cancer sentinel lymph node mapping

[(99m)Tc]DTPA-mannosyl-dextran is a receptor-binding radiopharmaceutical specifically designed for sentinel lymph node mapping. The purpose of this study was to test the biodistribution and safety of [(99m)Tc]DTPA-mannosyl-Dextran at different molar doses. Twenty-four female breast cancer patients participated in this study. Four groups of 6 patients received an injection of 0.2, 1.0, or 5.0 nmol of [(99m)Tc]DTPA-mannosyl-Dextran or filtered [(99m)Tc]sulfur colloid. The injection site clearance was monitored by dynamic imaging for three hours. Whole body scans were acquired at 2.5 and 12, and lymph nodes were assayed for radioactivity after gamma-guided sentinel lymph node biopsy. Injection site clearance of [(99m)Tc]DTPA-mannosyl-Dextran was not statistically different in a dose-dependent manner. Dose-dependent sentinel node uptake was observed (p = 0.03). There were no clinically significant alterations in laboratory parameters among all dose levels at 4 h or 24 h post injection compared to preoperative levels. Radiation absorbed doses did not differ among the three dose levels, but were lower than filtered [(99m)Tc]sulfur colloid.

Lymphatic mapping and sentinel lymphadenectomy for breast cancer

Lymphatic mapping and sentinel lymphadenectomy has become an important tool for axillary lymph node staging in women with early-stage breast cancer. This review examines data regarding the staging accuracy, indications and technical aspects of the procedure, and clinical trials investigating the technique. Multiple studies now confirm that sentinel lymphadenectomy accurately stages the axilla and is associated with less morbidity than axillary dissection. Blue dye, radiocolloid, or both can be used to identify the sentinel node, and several injection techniques may be used successfully. Many patient factors previously thought to affect accuracy of the procedure have now been shown to be of limited significance. The indications for the procedure are expanding, and the histopathologic evaluation of the sentinel node and the role of lymphoscintigraphy have been clarified. Clinical trials are now underway that will determine the prognostic significance of micrometastases and the therapeutic benefit of axillary dissection in women with and without sentinel node metastases. Incorporation of sentinel lymphadenectomy into routine clinical practice will maintain accurate axillary staging with lower morbidity and improved quality of life for women with early-stage breast cancer.

Influence of the New AJCC Breast Cancer Staging System on Sentinel Lymph Node Positivity and False-Negative Rates

The sixth and newest edition of the American Joint Committee on Cancer (AJCC) staging system for breast cancer now defines axillary sentinel lymph nodes with micrometastatic deposits 0.2 mm in diameter or smaller as node-negative. The aim of this study was to determine how this new classification scheme would affect axillary sentinel lymph node positivity, false-negative rate, and overall accuracy of an inception cohort of 205 breast cancer patients undergoing definitive surgery that included sentinel lymph node biopsy plus level I/II axillary lymphadenectomy. Based on the previous AJCC system for staging breast cancer, in which all sentinel lymph node metastases were considered positive, the rate of nodal positivity in this cohort was 47%, the overall accuracy was 99%, and the false-negative rate was 2.1%. According to the new classification system, the rate of nodal positivity in this cohort was 39.5% and the overall accuracy was 98%. The false-negative rate rose to 4.9% because two patients with micrometastatic deposits 0.2 mm or smaller, which are considered node-negative in the new system, had macroscopically positive disease in non-sentinel lymph nodes found in the completion lymphadenectomy.

Sentinel lymph node dissection in stage I/II melanoma patients: surgical management and clinical follow-up study

Selective sentinel lymph node (SLN) dissection is widely used in the management of cutaneous melanoma patients without clinical evidence of nodal metastases. A series of 274 consecutive melanoma patients who underwent melanoma primary excision and SLN mapping at our institutions since 1998, and were thereafter followed up and eventually treated, is reported in this prospective study. The aim was to analyse the parameters associated with a higher risk of occult nodal metastases, to evaluate the clinical outcome of melanoma patients who underwent SLN procedure, and to identify by means of multivariate analysis the prognostic parameters with independent predictive value on disease-free survival (DFS) in node-positive and negative patients. The SLN was tumour-negative in 228 patients (83.2%). A disease progression occurred in 25 (10.9%); among them, 10 patients in whom the initially identified SLN had been negative, developed a clinically and histologically evident positive lymph node in the same basin during follow-up. Five-year DFS and overall survival were 75% and 82%, respectively. In 46 patients (16.8%), the SLN proved to be tumour positive. The percentage of SLN-positive patients varied according to the primary thickness, from 11.8% in patients with Breslow of 2 mm or lower, to 34.7% in patients with Breslow from 2 to 4 mm, up to 55.9% in patients with Breslow greater than 4 mm (P<0.001). Only two patients with Breslow thickness lower than 1 mm had positive SLN biopsy. Five-year DFS and overall survival (OS) were 42 and 69%, respectively, significantly lower than those of negative SLN-patients (P<0.001). Multivariate analyses showed that the parameters with prognostic independent value on DFS were SLN status (micrometastases or macrometastases; P=0.0001), and to a lesser extent, Breslow thickness (P=0.04). In conclusion, our data support the clinical usefulness of SLN dissection as a reliable and accurate staging method in patients with cutaneous melanoma. SLN-positive patient OS (5-year survival 69%) seems to be superior to that historically reported for stage III patients treated with curative nodal dissection only after the clinical evidence of palpable adenopathies (5-year survival 36%). The prognostic relevance of the pattern of SLN invasion (micrometastases/macrometastases) could be the basis for the planning of adjuvant treatment trials on selected groups of patients.

Pathological work-up of sentinel lymph nodes in breast cancer. Review of current data to be considered for the formulation of guidelines

Controversies and inconsistencies regarding the pathological work-up of sentinel lymph nodes (SNs) led the European Working Group for Breast Screening Pathology (EWGBSP) to review published data and current evidence that can promote the formulation of European guidelines for the pathological work-up of SNs. After an evaluation of the accuracy of SN biopsy as a staging procedure, the yields of different sectioning methods and the immunohistochemical detection of metastatic cells are reviewed. Currently published data do not allow the significance of micrometastases or isolated tumour cells to be established, but it is suggested that approximately 18% of the cases may be associated with further nodal (non-SN) metastases, i.e. approximately 2% of all patients initially staged by SN biopsy. The methods for the intraoperative and molecular assessment of SNs are also surveyed.

Effect of Increasing the Surface Sampled by Imprint Cytology on the Intraoperative Assessment of Axillary Sentinel Lymph Nodes in Breast Cancer Patients

As axillary sentinel nodes predict the nodal status and may allow dissection of the axilla on a selective basis we assessed the effects of increasing the surface sampled during intraoperative imprint cytology. Sentinel nodes from 110 patients identified with Patent blue and/or the high radioactivity due to the uptake of 99m-Tc-labeled colloidal albumin were analyzed via hematoxylin and eosin-stained touch preparations. Imprint cytology was performed either on bisected nodes (Protocol One; n = 55) or on sentinel nodes sliced into multiple pieces at 2- to 3-mm intervals (Protocol Two; n = 55). The sentinel nodes were submitted in toto to permanent step sectioning and immunostaining for cytokeratins. There were equal numbers of patients with involved nodes in the two groups assessed. With Protocols One and Two the imprints had sensitivities of 52 and 61 per cent, negative predictive values of 74 and 78 per cent, and false negative rates of 47 and 39 per cent, respectively. No macrometastasis missed by Protocol Two was absent from the surface sampled. These data suggest that increasing the surface sampled improves the proportion of involved sentinel nodes detected intraoperatively by imprint cytology, but a number of metastatic nodes still remain undetected by this method. The sampling of multiple surfaces is encouraged for a more accurate intraoperative assessment.

Extracapsular extension of the sentinel lymph node metastasis: a predictor of nonsentinel node tumor burden

OBJECTIVE

To identify predictors of nonsentinel node (NSN) tumor involvement in patients with a tumor-involved sentinel node (SN).

SUMMARY BACKGROUND DATA

For many breast cancer patients who undergo intraoperative lymphatic mapping and sentinel lymphadenectomy (LM/SL), the SN is the only tumor-involved axillary node. Associations between NSN tumor involvement and several clinical and histopathologic factors have been identified. The authors hypothesize that extracapsular extension (ECE) of the SN metastasis is highly predictive of NSN tumor involvement.

METHODS

Between May 1998 and December 2001, 260 patients (263 cases) with clinical T1 or T2 (<5.0 cm) breast cancer underwent LM/SL at the University of North Carolina, using a combined blue dye and technetium sulfur colloid technique. In all cases with a tumor-involved SN, axillary lymph node dissection (ALND) was recommended. Statistical analysis, with Pearson chi-square tests, Fisher exact test, and multiple logistic regression, was performed.

RESULTS

The SN contained tumor in 74 (28.1%) cases. ALND was performed in 70 of the 74 cases. ECE of the SN metastasis was present in 18 (25.7%) of the 70 cases. Patients with ECE of the SN metastasis were more likely to have NSN tumor involvement and had a greater total number of tumor-involved nodes than patients without ECE of the SN metastasis. Increasing size of the SN metastasis and increasing size of the primary tumor, examined as continuous variables, were associated with an increased likelihood of NSN tumor involvement on univariate analysis. However, only ECE of the SN metastasis was associated with NSN tumor involvement on multivariate analysis.

CONCLUSIONS

ECE of the SN metastasis is a strong predictor of NSN tumor involvement. All patients with ECE of the SN metastasis should undergo mandatory completion ALND.

Complete sectioning of axillary sentinel nodes in patients with breast cancer. Analysis of two different step sectioning and immunohistochemistry protocols in 246 patients

AIMS

To evaluate two detailed step sectioning protocols for sentinel lymph nodes (SLNs).

METHODS

After vital dye or combined dye and radiocolloid guided biopsy, SLNs were fixed in formalin and embedded in paraffin wax. In protocol A, SLNs from 123 patients were sectioned in steps of 50-100 micro m, whereas in protocol B, SLNs from 123 patients were sectioned at steps of 250 micro m. Epithelial marker immunohistochemistry (IHC) was performed on multiple levels in cases with negative haematoxylin and eosin findings.

RESULTS

In groups A and B, 74 and 47 patients were found to have tumour cells in their axillary SLNs, and 19 (28%) and 18 (19%) patients, respectively, were upstaged as compared with the standard histological assessment. Nodal involvement detected by deeper sections was often micrometastatic or in isolated tumour cells

CONCLUSIONS

Serial sectioning and IHC are recommended for the evaluation of SLNs. The optimal extent of the histopathological work up should be studied further.