Biomedical subjects

Mark L Kayton

Publications and source records attributed to Mark L Kayton.

5 recordsLinked to original sources

PubMed2006

Clinical presentation, treatment, and outcome of alveolar soft part sarcoma in children, adolescents, and young adults.

PURPOSE: Alveolar soft part sarcoma is a rare soft tissue neoplasm that can affect children and adolescents. There are few reported series of these patients in the literature. To define the clinical presentation, treatment, and outcome of young people with this rare sarcoma, we reviewed our clinical experience. METHODS: After institutional review board approval, we examined the records of all patients younger than 25 years old who received treatment at our institution for alveolar soft part sarcoma in the past 30 years. Demographics, tumor sizes, sites and extent of disease, treatments used, progression-free survival, and overall follow-up were evaluated. RESULTS: Each of the 20 patients presented with a mass. Primary disease sites were thigh (n = 8), trunk (n = 6), retroperitoneum (n = 2), and scalp, neck, forearm, and calf (n = 1 each). Metastatic sites included lymph nodes, lung, and brain. Four patients presented to us with incomplete excision of the primary, and 1 had undergone embolization of what was thought to be a vascular malformation. Although wide local excision provided the best chance for a patient to remain free of disease, 14 (70%) of 20 patients exhibited metastases either at presentation or later. Thirty-one metastasectomies were performed. Chemotherapy was used in 11 patients; radiation was used in 8. Median overall follow-up was 36 months; median progression-free follow-up was 12.5 months. Younger patients tended to have Intergroup Rhabdomyosarcoma Study group I disease. Tumors smaller than 5 cm were associated with longer progression-free survival. CONCLUSIONS: Achievement of complete microscopic resection is critical in localized alveolar soft part sarcoma, but incomplete excision and misdiagnosis are often encountered. Despite the occurrence of metastases in 70% of patients, 5-year overall survival was 83%. We found an association between smaller tumor size and longer time to progression. We were not able to demonstrate any benefit from chemotherapy or radiation. Metastasectomies have been performed in multiple long-term survivors.

Adolescent↗

PubMed2006

Computed tomographic scan of the chest underestimates the number of metastatic lesions in osteosarcoma.

PURPOSE: Survival in osteosarcoma correlates with complete resection of primary and metastatic disease. The feasibility of complete pulmonary metastasectomy using thoracoscopy has been raised. Because palpation is not possible, minimally invasive techniques require preoperative radiological enumeration and localization of metastases not presenting at the lung surface. We hypothesized that computed tomographic (CT) scanning underestimated the number of pulmonary metastases in these patients. METHODS: Institutional review board approval was obtained. We determined the association between the number of lesions identified by CT scanning and the number of metastases found at thoracotomies for metastatic osteosarcoma from May 1996 to October 2004. Correlations between CT findings and pathology results were computed using the Kendall tau-b correlation coefficient. Depth, in millimeters, from the pleural surface was measured for those lesions seen on CT scan. RESULTS: We analyzed 54 consecutive thoracotomies performed in 28 patients for whom complete imaging was available. Computed tomographic scanning was performed a median of 20 days before thoracotomy (range, 1-85 days). Correlation between the number of lesions identified by CT and the number of metastases resected at surgery was poor, with a Kendall tau-b correlation coefficient of 0.45 (P < .001). In 19 (35%) of 54 thoracotomies, CT scanning underestimated the number of pathologically proven, viable and nonviable metastases found by the surgeon. Accounting for viable metastases only, correlation between the number of lesions identified by CT and the number of metastases resected at surgery was 0.50 (P < .001), and CT scanning underestimated the number of viable metastases present in 14 (26%) of 54 thoracotomies. Many lesions (32%) were pleural-based, but nearly half (47%) were 5 mm or deeper from the pleural surface of the lung. CONCLUSIONS: Even in the era of modern CT scanning, only a very rough correlation exists between CT findings and the number of lesions identified at thoracotomy. In more than one third of thoracotomies in our series, metastases would have been missed by any tactic besides manual palpation of the lung during open thoracotomy. Minimal access procedures should not be the approach of choice if the goal is resection of all pulmonary metastases in osteosarcoma.

Adolescent↗

PubMed2006

Pulmonary metastasectomy in pediatric patients.

This article describes the historical development of pediatric pulmonary metastasectomy but demonstrates that progress has been slow in understanding its proper applications. Because many pediatric metastatic tumors are rare, surgeons have grouped together patients of different histologies for the generation and analysis of case series. By examining tumor types individually, however, it is seen that certain histologies (adrenocortical carcinoma, alveolar soft part sarcoma, osteosarcoma) mandate surgical metastasectomy for patient survival. Other pediatric tumors (Wilms tumor, Ewing's sarcoma) are radiation sensitive, and the application of metastasectomy is controversial. In the case of still other types of tumor (neuroblastoma, differentiated thyroid cancer, rhabdomyosarcoma), metastasectomy is seldom performed except in highly unusual situations. Techniques for minimally invasive biopsy and for muscle-sparing thoracotomy are described for pediatric patients.

Biopsy↗

PubMed2004

A novel technique for quantifying changes in vascular density, endothelial cell proliferation and protein expression in response to modulators of angiogenesis using the chick chorioallantoic membrane (CAM) assay.

Reliable quantitative evaluation of molecular pathways is critical for both drug discovery and treatment monitoring. We have modified the CAM assay to quantitatively measure vascular density, endothelial proliferation, and changes in protein expression in response to anti-angiogenic and pro-angiogenic agents. This improved CAM assay can correlate changes in vascular density with changes seen on a molecular level. We expect that these described modifications will result in a single in vivo assay system, which will improve the ability to investigate molecular mechanisms underlying the angiogenic response.

Journal Article↗

PubMed2003

Peak stimulated insulin secretion is associated with specific changes in gene expression profiles in sporadic insulinomas.

BACKGROUND: The molecular pathways that are responsible for pathologic insulin secretion by insulinomas have not been characterized. We studied gene expression profiles from insulinomas and determined associations between these changes and preoperative peak serum insulin levels. METHODS: Ten patients with insulinomas underwent calcium-stimulated arteriography and surgical resection. Tumor RNA was isolated; corresponding complementary DNA was hybridized to 10K human complementary DNA arrays. Pooled human islet cell complementary DNA served as the control. Cluster analysis of gene expression and analysis of expression ratios was performed. RESULTS: Nineteen genes were up-regulated at least 3-fold in insulinomas compared with controls, which included the genes for islet amyloid polypeptide and proprotein convertase type 2. Cluster analysis revealed 2 groups of patients with insulinoma and with distinct patterns of gene expression. Mean peak serum insulin values between groups were 196 and 1100 (U/mL (P<.05), which demonstrates a significant difference in insulin response to calcium stimulation between these 2 groups. CONCLUSION: We show that genes that are relevant to the pathogenesis of hyperinsulinemia are expressed preferentially in insulinomas. In addition, patients with a distinct and common pattern of gene expression had significantly higher stimulated insulin secretion levels. The study of these genes may help to identify the biochemical pathways that are responsible for pathologic insulin secretion.

Adult↗