Biomedical subjects

Robert C Martin

Publications and source records attributed to Robert C Martin.

6 recordsLinked to original sources

PubMed2006

A novel external esophageal perfusion model for reflux esophageal injury.

The current animal models of esophagitis and Barrett's esophagus consist of surgeries that divert the gastroduodenal contents to the esophagus. The limitations of these models are the inability to control the amount and concentration of the refluxate and the causing of significant postoperative stress and morbidity. Eighteen adult rats were cannulated at the upper esophagus and connected to a subcutaneous osmotic micropump to perfuse the esophageal lumen with bile and acid. Animals were sacrificed after 7 days of perfusion. Histological changes were determined. Cell proliferation, apoptosis, lipid peroxidation, and glutathione were measured. Histopathological changes in the bile- or acid-perfused esophagus were consistent with the findings associated with reflux esophagitis. Enhanced proliferation and apoptosis were seen, along with increased oxidative stress. The external esophageal perfusion model enabled precise control of the injurious agent. It induced the histologic and cellular injury of reflux esophagitis after 7 days.

Acetic Acid↗

PubMed2006

Determinants of early distant metastatic disease in elderly patients with breast cancer.

BACKGROUND: The purpose of this analysis was to determine predictors of early distant metastasis in elderly breast cancer patients receiving hormonal therapy. METHODS: We analyzed data from 938 patients in the North American Fareston Tamoxifen Adjuvant Trial>or=65 years old to determine predictors of early metastatic disease. RESULTS: The median patient age was 73 (range 65 to 100). With a median follow-up of 34 months, 17 patients (1.8%) developed distant metastases. The median time to distant metastasis was 21 months. On univariate analysis, significant predictors of distant metastatic disease were as follows: progesterone receptor status (P=.032), lymphovascular invasion (P=.020), tumor grade (P=.007), tumor size (P<.01), and number of metastatic nodes (P<.01). On multivariate analysis, only the number of positive nodes (P=.029) remained significant. Patients with >or=4 positive nodes were more likely to develop early metastases than those with 0 to 3 positive nodes (odds ration 20.304; 95% confidence interval 2.777-148.456, P=.003). CONCLUSIONS: Lymph node status in the elderly breast cancer patient treated with hormonal therapy alone is a strong predictor of early distant recurrence.

Aged↗

PubMed2005

Biopsy type does not influence sentinel lymph node status.

BACKGROUND: This study sought to determine whether the type of biopsy examination independently affects sentinel lymph node (SLN) status in breast cancer patients. METHODS: A prospective multicenter study of patients who had SLN biopsy examination followed by axillary node dissection was analyzed to determine whether the type of biopsy examination influenced SLN status. RESULTS: Of the 3853 patients studied, 32% had a positive SLN. Patients were diagnosed by fine-needle (N = 293), core-needle (N = 2154), excisional (N = 1386), or incisional (N = 20) biopsy procedures. The rates of SLN positivity for these groups were 45%, 32%, 29%, and 65%, respectively (P < .001). Other factors predictive of SLN status included: patient age (P < .001), tumor size (P < .001), tumor palpability (P < .001), number of SLN removed (P < .001), type of surgery (mastectomy vs. lumpectomy) (P < .001), histologic subtype (P = .048), and the use of immunohistochemistry (P < .001). All of these factors remained significant in the multivariate model except for histologic subtype and biopsy examination type. CONCLUSIONS: Biopsy examination type does not independently influence the risk for nodal metastasis.

Adult↗

PubMed2005

Factors predicting failure to identify a sentinel lymph node in breast cancer.

BACKGROUND: Although sentinel lymph node (SLN) biopsy is widely accepted as a minimally invasive method of nodal staging, failure to identify an SLN mandates a level I/II axillary node dissection. The purpose of this study was to elucidate factors that independently predict failure to identify an SLN. METHODS: Using a large multicenter prospective study of SLN biopsy for patients with invasive breast cancer, we performed univariate and multivariate regression analyses to determine clinicopathologic factors predictive of failure to identify an SLN. RESULTS: Of the total 4131 patients in the study, an SLN was not identified in 249 (6.0%). Tumor location (P = .409), biopsy type (P = .079), surgery type (P = .380), and histologic subtype (P = .999) were not significant predictors of failure to identify an SLN. On multivariate analysis, age greater than 60 years (OR = 1.469; 95% CI, 1.116-1.934, P = .006), nonpalpable tumors (OR = 0.639; 95% CI, 0.479-0.852, P = .002), injection technique with blue dye alone (OR = 0.389, 95% CI, 0.259-5.86, P < .001), and surgical experience of less than 10 SLN biopsy cases (OR = 1.886; 1.428-2.492, P < .001) were significant independent predictors of failure to identify an SLN. Optimal SLN biopsy technique using an intradermal and/or subareolar injection of radioactive colloid and blue dye can improve SLN identification rates regardless of patient and tumor characteristics. CONCLUSIONS: Patient age and tumor palpability significantly affect the ability to identify an SLN in patients with breast cancer. Optimal injection technique can significantly improve sentinel node identification rate regardless of these factors.

Adult↗

PubMed2004

Validation of subareolar and periareolar injection techniques for breast sentinel lymph node biopsy.

HYPOTHESIS: Subareolar or periareolar injection of radioactive technetium sulfur colloid is equivalent to other injection techniques for breast cancer sentinel lymph node (SLN) biopsy. DESIGN AND SETTING: Prospective, multicenter clinical trial. PATIENTS: A total of 3961 individuals with clinical stage I and II breast cancer. INTERVENTIONS: All patients underwent attempted SLN biopsy followed by completion axillary dissection. Injection technique was determined by the preference of each participating surgeon. Most surgeons had little or no experience with SLN biopsy before participation in this study. MAIN OUTCOME MEASURES: The SLN identification and false-negative rates. RESULTS: An SLN biopsy was performed in 3961 patients using blue dye alone or radioactive colloid plus blue dye. Subareolar and periareolar radioactive colloid injection techniques were associated with SLN identification rates of 99.3% and 95.6%, respectively, with false-negative rates of 8.3% and 8.9%, respectively. The identification rates were significantly higher for these 2 techniques than for peritumoral injection of radioactive colloid (91.1%) or the use of blue dye alone (88.5%) (P<.001). The false-negative rates were similar for all techniques. CONCLUSIONS: Although many medical centers have adopted subareolar and periareolar radioactive colloid injections because of their simplicity and convenience, a paucity of data from a few single-institutional studies has existed to substantiate the false-negative rates associated with these techniques. The results of this multicenter study establish the validity of subareolar and periareolar radioactive colloid injections and support the hypothesis that the lymphatic drainage of the entire breast is to the same few SLNs.

Adult↗

PubMed2004

Progressive adoption of cryoablative therapy for breast fibroadenoma in community practice.

BACKGROUND: Cryoablation is a recent technological advance and has been used for the percutaneous treatment of breast fibroadenomas. Herein, we provide a retrospective summary of the early experience from a nationwide group. METHODS: We organized a national registry to document the community practice and adoption of an office-based system of cryoablation for breast fibroadenoma. Data were abstracted during the first 6 weeks after the procedure to assess acute outcome and potential complications. At 6-and 12-month follow-up intervals, additional data were collected regarding fibroadenoma resolution, cosmesis, and patient satisfaction. RESULTS: Fifty-three sites ablated 310 fibroadenomas. Early follow-up data on 256 lesions showed that the procedure was well tolerated with infrequent minor complications immediately after the procedure. At 6 and 12 months postprocedure, the remaining fibroadenoma volume progressively involuted. At both intervals, cosmesis was excellent, and patient satisfaction was rated high. CONCLUSIONS: An early community experience with office-based cryoablation of breast fibroadenomas is encouraging and comparable to the initial experience of high-volume tertiary centers. More follow-up is necessary to determine long-term results and residual mammographic changes.

Ambulatory Surgical Procedures↗