Radioguidance for nonpalpable primary lesions and sentinel lymph node(s).

BACKGROUND: Radioguided surgery can also be used for the simultaneous guidance to a nonpalpable primary tumor and sentinel lymph nodes. METHODS: Retrospective review of a prospective database. The surgeon used a gamma probe for guidance to an iodine-125 labeled titanium seed at the primary lesion and technetium-99 labeled sulfur colloid at the sentinel lymph node. RESULTS: Forty-three patients with nonpalpable breast carcinoma underwent dual isotope radioguided surgery. The radioactive seed and primary lesion were retrieved in the first excision in all 44 patients (100%). Eleven patients (25%) had pathologically involved margins. Sentinel lymph node mapping was successful in 42 patients (98%). A mean of 2.4 sentinel nodes were excised and metastatic carcinoma was present in four patients (10%). CONCLUSIONS: Dual isotopes can be effectively used in breast cancer patients for simultaneous radioguidance to both a nonpalpable primary lesion and sentinel lymph node and allows for improved logistics.

Randomized prospective evaluation of a novel technique for biopsy or lumpectomy of nonpalpable breast lesions: radioactive seed versus wire localization.

BACKGROUND: Standard wire localization (WL) and excision of nonpalpable breast lesions has several shortcomings. METHODS: Ninety-seven women with nonpalpable breast lesions were prospectively randomized to radioactive seed localization (RSL) or WL. For RSL, a titanium seed containing 125I was placed at the site of the lesion by using radiographical guidance. The surgeon used a handheld gamma detector to locate and excise the seed and lesion. RESULTS: Both techniques resulted in 100% retrieval of the lesions. Fewer RSL patients required resection of additional margins than WL patients (26% vs. 57%, respectively, P = .02). There were no significant differences in mean times for operative excision (5.4 vs. 6.1 minutes) or radiographical localization (13.9 vs. 13.2 minutes). There were also no significant differences in the subjective ease of the procedures as rated by surgeons, radiologists, and patients. All WLs were carried out on the same day as the excision, whereas RSL was performed up to 5 days before the operative procedure. CONCLUSIONS: RSL is as effective as WL for the excision of nonpalpable breast lesions and reduces the incidence of pathologically involved margins of excision. RSL also reduces scheduling conflicts and may allow elimination of intraoperative specimen mammography. RSL is an attractive alternative to WL.

Effects of ischemia on gene expression.

Microarray gene expression technology has recently made it feasible to characterize the RNA expression of thousands of genes across numerous tissue samples. We hypothesized that the warm ischemia commonly associated with the surgical extirpation of human tissue would have significant effects on gene expression profiles. To quantitate the effects of warm ischemia on human tissue, we rapidly dissected normal mucosa from a human colon cancer specimen. The specimen was divided and maintained at room temperature until snap-frozen in liquid nitrogen. Aliquots of tissue were frozen at times 5, 10, 15, 20, 40, and 60 min after extirpation. Spotted microarrays composed of 2400 distinct elements were used to assay mRNA derived from each time point in triplicate. Eisen's hierarchical clustering methodology and Bayesean statistical methods were then used to assay the effects of warm ischemia on gene expression. Application of time-course statistical models suggest that three patterns were induced by ischemia, accounting for 68.2, 17.8, and 13.4% of the evaluable genes, respectively. Pattern I corresponds to an average change of 27% over 60 min from 5 min baseline level of expression and 63.8% of the genes with at least 80% probability of membership in this pattern show average increases in expression over 60 min. The remainder decrease on average. Pattern II genes show the least ischemia-related effects, demonstrating an average change of only 12% over 60 min. In contrast to pattern I, we find that 67.5% of the genes with at least 80% probability of membership in this pattern are decreasing in expression on average over time. The remaining 32.5% in this pattern increase an average of 12% over 60 min. Finally, pattern III genes (13.4% of the sample) show the greatest sensitivity to ischemia, changing an average of 50% over 60 min, with about the same number increasing as are decreasing. Fold changes in RNA over- or under-expression were observed up to greater than 20-fold. Warm ischemia associated with the surgical extirpation of human tissues has significant effects on gene expression. These data support the careful monitoring of ischemic time for tissues harvested for the purpose of gene profiling.

Characteristics of the sentinel lymph node in breast cancer predict further involvement of higher-echelon nodes in the axilla: a study to evaluate the need for complete axillary lymph node dissection.

BACKGROUND: Sentinel lymph node (SLN) biopsy techniques provide accurate nodal staging for breast cancer. In the past, complete lymph node dissection (CLND) (levels 1 and 2) was performed for breast cancer staging, although the therapeutic benefit of this more extensive procedure has remained controversial. HYPOTHESIS: It has been demonstrated that if the axillary SLN has no evidence of micrometastases, the nonsentinel lymph nodes (NSLNs) are unlikely to have metastases. OBJECTIVE: To determine which variables predict the probability of NSLN involvement in patients with primary breast carcinoma and SLN metastases. METHODS: An analysis of 101 women with SLN metastases and subsequent CLND was performed. Variables included size of the primary tumor, tumor volume in the SLN, staining techniques used to initially identify the micrometastases (cytokeratin immunohistochemical vs hematoxylin-eosin), number of SLNs harvested, and number of NSLNs involved with the metastases. Tumor size was determined by the invasive component of the primary tumor. Patients with ductal carcinoma in situ who were upstaged with cytokeratin staining were considered to have stage T1a tumors. RESULTS: Sentinel lymph node micrometastases (<2 mm) detected initially by cytokeratin staining were associated with a 7.6% (2/26) incidence of positive CLND compared with a 25% (5/20) incidence when micrometastases were detected initially by routine hematoxylin-eosin staining. Sentinel lymph node micrometastases, regardless of identification technique, inferred a risk of 15.2% (7/46) for NSLN involvement. As the volume of tumor in the SLN increased (ie, <2 mm, >2 mm, grossly visible tumor), so did the risk of NSLN metastases (P<.001). CONCLUSIONS: Our study demonstrated that patients with micrometastases detected initially by cytokeratin staining had low-volume disease in the SLN with a small chance of having metastases in higher-echelon nodes in the regional basin other than the SLN. Characteristics of the SLN can provide information to determine the need for a complete axillary CLND. Complete lymph node dissection may not be necessary in patients with micrometastases detected initially by cytokeratin staining since the disease is confined to the SLN 92.4% of the time. However, the therapeutic value of CLND in breast cancer remains to be determined by further investigation.

Sentinel node biopsy in ductal carcinoma in situ patients.

BACKGROUND: Sentinel lymph node (SLN) mapping is an effective and accurate method of evaluating the regional lymph nodes in breast cancer patients. The SLN is the first node that receives lymphatic drainage from the primary tumor. Patients with micrometastatic disease, previously undetected by routine hematoxylin and eosin (H&E) stains, are now being detected with the new technology of SLN biopsy, followed by a more detailed examination of the SLN that includes serial sectioning and cytokeratin immunohistochemical (CK IHC) staining of the nodes. METHODS: At Moffitt Cancer Center, 87 patients with newly diagnosed pure ductal carcinoma in situ (DCIS) lesions were evaluated by using CK IHC staining of the SLN. Patients with any focus of microinvasive disease, detected on diagnostic breast biopsy by routine H&E, were excluded from this study. DCIS patients, with biopsy-proven in situ tumor by routine H&E stains, underwent intraoperative lymphatic mapping, using a combination of vital blue dye and technetium-labeled sulfur colloid. The excised SLNs were examined grossly, by imprint cytology, by standard H&E histology, and by IHC stains for CK. All SLNs that had only CK-positive cells were subsequently confirmed malignant by a more detailed histological examination of the nodes. RESULTS: CK IHC staining was performed on 177 SLNs in 87 DCIS breast cancer patients. Five of the 87 DCIS patients (6%) had positive SLNs. Three of these patients were only CK positive and two were both H&E and CK positive. Therefore, routine H&E staining missed microinvasive disease in three of five DCIS patients with positive SLNs. In addition, DCIS patients with occult micrometastatic disease to the SLN underwent a complete axillary lymph node dissection, and the SLNs were the only nodes found to have metastatic disease. Of interest, four of the five node-positive patients had comedo carcinoma associated with the DCIS lesion, and one patient had a large 9.5-cm low grade cribriform and micropapillary type of DCIS. CONCLUSIONS: This study confirms that lymphatic mapping in breast cancer patients with DCIS lesions is a technically feasible and a highly accurate method of staging patients with undetected micrometastatic disease to the regional lymphatic basin. This procedure can be performed with minimal morbidity, because only one or two SLNs, which are at highest risk for containing metastatic disease, are removed. This allows the pathologist to examine the one or two lymph nodes with greater detail by using serial sectioning and CK IHC staining of the SLNs. Because most patients with DCIS lesions detected by routine H&E stains do not have regional lymph node metastases, these patients can safely avoid the complications associated with a complete axillary lymph node dissection and systemic chemotherapy. However, DCIS patients with occult micrometastases of the regional lymphatic basin can be staged with higher accuracy and treated in a more selective fashion.

Lymphatic mapping with sentinel lymph node biopsy in patients with breast cancers <1 centimeter (T1A-T1B).

Because of its high cost and attendant morbidity, the necessity of axillary dissection in patients with small invasive primary tumors has been questioned. Lymphatic mapping with sentinel lymph node (SLN) biopsy is an alternative to complete axillary dissection; however, researchers have excluded patients with T1A-T1B lesions. Seven hundred patients with newly diagnosed breast cancers underwent an Institutional Review Board-approved prospective trial of intraoperative lymphatic mapping using a combination of Lymphazurin and filtered technetium-labeled sulfur colloid. An SLN was defined as a blue node and/or hot node with a 10:1 ex vivo radioactivity ratio in the SLN versus non-SLNs. All SLNs were evaluated by both hematoxylin and eosin and cytokeratin immunohistochemical stains. Of the 700 patients, 665 (95.0%) were mapped successfully. One hundred ninety-six (28.0%) had T1A-T1B tumors. Forty patients (20.4%) with T1A-T1B tumors had metastases to the SLNs. We conclude that breast cancer SLN mapping is highly accurate and sensitive when combined dye techniques (radiocolloid and vital blue dye) are utilized. This technique is particularly useful in patients with small invasive primary tumors, which, despite their size, still demonstrate a significant rate of axillary metastasis. These patients should not be excluded from lymphatic mapping protocols.

Sentinel node biopsy and cytokeratin staining for the accurate staging of 478 breast cancer patients.

Sentinel lymph node (SLN) mapping is an effective and accurate method of sampling the axillary nodal basin for metastatic disease. The SLN is the first node to receive afferent lymphatic drainage from the primary tumor. Lymphatic mapping and SLN biopsy have allowed pathologists to perform a more detailed examination of the SLN(s) and, therefore, provide more accurate staging of the regional lymphatic basin. Recently, more sensitive assays have been developed to increase the detection rate of micrometastatic to the axillary lymph nodes. Cytokeratin (CK) immunohistochemical (IHC) staining of the SLN detects micrometastatic disease, which is frequently missed on routine hematoxylin and eosin (H&E) histology. Therefore, lymphatic mapping combined with CK IHC staining of the SLN provides more accurate staging of the regional lymph nodes in patients with breast cancer. At Moffitt Cancer Center, 478 patients with newly diagnosed breast cancer underwent intraoperative lymphatic mapping using a combination of vital blue dye and technetium-labeled sulfur colloid. The excised SLNs were examined grossly, by intraoperative imprint cytology, by standard H&E histology, and by IHC stains for CK. SLNs that were only CK positive were confirmed malignant by sectioning the block, staining with H&E and finding cells with malignant cytology. Lymphatic mapping and CK IHC staining of the SLNs was successfully performed in 478 newly diagnosed breast cancer patients. Twenty-eight patients had unsuccessful lymphatic mapping for an overall failure rate of 5.5 per cent. A total of 134 (28%) patients had positive nodes (N1) detected. Ninety-three of these patients had both H&E and CK-positive lymph nodes, and an additional 41 patients had only CK-positive SLN(s). A total of 385 patients had H&E-negative SLNs, but only 344 patients had negative SLN(s) defined as both H&E and CK negative. Therefore, 41 (10.6%) of the 385 H&E-negative patients were upstaged, because of the detection of malignant cells by cytokeratin IHC staining of the SLN. Microstaging of SLNs with CK has shifted 10.6 per cent of our patient population from stage I to stage II disease. Undetected micrometastatic disease to the regional lymph nodes may account for the significant proportion of stage I breast cancer treatment failures. Furthermore, the ability to accurately stage the axilla by using lymphatic mapping techniques, SLN biopsy, and more sensitive assays may help identify a subgroup of truly node-negative patients with invasive breast cancer who can avoid the morbidity associated with a complete axillary dissection or systemic chemotherapy. Finally, those patients found to have micrometastatic disease to the regional lymph nodes can be treated appropriately in a more selective fashion.

Lymphatic mapping in breast cancer.

The most accurate predictor of survival in breast cancer is the presence or absence of lymph node metastases. Lymphatic mapping with sentinel node biopsy is a new technique that provides more accurate nodal staging compared with routine histology for women with breast cancer, but without the morbidity of a complete lymph node dissection. Sentinel lymph node (SLN) biopsy is a more conservative approach to the axilla that requires close collaboration from the surgical team, nuclear medicine, and pathology. National trials are investigating the clinical relevance of the upstaging that occurs with a more intense examination of the SLN. As is the case with breast preservation as a viable alternative to mastectomy for the definitive treatment of the primary node, selective lymphadenectomy has the ability to decrease morbidity without compromising patient care.