Gene expression profiling to predict the risk of locoregional recurrence in breast cancer: a pooled analysis.

The 70-gene signature (MammaPrint) has been developed to predict the risk of distant metastases in breast cancer and select those patients who may benefit from adjuvant treatment. Given the strong association between locoregional and distant recurrence, we hypothesize that the 70-gene signature will also be able to predict the risk of locoregional recurrence (LRR). 1,053 breast cancer patients primarily treated with breast-conserving treatment or mastectomy at the Netherlands Cancer Institute between 1984 and 2006 were included. Adjuvant treatment consisted of radiotherapy, chemotherapy, and/or endocrine therapy as indicated by guidelines used at the time. All patients were included in various 70-gene signature validation studies. After a median follow-up of 8.96 years with 87 LRRs, patients with a high-risk 70-gene signature (n = 492) had an LRR risk of 12.6% (95% CI 9.7-15.8) at 10 years, compared to 6.1% (95% CI 4.1-8.5) for low-risk patients (n = 561; P < 0.001). Adjusting the 70-gene signature in a competing risk model for the clinicopathological factors such as age, tumour size, grade, hormone receptor status, LVI, axillary lymph node involvement, surgical treatment, endocrine treatment, and chemotherapy resulted in a multivariable HR of 1.73 (95% CI 1.02-2.93; P = 0.042). Adding the signature to the model based on clinicopathological factors improved the discrimination, albeit non-significantly [C-index through 10 years changed from 0.731 (95% CI 0.682-0.782) to 0.741 (95% CI 0.693-0.790)]. Calibration of the prognostic models was excellent. The 70-gene signature is an independent prognostic factor for LRR. A significantly lower local recurrence risk was seen in patients with a low-risk 70-gene signature compared to those with high-risk 70-gene signature.

Improved lymphatic mapping technique for breast cancer.

Breast sentinel lymph node biopsy is becoming more common. However, the best injection technique is not well established. Currently the gold standard is peritumoral injection. However, for upper outer quadrant tumors there is considerable axillary "shine through" which makes the identification of the radioactive sentinel lymph node difficult. We undertook a study to compare an injection in Sappey's subareolar plexus to the gold standard of peritumoral injection. Between December 1997 and March 1998, 85 patients with breast cancer were enrolled in the study. All patients were injected with 2 cc of normal saline containing 1.0 mCi of unfiltered technetium sulfur colloid in Sappey's subareolar plexus in the clock position of the breast cancer. In the operating room the patients underwent a peritumoral injection of 5 cc of 1% isosulfan blue. All blue and radioactive lymph nodes were identified and removed. The majority of the tumors were in the upper outer quadrant and were diagnosed by core biopsy. Only half of the patients had palpable tumors and approximately 25% had previous upper outer quadrant biopsy incisions. Peritumoral blue dye injection yielded an identification rate of 94%, with 99% of these being blue and radioactive. Three patients had radioactive lymph nodes with no blue lymph nodes identified. One of these patients had a micrometastasis. Injection in Sappey's subareolar plexus in the clock position of the tumor drained to the same sentinel lymph node as peritumoral injection. This injection technique solved the two major problems confronting the wide adoption of sentinel lymph node biopsy for breast cancer staging. First, it eliminates axillary "shine through" which will allow nonspecialist surgeons to more easily identify the radioactive axillary sentinel lymph node. Second, it allows for easier isotope injection by the technician or nuclear medicine physician, by eliminating the need for three-dimensional localization. This new technique should allow the majority of breast cancer patients who are treated by nonspecialist surgeons to be offered this less morbid, more accurate procedure.

Detection of carcinoma cells in the blood of breast cancer patients.

BACKGROUND: Breast cancers shed cancer cells into the blood soon after they become invasive. We developed an assay for removing these circulating cancer cells. In this study, we wanted to determine the percentage of early stage and metastatic patients with circulating breast cancer cells. METHODS: Twenty milliliters of blood were drawn from patients with breast cancer. Epithelial cells were removed by immunomagnetic selection and analyzed by flow cytometry, cytomorphology, and immunocystochemistry. RESULTS: Early stage patients averaged 16 epithelial cells per 20 cc blood whereas metastatic patients averaged 122 tumor cells. Cytomorphology and immunostains confirmed that these were cancer cells. Control blood samples had 1.7 squamous epithelial cells per 20 cc blood. CONCLUSION: This assay can identify and characterize circulating breast cancer cells. Metastatic patients had more circulating cells than early stage patients. This assay could screen high-risk patients, determine the need for and monitor response to adjuvant therapy, and detect early recurrence of breast cancer.

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.

Sentinel lymph node biopsy, an alternative to elective axillary dissection for breast cancer.

BACKGROUND: Axillary metastases remain an important prognostic indicator in breast cancer. Axillary lymphadenectomy (ALND) carries significant morbidity and is unnecessary in most patients with early breast cancer; thus, sentinel lymph node (SLN) biopsy has been advocated for axillary staging. We studied the SLN identification rate and its accuracy in predicting axillary metastases. METHODS: One hundred nineteen women with breast carcinoma underwent SLN and ALND. Lymphoscintigraphy was performed using Technetium99 sulfur colloid supplemented by Isosulfan blue dye. Hematoxylin/eosin-stained lymph node sections were examined by light microscopy. RESULTS: The SLN identification rate was 81%. One SLN was negative (1%) in a patient with axillary disease. SLN histology correctly predicted the absence of axillary disease in 98.6%. Sensitivity, specificity, and positive and negative predictive values were 96%, 100%, 100%, and 99%, respectively. CONCLUSIONS: Sentinel lymph node biopsy accurately predicts total axillary status and is valuable in the surgical staging of breast cancer.

Incidence and predictors of axillary metastasis in T1 carcinoma of the breast.

BACKGROUND: The relatively low incidence (6 to 31 percent) of axillary metastasis in patients with T1 carcinoma of the breast (20 mm or smaller) has led some surgeons to question routine axillary lymphadenectomy (ALND) for patients with no palpable axillary metastases and T1 tumors. This study was undertaken to determine the incidence and predictors of axillary lymph node metastasis in patients with T1 carcinoma of the breast and evaluate the role of sentinel lymphadenectomy (SLND) in this context. STUDY DESIGN: All patients with T1 invasive carcinoma of the breast treated at the John Wayne Cancer Institute between January 1988 and June 1994 were prospectively studied. The study population was comprised of 259 women who had ALND. Of these patients, 114 were part of a pilot study examining the efficacy of SLND. RESULTS: Of the 259 women, 69 (27 percent) had axillary metastasis. Hematoxylin and eosin staining identified nodal involvement in 13 percent of patients with T1a and T1b tumors (10 mm or less) and in 30 percent of patients with T1c tumors (p = 0.002). Other factors such as age, hormone receptor status, presence of ductal carcinoma in situ, histology, ploidy, and S-phase were not significant predictors of involvement. A sentinel node was identified in 73 patients: this node accurately predicted axillary status in 72 patients, was the only positive node in nine of 16 patients with axillary involvement, and was 100 percent predictive of axillary status when the primary tumor was 10 mm or less. Retrospective immunohistochemical staining revealed an additional seven patients with positive sentinel nodes. With this technique, even T1a lesions had a 15 percent incidence of axillary metastasis. CONCLUSIONS: Tumor size is the only accurate predictor of axillary metastasis in patients with T1 carcinoma of the breast. The significant incidence of axillary involvement from T1 tumors mandates accurate staging, even when the tumor is 10 mm or less in size. Examination of a sentinel lymph node may accurately predict axillary metastasis.