Sentinel lymph node--why study it: implications of the B-32 study.

Surgical removal of the regional lymph nodes by a level I and level II axillary dissection remains the standard of care for patients with surgically resectable breast cancer. Axillary dissection provides accurate pathologic staging and excellent regional disease control, and likely provides a small benefit in patient survival. Axillary dissection, however, is associated with significant patient morbidity. Sentinel lymph node (SLN) biopsy procedures have been found to provide very accurate pathologic staging when compared to axillary dissection; however, their effect on regional disease control and patient survival is not yet known. The National Cancer Institute (NCI) has sponsored a Phase III prospective, randomized clinical trial (the B-32 trial) through the National Adjuvant Breast and Bowel Project (NSABP), to compare results of patients treated with SLN biopsy alone vs. SLN biopsy with completion axillary node dissection in patients with clinically node-negative breast cancer. Results of this trial will provide evidence of the safety of SLN biopsy procedures in the management of patients with breast cancer.

Gamma probe guided biopsy of the sentinel node in malignant melanoma: a multicentre study.

Sentinel lymph node biopsy was attempted in 336 patients with clinically node-negative cutaneous melanoma. All patients were injected with technetium-99m labelled radiocolloid, with 108 patients simultaneously receiving vital blue dye for sentinel node identification. Sentinel lymph nodes were identified in 329 patients, giving a technical success rate of 97.9%. Metastatic disease was identified in 39 (11.9%) of the patients in whom sentinel nodes were found. Patients with negative sentinel nodes were observed and patients with positive sentinel nodes underwent comprehensive lymph node dissection. The presence of metastatic disease in the sentinel nodes and primary tumour depth by Breslow or Clark levels were joint predictors of survival based on Cox proportional hazards modelling. Disease recurrences occurred in 26 (8.8%) patients with negative sentinel lymph nodes, with isolated regional recurrences as the first site in 10 (3.4%). No patients with Clark level II primary tumours were found to have positive sentinel nodes or disease recurrences. One patient with a thin (<0.75 mm) Clark level III primary had metastatic disease in a sentinel node. Patients with metastases confined to the sentinel nodes had similar survival rates regardless of the number of nodes involved.

Sentinel lymph node biopsy in breast cancer.

Sentinel lymph node biopsy techniques have evolved in a short period of time to become a highly accurate method for the pathologic staging of clinically node-negative breast cancers. Multiple single and multi-institutional studies have confirmed a high accuracy of pathologic staging (95-100%) with reasonable false-negative rates (0-15%). The use of vital blue dyes, radioactive isotopes, or a combination of the two are the most commonly employed techniques used for this procedure. Currently, two large prospective randomized Phase III clinical trials supported by the National Cancer Institute are underway, which will define the effectiveness of these techniques as compared to standard axillary dissection in regards to regional disease control and patient survival.

Pathologic analysis of sentinel and nonsentinel lymph nodes in breast carcinoma: a multicenter study.

BACKGROUND: Axillary lymph node status is a powerful prognostic factor in breast carcinoma; however, complications after axillary lymph node dissection are common. Sentinel lymph node biopsy is an alternative staging procedure. The sentinel lymph node postulate is that tumor cells migrating from the primary tumor colonize one or a few lymph nodes before colonizing subsequent lymph nodes. To validate this hypothesis, the distribution of occult and nonoccult metastases in sentinel and nonsentinel lymph nodes was evaluated. METHODS: Original pathology material was reviewed from 431 patients enrolled on a multicenter validation study of sentinel lymph node biopsy in breast carcinoma patients. Paraffin embedded tissue blocks of sentinel and nonsentinel lymph nodes were obtained for 214 lymph node negative patients. Additional sections from 100 and 200 microm deeper into the paraffin block were examined for the presence of occult metastatic carcinoma. Both routine and cytokeratin immunohistochemical stains were employed. RESULTS: Metastases were identified in 15.9% of sentinel lymph nodes and 4.2% of nonsentinel lymph nodes (odds ratio [OR] 4.3[ P < 0.001]; 95% confidence interval [95% CI], 3.5-5.4). Occult metastases were identified in 4. 09% of sentinel lymph nodes and 0.35% of nonsentinel lymph nodes (OR 12.3 [P < 0.001]; 95% CI, 5.6-28.6). The overall case conversion rate was 10.3%. All the occult metastases identified were < or = 1 mm in greatest individual dimension. The likelihood (OR) of metastases in nonsentinel lymph nodes was 13.4 times higher for sentinel lymph node positive than for sentinel lymph node negative patients (P < 0. 001; 95% CI, 6.7-28.1). CONCLUSIONS: The distribution of occult and nonoccult metastases in axillary lymph nodes validates the sentinel lymph node hypothesis. In addition, pathology review of cases confirmed the authors' previously reported finding that the sentinel lymph nodes are predictive of the final axillary lymph node status. Occult metastatic disease is more likely to be identified in sentinel lymph nodes, allowing future studies to focus attention on one or a few sentinel lymph nodes. However, the relation between occult metastatic disease in sentinel lymph nodes, disease free survival, and overall survival must be evaluated prior to endorsing the intensive analysis of sentinel lymph nodes in routine practice. [See editorial on pages 971-7, this issue.]

Intraoperative ultrasound localization to guide surgical excision of nonpalpable breast carcinoma.

BACKGROUND: This report describes a technique of intraoperative tumor localization by ultrasound without the use of a needle or wire to guide the excision of nonpalpable breast cancers. The results of our experience with pathologic margin status are reviewed. STUDY DESIGN: From 1994 to 1998, 65 breast cancers in 62 patients with biopsy-proved nonpalpable breast cancer were excised using intraoperative ultrasound localization. The pathologic status of the margins from the initial surgical excision specimen and any further excisions, either at the first operation or later procedures, was recorded. The distance from the tumor to the closest margin of excision was also determined. RESULTS: The overall success in achieving pathologically negative excision margins at first operation was 97% (63 of 65 cancers). Three patients underwent a second operative procedure, two for positive margins and one for a margin less than 1 mm (second operation = 4.8% of patients). After completion of the first operative procedure, the mean distance to the closest margin of excision was 0.8 cm. CONCLUSIONS: Intraoperative ultrasound localization for excision of nonpalpable breast cancers is feasible and gives results, in terms of pathologic margins, that are comparable with those achieved by standard needle-wire-guided excisions.

Submission of lymph node tissue for ancillary studies decreases the accuracy of conventional breast cancer axillary node staging.

Pathologists are under increasing pressure to submit fresh tissue for ancillary studies and research protocols. In several tumor types (breast, lung, melanoma, colorectal, prostate), increased interest in detecting submicroscopic nodal metastases through reverse transcriptase polymerase chain reaction analysis of mRNA from portions of lymph nodes has precluded histologic analysis of the entire node for metastases. A retrospective review was undertaken of 227 breast cancer patients prospectively entered on a research protocol examining the usefulness of sentinel lymph node surgery. All of the patients ultimately underwent complete lymph node dissection. The research protocol required that all nodes greater than 8 mm in size be bisected and submitted separately. Positive lymph nodes were evaluated for unilateral or bilateral involvement in the node sections. Sixty node-positive patients were identified, yielding 230 positive nodes. One hundred seven of these nodes were confirmed to have been bisected. Carcinoma was identified in both lymph node sections in 64 (59.8%) nodes and in only one-half of the bisected lymph node in 43 (40.2%) nodes. Involvement of both sections was more likely when patients had multiple nodes positive. In 12 patients, involvement of one-half of the bisected nodes was the only evidence of metastatic disease (20.0% of node-positive patients). This evidence suggests that submission of less than the complete lymph node for histologic evaluation of metastatic disease decreases the accuracy of lymph node staging. Furthermore, a significant proportion of patients may be erroneously classified as histologically node negative.

Breast Cancer Cells in the Blood: A Pilot Study.

The goal of this pilot study was to determine in patients with operable breast cancer the incidence of breast cancer cells present in the blood, the clearance rate after surgical resection of the primary tumor, and the incidence of patients with persistent cancer cells in the blood after the primary tumor was removed. Twenty-one patients with operable breast cancer had 15 ml venous blood obtained twice prior to surgery and after surgery at 2, 4, 8, 12, 24, and 48 hours and also on days 7 and 14. Immunomagnetic selection of malignant cells was performed on each sample. Cells were then fixed on slides and immunocytochemistry performed on the collected cells. Cells that had a rosette of magnetic beads, cytoplasmic staining for keratin, and malignant morphology were counted as breast cancer cells. Eighteen of 19 of patients had cancer cells detected in at least one of the two blood samples preceding surgical removal of the primary tumor. The incidence of cancer cells in the blood of patients rapidly declined during the 48 hours postsurgery. The incidence of cancer cells in the blood remained stable in approximately 30% of patients to 14 days. The majority of breast cancer patients in this pilot study (even with small tumors and negative nodes) had detectable cancer cells in the blood prior to resection of the primary tumor. These findings justify further investigation. Successful application of this methodology may serve as a powerful indicator of which patients need systemic adjuvant therapy, the effectiveness of systemic adjuvant therapy, tumor recurrence, and early detection of breast cancer.

Melanoma complicating pregnancy.

The incidence of malignant melanoma is rising, and this may be the most frequently encountered malignancy during pregnancy. Because effective treatment of advanced or metastatic disease remains elusive, the key to adequate therapy is surveillance for early disease with prompt diagnostic work-up and treatment. Review of the most prominent reports in the literature fails to yield a consensus on whether pregnancy contributes to a worse prognosis. It seems clear that after controlling for all known prognostic variables, prognosis is unchanged; however, groups of patients diagnosed during pregnancy may have a disproportionately high incidence of high-risk primary lesion sites and increased tumor thickness. Surgical treatment during pregnancy should be prompt, with appropriate avoidance of general anesthesia during the first trimester. There is as yet insufficient evidence to warrant the use of adjuvant chemotherapy or biologic therapy during pregnancy.

Localization of regional lymph nodes in melanomas of the head and neck.

OBJECTIVES: To study the efficacy of gamma-probe radiolocalization of the first draining (sentinel) lymph node (SLN) in stage N0 melanoma of the head and neck and to evaluate its potential role in the staging and treatment of this disease. DESIGN: Gamma-probe radiolocalization, a new alternative to blue-dye lymphatic mapping, uses a scintillation (gamma) probe to identify radiolabeled SLNs. In a consecutive sample clinical trial, gamma-probe radiolocalization of the SLN is compared with lymphoscintigraphy and blue-dye lymphatic mapping. Follow-ups ranged from 1.7 years to 4 years, with a mean follow-up of 2.5 years. SETTING: Tertiary and private care teaching hospital. PATIENTS: Between June 1993 and November 1995, 23 patients with stage N0 intermediate-thickness melanoma of the head and neck were enrolled in this volunteer sample. INTERVENTIONS: Twenty-four hours prior to surgery, a radioactive tracer was intradermally injected around the circumference of a primary melanoma. Twelve patients also had blue dye injected just prior to surgical resection. Using a handheld gamma probe, radiolabeled lymph nodes were identified and selectively removed with minimal dissection. In patients with nodes with histologic evidence of metastases, a regional lymphadenectomy was performed. MAIN OUTCOME MEASURES: The successful identification of radiolabeled SLNs, the correlation of SLN radiolabeling to lymphoscintigraphy and blue-dye mapping, and the long-term development of regional metastases. RESULTS: Surgeons successfully resected the radiolabeled SLNs in 22 (96%) of 23 patients. The success rate of blue-dye lymphatic mapping was 8 (75%) of 12 patients and lymphoscintigraphy was 20 (91%) of 22 patients. One hundred percent of blue-stained lymph nodes were radiolabeled. The one patient in whom no SLN could be identified developed regional disease at 17 months. CONCLUSIONS: Gamma-probe radiolocalization and resection of the radiolabeled SLN is a simple and reliable method of staging regional lymph nodes and determining the need for elective lymphadenectomy.

Minimal-access surgery for staging of malignant melanoma.

OBJECTIVE: To develop a simple, minimally invasive technique of determining whether regional node metastasis has occurred in patients with melanoma. SETTING: Teaching hospital tertiary care and private practice settings. PATIENTS: Between February 1993 and October 1994, 121 patients with invasive malignant melanoma and clinically negative lymph nodes were enrolled in this clinical trial. DESIGN: Consecutive sample clinical trial. Within 24 hours prior to lymph node resection, a radioactive tracer was injected into the dermis around the site of the primary melanoma. Forty-four patients also had blue dye injected immediately prior to surgical resection. Measurement of radioactivity in the lymph nodes and surgical localization were made using a handheld gamma detector. Radiolabeled nodes were selectively removed with the least dissection possible. In patients with pathologically positive radiolabeled nodes, regional lymphadenectomy was performed. OUTCOME MEASURES: Successful identification of radiolabeled sentinel lymph nodes, correlation of radiolabeling with injection of blue dye, and regional node recurrence rate. RESULTS: Surgeons successfully resected the radiolabeled sentinel lymph nodes in 118 (98%) of 121 patients. One hundred percent of blue-stained lymph nodes were successfully radiolabeled. Fifteen patients had pathologically positive sentinel lymph nodes. In 10 patients, the sentinel node was the only node with metastasis. Two systemic and one regional node recurrences occurred during a mean follow-up of 220 days. CONCLUSIONS: Selective gamma probe-guided resection of the radiolabeled sentinel lymph node is possible in over 95% of patients with melanoma. This technique offers a simple and reliable method of staging of regional lymph nodes in these patients without performing a regional lymphadenectomy.

Intraoperative photodynamic therapy as an adjunct to surgery for recurrent rectal cancer.

BACKGROUND: Locally recurrent rectal cancer is a difficult management problem for the surgical oncologist. Current therapies including radical surgery, radiation and chemotherapy have had little success in producing curative results for these patients. This study incorporated intraoperative photodynamic therapy (PDT) as an adjunct to radical surgery for the treatment of locally recurrent rectal cancer. METHODS: Twenty-two patients were enrolled in a prospective feasibility study and injected with Photofrin (Quadra Logic Technologies, Vancouver, British Columbia, Canada) before surgery. Eight patients were found to be candidates and received PDT after surgical exploration and resection. Seven patients had rectal adenocarcinoma and one had squamous cell carcinoma of the anal canal. RESULTS: Based on the indication for PDT, three patient groups were evaluated: group A, resection of all gross disease with negative pathologic margins in four patients; group B, resection of gross disease with positive pathologic margins in two; and group C, residual bulky tumor in two patients. There was one perioperative death (12.5%), not related to PDT, and one major morbidity due to PDT (12.5%). Local recurrence occurred in six patients (two in group A, two in group B, two in group C). Mean overall survival was 15.4 months for group A, 6.5 months for group B, and 24.5 months for group C. CONCLUSIONS: The results of this study suggest that intraoperative PDT may be administered safely in patients undergoing resection of recurrent rectal cancer. However, its use in the present state of technology appears to be inadequate for control of disease, particularly if bulky tumor or residual microscopic disease is left behind.

Detection of HER-2/neu oncogene amplification in flow cytometry-sorted breast ductal cells by competitive polymerase chain reaction.

BACKGROUND: The amplification and/or overexpression of the HER-2/neu oncogene has been proposed as an important prognostic marker in breast cancer. However, contradictory results from various groups regarding whether there is statistical significance in HER-2 amplification or overexpression in predicting overall and disease free survival in node positive versus node negative patients exist in the literature. Current assays on quantifying the HER-2 oncogene rely on DNA extracted from homogenized breast tissue. Not only is a large amount of tissue required, but also, the DNA extract is contaminated with DNA from stromal cells and leukocytes, leading to decreased specificity and sensitivity of the HER-2 assay. Improving the specificity (DNA from breast ductal cells) and the sensitivity (competitive polymerase chain reaction [PCR]) of the HER-2 amplification detection assay will help resolve some of these controversies. METHODS: Using multiparameter flow cytometry (FCM), ductal cells from breast biopsies and fine needle aspirations (FNAs) are identified and selectively sorted using anti-cytokeratin, anti-HER-2 antibody labeling and DNA staining. HER-2 amplification in these sorted cells is then quantified by competitive DNA PCR using a competitive reference standard mutant template that is susceptible to the restriction enzyme Sma-1. RESULTS: Applying this strategy, SK-BR-3, an HER-2 amplified breast cancer cell line, was found to have approximately 9x baseline HER-2 oncogene copies. In addition, MCF-7, a known HER-2 nonamplified breast cancer cell line, was found to have baseline HER-2 oncogene copies. In the 10 clinical breast samples tested, 4 of the 10 breast cancers were HER-2 amplified using as few as 1000 cells. The cytokeratin positive cells of these cancers, in contrast to the cytokeratin negative cells, have detectably higher HER-2 amplification (7.2 +/- 2.8x versus 3.2 +/- 1.1x, respectively). Hence, HER-2 gene amplification would have been underestimated if unsorted cells were used because of stromal dilution. In the cytokeratin positive cells that were HER-2 oncogene amplified, corresponding HER-2 oncoprotein overexpression was detected by FCM. CONCLUSIONS: Using FCM, the ductal cell subpopulation of a breast specimen can be successfully sorted from breast biopsy and FNA specimens. Moreover, by applying the technique of competitive PCR, improved specificity and sensitivity in HER-2 oncogene amplification detection is achieved. The entire procedure can be accomplished in 1 day, allowing for a cost-effective assay and rapid turnaround time.

Quantitation of c-myc gene amplification by a competitive PCR assay system.

Gene amplification is a common event in the progression of human cancers. The detection and quantitation of certain amplified oncogenes has been shown to have prognostic importance in certain human malignancies. A method is described that utilizes the principles of competitive PCR for quantitation of the c-myc gene copy number in relation to the copy number of a reference gene (tissue plasminogen activator [t-PA] gene) located on the same chromosome (8) as the c-myc gene. This ratio gives the true level of amplification of the c-myc gene, accounting for variables such as cell number, cell cycle phase, and chromosome 8 ploidy. The determination of gene amplification depends on the precise measurement of the ratio of target and reference genes. An important feature of this assay is that the competitive reference standards used for target gene c-myc and reference gene t-PA have been linked to form a hybrid. This simple modification guarantees that both reference gene and target gene assay tubes get identical amounts of the competitive template for each gene, thereby eliminating a significant source of error. This method has the same desirable attributes of standard PCR in that very small sample sizes are required and that results can easily be obtained in < 24 hr. In addition, this technique does not require the use of radioactivity or expensive DNA detection kits, and thus, may give it wider applicability for the study of human cancers.

Chromosomes 8, 12, and 17 copy number in Astler-Coller stage C colon cancer in relation to proliferative activity and DNA ploidy.

Fluorescence in situ hybridization using centromere-specific DNA probes to chromosomes 8, 12, and 17 was applied to 23 archival paraffin-embedded stage C colonic cancer specimens. Chromosome copy number was related to flow cytometric determinations of S-phase fraction and DNA ploidy. Three to eight copies of chromosomes 8, 12, and 17 were observed at mean frequencies of 28.7%, 37.8%, and 20.9%, respectively. The mean frequency of multiple copies of chromosome 12 was significantly greater than that for chromosome 17 (P < 0.0025). The mean frequency of single copies of chromosome 17 was significantly greater than that for chromosomes 8 and 12 (P < 0.0025 and P < 0.0005, respectively). Regarding the fourth quartile of cases, defined on the basis of the frequency of multiple chromosome copies, the proportion demonstrating moderate to high proliferative activity greatly exceeded the proportion displaying low proliferative activity. The same cases (most chromosomally aberrant) also generally demonstrated DNA aneuploidy. The results indicate a substantial degree of karyotypic instability in advanced colon cancer, particularly in cases with high proliferative activity and DNA aneuploidy.

Diagnostic utility of DNA content flow cytometry in follicular neoplasms of the thyroid.

Preoperative diagnosis of follicular carcinoma of the thyroid remains a clinical challenge. This study determined the DNA content parameters of ploidy and proliferative activity levels from cells of normal thyroid tissue, follicular adenomas, and follicular carcinomas to evaluate if these parameters could be used as an adjunct to fine needle aspiration in their diagnosis. Statistically significant higher proliferative activity levels were found in the carcinoma groups (mean S-phase fraction [SPF] = 5.0%) compared to 2.9% for follicular adenomas and 1.3% for normal thyroid. DNA aneuploidy was identified in 73% of carcinomas and 36% of adenomas. Because of overlap of SPF values between groups, one could not rule out the presence or absence of malignancy based on DNA content parameters alone. These measurements may, however, be an aid to the decision making in patients who are poor surgical risks.

Prognostic implications of proliferative activity and DNA aneuploidy in Astler-Coller Dukes stage C colonic adenocarcinomas.

Paraffin-embedded surgical specimens from 69 patients who underwent resections of otherwise untreated Dukes stage C adenocarcinoma of the colon were examined for proliferative activity, DNA aneuploidy, DNA index, and proportion of aneuploid cells by flow cytometry. Results were correlated to clinical characteristics of the patients and to overall survival times. DNA aneuploid tumors were identified in 60 cases (87%), diploid tumors in 9 cases (13%). The mean S-phase fraction for all cases was 17.6%, with a standard deviation (SD) of 7.8. In univariate statistical analysis, younger patient age, lower tumor proliferative activity, DNA index less than or equal to 1.2, and presence of only 1-4 lymph nodes with tumor involvement were found to be significant predictors of improved patient survival. In multivariate Cox regression analysis, low tumor proliferative activity, younger patient age, and location of the tumor in the right or transverse colon were found to be significant independent predictors of increased patient survival. When tumor proliferative activity was stratified into statistically defined subgroups, patients with tumors of low proliferative activity (S-phase less than mean - 0.5 SD) had significantly longer survival than patients with tumors of moderate proliferative activity (S-phase value greater than mean - 0.5 SD and less than mean +0.5 SD) or high proliferative activity (S-phase greater than mean +0.5 SD). These results suggest that tumor proliferative activity in Dukes C colon carcinoma may be an important biological factor in determining patient prognosis.