Caution concerning micrometastatic breast carcinoma in sentinel lymph nodes

The Sentinel Lymph Node in Breast Cancer: Problems Posed by Examination During Surgery. A Review of Current Literature and Management

The presence of tumor cells can be identified in the lymph node when metastasis has occurred from the primary cancer site into the lymph node (1) If the sentinel lymph node ganglion is negative for the presence of tumor cells at the time of histological examination, the other lymph nodes are also negative in 99% of cases. If no tumor cells are identified in the sentinel lymph node ganglion by histological examination, the other lymph nodes are also negative for the presence of tumor cells in 99% of cases. The sentinel lymph node advantageously replaces axillary dissection as a staging method in breast cancer T1 and T2 (2). Approximately 40% of breast cancers metastasize to axillary lymph nodes and metastatic extension depends on disease stage. Sentinel lymph nodes are affected in the following stages: T1a (4.3%), T1b (19.5%), T1c (23.8%), T2 (48.9%), T3 (66.7%).

Immunohistochemistry and Reverse Transcriptase Polymerase Chain Reaction on Sentinel Lymph Nodes can Improve the Accuracy of Nodal Staging in Breast Cancer Patients

In this study the nodal staging sensitivity of sentinel lymph node biopsy (SLNB) with detailed pathological and molecular biological examination has been investigated and compared to that of axillary lymph node dissection (ALND) with routine histological evaluation. Sentinel lymph nodes (SLNs) were removed by the dual-agent injection technique in 68 patients with primary, clinically node-negative breast cancer. Forty-seven patients had negative SLNs according to hematoxylin and eosin (H&E) staining. These H&E-negative SLNs were serially sectioned and examined at 250 μm levels by anticytokeratin immunohistochemistry (IHC). In 14 patients the SLNs were also investigated by cytokeratin 20 (CK20) reverse transcriptase polymerase chain reaction (RT-PCR). SLNB with IHC increased the node-positive rate by 26% (by 40% in tumors less than or equal to 2 cm in size (pT1) and by 9% in tumors more than 2 cm but less than or equal to 5 cm in size (pT2)). The sensitivity of SLNB with IHC was superior to that of ALND with routine histology in pT1 tumors and identical in pT2 tumors. The concordance between histology and RT-PCR was only 21%, and in two of three cases with positive histological results RT-PCR was negative. In conclusion, SLNB with detailed pathological and/or molecular biological evaluation can improve the sensitivity of regional staging. ALND can probably be abandoned in patients with pT1 SLN-negative breast cancer. Further prospective studies are required to determine the clinical significance of these detailed SLN evaluation techniques, but at present these methods are still investigational.

Intraoperative Frozen Section Evaluation of Sentinel Lymph Nodes in Breast Carcinoma: Single-Institution Indian Experience

Sentinel lymph node biopsy is an established way of predicting axillary nodal metastasis in early breast cancer. Intraoperative frozen sections (FS) of sentinel lymph nodes (SLNs) can be used to detect metastatic disease, allowing immediate axillary lymph node dissection. The purpose of this study was to evaluate the accuracy of intraoperative frozen sections in evaluation of sentinel lymph nodes in cases of breast cancer. Between March 2006 and August 2010, a total of 164 patients with clinically node-negative operable breast cancer were subjected to sentinel lymph node biopsy of axillary lymph nodes using preoperative peritumoral injection of radioactive colloid and methylene blue. Intraoperative identification of sentinel nodes was done using a handheld gamma probe and identification of blue-stained nodes. The nodes were sent for frozen section examination. The results of frozen section were compared with the final histopathology. Out of the 164 cases, metastases were detected in SLN by frozen section in 38 cases. There were three false-negative cases (all showing micrometastasis on final histopathology). FS had sensitivity of 92.6 %, specificity of 100 %, and overall accuracy of 98.1 %. The positive predictive value was 100 %, and the negative predictive value was 97.6 %. FS for diagnosis of metastasis of SLNs is reliable. Patients with negative SLNs by the FS diagnosis can avoid reoperation for axillary lymph node dissection. However, FS may fail to detect micrometastases, especially in cases with small tumors.

MYC is expressed in the stromal and epithelial cells of primary breast carcinoma and paired nodal metastases

The MYC oncogene is directly involved in the proliferation, metabolism, progression and distant metastasis of breast cancer. Since metastatic spread to the lymph nodes is often the first indication of propensity for metastatic dissemination, the MYC status in nodal disease may represent a decision-making variable. However, the analysis of MYC expression in stromal cells, namely cancer-associated fibroblasts (CAFs), which are known to play a critical role in cancer progression, remains poorly reported. The aim of this study was to determine the expression of MYC and other markers, including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), p53, Ki67, epidermal growth factor receptor (EGFR), phosphorylated AKT (p-AKT) and phospho-mammalian target of rapamycin (p-mTOR) by immunohistochemistry in representative samples from 80 patients with ductal infiltrative breast cancer and 43 paired compromised axillary lymph nodes allocated in tissue microarrays (TMAs). The epithelial and stromal components of primary tumors and respective lymph node metastases were separately analyzed. MYC expression (cytoplasmic and nuclear) was a frequent event in the epithelial and stromal components of the primary tumors. The epithelial cells in the nodal metastases exhibited a trend for decreased MYC expression compared to that in the primary tumors (P=0.08) but retained the original status of the primary tumors for all other markers. The stromal cells were uniformly negative for ER, PR, HER2, p53, Ki67 and EGFR. Comparison of the stromas of primary tumors and respective lymph node metastases revealed a reduced frequency of nuclear MYC in 15% of the cases (P=0.003), whereas p-mTOR followed a similar trend (P=0.09). Analyses of the possible correlations among markers revealed that epithelial nuclear MYC was associated with p53 (P=0.048). This is an original study demonstrating a significant proportion of MYC expression (nuclear or cytoplasmic), as well p-mTOR and p-AKT expression, in the epithelial and stromal components of either the primary tumor or the nodal metastases. CAFs expressing MYC may establish an angiogenic microenvironment supporting cancer survival and facilitating colonization at the nodal metastatic site.

Comprehensive examination of sentinel lymph node in breast cancer: a solution without a problem?

Although several methods have been devised to examine sentinel lymph node (SLN) specimens in breast cancer, the extent of examination and whether it should routinely include multilevel sectioning to detect micrometastases (MM) (<2.0 mm) is still debated. In this study all "positive'' SLN biopsies from 67 consecutive patients with breast carcinoma and evaluated by means of an extended protocol were reviewed. Abnormal findings included micrometastases (MM) between 0.2 and 1.0 mm (14 cases), (MM) between 1.0 and 2.0 mm (8 cases), metastases>2.0 mm (22 cases), and isolated tumor cells (ITCs) (23 cases). The likelihood of finding metastatic deposits was comparable if sections were carried out at 100-, 150-, 200-, 250-, and 500-microm intervals. No metastatic foci>2.0 mm would have been missed. 1 MM (1.1 mm focus) was missed within the 250- and 500-microm levels on hematoxylin-eosin, but not complementary cytokeratin staining. Our data show that SLN step sectioning does not add significant yield if compared to standard examination carried on initial levels, if the minimal target of 1.0 mm micrometastatic deposit is sought.

The safety and accuracy of sentinel-node biopsy in early-stage invasive breast cancer--Turkish experience

The purpose of this prospective study was to investigate the correlation of sentinel lymph node (SLN) and axillary lymph node (ALN) metastasis in early-stage invasive breast cancer in a single institution. One hundred and fifteen patients with early-stage invasive breast cancer first underwent SLND followed by an appropriate surgical procedure (modified radical mastectomy, lumpectomy + axillary dissection, simple mastectomy + mammoplasty). In this series, a radioactive agent (technetium) was used to investigate the sentinel lymph node/nodes. In 28 (24.3%) patients, metastases were found in both SLN and axillary dissections. There were no metastases in either of these procedures in 69 (60%) patients. SLN metastasis was found in 13 (11.3%) patients, but no axillary metastasis was found. No skip metastasis was detected. Five patients in whom the sentinel node was not found were also negative for axillary metastasis. As the studies progress in this direction, it might be possible to avoid axillary dissection in patients with early breast cancer in whom metastasis in SLN cannot be detected. We believe this will reduce morbidity from breast cancer surgeries.

Clinical significance of lympho vascular space involvement and lymph node micrometastases in early-stage cervical cancer: A retrospective case-control surgico-pathological study

OBJECTIVE

Several studies have shown that lympho vascular space involvement (LVSI) and lymph node micrometastases (LNmM) may be risk factors for recurrence in early-stage cervical cancer with no apparent lymph node metastases. We performed a retrospective case-control study to reassess whether the presence of lymph node micrometastases and LVSI is predictive of subsequent recurrence following surgical resection of early-stage cervical cancer.

METHODS

In a series of 292 patients diagnosed with early cervical cancer and treated by the same surgical procedure (laparoscopic-vaginal radical hysterectomy) during the same time period, two paired series were selected. The first series consisted of 26 cases who recurred in a median time of 36.8 months and the second series were 26 cases matched for age, histological sub-type, surgico-pathological stage and maximal tumor diameter, who did not recur after a median follow-up of 122 months. Sections taken from the hysterectomy specimens were reassessed for LVSI. All the lymph node blocks which have initially been considered as uninvolved were submitted to serial sectioning. Immunohistochemical staining using anti-cytokeratins AE1 and AE3 was used for identifying LNmM.

RESULTS

LVSI was twice more frequent and LNmM ten-fold more frequent in the group of patients who recurred: 20/26 (77%) versus 9/26 (35%) and 11/26 (42%) versus 1/26 (4%) respectively. The relative risk of recurrence is 2.64 (1.67-5.49, P < 0.01) in the presence of LVSI and 2.44 (1.58-3.78, P < 0.01) in the presence of LNmM. All the patients with LNmM were LVSI positive. At bivariate analysis, the true LNmM (deposits more than 200 um in size) was the only independent risk factor.

CONCLUSIONS

LNmM is an important risk factor of tumor recurrence in patients with early cervical cancer with no apparent lymph node metastases. LNmM seems to occur only in LVSI positive tumors. These data may lead to improve management of early-stage cervical cancer to reduce the risk of recurrence in those cases.

Size of breast cancer metastases in axillary lymph nodes: clinical relevance of minimal lymph node involvement

BACKGROUND

Overt ipsilateral axillary lymph node metastases of breast cancer are the most significant prognostic indicators for women who have undergone surgery, yet the clinical relevance of minimal involvement (isolated tumor cells and micrometastases) of these nodes is uncertain.

PATIENTS AND METHODS

We evaluated biologic features, adjuvant treatment recommendations, and prognosis for 1,959 consecutive patients with pT1-3, pN0, minimal lymph node involvement (pN1mi or pN0i+), or pN1a (single positive node) and M0, who were operated on and counseled for medical therapy from April 1997 to December 2000.

RESULTS

Patients with pN1a and pN1mi/pN0i+, when compared with patients with pN0 disease, were more often prescribed anthracycline-containing chemotherapy (39.1% v 33.2% v 6.1%, respectively; P < .0001) and were less likely to receive endocrine therapy alone (9.8% v 19.4% v 41.9%, respectively; P < .0001). At the multivariate analysis, a statistically significant difference in disease-free survival (DFS) and in the risk of distant metastases was observed for patients with pN1a versus pN0 disease (hazard ratio [HR] = 2.04; 95% CI, 1.46 to 2.86; P < .0001 for DFS; HR = 2.32; 95% CI, 1.42 to 3.80; P = .0007 for distant metastases) and for patients with pN1mi/pN0i+ versus pN0 disease (HR = 1.58; 95% CI, 1.01 to 2.47; P = .047 for DFS; HR = 1.94; 95% CI, 1.04 to 3.64; P = .037 for distant metastases).

CONCLUSION

Even minimal involvement of a single axillary node in breast cancer significantly correlates with worse prognosis compared with no axillary node involvement. Further studies are required before widespread modification of clinical practice.

Frozen section diagnosis for axillary sentinel lymph nodes: the first six years

Intraoperative frozen section of axillary lymph nodes for the detection of metastatic breast cancer has been controversial because of the labor-intensive techniques necessary to obtain a highly sensitive test, and because of the uncertain significance of frequently detected submicrometastatic carcinoma. In total, 874 consecutive axillary sentinel lymph node cases examined by intraoperative frozen section over a 6-year period were reviewed retrospectively. Frozen section had a sensitivity of 60% and was 100% specific, but when cases with submicrometastatic tumor cells were considered negative, the sensitivity rose to 83%. Rare cases were called 'atypical' on frozen section; almost all of these cases were negative for carcinoma on permanent sections.

Sentinel lymph node biopsy is not accurate in predicting lymph node status for patients with cervical carcinoma

BACKGROUND

The authors evaluated the accuracy of sentinel lymph node biopsy in predicting lymph node status for patients with early cervical carcinoma. In particular, the authors set out to determine the false-negative rate associated with sentinel lymph node biopsy in this setting.

METHODS

Twenty-nine consecutive patients with early cervical carcinoma who were treated with pelvic laparoscopic lymphadenectomy and radical surgery underwent sentinel lymph node biopsy following lymphatic mapping with patent blue dye. All sentinel and nonsentinel lymph nodes were evaluated for micrometastases via multilevel sectioning followed by immunohistochemical staining.

RESULTS

At least one sentinel lymph node was identified for each patient. On routine pathologic evaluation, 3 patients (10%) were found to have positive lymph nodes. Among the remaining 26 patients, multilevel sectioning in conjunction with immunohistochemical analysis identified 5 patients (19%) who had micrometastases in the pelvic lymph nodes. Two of these five patients had micrometastases in a sentinel lymph node; however, the more notable finding was that the other three patients had micrometastases in nonsentinel pelvic lymph nodes despite having negative findings on sentinel lymph node biopsy. Thus, the negative predictive value of sentinel lymph node biopsy in the current study was 87.5%.

CONCLUSIONS

Multilevel sectioning followed by cytokeratin immunohistochemistry may identify additional patients who have lymph node micrometastases; in the current study, this technique identified cases in which micrometastases were present in nonsentinel lymph nodes even when sentinel lymph nodes were found to be negative for disease on biopsy. This high false-negative rate associated with sentinel lymph node biopsy, raises questions regarding the validity of the sentinel lymph node concept in cervical carcinoma.

The Use of Frozen Section and Immunohistochemistry for Sentinel Lymph Node Biopsy in Breast Cancer

Intraoperative pathologic evaluation of the sentinel lymph node (SLN) may guide immediate (synchronous) completion axillary lymph node dissection (ALND) for up to two-thirds of patients with nodal disease for breast cancer. The false-negative rates average one-third of cases, and one must be aware of false-positive results as this would result in unnecessary and morbid completion ALND. Currently, the use of immunohistochemistry (IHC) is controversial. There is no question that cytokeratin staining improves the sensitivity; however, there is no evidence that any of these “positive” cells are clinically significant and warrant therapy. Prospective randomized trials will be necessary to confirm or debunk the hypothesis that “sub-micrometastatic” disease has clinical significance.

Occult Metastases in Axillary Lymph Nodes as a Predictor of Survival in Node-Negative Breast Carcinoma with Long-term Follow-up

Increased detection rate in the lymph nodes is seen with serial sectioning or immunohistochemistry (IHC), but the importance of occult metastases is not resolved. IHC is still not recommended in routine examination of lymph nodes. Axillary lymph nodes from 385 node-negative breast cancer patients with a median follow-up of 25 years were examined with IHC for cytokeratins, applied on routine sections. The association between classic histopathologic prognostic factors and the presence of occult metastases was evaluated. Metastases were found in 45 of 385 cases (12%), 21 metastases (47%) measured < or =0.2 mm, 8 (18%) were larger than 2 mm; 14 metastases were located in the subcapsular sinus, 22 in the parenchyma of the lymph node; and 51% (23/45) of the metastases were recognized on hematoxylin-eosin staining on "second look." The detection of metastases was significantly associated with the number of sectioned lymph nodes (6% metastases for one to five lymph nodes examined versus 17% for more than five lymph nodes) and with histologic subtype (metastases in 11% of the ductal versus 33% of the lobular carcinomas). No significant association was found between occult metastases and age, tumor size, histologic grade, estrogen or progesterone receptor status, p53, or c-erbB-2. Metastases larger than 2 mm predicted a poorer recurrence-free survival rate for the whole series. A subcapsular location of the metastases was a strong predictor of overall survival. Whether or not the metastases could be identified on hematoxylin-eosin sections did not have any prognostic significance. In the multivariate analysis, histologic grade, tumor size of the primary tumor, progesterone receptor status, and the presence of occult metastasis in the lymph nodes had a prognostic impact on survival with a 25-year follow-up.

Touch imprint cytology of axillary lymph nodes after neoadjuvant chemotherapy in patients with breast carcinoma

BACKGROUND

Neoadjuvant chemotherapy (NC) reportedly downstages axilla in approximately one-third of patients with locally advanced breast carcinoma (LABC). Postchemotherapy axillary lymph node status is an important prognostic factor. In the current study, the authors evaluated the reliability of touch imprint cytology (TIC) in detecting axillary lymph node metastasis after NC and identified chemotherapy-induced changes that may influence this assessment.

METHODS

Thirty-three patients with LABC were studied. Seventeen patients had received chemotherapy before surgery (NC group) and 16 patients had not (non-NC group). Touch imprints were made from either the largest axillary lymph node (in 13 patients from the NC group and 16 patients from the non-NC) or the sentinel lymph node (in 4 patients from the NC group). Imprints from the NC group were evaluated for metastasis and were correlated with histopathology. Touch imprints from both groups were compared for cellularity, tumor load, necrosis/degeneration, and histiocytes.

RESULTS

Cytologic evaluation for metastasis was 100% concordant with histopathology in all 17 patients from the NC group (9 positive results [53%] and 8 negative results [47%]). The presence of few tumor cells in sparsely cellular imprints that exhibited necrosis (two patients) and the presence of only degenerating/necrotic tumor cells (two patients) were two cytologic patterns unique to post-NC imprints that may have influenced their accurate assessment.

CONCLUSIONS

TIC was found to be reliable for the intraoperative evaluation of axillary lymph node metastasis after NC. However, a careful examination is warranted in sparsely cellular imprints, because there is the possibility of overlooking a small group of tumor cells. To the authors' knowledge, the significance of finding extensive necrosis in axillary lymph nodes after NC is not known and may be investigated.

Interpretive disparity among pathologists in breast sentinel lymph node evaluation

BACKGROUND

Immunohistochemical staining on breast sentinel lymph nodes (SLN) is controversial.

METHODS

Twenty-five SLN cases were reviewed by 10 pathologists (three academic, seven private) including 5 negative by both hematoxylin and eosin (H&E) and immunohistochemistry, 11 micrometastases (<2 mm) negative by H&E but positive by immunohistochemistry, and 8 micrometastases and 1 macrometastasis (>2 mm) positive for both H&E and immunohistochemistry. Answers included "positive," "negative," and "indeterminate" for each slide.

RESULTS

The mean number of incorrect responses was 6.6 for immunohistochemistry and 5 for H&E. Twelve percent of cases were correct by all 10 pathologists; 80% of positive IHC cases had at least one pathologist score it incorrectly. As tumor cells decrease in number, incorrect responses increase. When tumor cells numbered less than 10, more than 30% of pathologists answered incorrectly.

CONCLUSIONS

As tumor cells decrease in number pathologists' ability to recognize them decreases. We propose adding "indeterminate" to "positive" and "negative" when tumor cells number less than 10.

Immunohistochemical evaluation of sentinel lymph nodes in breast carcinoma patients

Sentinel lymph node sampling has become an alternative to axillary lymph node dissection to provide prognostic and treatment information in breast cancer patients. The role of immunohistochemistry has yet to be established. A total of 241 sentinel lymph nodes (in 270 slides) from 91 patients with invasive carcinoma (73 ductal, 9 lobular, 8 mixed lobular/ductal, 1 NOS) were studied for presence of macrometastases (> 0.2 cm), identified in hematoxylin and eosin sections, and occult metastases (micrometastases [< or = 0.2 cm], clusters of cells, isolated carcinoma cells), identified only by immunohistochemistry. Intraoperative touch preparations, frozen sections, seven hematoxylin and eosin levels (L1-L7), and two AE1-3 cytokeratin immunohistochemistries (L1, L4-5) of the entire bisected or trisected sentinel lymph node were examined. Thirty-one (34%) patients had 50 positive sentinel lymph nodes. Twenty-six (33%) sentinel lymph nodes had metastatic carcinoma (11 macrometastases, 11 micrometastases, 3 clusters of cells, 1 isolated carcinoma cells) by touch preparations, frozen sections, and one hematoxylin and eosin (L1). Thirty-eight (43%) were positive by AE1-3 immunohistochemistry (L1) (11 macrometastases, 8 micrometastases, 13 clusters of cells, 6 isolated carcinoma cells), significantly more than by touch preparations, frozen sections, hematoxylin and eosin L1, or hematoxylin and eosin L2-7. Cytokeratin immunostain on L4-5 demonstrated 31 (34%) positive sentinel lymph nodes, a similar frequency to cytokeratin immunostain on L1. Size of sentinel lymph node metastasis did not correlate with size, histologic grade, or type of primary breast carcinoma. AE1-3 (L1) immunohistochemistry is highly sensitive in delineating sentinel lymph node metastasis, especially clusters of cells and isolated carcinoma cells. The prognostic significance of clusters of cells and isolated carcinoma cells and the value of AE1-3 immunohistochemistry on frozen sections need to be determined.

Traditional and newer pathologic factors

There has long been a pressing clinical need to identify prognostic and predictive factors for patients with breast cancer. Although numerous candidate biological and molecular markers have been identified during the last two decades, traditional factors such as lymph node status, tumor size, histologic type, histologic grade, and hormone receptor status remain the most useful indicators of prognosis and therapeutic response. A major obstacle to the translation of research advances into clinically useful prognostic and predictive markers has been the considerable methodologic variability used in the evaluation of the newer markers. It is now generally accepted that, to be useful in patient management, a putative prognostic or predictive marker must have clinical importance, independence, significance, and standardization with regard to methods, interpretation, and reporting. It is hoped that recognition and adoption of these criteria will serve to clarify the value of newer biologic and molecular markers.

Histological detection of minimal metastatic involvement in axillary sentinel nodes: a rational basis for a sensitive methodology usable in daily practice

There is no consensus method for the histological analysis of axillary sentinel nodes (SN). This study aimed to (1) assess the rate of occult metastases in SN using large serial sectioning and immunohistochemistry (IHC), (2) evaluate whether occult metastases were predictive of metastases in the downstream axillary nodes, and (3) specify a methodology of analysis of SN that could be both sensitive and applicable in daily practice. One hundred three patients with breast carcinoma underwent SN biopsy and then axillary dissection. SN free of tumor at standard examination of one section were sectioned at six levels (150-microm intervals) and immunostained for cytokeratin. The number and localization of labeled metastatic cells (occult metastases) were recorded. In 29 of the 103 patients (28%), SN were found to be metastatic after standard examination. The SN of the remaining 74 patients were further analyzed using IHC. Occult metastases were detected in 35 of these patients (47.3%), leading to an overall SN involvement rate of 62% (29+35/103). In 33 of these 35 cases, the plurality and the dispersion of the immunostained cells implied that the screening of only 3 of the 6 levels would have led to the detection of diagnostic positive events. Only one of the 35 patients (2.8%) with occult metastases showed metastatic lymph node in the downstream axilla. In our series of axillary SN, the analysis of one standard histologic section and, when negative, of only three additional sections after IHC revealed >60% of metastasis or occult metastasis. Metastasis detected by standard analysis had a high predictive value of downstream node metastasis, whereas the predictive value of occult metastasis revealed by IHC was poor. The clinical significance of occult metastases in SN needs to be specified by long-term follow-up analysis.

Cytokeratin immunostaining patterns of benign, reactive lymph nodes: applications for the evaluation of sentinel lymph node specimen

The use and interpretation of cytokeratin (CK) immunostains of sentinel lymph node specimens for breast carcinoma remain controversial. Variable immunoreactivity with anti-CK antibodies and CK-positive interstitial reticulum cells may complicate interpretation. The authors examined a series of reactive lymph nodes selected from patients without a history of malignancy. To demonstrate potential diagnostic pitfalls, three different CK antibody combinations were studied to characterize the immunostaining patterns. Formalin-fixed sections of lymph nodes were immunostained with a labeled streptavidin-biotin method using a DAKO autostainer. The anti-CK antibody preparations evaluated were AE1/AE3, CAM 5.2, and an in-house-prepared CK cocktail composed of 7 antibodies. The authors observed that up to 10% of cells in benign, reactive lymph nodes may be immunoreactive with anti-CK antibodies. AE1/AE3 stained 2 of 20 cases with rare immunoreactive reticulum cells, whereas CAM 5.2 and the CK cocktail immunostained cells in 85% of cases with reticulum cells in sinuses and the paracortex. Rare positive to 2+ cells were present in a similar distribution with these two antibodies. Careful interpretation of CK immunostaining of sentinel lymph node biopsies is essential, as is awareness of the presence of CK-positive native reticulum cells, to avoid confusion with single cells of metastatic carcinoma.

Sentinel lymph-node biopsy-based prediction of further breast cancer metastases in the axilla

BACKGROUND

Histopathological factors may help identifying a subgroup of breast cancer patients with metastases confined to the sentinel lymph nodes (SLNs).

METHODS

A retrospective analysis was carried out on 111 tumours successfully mapped with Patent blue, 69 of which had SLN metastases.

RESULTS

Multivariate analysis revealed that SLN metastases situated in the sinuses and a small tumour size are the two most important predictors of involvement of only one SLN. The metastasis size and a small tumour size were found important in the model discriminating between tumours with metastases to SLNs only and those with non-SLN involvement. Classification of tumours with only one SLN metastasis and those with a multinodal involvement resulted in a smaller error rate, falsely classified as lesser nodal involvement. Patients with tumours <1.8 cm and metastatic to the sinuses of a single SLN had a low probability of non-SLN metastasis, and might be candidates for axillary sparing after a positive SLN biopsy.

CONCLUSIONS

Further investigations are required to assess the validity of such predictive models for the identification of patients with no metastases beyond the SLN. Axillary treatment must remain the rule until predictive models of non-SLN involvement are fully validated.

National practice patterns of sentinel lymph node dissection for breast carcinoma

BACKGROUND

The sentinel node is the first regional lymph node to receive tumor cells that metastasize through the lymphatic channel from a primary tumor. The tumor status of the sentinel node should reflect the tumor status of the entire regional node basin. Sentinel lymph node dissection (SLND) has recently been investigated for use in patients with early breast carcinoma to avoid the sequelae of complete axillary lymph node dissection (ALND). Published studies of SLND in breast cancer patients identify marked variations in technique, and there are few guidelines for credentialing surgeons to perform SLND.

STUDY DESIGN

The purpose of this study was to assess the current practice of SLND for breast cancer in the United States. A 27-item questionnaire was mailed to 1,000 randomly selected Fellows of the American College of Surgeons. Responses were anonymous. Statistical analysis was performed using SAS software (SAS Institute, Cary, NC).

RESULTS

Response rate was 41% (n = 410), and 77% of those who responded performed SLND for breast cancer. The majority (60%) of surgeons responding routinely ordered preoperative lymphoscintigraphy. Of those who did lymphoscintigraphy, 28% removed internal mammary lymph nodes when lymphoscintigraphy showed drainage to these nodes. Ninety percent of surgeons used both blue dye and radiocolloid. Eighty percent of centers responding performed routine immunohistochemistry on sentinel lymph nodes, and 15% performed reverse transcription polymerase chain reaction. Ninety-six percent of surgeons performed SLND for primary tumors 5 cm or smaller, and 95% performed SLND for an excisional cavity 6 cm and smaller. Twenty-eight percent performed SLND for high-grade ductal carcinoma in situ, and 28% of respondents performed 10 or fewer SLND procedures with subsequent ALND before performing SLND alone. Surgeons learned SLND through courses (35%), oncology fellowships (26%), observation of other surgeons (31%), or were self-taught (26%).

CONCLUSIONS

The majority of surgeons in the United States use similar technique for SLND breast cancer. But, there was marked variation in the number of SLND cases validated by an ALND before performing SLND only.

[Lymph node mapping and axillary sentinel lymph node biopsy in 243 invasive breast cancers with no palpable nodes. The south Lyon hospital center experience]

STUDY AIM

To evaluate the effect of intraoperative lymph node mapping and sentinel lymph node dissection (SLND) on the axillary staging of patients with N0 breast carcinoma. Two techniques were used: blue dye alone (Evans Blue and Patent Blue) and combined technique (blue dye and isotope).

METHODS

The incidence of axillary node metastasis in axillary lymph node dissection (ALND) and SLND was compared prospectively. Multiple sections of each SLN were examined by HPS staining and immunohistochemical techniques. Two sections of each non sentinel node in ALND specimens were examined by routine HPS staining.

RESULTS

243 patients underwent ALND after SLN biopsy. The SLN detection rate was 225/243 cases (92.59%): 89.94% with blue dye alone and 100% with the combined technique. The false-negative rate was less than 2%.

CONCLUSION

SN biopsy is an accurate staging technique for N0 breast cancer. SLN biopsy with multiple sections and immunohistochemical staining of the SLN can identify significantly more patients with lymph node metastases than ALND with routine HPS staining.

Are microinvasion and micrometastasis in breast cancer mountains or molehills?

BACKGROUND

The increased rate of early detection of breast cancer due to widespread mammographic screening has led to an increased incidence of in situ as well as microinvasive carcinoma. The enhanced pathological examination to which sentinel lymph nodes are subjected has led to an increased rate of detection of micrometastatic carcinoma. Despite the augmented rate of diagnoses of both diseases, the pathological diagnoses as well as clinical management of these entities continue to be controversial.

DATA SOURCES

A computerized literature search was performed on the Medline and PubMed database from 1990 to date. Relevant earlier publications were also perused. The database of the Department of Pathology at New York Presbyterian Hospital-Well Medical College of Cornell University were also accessed.

CONCLUSIONS

Based on cumulative data, patients diagnosed with either microinvasive or micrometastatic carcinoma of breast have a relatively favorable, albeit guarded, prognosis. Treatment recommendations for both of these disease entities continue to be controversial, and may remain so until additional refined clinicopathological data becomes available.

The pathology of neck dissection in cancer of the larynx

Cancer of the larynx is a common problem in a head and neck oncological surgical practice; as such, pathology departments supporting such surgical practices will examine cervical lymph node dissection specimens with some frequency. Issues to be settled among pathologists and surgeons include--How precise an anatomic dissection of the specimen is called for? What histological features of the specimen will be of most use to the clinicians who are devising a course of postoperative therapy for the patient? What sorts of methods are needed to identify the maximum number of micrometastases which may be lurking within the lymph nodes of the specimen? Is there a role for routine application of special techniques--such as immunohistochemistry or molecular biology--in the analysis of these specimens? While the answers to these questions are likely to vary somewhat from one center to another, patients are best served when these questions are discussed amongst the respective physicians before surgical procedures are undertaken, rather than after the fact.

False negative conventional histology of lymph nodes in patients with head and neck cancer

Lymph node micrometastases in patients with head and neck cancer found node-negative by clinical examination and conventional histology may be discovered with additional sectioning of the lymph nodes, by immunohistochemistry and by molecular biology.

Molecular biology of breast cancer metastasis. Clinical implications of experimental studies on metastatic inefficiency

Recent technological advances have led to an increasing ability to detect isolated tumour cells and groups of tumour cells in patients' blood, lymph nodes or bone marrow. However, the clinical significance of these cells is unclear. Should they be considered as evidence of metastasis, necessitating aggressive treatment, or are they in some cases unrelated to clinical outcome? Quantitative experimental studies on the basic biology of metastatic inefficiency are providing clues that may help in understanding the significance of these cells. This understanding will be of use in guiding clinical studies to assess the significance of isolated tumour cells and micrometastases in cancer patients.