Flow-cytometric determination of tumor cells in lymph nodes

Comparison of mastoscopic and conventional axillary lymph node dissection in breast cancer: long-term results from a randomized, multicenter trial

OBJECTIVE

To compare the long-term results of mastoscopic axillary lymph node dissection (MALND) and conventional axillary lymph node dissection (CALND).

PATIENTS AND METHODS

From January 1, 2003, through December 31, 2005, a group of 1027 consecutive patients with operable breast cancer were randomly assigned to 1 of 2 study groups: MALND and CALND. The median follow-up was 63 months. The primary end points of the study were operative outcomes, complication reduction, function conservation, and cosmetics. The secondary end points were disease-free and overall survival.

RESULTS

The mean operative blood loss in the MALND group was less than in the CALND group (P<.001). The patients who underwent MALND had less axillary pain, numbness or paresthesias, and arm swelling (P<.001). The aesthetic appearance of the axilla in the MALND group was much better than that in the CALND group (P=.001 at 6 months and P=.002 at 24 months). A significant difference was found between the 2 groups in distant metastasis (P=.04). The disease-free survival rate was 64.5% in the MALND group and 60.8% in the CALND group (P=.88). The overall survival rate was 81.7% in the MALND group and 78.6% in the CALND group (P=.95).

CONCLUSION

Compared with CALND, MALND has advantages in operative outcomes, complication reduction, function conservation, and cosmetics.

Affinity of the alpha4-beta1 integrin-targeting peptide LLP2A to canine lymphoma

Lymphoma is an important disease in dogs and people, with similar biological characteristics. We tested the binding affinity of a peptidomimetic LLP2A, previously shown to bind the alpha4-beta1 integrin on human lymphoma cell lines, to lymphocytes of dogs with spontaneously occurring lymphoma. Fine needle aspirates of lymph nodes from 32 dogs with B-cell lymphoma and 7 dogs with T-cell lymphoma were evaluated using flow cytometry. For B cells, the lowest MFI levels were in unlabeled, non-neoplastic lymphocytes. The highest median fluorescent intensity (MFI) levels occurred in LLP2A-labeled lymphoma cells from dogs that had not received chemotherapy followed by labeled lymphoma cells from dogs that had received chemotherapy. The fluorescence profile of the T-cell samples was similar although many of the differences were not statistically significant, likely due to low sample number. Specifically, LLP2A-labeled T-cell lymphoma cells had a significantly higher MFI compared to unlabeled non-neoplastic lymphocytes. LLP2A affinity was not significantly different in unlabeled and labeled T-cell lymphoma cells, and labeled non-neoplastic lymphocytes. For both B and T cells, labeling with LLP2A tended to increase MFI in both normal and lymphoma cells. Lymphoma cells had higher mean MFI levels than non-neoplastic lymphocytes, and chemotherapy acted to decrease MFI. In summary, these data demonstrate that LLP2A has affinity to canine lymphoma cells and indicates expression of the alpha4-beta1 integrin on these cells. In fact, LLP2A preferentially binds neoplastic B-cells, suggesting that this small molecule may be of use in cross-species clinical trials of targeted therapeutics.

Lymphadenectomy improves survival of patients with renal cell carcinoma and nodal metastases

PURPOSE

In a population based cohort we determined whether an increase in the number of lymph nodes removed is associated with improved disease specific survival of patients with renal cell carcinoma treated with nephrectomy.

MATERIALS AND METHODS

Patients in the Surveillance, Epidemiology and End Results database with renal cell carcinoma and no evidence of distant metastases were identified. Those patients included in the study underwent radical or partial nephrectomy with lymphadenectomy. Cox regression analyses were performed to identify factors associated with disease specific survival including an interaction between lymph node status and the number of lymph nodes removed.

RESULTS

Between 1988 and 2006, 9,586 patients with renal cell carcinoma met the study inclusion criteria. Median followup was 3.5 years (range 1.4 to 6.8). Of the patients 2,382 (25%) died of renal cell carcinoma, including 1,646 (20%) with lymph node negative disease and 736 (58%) with lymph node positive disease. There was no effect on disease specific survival with increasing the extent of lymphadenectomy in patients with negative lymph nodes (HR 1.0, 95% CI 0.9-1.1, p = 0.93). However, patients with positive lymph nodes had increased disease specific survival with extent of lymphadenectomy (HR 0.8 per 10 lymph nodes removed, 95% CI 0.7-1.0, p = 0.04). An increase of 10 lymph nodes in a patient with 1 positive lymph node was associated with a 10% absolute increase in disease specific survival at 5 years (p = 0.004).

CONCLUSIONS

This study shows an association between increased lymph node yield and improved disease specific survival of patients with lymph node positive nonmetastatic renal cell carcinoma who underwent lymphadenectomy. Patients at high risk for nodal disease should be considered for regional or extended lymphadenectomy. Clinical variables to predict risk and validation of dissection templates are important areas for future research.

Evaluation of multiparameter flow cytometry for the detection of breast cancer tumor cells in blood samples

We comparatively evaluated different cytokeratin (CK) reagents analyzed by flow cytometry (FCM) for the identification of the best combination of DNA/CK staining for detecting minimal numbers of breast cancer cells in peripheral blood (PB). In 59 primary breast cancer tumors, we comparatively analyzed the reactivity for up to 6 different anti-CK reagents using multiparameter FCM: anti-CK7, anti-CK20, anti-pan-CK, anti-CK8/CK18, anti-CK8, and anti-CK18. Afterward, dilutional experiments of Michigan Cancer Foundation (MCF)7 breast cancer cells in PB were performed, and the sensitivity of a DNA/CK18 staining was evaluated. Our results showed that anti-CK18 reagents were those providing the brightest and more sensitive staining for primary breast cancer tumor cells by FCM. Dilutional experiments of MCF cells in PB showed that the DNA/anti-CK18 double staining was highly specific for the identification of epithelial cells; its sensitivity ranged between 10(-6) and 10(-7) (detection of 1 tumor cell among 10(6) to 10(7) nucleated blood cells). Combined assessment of DNA cell contents and reactivity for CK18 by FCM is a sensitive method for the specific identification of breast cancer cells in PB.

Enrichment methods to detect bone marrow micrometastases in breast carcinoma patients: clinical relevance

Introduction

Improving technologies for the detection and purification of bone marrow (BM) micrometastatic cells in breast cancer patients should lead to earlier prognosis of the risk of relapse and should make it possible to design more appropriate therapies. The technique used has to overcome the challenges resulting from the small number of target cells (one per million hematopoietic cells) and the heterogeneous expression of micrometastatic cell markers. In the present study, we have assessed the clinical relevance of current methods aimed at detecting rare disseminated carcinoma cells.

Methods

BM aspirates from 32 carcinoma patients were screened for the presence of micrometastatic cells positive for epithelial cell adhesion molecule and positive for cytokeratins, using optimized immunodetection methods. A comparison with data obtained for 46 control BM aspirates and a correlation with the clinical status of patients were performed.

Results

We developed a sensitive and efficient immunomagnetic protocol for the enrichment of BM micrometastases. This method was used to divide 32 breast carcinoma patients into three categories according to their epithelial cell adhesion molecule status. These categories were highly correlated with the recently revised American Joint Committee on Cancer staging system for breast cancer, demonstrating the clinical relevance of this simple and reliable immunomagnetic technique. We also evaluated immunocytochemical detection of cytokeratin-positive cells and cytomorphological parameters. Immunocytochemistry-based methods for the detection of BM micrometastases did not provide any information about the clinical status of patients, but helped to refine the immunomagnetic data by confirming the presence of micrometastases in some cases. We also tested a new density gradient centrifugation system, able to enrich the tumor fraction of BM specimens by twofold to threefold as compared with standard Ficoll methods.

Conclusion

These improved methods for the detection of micrometastatic cells in patient BM should help clinicians to predict the clinical status of breast cancer patients at the time of surgery or treatment.