PubMed Health⌕ Search

Biomedical subjects

K M McMasters

Publications and source records attributed to K M McMasters.

At least 37 records · Page 2Linked to original sources
PubMed2001

Dermal injection of radioactive colloid is superior to peritumoral injection for breast cancer sentinel lymph node biopsy: results of a multiinstitutional study.

OBJECTIVE: To determine the optimal radioactive colloid injection technique for sentinel lymph node (SLN) biopsy for breast cancer. SUMMARY BACKGROUND DATA: The optimal radioactive colloid injection technique for breast cancer SLN biopsy has not yet been defined. Peritumoral injection of radioactive colloid has been used in most studies. Although dermal injection of radioactive colloid has been proposed, no published data exist to establish the false-negative rate associated with this technique. METHODS: The University of Louisville Breast Cancer Sentinel Lymph Node Study is a multiinstitutional study involving 229 surgeons. Patients with clinical stage T1-2, N0 breast cancer were eligible for the study. All patients underwent SLN biopsy, followed by level I/II axillary dissection. Peritumoral, subdermal, or dermal injection of radioactive colloid was performed at the discretion of the operating surgeon. Peritumoral injection of isosulfan blue dye was performed concomitantly in most patients. The SLN identification rates and false-negative rates were compared. The ratios of the transcutaneous and ex vivo radioactive SLN count to the final background count were calculated as a measure of the relative degree of radioactivity of the nodes. One-way analysis of variance and chi-square tests were used for statistical analysis. RESULTS: A total of 2,206 patients were enrolled. Peritumoral, subdermal, or dermal injection of radioactive colloid was performed in 1,074, 297, and 511 patients, respectively. Most of the patients (94%) who underwent radioactive colloid injection also received peritumoral blue dye injection. The SLN identification rate was improved by the use of dermal injection compared with subdermal or peritumoral injection of radioactive colloid. The false-negative rates were 9.5%, 7.8%, and 6.5% (not significant) for peritumoral, subdermal, and dermal injection techniques, respectively. The relative degree of radioactivity of the SLN was five- to sevenfold higher with the dermal injection technique compared with peritumoral injection. CONCLUSIONS: Dermal injection of radioactive colloid significantly improves the SLN identification rate compared with peritumoral or subdermal injection. The false-negative rate is also minimized by the use of dermal injection. Dermal injection also is associated with SLNs that are five- to sevenfold more radioactive than with peritumoral injection, which simplifies SLN localization and may shorten the learning curve.

Breast Neoplasms↗
PubMed2001

Defining the optimal surgeon experience for breast cancer sentinel lymph node biopsy: a model for implementation of new surgical techniques.

OBJECTIVE: To determine the optimal experience required to minimize the false-negative rate of sentinel lymph node (SLN) biopsy for breast cancer. SUMMARY BACKGROUND DATA: Before abandoning routine axillary dissection in favor of SLN biopsy for breast cancer, each surgeon and institution must document acceptable SLN identification and false-negative rates. Although some studies have examined the impact of individual surgeon experience on the SLN identification rate, minimal data exist to determine the optimal experience required to minimize the more crucial false-negative rate. METHODS: Analysis was performed of a large prospective multiinstitutional study involving 226 surgeons. SLN biopsy was performed using blue dye, radioactive colloid, or both. SLN biopsy was performed with completion axillary LN dissection in all patients. The impact of surgeon experience on the SLN identification and false-negative rates was examined. Logistic regression analysis was performed to evaluate independent factors in addition to surgeon experience associated with these outcomes. RESULTS: A total of 2,148 patients were enrolled in the study. Improvement in the SLN identification and false-negative rates was found after 20 cases had been performed. Multivariate analysis revealed that patient age, nonpalpable tumors, and injection of blue dye alone for SLN biopsy were independently associated with decreased SLN identification rates, whereas upper outer quadrant tumor location was the only factor associated with an increased false-negative rate. CONCLUSIONS: Surgeons should perform at least 20 SLN cases with acceptable results before abandoning routine axillary dissection. This study provides a model for surgeon training and experience that may be applicable to the implementation of other new surgical technologies.

Breast Neoplasms↗
PubMed2001

Histoplasmosis as an isolated liver lesion: review and surgical therapy.

Histoplasmosis is the most common cause of fungal infection in the Ohio River Valley of the United States. Ninety-nine per cent of patients exposed to histoplasmosis develop only subclinical infections. Liver involvement is common in disseminated histoplasmosis, which usually originates in the lungs. There has been only one prior case described in the literature of histoplasmosis presenting as an isolated liver mass. We report a rare case that presented as a solitary right-sided liver lesion invading the diaphragm, with review of the literature for therapy of histoplasmosis of the liver.

Adult↗
PubMed2001

Accuracy of sentinel lymph node biopsy for patients with T2 and T3 breast cancers.

Although numerous studies have demonstrated that sentinel lymph node (SLN) biopsy can accurately determine the axillary nodal status for early breast cancer some studies have suggested that SLN biopsy may be less reliable for tumors >2 cm in size. This analysis was performed to determine whether tumor size affects the accuracy of SLN biopsy. The University of Louisville Breast Cancer Sentinel Lymph Node Study is a prospective multi-institutional study involving 226 surgeons. The study was approved by the Institutional Review Board of each institution, and informed consent was obtained from all patients. Patients with clinical stage T1-2 N0 breast cancer were eligible for the study. Some patients with T3 tumors were included because they were clinically staged as T2 but on final pathology were found to have tumors >5 cm. This analysis includes 2148 patients who were enrolled from August 1997 through October 2000. All patients underwent SLN biopsy using a combination of radioactive colloid and blue dye injection followed by completion Level I/II axillary dissection. Statistical comparison was performed by chi-square analysis. The SLN identification rate, false negative rate, and overall accuracy of SLN biopsy were not significantly different among tumor stages T1, T2, and T3. We conclude that SLN biopsy is no less accurate for T2-3 breast cancers compared with T1 tumors.

Breast Neoplasms↗
PubMed2001

The Sunbelt Melanoma Trial.

The Sunbelt Melanoma Trial is a prospective randomized trial to evaluate the role of lymph node dissection and adjuvant interferon alfa-2b for patients with early lymph node metastases.

Aged↗
PubMed2001

E2F-1 up-regulates c-Myc and p14(ARF) and induces apoptosis in colon cancer cells.

Although overexpression of E2F-1 can induce apoptosis in a variety of tumor cell lines, the mechanisms by which E2F-1 induces apoptosis remain ambiguous. In this study, we examine the ability of E2F-1 to induce apoptosis in colon cancer and the molecular mechanisms underlying E2F-1-mediated apoptosis. HT-29 and SW-620 colon adenocarcinoma cells (both mutant p53) were treated by mock infection or adenoviral vectors Ad5CMV (empty vector), Ad5CMVLacZ (beta-galactosidase), and Ad5CMVE2F-1 (E2F-1) at multiplicity of infection of 100. Western blot analysis confirmed marked overexpression of E2F-1 in both cell lines. By 5 days after infection, E2F-1 overexpression resulted in >25-fold reduction in cell growth and >90% loss of cell viability in both cell lines. Cell cycle analysis of Ad-E2F-1-infected cells revealed an increase in G(2)/M and sub-G(1) populations. By in situ terminal deoxynucleotidyl transferase (Tdt)-mediated nick end labeling analysis, evidence of apoptosis was observed including internucleosomal DNA fragmentation and the formation of apoptotic bodies. In addition, caspase-3 and poly(ADP-ribose) polymerase apoptotic fragments were detected by 48 h after treatment with Ad-E2F-1. Of mechanistic importance, overexpression of E2F-1 caused a G(2)/M arrest followed by increased levels of c-Myc and p14(ARF) proteins. Additionally, expression of the antiapoptotic Bcl-2 family member Mcl-1 was down-regulated in E2F-1-overexpressing cells. In conclusion, E2F-1 overexpression initiates apoptosis and suppresses growth in HT-29 and SW620 colon adenocarcinoma cells. Overexpression of E2F-1 triggers apoptosis and is associated with up-regulation of c-Myc and p14(ARF) proteins and down-regulation of Mcl-1. Therefore, E2F-1 is a potentially active gene therapy agent for the treatment of colon cancer.

Adenoviridae↗
PubMed2000

Basosquamous carcinoma: analysis of prognostic factors influencing recurrence.

BACKGROUND: Basosquamous carcinoma is a rare malignancy, with features of both basal cell carcinoma and squamous cell carcinoma. Some authors believe that basosquamous carcinoma merely is a variant of basal cell carcinoma, whereas others have suggested that basosquamous carcinoma may behave more aggressively. To the authors' knowledge the largest published series to date, comprised of 35 cases, was reported >20 years ago. The authors reviewed their recent experience with basosquamous carcinoma to identify prognostic factors influencing recurrence. METHODS: The medical records of all patients with the diagnosis of basosquamous carcinoma treated at the University of Louisville-affiliated hospitals between 1985-1988 were reviewed by a senior pathologist. Prognostic factors were analyzed using Cox regression analysis and the log rank test. RESULTS: Thirty-one cases of basosquamous carcinoma were identified in 28 patients. The median age at diagnosis was 68 years (range, 10-94 years). The median follow-up was 60 months (range, 12-312 months). Seventy-five percent of cases were located on the face, neck, and scalp. One patient had regional lymph node metastasis synchronous with the primary tumor. Patterns of recurrence were: local recurrence only (five patients), local recurrence plus regional lymph nodes (three patients), and pulmonary plus regional lymph nodes (one patient). One patient died of pulmonary metastasis. Significant factors predictive of recurrence (P<0.01) were male gender, positive surgical resection margin, lymphatic invasion, and perineural invasion. Although tumor size was not a statistically significant factor overall (P = 0.076), the 3 patients with lymph node metastases had large tumors (measuring 2 cm, 5 cm, and 5 cm, respectively). CONCLUSIONS: Basosquamous carcinoma is an aggressive epithelial neoplasm with a propensity for local recurrence and potential for distant metastatic spread. This behavior differs substantially from basal cell carcinoma. Complete resection with negative surgical margins is essential. Long term follow-up for the detection of local recurrence and distant metastatic spread is recommended.

Adolescent↗
PubMed2000

A new American Joint Committee on Cancer staging system for cutaneous melanoma.

The Melanoma Staging Committee of the AJCC has proposed major revisions of the melanoma TNM and stage grouping criteria. The committee members represent most of the major cooperative groups and cancer centers worldwide with a special interest in melanoma; the committee also collectively has had clinical experience with over 40,000 patients. The new staging system better reflects independent prognostic factors that are used in clinical trials and in reporting the outcomes of various melanoma treatment modalities. Major revisions include 1) melanoma thickness and ulceration, but not level of invasion, to be used in the T classification; 2) the number of metastatic lymph nodes, rather than their gross dimensions, the delineation of microscopic versus macroscopic lymph node metastases, and presence of ulceration of the primary melanoma to be used in the N classification; 3) the site of distant metastases and the presence of elevated serum LDH, to be used in the M classification; 4) an upstaging of all patients with Stage I,II, and III disease when a primary melanoma is ulcerated; 5) a merging of satellite metastases around a primary melanoma and in-transit metastases into a single staging entity that is grouped into Stage III disease; and 6) a new convention for defining clinical and pathologic staging so as to take into account the new staging information gained from intraoperative lymphatic mapping and sentinel lymph node biopsy. The AJC Melanoma Staging Committee invites comments and suggestions regarding this proposed staging system before a final recommendation is made.

Biopsy↗
PubMed2000

DNA flow cytometry does not predict 5- or 10-year recurrence rates for T1-2 node-negative breast cancer.

BACKGROUND: A small proportion of T1 or T2 node-negative breast cancer tumors will recur in patients by 5 years, and more by 10 years. Results of recent studies have suggested improvement in overall survival with administration of adjuvant chemotherapy to all patients. More sensitive and specific methods are needed to identify patients at highest risk for recurrence who might benefit most from adjuvant therapy, saving others from unnecessary treatment. Some investigators have suggested DNA flow cytometry as a method to discriminate patients at greatest risk for recurrence. HYPOTHESIS: DNA flow cytometry has predictive value for breast cancer recurrence in node-negative patients. METHODS: The cancer registry of a medium-sized university-affiliated hospital was used to identify patients with T1-2 N0 M0 breast cancer treated with a uniform surgical approach and no adjuvant therapy who had completed at least 5 years of follow-up or had recurrence. Flow cytometric analysis was performed on paraffin-embedded specimens. RESULTS: Of 115 patients, 92 (80%) had disease-free survival without recurrence and 23 (20%) had recurrence. Comparison of diploid and nondiploid tumors for likelihood of recurrence revealed no association (P = .79). Furthermore, the DNA index and S-phase fraction were not significantly different between recurrent and nonrecurrent groups. CONCLUSIONS: The likelihood of recurrence of small node-negative breast cancers after mastectomy cannot be accurately predicted on the basis of DNA flow cytometric analysis. Traditional methods for determining risks-such as nuclear and histological grade, lymph node status, and tumor size-seem to be more useful. Sentinel lymph node biopsy techniques may increase the detection of micrometastases.

Breast Neoplasms↗
PubMed2000

State-of-the-art lymph node staging for breast cancer in the year 2000.

Axillary staging for breast cancer is vitally important for determining appropriate adjuvant hormone and chemotherapy. In the absence of distant metastases, axillary lymph node status remains the most accurate predictor of clinical outcome. Sentinel lymph node biopsy is a minimally invasive approach with enhanced accuracy and less morbidity than conventional axillary dissection. The stage is now set for the sentinel lymphadenectomy staging to move from state-of-the-art care to the standard care in coming years.

Axilla↗
PubMed2000

Credentialing issues with sentinel lymph node staging for breast cancer.

Sentinel lymphadenectomy (SL) is a minimally invasive approach for staging patients with breast cancer. SL, when performed in lieu of axillary dissection, is associated with less morbidity and is potentially more cost effective and more accurate than the historical axillary dissection in the detection of regional nodal metastases. The credentialing and privileging of SL, as with any surgical procedure, is by the policies of the local hospital or institution. The suggested credentialing criteria for local hospitals has been an area of controversy. Herein the authors outline the credentialing controversy and suggest criteria for the implementation of sentinel lymph node staging for breast cancer.

Breast↗
PubMed2000

The details of successful sentinel lymph node staging for breast cancer.

Sentinel lymphadenectomy is an effective and accurate tool for staging breast cancer. In recent years the details of a successful program have become better defined. The authors outline practical considerations for the performance of successful sentinel lymph node staging from a multidisciplinary perspective.

Breast Neoplasms↗
PubMed2000

Minimally invasive radioguided parathyroidectomy.

BACKGROUND: Minimally invasive radioguided parathyroidectomy (MIRP) combines technetium sestamibi scan, intraoperative gamma probe, methylene blue dye, and measurement of circulating parathyroid hormone (PTH) levels. STUDY DESIGN: All patients presented with biochemically proved primary hyperparathyroidism. A technetium sestamibi scan was performed preoperatively. Technetium sestamibi and methylene blue dye (7.5 mg/kg) were administered IV on the day of operation. Operative dissection was directed by the gamma probe. Blood samples for PTH assay were obtained before and after excision of an abnormal gland. When an appropriate decrease in the PTH assay was obtained, the exploration was concluded. Persistent PTH elevation instigated further neck exploration. RESULTS: Thirty-six consecutive patients were explored for untreated primary hyperparathyroidism and three for recurrent hyperparathyroidism. Hypercalcemia was corrected in all 39 patients. A single adenoma was found in 32 of 36 patients with untreated primary hyperparathyroidism, and a single abnormal gland was identified in all of those with recurrent hyperparathyroidism. Persistently elevated PTH prompted further exploration in two patients, identifying a second abnormal gland in one and hyperplasia in the other. Minor local complications occurred in 8% (3 of 39) of the patients. Forty-four percent (16 of 36) of the patients were discharged on the day of operation and 83% (30 of 36) within 23 hours after the initial neck exploration for primary hyperparathyroidism. Comparison of charges for MIRP with charges for "standard" neck exploration revealed lower costs with MIRP because of decreased duration of the operation, anesthesia, and hospital stay, and elimination of intraoperative histologic analysis. CONCLUSIONS: MIRP is a safe and effective procedure, resulting in the correction of hypercalcemia in all patients. The combination of intraoperative gamma probe and methylene blue dye allows rapid identification of the abnormal gland with minimal dissection through a small incision. PTH assay after excision provides biochemical confirmation that the abnormal gland has been removed. Most patients undergoing MIRP can be treated on an outpatient basis. Low postoperative complications, a small incision, and rapid return to normal activities resulted in very high patient acceptance of the procedure.

Adenoma↗
PubMed2000

Practical guidelines for optimal gamma probe detection of sentinel lymph nodes in breast cancer: results of a multi-institutional study. For the University of Louisville Breast Cancer Study Group.

INTRODUCTION: Multiple radioactive lymph nodes are often removed during the course of sentinel lymph node (SLN) biopsy for breast cancer when both blue dye and radioactive colloid injection are used. Some of the less radioactive lymph nodes are second echelon nodes, not true SLNs. The purpose of this analysis was to determine whether harvesting these less radioactive nodes, in addition to the "hottest" SLNs, reduces the false-negative rate. METHODS: Patients were enrolled in this multicenter (121 surgeons) prospective, institutional review board-approved study after informed consent was obtained. Patients with clinical stage T1-2, N0, M0 invasive breast cancer were eligible. This analysis includes all patients who underwent axillary SLN biopsy with the use of an injection of both isosulfan blue dye and radioactive colloid. The protocol specified that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest node should be removed and designated SLNs. All patients underwent completion level I/II axillary dissection. RESULTS: SLNs were identified in 672 of 758 patients (89%). Of the patients with SLNs identified, 403 patients (60%) had more than 1 SLN removed (mean, 1.96 SLN/patient) and 207 patients (31%) had nodal metastases. The use of filtered or unfiltered technetium sulfur colloid had no impact on the number of SLNs identified. Overall, 33% of histologically positive SLNs had no evidence of blue dye staining. Of those patients with multiple SLNs removed, histologically positive SLNs were found in 130 patients. In 15 of these 130 patients (11.5%), the hottest SLN was negative when a less radioactive node was positive for tumor. If only the hottest node had been removed, the false-negative rate would have been 13.0% versus 5.8% when all nodes with 10% or more of the ex vivo count of the hottest node were removed (P =.01). CONCLUSIONS: These data support the policy that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest SLN should be harvested for optimal nodal staging.

Biopsy↗
PubMed2000

Preoperative lymphoscintigraphy for breast cancer does not improve the ability to identify axillary sentinel lymph nodes.

OBJECTIVE: To evaluate the role of preoperative lymphoscintigraphy in sentinel lymph node (SLN) biopsy for breast cancer. SUMMARY BACKGROUND DATA: Numerous studies have demonstrated that SLN biopsy can be used to stage axillary lymph nodes for breast cancer. SLN biopsy is performed using injection of radioactive colloid, blue dye, or both. When radioactive colloid is used, a preoperative lymphoscintigram (nuclear medicine scan) is often obtained to ease SLN identification. Whether a preoperative lymphoscintigram adds diagnostic accuracy to offset the additional time and cost required is not clear. METHODS: After informed consent was obtained, 805 patients were enrolled in the University of Louisville Breast Cancer Sentinel Lymph Node Study, a multiinstitutional study involving 99 surgeons. Patients with clinical stage T1-2, N0 breast cancer were eligible for the study. All patients underwent SLN biopsy, followed by level I/II axillary dissection. Preoperative lymphoscintigraphy was performed at the discretion of the individual surgeon. Biopsy of nonaxillary SLNs was not required in the protocol. Chi-square analysis and analysis of variance were used for statistical comparison. RESULTS: Radioactive colloid injection was performed in 588 patients. In 560, peritumoral injection of isosulfan blue dye was also performed. A preoperative lymphoscintigram was obtained in 348 of the 588 patients (59%). The SLN was identified in 221 of 240 patients (92.1%) who did not undergo a preoperative lymphoscintigram, with a false-negative rate of 1.6%. In the 348 patients who underwent a preoperative lymphoscintigram, the SLN was identified in 310 (89.1%), with a false-negative rate of 8.7%. A mean of 2.2 and 2. 0 SLNs per patient were removed in the groups without and with a preoperative lymphoscintigram, respectively. There was no statistically significant difference in the SLN identification rate, false-negative rate, or number of SLNs removed when a preoperative lymphoscintigram was obtained. CONCLUSIONS: Preoperative lymphoscintigraphy does not improve the ability to identify axillary SLN during surgery, nor does it decrease the false-negative rate. Routine preoperative lymphoscintigraphy is not necessary for the identification of axillary SLNs in breast cancer.

Axilla↗