Mutation analysis of the putative tumor suppressor gene PTEN/MMAC1 in primary breast carcinomas.

A novel gene was identified recently at chromosome 10q23, named PTEN or MMAC1, and based on several criteria it was designated as a potential human tumor suppressor gene. Loss of heterozygosity affecting this region of 10q is observed in several cancer types, especially glioblastoma, and inactivating mutations of the PTEN/MMAC1 gene are found in some of these cancers as well as cell lines and xenografts. Breast cancer is among the tumor types in which mutations are documented, and germline mutations of the gene appear to be responsible for the rare autosomal dominant familial cancer syndrome known as Cowden disease, which includes breast cancer among its clinical features. To further determine the role that PTEN/MMAC1 mutations may play in breast tumorigenesis, the entire coding region was screened for mutations in 54 unselected primary breast cancers. Two mutations were identified, a somatic 2-bp deletion in an apparently sporadic breast cancer, and a germ-line 4-bp deletion in a breast cancer patient with a clinical history consistent with Cowden disease. These data indicate that somatic mutations of PTEN/ MMAC1 occur in only a small fraction of primary breast cancers and confirm the role of this gene in the etiology of Cowden disease. Evidence is also presented suggesting that numerous polymorphisms and missense variants exist in the PTEN/MMAC1 transcript.

Biological behavior of human breast cancer micrometastases.

PURPOSE: Clinically undetectable micrometastases may account for disease recurrence in breast cancer patients after variable disease-free intervals. However, little is known about the cellular mechanisms controlling human breast cancer micrometastases. We compared tumor proliferation rate, apoptotic index, and angiogenesis in human breast cancer micrometastases with those of macroscopic axillary lymph node metastases. EXPERIMENTAL DESIGN: Seven breast cancer micrometastases (<2 mm) obtained from the sentinel nodes of seven patients were compared with 13 macrometastases (lymph node replaced with tumor) obtained from 13 patients. The tissue was fixed in formalin, embedded in paraffin, serially sectioned, and evaluated by H&E and immunohistochemistry for cytokeratin. Tumor proliferation rate was assessed as the number of Ki-67-positive nuclei/total number of tumor nuclei. Tumor vascularity was quantified using antibody to factor VIII to identify microvessels per high-power field (at x400). Apoptosis was quantified using the terminal deoxynucleotidyl transferase (Tdt)-mediated nick end labeling method. Results were analyzed with the Wilcoxon rank-sum test. RESULTS: Median size of micrometastases was 0.5 mm (range, 0.4-1.0), and the median number of tumor nuclei/section was 143 (range, 90-312). Median proliferation rate for macrometastases was greater than for micrometastases (35% versus 12%; P = 0.003). Median microvessel density/high-power field for macrometastases was greater than for micrometastases (17 versus 1; P < 0.001). There was no difference in apoptotic index between macrometastases and micrometastases (1.1% versus 0.7%; P = not significant). CONCLUSIONS: Human breast cancer micrometastases have lower tumor proliferation rates and angiogenesis than breast cancer macrometastases. These characteristics may explain their differential growth patterns.

Infiltrating breast carcinoma in patients age 30 years and younger: long term outcome for life, relapse, and second primary tumors.

A retrospective study examining the influence of young age, defined as 30 years or less on the outcome of early-staged (American Joint Committee 1978-I, II) breast cancer was undertaken using patients treated between 1950 and 1970 to ensure a long follow-up period. Because of the era of treatment, radical mastectomy without systemic chemotherapy was the predominant treatment. Ninety-nine patients met study criteria, with a median follow-up of 11.4 years (range 0.5 to 41 years). The patient group was compared to patients of all ages, treated at Memorial Sloan-Kettering Cancer Center in 1960 (5 and 10 years) and to patients treated between 1940 and 1943 (30 year follow-up). At the 5, 10, and 30 year follow-up periods, patients in the young age group consistently had disease-specific survival 10-20% lower than their older counterparts. For young patients who survived their first cancer diagnosis, second primaries both in the contralateral breast and elsewhere, played a significant role in determining their subsequent life span. When compared to risks of second primary cancers in the National Cancer Institute's SEER (Surveillance, Epidemiology and End Results Program) Cancer Registry for all ages, the increased risk for very young breast cancer patients was significant (p = 0.000). With these two findings in mind, treatment for young patients with breast cancer should focus not on local therapy options alone but on the increased risk of both systemic disease and of second primaries.

Microdissection and molecular genetic analysis of HER2/neu in breast carcinoma.

Precise correlation of histomorphology with molecular genetic analysis is difficult in tissues composed of heterogeneous cell populations. We describe here a novel microdissection technique employed to correlate HER2/neu (HER2) immunohistochemical staining with HER2 genetic analysis in formalin-fixed, paraffin-embedded breast tissue. Fourteen invasive ductal carcinomas were selected from the pathology files of Memorial Sloan-Kettering Cancer Center that had been immunostained for HER2. Seven tumors showed typical membrane immunoreactivity and seven were negative. A dissecting microscope was then used to isolate minute (< or = 1 mm x 1 mm) areas of invasive carcinoma and normal breast tissue for molecular study. To document the type of cell sample submitted for polymerase chain reaction (PCR) analysis, each microdissected piece of tissue was photographed prior to removal from the glass slide. A preliminary study of four cases compared the results of PCR and genetic analysis using microdissected hematoxylin and eosin (H & E)-stained tissue, unstained dewaxed tissue, and destained dewaxed tissue in four specimens. Similar results were obtained with all three tissue preparations. Thereafter, H & E stained sections were selected as the tissue preparation of choice because tissue details were seen more clearly. There was complete correlation of immunohistochemical staining and HER2 analysis by PCR in all 14 cases. In the final 10 cases, the PCR product was resolved by gel electrophoresis and quantified by optical densitometry. Fourfold to eightfold amplification of HER2 was found in the five tumor specimens that immunohistochemically stained for HER2. A single copy of HER2 was found in all HER2-negative tumors and in normal breast tissue. We conclude that it is possible to quantify gene amplification of HER2 in minute samples of H & E-stained normal and malignant breast tissue. This microdissection technique can be applied to correlative histologic--molecular genetic analysis in a wide variety of tumor types.

Analysis of MTS1/CDK4 in female breast carcinomas.

Multiple factors, both environmental and genetic, are thought to play roles in breast carcinogenesis. The recently cloned multiple tumor suppressor gene (MTS1), the product of which interacts with CDK4 to regulate cell growth, has been found to be mutated with high frequency in a variety of cell lines as well as primary tumors of different histologic types. Using PCR-SSCP, we analyzed exons one (126 bp) and two (307 bp) of the MTS1 gene to determine the incidence of mutation in a population of 50 primary breast adenocarcinomas and corresponding normal tissue. Analysis of five breast tumor cell lines was also performed. We found no mutations in the MTS1 gene in the primary breast tumor samples. One cell line was found to have a homozygous deletion of the gene. Our results suggest that the MTS1 gene is not mutated with increased frequency in primary breast tumors, and thus may not play a major role in breast carcinogenesis.

Intradermal isotope injection is superior to intramammary in sentinel node biopsy for breast cancer.

BACKGROUND: The optimal sentinel lymph node (SLN) biopsy technique remains undefined in breast cancer. Injecting radiotracer or blue dye by a variety of routes seems to stage the axilla with comparable accuracy, and we have hypothesized that the dermal and the parenchymal lymphatics of the breast drain to the same SLN in most patients. Two previous studies from our institution support this concept: (1) a single-surgeon series of 200 consecutive SLN biopsy procedures demonstrating a high dye-isotope concordance for both intradermal (ID) and intraparenchymal (IP) isotope injection, and (2) a series of 100 procedures validated by a backup axillary dissection (ALND) in which the false-negative rate following ID isotope injection was comparable to that of our previous results with IP injection. Here, we directly compare the results of SLN biopsy using either ID or IP isotope injection for our entire experience of SLN biopsy procedures in which a backup ALND was done. METHODS: This is a retrospective, nonrandomized study of 298 clinical stage I to II breast cancer patients having SLN biopsy with a backup ALND planned in advance, comparing the results of ID (n = 164) and IP (n = 134) isotope injection. All patients had IP injection of blue dye. Endpoints included (1) successful SLN identification, (2) false-negative rate, (3) dye-isotope concordance, and (4) the SLN/axillary background isotope count ratio. RESULTS: ID isotope was more successful than IP, identifying the SLN in 98% versus 89% of cases, respectively. False-negative results (4.8% vs 4.4%) and dye-isotope concordance (92% vs 93%) were comparable between the 2 groups, and SLN/axillary background isotope count ratios were significantly higher with ID than with IP injection (288/1 vs 59/1). CONCLUSIONS: ID isotope injection identifies the SLN more often than IP, stages the axilla with comparable accuracy, and is associated with higher levels of SLN isotope uptake. The dermal and parenchymal lymphatics of the breast drain to the same axillary SLN in most breast cancer patients, and ID isotope injection is the procedure of choice in this setting.

Molecular analysis of the INK4A and INK4B gene loci in human breast cancer cell lines and primary carcinomas.

The INK4A and INK4B loci are located at 9p21 and have been implicated in the tumorigenesis of various human malignancies. The INK4A gene encodes two cell cycle regulators, p16(INK4A) and ARF, while INK4B encodes p15(INK4B). Previously, we have shown that the p16(INK4) tumor suppressor was not mutated or deleted in primary breast carcinomas. However, primary and metastatic breast carcinomas exhibited a relative hypomethylation of p16(INK4A), which is associated with expression, compared to normal breast tissue. The present study was conducted to determine if inactivation of p15(INK4B) and INK4A exon 1beta (ARF) are common events in breast carcinoma. Mutational analysis was performed by PCR-SSCP, and mRNA expression was evaluated by RT-PCR. Methylation-specific PCR was used to determine the methylation status of the p15(INK4B) promoter. Our results demonstrate that the p15(INK4B) gene was altered in 3 (21%) of the 14 breast cell lines; one had a silent mutation and two had homozygous deletion of the gene. None of the cell lines showed methylation of p15(INK4B). Two (14%) cell lines had homozygous deletion of INK4A exon 1beta. All normal and malignant breast tissue samples were wild-type and non-methylated for p15(INK4B) and wild-type for exon 1beta. Our results show that these structurally and functionally related genes are not invariably affected together, and the most frequently observed alteration at the INK4A and INK4B loci in breast carcinoma appears to be p16(INK4A) hypomethylation.

Women 35 years of age or younger have higher locoregional relapse rates after undergoing breast conservation therapy.

BACKGROUND: The use of breast conservation therapy (BCT) in young women with invasive breast cancer is controversial. To examine this important issue, rates of locoregional recurrence and overall survival after BCT were compared in two subsets of women--those < or = 35 years of age at time of surgery and their older counterparts. STUDY DESIGN: We examined records of 290 women with invasive breast cancer treated with BCT (local excision and axillary dissection) at Memorial Sloan-Kettering Cancer Center between 1984 and 1993. These included 87 patients < or = 35 years of age at time of surgery and 203 randomly selected patients > 35 years of age. Followup was obtained from physician charts or patient interviews, or both. Complete data on clinicopathologic factors, recurrence, and survival were available on 280 patients. RESULTS: Median followup from time of operation was 8.0 years for the entire group. Mean tumor size was 2.0 cm for women < or = 35 years and 1.8 cm for those > 35 (p = 0.07). Involved nodes were found in 48% of the young patients and 36% of the older patients (p = 0.08). Within our study group (n = 280), 274 patients received radiotherapy. Women < or = 35 years of age had significantly higher rates of locoregional recurrence and lower rates of overall survival than their older counterparts (p < 0.05). On multivariate analysis, these results were independent of tumor size and nodal status. A history of locoregional relapse, however, was not associated with a higher rate of death from disease in the entire cohort or in either age group. CONCLUSIONS: Patients < or = 35 years of age undergoing BCT for invasive breast cancer are at higher risk for locoregional recurrence and death from disease. The higher mortality rate, however, does not appear to be a direct result of locoregional relapse. Additional study is required to verify these findings. Currently, young age does not exclude patients from BCT in our practice. But, we include this data as part of the informed consent process.

The breast cancer patient with multiple sentinel nodes: when to stop?

BACKGROUND: During sentinel lymph node (SLN) biopsy for breast cancer, most authors report identifying a mean of 1 to 3 SLNs, but a range of 1 to 8 (or more) SLNs per patient. A significant minority of patients have 4 or more SLNs. Here we seek to determine the significance for the breast cancer patient of finding multiple SLNs, and whether there is an optimal threshold number of SLNs that should be removed. STUDY DESIGN: 1,561 patients who underwent successful SLN biopsy using blue dye and radioisotope in combination. Each SLN site was categorized prospectively by the operating surgeon as a dye success, an isotope success, or both. All SLNs containing counts at least four times greater than the postexcision axillary background were considered to be isotope successes. RESULTS: Fifteen percent of patients (241) had multiple (>3) SLNs. Ninety-eight percent of node-positive patients (440 of 449) were identified within the first three SLN sites examined. In 2% of all SLN positive patients (9 of 449) or 4% of patients with multiple SLN (9 of 241), a positive SLN was detected at site four or more. In eight patients the first positive SLN was found at sites four or more. Blue dye and isotope were equally effective in identifying metastases in patients with multiple SLNs. CONCLUSIONS: Fifteen percent of patients having SLN biopsy for breast cancer have multiple SLNs. Although 98% of positive SLNs were identified within the first three sites sampled, a small number of patients had their first positive SLN at sites 4 to 8. These data suggest that there is no absolute upper threshold for the number of SLNs that should be removed. Sampling a few additional SLNs probably adds little morbidity to the procedure, yet may significantly alter the treatment of some individuals. SLN biopsy should be continued until all blue and hot nodes are removed.

Sentinel lymphadenectomy accurately predicts nodal status in T2 breast cancer.

BACKGROUND: Sentinel lymph node biopsy (SLNB) has emerged as a reliable, accurate method of staging the axilla for early breast cancer. Although widely accepted for T1 lesions, its use in larger tumors remains controversial. This study was undertaken to define the role of SLNB for T2 breast cancer. STUDY DESIGN: From a prospective breast sentinel lymph node database of 1,627 patients accrued between September 1996 and November 1999, we identified 223 patients with clinical T1-2N0 breast cancer who underwent 224 lymphatic mapping procedures and SLNB followed by a standard axillary lymph node dissection (ALND). Preoperative lymphatic mapping was performed by injection of unfiltered technetium 99 sulfur colloid and isosulfan blue dye. Data about patient and tumor characteristics and the status of the sentinel lymph nodes and the axillary nodes were analyzed. Statistics were performed using Fisher's exact test. RESULTS: Two hundred four of 224 sentinel lymph node mapping procedures (91%) were successful. Median tumor size was 2.0 cm (range 0.2 to 4.8 cm). One hundred forty-five of the 204 patients had T1 lesions and 59 patients had T2 lesions. There were 92 pathologically positive axillae, 5 (5%) of which were not evident either by SLNB or by intraoperative clinical examination. The false-negative rate and accuracy were not significantly different between the two groups, but axillary node metastases were observed more frequently with T2 than with T1 tumors (p = 0.005); other factors, including patient age, prior surgical biopsy, upper-outer quadrant tumor location, and tumor lymphovascular invasion were not associated with a higher incidence of false-negative SLNB in either T1 or T2 tumors. CONCLUSIONS: SLNB is as accurate for T2 tumors as it is for T1 tumors. Because no tumor or patient characteristics predict a high false-negative rate, all patients with T1-2N0 breast cancer should be considered candidates for the procedure. Complete clinical examination of the axilla should be undertaken to avoid missing palpable axillary nodal metastases.

Sentinel lymph node biopsy in breast cancer: unfiltered radioisotope is superior to filtered.

BACKGROUND: The combination of gamma-probe radiolocalization and blue-dye mapping of sentinel lymph nodes (SLNs) has been advocated as the most accurate method for staging the clinically negative axilla in breast cancer patients, but the technical aspects of these procedures are not fully characterized in the literature. In this study, we compared the success of SLN localization in 134 consecutive breast cancer patients using blue dye plus two different preparations of radiocolloid. STUDY DESIGN: A retrospective analysis of a prospectively maintained data base was performed to assess SLN localization in two cohorts of patients. Unfiltered technetium-99m (Tc-99m) sulfur colloid (in 77 patients; group I) was compared with filtered Tc-99m sulfur colloid (in 57 patients; group II). All patients had a peritumoral injection of blue dye and isotope, followed immediately by lymphoscintigraphy to confirm radioactivity at the injection site and to image the SLN. Statistical analysis was performed using the Pearson chi-square test. RESULTS: Unfiltered Tc-99m sulfur colloid was superior to the filtered radiocolloid in localizing the SLN (88% versus 73%; p = 0.03). SLN imaging by lymphoscintigraphy was also more successful in the unfiltered group. Using the combination of blue dye and radiolocalization, SLNs were identified in 94% of patients. CONCLUSIONS: For optimal localization of the SLN in breast cancer patients, surgeons should use the combined technique of blue-dye mapping and gamma-probe localization using unfiltered Tc-99m sulfur colloid.

Sentinel lymph node biopsy in breast cancer: initial experience at Memorial Sloan-Kettering Cancer Center.

BACKGROUND: Sentinel node biopsy (SNB) has emerged as a potential alternative to routine axillary dissection in clinically node-negative breast cancer. STUDY DESIGN: From September 1995 to June 1996 at Memorial Sloan-Kettering Cancer Center, 60 patients with clinically node-negative cancer underwent SNB, which was immediately followed by standard axillary dissection. Both blue dye and radioisotope were used to identify the sentinel node. SNB was compared with standard axillary dissection for its ability to accurately reflect the final pathologic status of the axillary nodes. RESULTS: The sentinel node was successfully identified by lymphoscintigraphy in 75% (42 of 56), by blue dye in 75% (44 of 59), by isotope in 88% (52 of 59), and by the combination of blue dye and isotope in 93% (55 of 59) of all 59 evaluable patients. Of the 55 patients in this study where sentinel nodes were identified, 20 (36%) were histologically positive. The sentinel node was falsely negative in three patients, yielding an accuracy of 95%. SNB was more accurate for T1 (98%) than for T2-T3 tumors (82%). CONCLUSIONS: Lymphatic mapping is technically feasible, reliably identifies a sentinel node in most cases, and appears more accurate for T1 tumors than for larger lesions. Blue dye and radioisotope are complementary techniques, and the overall success of the procedure is maximized when the two are used together.

A trend analysis of the relative value of blue dye and isotope localization in 2,000 consecutive cases of sentinel node biopsy for breast cancer.

BACKGROUND: Among the advocates of blue dye, isotope, or combined dye-isotope mapping of the sentinel lymph node (SLN) for breast cancer, there is no universal consensus as to which technique is optimal and whether the relative value of each method changes with increasing experience. The objective of this study was to examine the relative contributions of blue dye and radioisotope to successful identification of the SLN as the SLN-mapping technique evolved over our first 2,000 consecutive cases. STUDY DESIGN: Using the first 2,000 consecutive SLN biopsy procedures for breast cancer, performed by eight surgeons (none previously experienced in SLN techniques) at one institution, using a combined technique of blue dye and isotope mapping, we report the institutional learning curve and the relative contributions of dye and isotope to identifying both the SLN and the positive SLN, by increments of 500 cases. RESULTS: Comparing the first 500 with the most recent 500 cases, success in identifying the SLN by blue dye did not improve with experience, although success in isotope localization steadily increased, from 86% to 94% (p < 0.00005). With the increasing success of isotope mapping, the marginal benefit of blue dye (the proportion of cases in which the SLN was identified by blue dye alone) steadily declined, from 9% to 3% (p = 0.0001). Parallel to this trend, the proportion of positive SLNs identified by blue dye did not change with experience (89% to 90%), but isotope success steadily increased, from 88% to 98% (p = 0.0015). The proportion of positive SLNs identified by blue dye alone declined from 12% to 2% (p = 0.0015). CONCLUSIONS: Using a combined technique of blue dye and radioisotope mapping, and with refinement of the radioisotope technique, we report 97% success identifying the SLN. Although we continue to recommend the use of both methods in SLN mapping for breast cancer, we observe with experience a declining marginal benefit for blue dye.

State-of-the-art approaches to sentinel node biopsy for breast cancer: study design, patient selection, technique, and quality control at Memorial Sloan-Kettering Cancer Center.

Sentinel lymph node (SLN) biopsy has the potential to become a standard operation for most patients with operable breast cancer, but raises a number of issues for the surgeon and institution wishing to start a SLN program. We began to perform SLN biopsy for breast cancer at Memorial Sloan-Kettering Cancer Center in September of 1996. Based on a pilot study of 60 patients, detailed analyses of our first 500 and 1000 cases, and a cumulative experience of 1500 procedures, we report the lessons learned in starting a SLN program, emphasizing study design, case selection, technique and quality control. All patients had clinical T1-2N0 breast cancers and isotope plus blue dye mapping. The combination of blue dye and isotope localization was superior to either method alone, unfiltered technetium sulfur colloid was superior to filtered, and optimum isotope localization was achieved with a low-volume, low-dose intradermal injection. In our first 1000 cases, 14% of SLN were found by isotope alone, and 8% by dye alone. 10% of positive SLN were found by isotope alone, and 11% by dye alone. Failed and false-negative SLN procedures were less frequent as experience increased.

Sentinel lymph node biopsy: an American perspective.

The current protocol for use of sentinel lymph node biopsy at Memorial Sloan-Kettering Cancer Center, NY, USA is described. The technique requires to be validated both by individual surgeons and institutions prior to use. Ongoing American multi-institutional trials to investigate the true role of sentinel lymph node biopsy are underway.

A prospective validated model for predicting axillary node metastases based on 2,000 sentinel node procedures: the role of tumour location [corrected].

AIMS: The purpose was to identify the independent predictive factors of axillary lymph-node metastases (ALNM) in infiltrating ductal carcinoma (IFDC) and to create a prospective, validated statistical model to predict the likelihood of ALNM in patients in the present era of sentinel lymph-node (SLN) biopsy and enhanced histopathology. METHODS: Univariate and multivariate analyses of 13 clinicopathological variables (including tumour location) were performed to determine predictors of ALNM in 1659 eligible SLN biopsy procedures. A logistic regression model was developed and then prospectively validated on a second population of 187 subsequent consecutive procedures. RESULTS: Age, pathological tumour size, palpability, lymphovascular invasion (LVI), histological grade, nuclear grade, ductal histological subtype, tumour location (quadrant) and multifocality were associated with ALNM in univariate analyses (P < 0.001). Of these, only palpability and histological grade were not statistically associated with ALNM in the multivariate analysis (P> 0.05). The frequency of ALNM in upper-inner-quadrant (UIQ) tumours was 20.6%, compared with 33.2% for all other quadrants (P<0.0005). There was no statistical difference between UIQ and other-quadrant tumours in any clinicopathological variables analysed. The logistic regression model, developed based on the population of 1659, had the same accuracy, sensitivity, specificity, positive predictive value and negative predictive value when applied prospectively to the second population. CONCLUSION: Tumour size, LVI, age, nuclear grade, histological subtype, multifocality and location in the breast were independent predictive factors for ALNM in IFDC. ALNM is less frequent in UIQ tumours than in other-quadrant tumours. Our prospectively validated predictive model could be valuable in pre-operative patient discussions, although staging of the axilla in the individual patient remains necessary.

A selection algorithm for internal mammary sentinel lymph node biopsy in breast cancer.

Internal mammary lymph-node (IMN) metastases in breast carcinomas have a major influence on survival, comparable with the influence of axillary lymph-node metastases (ALNM). Prospective, randomized trials have demonstrated that complete IMN dissection as part of extended radical mastectomy does not improve overall or disease-free survival. In the subset of patients with tumours 1cm or less in size and no ALNM, information on IMN status would provide important information. In these cases, the presence of IMN metastases would change the staging from stage I to stage IIIB, according to the current tumour, node and metastasis classification. More importantly, it would influence these patients' adjuvant treatment. Lymphatic mapping for sentinel lymph-node (SLN) biopsy has demonstrated extra-axillary drainage in up to 35% of patients. Recent reports have demonstrated the feasibility of internal mammary sentinel lymph-node (IM-SLN) biopsy. Here we review the general prognostic and clinical significance of tumor location and lymph-node metastases in breast cancer and discuss the specific factors associated with IMN identification, metastases and treatment in the pre-SLN and SLN eras. Based on our review, we propose an algorithm for a selective approach to IM-SLN in breast cancer.

HER-2/neu amplification and overexpression in primary human breast cancer is associated with early metastasis.

The etiology of human breast cancer is poorly understood and no specific marker of transformation has been identified. Amplification of HER-2/neu, as reported in a comprehensive study by Slamon et al, was found to be the most powerful predictor of disease-free and overall survival after the status of the axillary lymph nodes. Our study examines the HER-2/neu oncogene in 61 primary human breast cancers at both the DNA level (by Southern blotting) and the protein level (by immunohistochemical methods). Of the 61 tumors analyzed in our study, 17 (28%) had amplification of HER-2/neu. There was no significant correlation of HER-2/neu amplification with age, tumor diameter or hormone receptor status; however, amplification and overexpression of HER-2/neu was significantly correlated with the status of the axillary lymph nodes (P = 0.02). Of 16 patients with amplification of HER-2/neu, 14 (88%) had positive regional nodes. One of the two node negative cases with amplified HER-2/neu had bone marrow micrometastasis. Overall, 16 out of 17 (94%) tumors of the patients having amplified HER-2/neu had metastatic disease at the time of diagnosis. In summary, HER-2/neu amplification is associated with early tumor dissemination in primary human breast cancer and may be a marker of poor prognosis.

Role of mastectomy in breast cancer.

The surgical management of breast cancer continues to evolve in an attempt to define the ideal line between therapeutic efficacy and morbidity. It is clear that breast cancer is a biologically heterogeneous group of diseases, and no single hypothesis explains its behavior. The surgical options proposed to the individual patient must draw from the experience of retrospective clinical studies and prospective randomized trials in an attempt to optimize the treatment plan. Most patients without distant disease are eligible to consider mastectomy, which can accomplish excellent local control and significantly improve survival for earlier stages of disease. However, breast conservation remains an appropriate alternative for a carefully defined subset of patients. Today, with early-stage disease, no patient need leave the operating room without a breast. Recent advances in reconstructive surgery make mastectomy with immediate reconstruction or limited resection plus axillary dissection with postoperative radiation therapy the two principal treatment choices available. Future studies will focus on the integration of other treatment modalities. Clinical research into the use of preoperative chemotherapy to downstage the disease to permit less extensive surgery is of interest. Recent application of molecular biologic techniques such as oncogene analysis, cytogenetic studies, proliferative indices, and the highly sensitive detection of distant micrometastases using monoclonal antibodies may assist in the design of innovative approaches to surgery, radiation therapy, and systemic drug treatment. These advances show great promise for improving the quality of life and the cure rate for patients with breast cancer. Today, surgical treatment options have evolved that fulfill some of the objectives outlined by Dr. James Ewing of Memorial Hospital some 50 years ago. His concerns about breast cancer remain as relevant today as they were half a century ago: "I have drawn the impression that in dealing with mammary cancer, surgery meets with more peculiar difficulties and uncertainties than with almost any other form of the disease. The anatomical types are so numerous, the variations in clinical course so wide, the paths of dissemination so free and diverse, the difficulties of determining the actual conditions so complex, and the sacrifice of tissues so great, as to render impossible in the majority of cases a reasonably accurate adjustment of a means to an end."

Breast cancer and pregnancy.

Pregnancy-associated breast cancer has an overall worse prognosis than nonpregnancy-associated breast cancers because a large proportion present with more advanced disease. Stage for stage, however, the prognosis is similar. The various modalities used for screening, diagnosis, and staging of breast cancer are not always applicable during pregnancy. Often, a delay in diagnosis may contribute to a more advanced stage at presentation. The management of pregnant women with breast cancer is also different because it involves assessing the possible risks to the fetus versus the maternal benefits.