Biomedical subjects

S G Economou

Publications and source records attributed to S G Economou.

At least 19 recordsLinked to original sources

PubMed1995

Synchronous, bilateral mastectomy.

Sixty-four patients (mean age, 51 years) had mastectomies which were synchronous and bilateral. Sixty-one premastectomy biopsies (bilateral, 34 and unilateral, 27) demonstrated the following: invasive carcinoma, 17; noninvasive carcinoma, 24; combination of above, 10; and benign disease, 10. Twenty-two patients had bilateral mastectomy because of bilateral positive biopsy. Twenty-nine patients with unilateral carcinoma on biopsy had bilateral mastectomy. Thirteen patients had bilateral mastectomy despite benign disease only on biopsy (10) or no biopsy (3). Ten unexpected carcinomas (34%) were found in the contralateral breast in the 29 patients with carcinoma diagnosed on unilateral biopsy. The biopsy pathology of these 10 specimens was invasive ductal carcinoma in 1 and multifocal, noninvasive carcinoma (ductal, 3 and lobular, 6) in 9. An unexpected carcinoma may be found in the contralateral breast in a significant number of patients who are selected for bilateral mastectomy, particularly if the selection is on the basis of a noninvasive, lobular histology. Bilateral mastectomy may be appropriate for such patients, particularly when complicated by a strong family history and breasts which are difficult to assess by physical or mammographic examination.

Adult↗

PubMed1995

Fractionated irradiation of the regenerated rat liver.

Fractionated radiation therapy after liver resection for metastatic cancer has traditionally been a palliative procedure. Here, we consider that radiation may be an appropriate adjuvant therapy for cure after liver resection for metastases. This pilot study in rats establishes a model for evaluating the effects of fractionated irradiation posthepatectomy. Sixty Sprague-Dawley rats were randomized to four groups. The groups underwent laparotomy, laparotomy and radiation, hepatectomy, and hepatectomy and radiation. We found that the rats treated with radiation had statistically significant (P < 0.0001) clinical radiation change by liver function tests at 6 months. This damage was resolved to normal at 1 year regardless of hepatectomy. In fact, we demonstrate the possibility of a protective effect from radiation damage in the regenerated liver. We also demonstrate statistically significant histologic change at 8 months (P < 0.01) in the radiation-treated rats which does not resolve at 1 year.

Alanine Transaminase↗

PubMed1994

Predicting lymph node metastases in rectal cancer.

UNLABELLED: For properly selected rectal cancers, local excision is a sphincter-saving alternative to abdominoperineal resection. If histologic assessment of a locally excised tumor reveals ominous features, further treatment with radical resection or irradiation may be necessary to treat potential lymph node metastases. PURPOSE: We wished to determine which features, if any, were predictors of nodal metastases. METHODS: Nine histologic and morphologic features of 62 radically excised rectal cancers were reviewed to determine which factors, if any, were associated with nodal disease. RESULTS: Using a chi-squared analysis, we found worsening differentiation (P = 0.0001), increasing depth of penetration (P = 0.026), a microtubular configuration of 20 percent or more (P = 0.023), and the presence of venous (P = 0.001) or perineural invasion (P = 0.002) to significantly influence nodal disease. Lymphatic invasion was witnessed too infrequently to determine significance but, when present, was associated with nodal metastases in every case. Exophytic tumor morphology, mitotic count, and tumor size were not significant predictors. An analysis of variables determined that, of all factors or combination of factors examined, Broder's classification was the strongest predictor of nodal disease. CONCLUSIONS: If a rectal cancer is accessible and of small size to facilitate local excision, an in-depth histologic assessment is needed to determine if nodal metastases are likely on a statistical basis.

Humans↗

PubMed1993

Thoracotomy for colon and rectal cancer metastases.

Between 1978 and 1990, 23 patients underwent 35 thoracotomies for metastatic colorectal cancer. The pulmonary disease was diagnosed within an interval of 0 to 105 (average, 33.4) months after colon resection. Fifteen patients underwent a single thoracotomy; 12 patients had solitary lesions, and three patients had multiple nodules. Eight patients underwent multiple thoracotomies. The median survival following thoracotomy was 28 months; three-year survival was 45 percent, and five-year survival was 16 percent. Factors that had no significant bearing on survival included origin and stage of the primary tumor and patient age and sex. An interval before thoracotomy of three years had an impact on survival approaching statistical significance (P = 0.17). Patients who underwent multiple thoracotomies had a significantly prolonged survival (P = 0.04). Patients who underwent a single thoracotomy for a solitary lesion had a significantly prolonged survival compared with patients who had a single thoracotomy for multiple metastases. After thoracotomy, 14 patients eventually developed recurrent disease, which was confined to the lung in only four patients. Of these 14 patients, 11 subsequently died of cancer. We conclude that thoracotomy for metastatic disease should be considered when the primary tumor is controlled, the lungs are the only site of metastatic disease, and there is adequate lung reserve to withstand surgery. Survival following thoracotomy may be influenced by the interval before diagnosis, the number of pulmonary nodules, and the number of thoracotomies performed.

Adult↗

PubMed1993

Importance of repeat fine-needle biopsy in the management of thyroid nodules.

Fine-needle aspiration (FNA) biopsy of a thyroid nodule was performed in 797 patients. Ninety-six patients had resection of the thyroid nodule performed subsequent to a one-time FNA biopsy. The surgical pathology of these 96 cases demonstrated a 5.8% false-negative rate and a 9.9% false-positive rate. As a consequence, we prospectively evaluated the routine practice of repeat FNA of cytologically benign thyroid nodules. Repeat FNA confirmed the original benign cytology in 183 (93%) of 196 patients. Seventeen of these 183 patients with benign FNA on both biopsies had resection of the nodule performed because of the development of suspicious clinical signs or in response to the patient's choice; 1 recurrent cyst was found to be carcinomatous. Of the 13 patients demonstrating a change in cytology on repeat FNA biopsy, 9 had a nodule that was classified as possibly malignant (suspicious); 6 of these patients underwent resection, and 1 patient was found to have a carcinomatous nodule. Four patients had nodules that were classified as probably malignant on repeat FNA biopsy; all of their nodules were resected, and three of them were found to be carcinomatous. This study demonstrates that, although one-time FNA biopsy of thyroid nodules is highly accurate, with a relatively low false-negative rate, repeat fine-needle biopsy improves on this diagnostic accuracy, thereby decreasing the risk of misdiagnosing a thyroid nodule that is malignant.

Adult↗

PubMed1993

Complications of laparoscopic cholecystectomy: a national survey of 4,292 hospitals and an analysis of 77,604 cases.

Complications of laparoscopic cholecystectomy were evaluated by a survey of surgical department chairpersons at 4,292 US hospitals. The 77,604 cases were reported by 1,750 respondents. Laparotomy was required for treatment of a complication in 1.2% of patients. The mean rate of bile duct injury (exclusive of cystic duct) was 0.6% and was significantly lower at institutions that had performed more than 100 cases. Bile duct injuries were recognized postoperatively in half of the cases and most frequently required anastomotic repair. Intraoperative cholangiography was practiced selectively by 52% of the respondents and routinely by 31%. Bowel and vascular injuries, which occurred in 0.14% and 0.25% of cases, respectively, were the most lethal complications. Postoperative bile leak was recognized in 0.3% of patients, most commonly originating from the cystic duct. Eighteen of 33 postoperative deaths resulted from operative injury. These data demonstrate that laparoscopic cholecystectomy is associated with low rates of morbidity and mortality but a significant rate of bile duct injury.

Bile Ducts↗

PubMed1992

Fibrin glue improves the healing of irradiated bowel anastomoses.

Many surgeons are reluctant to construct a bowel anastomosis with irradiated intestine. Previous studies have demonstrated diminished tensile strength of rat small bowel anastomoses that have been irradiated intraoperatively. To determine whether fibrin glue, a known tissue adhesive, improves the healing of these anastomoses, 69 male Sprague-Dawley rats were randomized into three anastomotic groups: Group 1, sutured ileal anastomosis without radiation or fibrin glue; Group 2, irradiated sutured ileal anastomosis without fibrin glue; and Group 3, irradiated ileal anastomosis with fibrin glue added to the suture line. Groups 2 and 3 received a single dose of 2,000 R intraoperatively. At seven days, the rats were sacrificed and the anastomotic segment was tested for breaking (tensile) strength. Anastomotic collagen content was evaluated using a hydroxyproline assay. Tensile strength results demonstrated that Group 2 was significantly weaker than Groups 1 and 3 (P = 0.001) and that the hydroxyproline content of Group 3 was significantly greater than that of Group 2 (P = 0.015). These results show that the addition of fibrin glue to an intraoperatively irradiated small bowel anastomosis improves healing, as demonstrated by both tensile strength and hydroxyproline content studies.

Anastomosis, Surgical↗

PubMed1991

A prospective study of double diagnosis of nonpalpable lesions of the breast.

Approximately three-fourths of open biopsies of the breast performed for mammographically detected suspicious lesions are shown histologically to be benign. Under the narrow conditions described herein, stereotaxic fine-needle aspiration (FNA) can identify these lesions with an accuracy of more than 90 per cent and a false-negative rate of 5 per cent. In an effort to reduce this failure rate, the mammographic appearance and stereotaxic FNA results of these lesions each were given scores on a scale of zero (benign) to five (malignant), to derive an over-all risk score prospectively applied to 264 suspicious occult lesions of the breast prior to open, biopsy. While all 264 lesions could be assigned a mammographic score, adequate tissue for assignment of a cytologic score could be obtained from 150 lesions. Of the 150 evaluable lesions, 53 were malignant and 97 were benign, historically. With a total score of two as the threshold for open biopsy, 21 of 150 (14 per cent) were proved to be benign, with no false-negative findings. If the total threshold score mandating an open biopsy was raised to four, the comparable figures were 61 of 150 (40 per cent) benign lesions and two false-negative instances of carcinoma in situ. Provided adequate tissue is aspirated for cytologic examination, we conclude that this algorithm has practical value in the management of nonpalpable lesions of the breast in that it can reliably identify a fraction of the benign lesions and spare these patients an operation.

Algorithms↗

PubMed1990

Protection of fiber function by para-axial fluid flow in interstitial laser therapy of malignant tumors.

In the past, interstitial laser therapy frequently has failed because of the damage to the bare fiber tip due to intense heat generated at the point of contact. Using a rat mammary tumor model, we describe a method of placing a 600 micron fiber inside a gauge 19 needle cannula after its insertion into the tumor. With this device continuous wave Nd:YAG laser is delivered to the target tumor while 0.9% saline flows para-axially into the tumor. Significant coagulation necrosis was induced with 500 joules at 5 watts, 100 seconds and 1 cc per minute of saline while the needle-fiber is pulled out of the tumor by 10 mm. The mean transmission loss after 500 joules was 2% in ten experiments. The tumor edema due to 1.5 ml of saline was transient. We conclude that successful hyperthermic coagulation necrosis by Nd:YAG laser can be achieved with minimal transmission loss by employing the above technique.

Animals↗

PubMed1990

Neuroendocrine differentiation in "poorly differentiated" colon carcinomas.

The diagnosis of "poorly differentiated" carcinoma was made in 47 of 683 colon cancers on the basis of conventional light microscopy which showed poorly defined glands, solid architecture or variable admixtures thereof. Samples from 44 of these 47 tumors were assessed by immunohistochemical analysis for the presence of neuroendocrine (NE) antigens. Paraffin sections were immunostained with antibodies to NSE, chromogranin, serotonin, VIP, substance P and somatostatin. Additional sections were also stained with monoclonal antibody (Mab) A-80 that recognizes a glycoprotein related to exocrine (EX) differentiation. Based on our findings, the tumors were phenotypically reclassified as follows: I) pure EX (n = 8), II) pure NE (n = 4), III) mixed EX-NE carcinomas (n = 23), and IV) predominantly EX carcinomas with occasional NE cells (n = 9). Survival among groups II and III appeared to be less than group I and survival in group IV was significantly less than group I. Survival among the four pure NE (group II) and 11 predominantly NE mixed carcinomas (group III) taken together was significantly less than the pure EX carcinomas. This study indicates: 1) The incidence of NE differentiation in tumors of the colon and rectum is higher than previously believed. 2) The poorly differentiated colon carcinomas comprise four distinct groups: pure EX, pure NE, mixed EX-NE carcinomas, and predominantly EX carcinomas with a NE cell subpopulation. 3) The presence of NE differentiation or of a NE cell subpopulation in colon carcinoma appears to be associated with a poorer prognosis.

Aged↗

PubMed1989

Lymphokine-activated killer cell induction in tumor-infiltrating leukocytes from colon cancer patients.

Lymphokine-activated killer (LAK) cell induction was evaluated in the peripheral blood mononuclear cells (PBMC) from 28 colon cancer patients and in the tumor-infiltrating leukocytes (TIL) from 20 of the patients' colon cancer specimens. Modulation of LAK cell induction in TIL and PBMC by inhibitors of arachidonic acid metabolism also was examined. LAK cells were induced in vitro in isolated TIL and PBMC by culturing with 500 U/ml of recombinant interleukin-2 (IL-2) for 3 to 5 days, and this was followed by the assessment of cytolytic activity against natural killer (NK)-resistant Chang hepatoma cells. LAK cell induction in the TIL was depressed significantly, compared with LAK cell induction in the PBMC of colon cancer patients (P less than 0.01). In the majority of cases, indomethacin augmented LAK cell induction in the TIL (P = 0.073 for the entire group, compared with cultures not treated with indomethacin) and nordihydroguaiaretic acid (NDGA) depressed LAK cell induction (P less than 0.05 for the entire group, compared with cultures not treated with NDGA). Further characterization of the mechanisms responsible for modulating LAK cell induction in the TIL of cancer patients may identify ways to optimize their use in adoptive cellular immunotherapy.

Adult↗

PubMed1989

Fine-needle aspiration biopsy of the thyroid. Diagnostic accuracy when performing a moderate number of such procedures.

The diagnostic accuracy of fine-needle aspiration biopsy of the thyroid was evaluated. Between June 1982 and July 1987, 354 fine-needle aspiration biopsies were performed on 289 patients with thyroid nodules. The ages of the patients ranged from 21 to 86 years (median, 45 years); 61 (21%) were men and 228 (79%) were women. Surgical confirmation of the cytologic diagnosis was obtained in 59 patients. Fine-needle aspiration biopsy identified 10% of the nodules as probably malignant and 10% as possibly malignant. Of these nodules, 30.5% were proved to be malignant by histologic examination. The accuracy of distinction between a benign (class I or II) or probably malignant (class IV) diagnosis was 95.2%. Patient acceptance of this procedure was good and complications were infrequent. These results indicate that fine-needle aspiration biopsy of the thyroid is accurate, safe, well tolerated, and easily applied, without its highly desirable features being compromised, even when a moderate number of such procedures are performed.

Adult↗

PubMed1988

Primary retroperitoneal pure choriocarcinoma. Two long-term complete responders from a rare fatal disease.

Extragonadal germ cell tumors may have a worse prognosis than germ cell tumors of gonadal origin, even when tumor bulk and extent of dissemination are equal. Primary retroperitoneal pure choriocarcinoma is one of the least common subgroups of the extragonadal germ cell tumors and has previously appeared to have the worst prognosis. Two new case reports on the treatment and follow-up of two patients with primary retroperitoneal pure choriocarcinoma are discussed. Both patients are disease-free at 24 and 81 months, respectively. After aggressive primary multiagent drug therapy for primary retroperitoneal pure choriocarcinoma, a favorable prognosis may be anticipated.

Adult↗

PubMed1988

The characterization of Ia+ cells in human parathyroid and islets.

Recent studies in animals have shown prolonged survival of endocrine allografts after treatment of the graft with Ia antibody prior to transplant. In this study, we documented the presence of Ia bearing passenger cells in human parathyroid and islets of Langerhans. Furthermore, we characterized these cells with regard to their expression of HLA-DQ and HLA-DR molecules using indirect immunofluorescence. We found that passenger cells in parathyroid express both HLA-DQ and HLA-DR. In contrast, islets express only HLA-DR. Parathyroid tissue treated first with polyclonal anti-DR or anti-DQ and complement eliminated cells that reacted with monoclonal anti-DR or -DQ probes, respectively. Similarly, islets treated with polyclonal anti-DR and complement eliminated cells that reacted with monoclonal anti-DR reagents. We believe that further characterization of Ia+ cells in human endocrine tissue will provide information that could be used to enhance allograft survival.

Cytotoxicity Tests, Immunologic↗

PubMed1988

Carcinoma of the breast: detection with MR imaging versus xeromammography.

Detectability of breast cancer with magnetic resonance (MR) imaging versus xeromammography was quantitatively compared. MR images were obtained of breasts of 120 women who underwent xeromammography. T1 values were determined for masses larger than 2 cm. Cancer was histologically confirmed in 39 breasts and was considered excluded from 81 due to results of biopsy, cyst aspiration, or sonography or absence of change in xeromammographic findings over time. Images were blindly interpreted by three observers, and results were expressed as receiver operating characteristic curves. Detectability of breast cancer was substantially better with xeromammography than with MR imaging for all observers (P less than .03, 10(-6), and .001). On MR images, spiculation of a mass, distorted architecture, skin thickening, and nipple or skin retraction were specific but relatively insensitive indicators of cancer. Masses with smooth, distinct margins and signal intensity greater than that of fat on T2-weighted images were always benign. Other findings and T1 values were not diagnostically useful. The authors conclude that xeromammography is superior to MR imaging in detection of breast cancer.

Breast Diseases↗

PubMed1988

Neuroendocrine carcinomas of the colon and rectum: a clinicopathologic evaluation.

Neuroendocrine carcinomas were diagnosed in 13 of 683 patients who had colon cancers removed from January 1980 to June 1987 for an incidence of 1.9%. The patients were 28 to 89 years of age (median, 72 years). There were seven male and six female patients. The treatment was as follows: right hemicolectomy, 5; transverse colectomy, 1; left hemicolectomy, 1; low anterior resection, 2; abdominal-perineal resection, 1; and in 3 patients with rectal tumors, biopsy examination only was performed. Microscopic stages were as follows: Dukes' stage B, 1; stage C, 6; stage D, 5; and stage indeterminate, 1. By light microscopy, the tumors showed solid clusters or ribbons of round to fusiform, small to intermediate-sized cells with variably abundant mitoses. Eight tumors had foci of glandular and/or squamous differentiation. By immunohistochemistry, all tumors showed one or more neuroendocrine markers, including neuron-specific enolase, chromogranin, synaptophysin, serotonin, and various neuropeptides. By electron microscopy, single membrane-bound neurosecretory granules were noted. The sites of metastases included regional nodes, 8; liver, 5; bone, 1. Four patients were treated with a combination of chemotherapy and radiation therapy. These tumors were, as a group, aggressive, with eight patients dead within 12 months of diagnosis. Median survival was 7 months, with three patients alive at 2, 38, and 68 months, respectively. Specifically, small- and intermediate-cell neuroendocrine carcinomas of the colon and rectum behaved very aggressively and displayed numerous structural and functional similarities with their bronchopulmonary counterparts.

Adult↗

PubMed1988

Sequential hormone therapy for advanced breast cancer.

Sequential hormone therapy for advanced breast cancer can offer significant and prolonged disease control with minimal morbidity. Predictors of response to sequential hormone therapy have not previously been identified. Sixty postmenopausal women with advanced or recurrent breast cancer treated with sequential megestrol acetate and tamoxifen were evaluated to identify factors which predict response to sequential therapy. The response rate to first-line therapy was 28% (17/60). Forty-seven percent of patients who responded to the first therapy responded to the second (8/17). Four of 16 patients (25%) who failed the first hormone therapy responded to the second. The response rate to a second hormone therapy was 25% (15/60). Chi-square tests were used to test the association between a response to sequential hormonal therapy and prior chemotherapy, age at first hormone trial, number of sites of disease, dominant site of disease, sequence of hormonal therapy, second response on the basis of first response, presence of soft tissue disease or bone disease alone, and receptor value. A one-tailed Fisher exact probability test revealed that a greater proportion of receptor-positive patients exhibited positive responses to sequential hormonal therapies than did receptor-negative patients. All of the patients who responded to a second hormonal therapy were estrogen receptor (ER)- and progestogen receptor (PgR)-positive. Fisher exact probability tests revealed a statistically significant association between response to initial hormone therapy and response to a subsequent hormone trial. This study suggests that patients who fail their initial hormone trial should be considered for a second hormonal trial if they are ER- and PR-positive.

Adult↗

PubMed1987

Hormone receptor studies in axillary metastases from occult breast cancers.

The authors describe 11 patients with occult breast carcinoma, who initially presented with axillary nodal metastases of unknown origin. In all 11 cases, physical examination and mammography results were normal. Steroid hormone receptor studies were done on tissue from all 11 axillary masses and 2 masses underwent lactalbumin staining as well. In 8 of the 11 patients these studies were positive, suggesting breast as the primary tumor site. Estrogen (30 to 445 fmol/g) or progesterone (30 to 1059 fmol/g) receptors, or both, were positive in seven cases. Although a breast carcinoma was subsequently found in all 11 patients, receptor studies on the primary tumor could not be done in every instance. The authors concluded that performing steroid hormone receptor assays on axillary metastases from occult tumors not only may provide information regarding the identity of the primary tumor but also may be the sole opportunity to determine its hormone receptor status.

Adenocarcinoma↗