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H I Vargas

Publications and source records attributed to H I Vargas.

At least 19 recordsLinked to original sources
PubMed2001

The role of nuclear medicine in breast cancer detection: functional breast imaging.

Mammography remains the imaging modality of choice in detection of early, nonpalpable breast cancer. Scintimammography using SPECT, however, may prove to be a very useful adjunct to a nondiagnostic or difficult mammogram. Further prospective studies have to be designed so that the specific clinical applications of this technique are more defined. As with any new imaging procedure, special care to obtain high-quality scintimammographic studies and sufficient training of staff to perform and interpret the imaging are necessary.

Breast Neoplasms↗
PubMed2001

The clinical utility of Tc-99m sestamibi scintimammography in detecting multicentric breast cancer.

The ability to recognize multicentric breast cancer preoperatively would assist in identifying appropriate candidates for breast conservation surgery. Tc-99m scintimammography (SMM) is an adjunct to conventional mammography in identifying selected patients with breast cancer. The purpose of this study is to report the utility of SMM in identifying patients with multicentric breast cancer. Breast cancer patients treated by mastectomy who underwent a preoperative SMM between 1992 and 1999 were identified using the institution's Tumor Registry. The pathology report of each patient was reviewed for multicentric disease defined as an additional focus of cancer within a different quadrant of the breast or greater than 2.5 cm from the dominant tumor mass. Each patient's preoperative SMM was reviewed and compared with the pathologic findings to obtain correlative data. Fifty-eight women treated by mastectomy had preoperative SMM (age range 35-78 years; median 52 years). Pathology revealed infiltrating ductal carcinoma in 49 patients (84.5%), infiltrating lobular carcinoma in five patients (8.6%), ductal carcinoma in situ in three patients (5.1%), and colloid carcinoma in one patient (1.7%). Multicentric disease was present in the specimens of eight patients for a prevalence of 10.3 per cent. SMM was positive for uptake in 36 of 58 patients (sensitivity 62.1%). The sensitivity, specificity, positive predictive value, and negative predictive value of SMM in the detection of multicentric disease were 62.5, 96, 71, and 94 per cent, respectively. Although the overall sensitivity of SMM in the detection of breast cancer is superior to that of conventional mammography and physical examination in identifying multicentric breast cancer it is not an accurate modality for detecting multicentric disease in this study group. However, it may have limited applications in specific cases.

Adult↗
PubMed2000

Patterns of recurrence in anal canal carcinoma.

HYPOTHESIS: The initial modality of treatment of anal canal carcinoma (ACC) influences the pattern of recurrence of disease. DESIGN: A retrospective analysis comparing patterns of recurrence in patients with ACC undergoing either surgery or chemoradiotherapy as their initial therapeutic intervention. Anal margin cancers and adenocarcinomas were excluded. SETTING: A university-affiliated urban medical center. PATIENTS: Eighty-one patients were given a diagnosis of ACC between February 1, 1952, and December 31, 1998. Fifty-one (63%) of the patients initially underwent surgery: abdominoperineal resection in 38 patients (75%) and local excision in 13 patients (25%). Chemoradiotherapy was the initial therapeutic intervention in 30 patients (37%). MAIN OUTCOME MEASURES: The patterns of recurrence (local vs distant disease) and survival were compared between the group that underwent palliative surgery (hereafter referred to as the surgical group) and the group that received chemoradiotherapy (hereafter referred to as the chemoradiotherapy group). RESULTS: The mean follow-up was 40 months. Local recurrence occurred in 7 patients (14%) in the surgical group vs 7 patients (23%) in the chemoradiotherapy group (P =.46). Using Kaplan-Meier actuarial analysis, local recurrence rates for the surgical and chemoradiotherapy groups at 1 year were 0% and 6%, respectively (P =.32), and at 5 years were 17% and 36%, respectively (P =.02). The average (+/-SD) time to local recurrence in the surgical group was 23 +/- 0.7 months and for the chemoradiotherapy group 16 +/- 2.9 months (P =.27). Five (71%) of the 7 patients with local recurrences in the chemoradiotherapy group underwent salvage abdominoperineal resection with 100% disease-free survival at a mean follow-up of 35 months. When patients presenting with metastatic disease were excluded, distant recurrences developed in 7 patients (16%) in the surgical group and 2 (7%) in the chemoradiotherapy group (P =.31). Actuarial 5-year distant recurrence rates for the surgical and chemoradiotherapy groups were 26% and 19%, respectively (P =.65). Five-year survival was 42% in the surgical group and 74% in the chemoradiotherapy group (P =.01). CONCLUSION: There was a higher rate of local recurrence in patients with ACC treated with chemoradiotherapy vs surgical resection as the initial therapeutic intervention. However, when this occurred, abdominoperineal resection was effective salvage therapy and was associated with a 100% disease-free survival at 3 years. Therefore, chemoradiotherapy is justified as the initial treatment for ACC and has an overall 5-year survival that is significantly higher than that attained with initial surgical treatment.

Adult↗
PubMed2000

State of the art of minimally invasive breast biopsy: principles and practice.

In the last two decades, the increasing use of screening mammography with the early detection of breast cancer and the newly gained understanding of the biology and changing therapy of breast cancer, emphasizing systemic therapy and minimizing extensive local surgery, has contributed to the increasing development of minimally invasive techniques for the diagnosis of breast lesions. Minimally invasive techniques provide increased patient comfort, excellent cosmetic result and minimal morbidity They are also responsible for decreased costs and better medical care by allowing an informed discussion of breast cancer therapy and planning of surgery with an emphasis on negative margins and the dissection of the sentinel node. Techniques in use include Fine-Needle Aspiration Cytology, Core-Needle biopsy, Vacuum-Assisted Core biopsy (Mammotome) and Large Core biopsy (ABBI, Site-select). We present a balanced, evidence-based approach to the diagnosis of patients with palpable or mammographic abnormalities.

Biopsy↗
PubMed1999

Status of scintimammography and its relationship to other detection methods for breast cancer.

Breast cancer is the most important malignancy for women of the world's industrialized nations. It is second only to lung cancer in cancer-related mortality. Early detection is the best means of improving survival; the cornerstone of early diagnosis is mammography. Given the endemic nature of breast cancer, screening mammography has secured a routine place in health maintenance for women, although it is less than perfect. To aid in the diagnosis of malignant breast disease, other imaging modalities have evolved: ultrasound, magnetic resonance imaging (MRI), positron emission tomography (PET), and SMM. Scintimammography (SMM) is rapidly with a variety of applications for the management of breast disease. This technology has become a complementary modality to other conventional methods of breast imaging. This review will focus on the science behind SMM and how it is currently used in the management of breast lesions.

Breast Neoplasms↗
PubMed1999

Objective assessment of axillary morbidity in breast cancer treatment.

Historically, axillary lymph node dissection (ALND) was a critical aspect of the operative management of breast cancer. Recently, the role of ALND has been questioned, with postoperative morbidity possibly overshadowing patient benefit. Our objective was to quantitatively assess the long-term morbidity of ALND in patients with breast cancer. We conducted a cross-sectional study of patients being followed by the Breast Surgery Clinic at a university-affiliated urban hospital. Ninety-five patients with unilateral breast cancer who had undergone ALND were evaluated at routine follow-up visits in the latter half of 1998. A questionnaire was used to quantify the degree of subjective findings, including arm swelling, chest wall pain, decreased mobility, and weakness. Upper extremity strength, active range of motion, and circumference were measured. Overall, 70 per cent of patients had at least one complaint, with 18 per cent having moderate to severe symptoms. Twenty-one per cent had notable decrements in strength or range of motion, 9.3 per cent of patients required chronic compression garments for lymphedema, and 6.4 per cent changed their vocational status because of surgical morbidity. We conclude that adverse effects from ALND occur commonly. Objective findings are less common, perhaps causing clinicians to underappreciate postoperative morbidity. A significant subset of patients had enduring disability.

Adult↗
PubMed1998

Scintimammographic analysis of nonpalpable breast lesions previously identified by conventional mammography.

BACKGROUND: In randomized trials, screening mammography has led to decreased mortality from breast cancer. However, the low positive predictive value of mammography (i.e., the proportion of patients with a positive test result who actually have breast cancer) results in a large number of unnecessary biopsies. We determined whether scintimammography with technetium-99m-sestamibi is a useful supplemental diagnostic tool for women with nonpalpable breast abnormalities identified by conventional mammography. METHODS: Scintimammography was performed preoperatively on 70 women who were 31-66 years of age (mean age and median age = 51 years). These women had nonpalpable breast abnormalities identified by conventional mammography; subsequently, a needle-localization excisional biopsy of each suspicious lesion was performed. Scintimammographic images were interpreted independently by two nuclear medicine physicians who were blinded to all clinical and pathologic data, and an interobserver variation analysis was performed. RESULTS: Interobserver variation analysis of the scintimammographic findings showed an agreement for breast diagnosis of 97% and a kappa coefficient of 0.90. Comparison of scintimammographic findings and histopathologic results revealed that the sensitivity (proportion of patients with breast cancer who had a positive test result), the specificity (proportion of patients without breast cancer who had a negative test result), the positive predictive value and the negative predictive value (proportion of patients with a negative test result who actually did not have breast cancer) of scintimammography were 56% (95% confidence interval [CI] = 23%-85%), 87% (95% CI = 75%-94%), 38% (95% CI = 15%-68%), and 93% (95% CI = 82%-98%), respectively. Four of nine breast cancers were not detected by scintimammography. CONCLUSION: Because of excellent interobserver agreement, scintimammography provides an objective way of detecting primary breast carcinoma. In view of its low sensitivity and positive predictive value, however, scintimammography is not currently recommended as a screening test in patients with nonpalpable positive mammographic findings.

Adult↗
PubMed1997

Laparoscopic adrenalectomy: a new standard of care.

OBJECTIVES: Adrenalectomy is the mainstay of treatment for adrenal tumors. A variety of surgical approaches to the adrenal gland have been described. We studied the feasibility of laparoscopic adrenalectomy (LA), compared laparoscopic with open adrenalectomy (OA), and studied the hemodynamic changes in patients with pheochromocytoma. METHODS: Our early experience with 20 consecutive LAs is compared with a contemporaneous, matched control cohort of 20 patients who underwent OA via a flank or subcostal incision. LA was performed via a transperitoneal approach, following a standardized surgical technique. RESULTS: LA was successfully completed in 18 of 20 cases. Average operating time in the first 5 cases was 261 minutes, but, with further experience, a significant decrease in operative time was seen in the last cohort of 4 patients (155 minutes) (P = 0.0018). There was no significant difference in operative time or degree of blood loss between LA and OA groups. Patients who underwent LA required lower doses of postoperative parenteral narcotics (P = 0.0169), had a shorter hospital stay (mean 3.2 days) (P < 0.0001), and had a shorter convalescent period (mean 3.1 weeks) (P < 0.0001). Complications in the laparoscopic group (chronic port site pain in 1 patient, intra-abdominal fluid collection in another) occurred in the 2 patients who required open conversion. These 2 patients had large adrenal tumors (9 and 7 cm in diameter, respectively). LA resulted in similar hemodynamic changes as OA in patients with pheochromocytoma. CONCLUSIONS: LA is a safe and effective approach in most patients with adrenal pathology. Benefits include excellent operative exposure and visualization, less postoperative pain, shorter hospital stay and convalescent period, and improved cosmetic result. Pheochromocytoma is not a contraindication to LA. Patients with large adrenal tumors (larger than 6 cm), evidence of venous involvement, or invasion into surrounding tissue should be approached cautiously.

Adrenal Gland Neoplasms↗
PubMed1997

Adrenocortical neoplasms: role of prognostic markers MIB-1, P53, and RB.

Differentiation between benign and malignant adrenocortical neoplasms is made using a combination of clinical and pathologic parameters. Despite these parameters, it is still difficult to predict the biologic potential of some tumors. Forty adrenocortical lesions, including 10 hyperplasias, 10 adenomas, 12 carcinomas and eight metastatic/recurrent adrenocortical carcinomas were studied for the expression of MiB-1, p53, and the retinoblastoma gene product (RB) utilizing immunohistochemical techniques. The mean tumor proliferating fraction (TPF), expressed as the number of MiB-1-positive nuclei per 1,000 tumor cells, was 14.9 in adenomas, 31.5 in hyperplasias, 208.1 in carcinomas and 166.1 in recurrent or metastatic disease. None of the 20 benign lesions had a TPF of > 80, and only one of the 20 malignancies had a TPF of < 80. Nine of the 20 carcinomas were positive for p53. None of the benign lesions were p53 positive. Thirty-nine cases, including benign and malignant ones, were RB positive, and one was uninterpretable. We conclude that prognostic markers can be of great assistance in recognizing adrenocortical carcinomas. High TPF (> 80), as measured by staining with MiB-1, and positive p53 strongly correlate with malignant behavior and therefore may be useful in distinguishing benign from malignant adrenal lesions. Staining for RB does not appear to be a helpful technique.

Adenoma↗
PubMed1997

The role of prognostic markers (MiB-1, RB, and bcl-2) in the diagnosis of parathyroid tumors.

Assessment of the malignant potential of parathyroid tumors in the absence of metastasis can be difficult using morphologic criteria alone. The role of prognostic markers that may assist in evaluating aggressive behavior in these tumors has not been fully studied. We performed a retrospective study of 31 parathyroid lesions, including 10 adenomas, 10 atypical lesions, and 11 carcinomas, to evaluate the diagnostic and prognostic role of the MiB-1, p53, RB, and bcl-2 markers by immunohistochemical techniques. The mean tumor proliferative fraction (TPF), expressed as the number of MiB-1-positive nuclei per 1000 cells, was 20.3 in adenomas (range, 5-51), 20.0 in atypical lesions (range, 8-36), and 79.8 in carcinomas (range, 4-133). Only 1 of 20 benign lesions had a TPF more than 40, and only 2 of 11 carcinomas had a TPF less than 40. One atypical lesion and two carcinomas showed scattered cells positive for p53. Patients with the adenoma with increased TPF and the atypical lesion with positive p53 have been free of disease for 16 months. bcl-2 was expressed in 7 (70%) of 10 adenomas, 2 (20%) of 10 atypical lesions, and 4 (36%) of 11 carcinomas. Two of the 11 carcinomas were RB negative, whereas all of the 20 benign lesions were RB positive. We conclude that high TPF (greater than 40 as measured by staining with MiB-1) strongly correlates with malignancy and, therefore, may be useful in the diagnosis of carcinomas. Negative RB stain, although not a common event, may be helpful to exclude benign lesions. Other tumor markers (p53 and bcl-2) were not useful in distinguishing malignant from benign lesions.

Adenoma↗
PubMed1997

A forty-year experience with anal carcinoma: changing trends and impact of multimodality therapy.

Anal canal carcinoma is a rare clinical entity accounting for 1 to 3 per cent of all gastrointestinal malignancies. Abdominoperineal resection used to be the primary modality of treatment. However, recurrence rates of 20 to 40 per cent were observed after this mutilating procedure. In recent years, multimodality therapy with radiation and chemotherapy has shown at least equal results with the intention to preserve sphincter function. The objective of this study is to describe our experience at Harbor-UCLA Medical Center during the past 4 decades (1955-95), emphasizing changes in demographics, clinical presentation, and impact of multimodality therapy. Seventy-eight patients with the diagnosis of anal canal carcinoma were included. A steady increase in the incidence of anal carcinoma in younger people was observed (24% less than 64 years old for the 1955-65 period versus 75% for 1986-95 period). A female predominance was found in 1955-65 period, with F:M ratio 1.5, and a majority of male cases was seen in the last period (1986-95). Abdominoperineal resection was the preferred treatment during 1955-65, whereas during 1986-95 chemoradiation was the treatment of choice. We observed a trend from primary surgical treatment toward chemoradiotherapy with improvement in survival and preservation of ano-rectal function. Since 1988, we have not performed an abdominoperineal resection for primary treatment of anal carcinoma. Survival analysis was made grouping the patient population according to primary treatment. Higher survival rates were observed in the groups that received chemoradiotherapy (P = 0.0368) either as adjuvant or primary therapy. Chemoradiotherapy should be recommended as primary therapy to most patients.

Abdomen↗
PubMed1996

Technique of transperitoneal laparoscopic adrenalectomy.

Adrenalectomy can be successfully and safely carried out with a laparoscopic technique, using standard instrumentation via a transperitoneal approach. We describe five tasks to be completed by the surgeon: (a) generation of pneumoperitoneum and port placement, (b) exposure of the adrenal gland, (c) dissection of the adrenal gland, (d) clipping of the adrenal vein, and (e) removal of the adrenal gland and fascial closure of port sites. Each step is described in detail for right and left adrenalectomy. Laparoscopic adrenalectomy is advocated on the same grounds as other laparoscopic procedure, namely, decreased postoperative pain and ileus, a better cosmetic result, decreased hospital stay, and a shorter convalescent period. Some other advantages of the laparoscopic technique are: minimal extent of dissection and excellent visibility and exposure of the adrenal gland.

Adrenal Gland Neoplasms↗
PubMed1995

Scintimammography: the complementary role of Tc-99m sestamibi prone breast imaging for the diagnosis of breast carcinoma.

PURPOSE: To evaluate the complementary role of technetium-99m sestamibi scintimammography in improvement of the sensitivity and specificity of mammography in detection of carcinoma of the breast. MATERIALS AND METHODS: At 5 and 60 minutes after intravenous injection of Tc-99m sestamibi, scintimammograms were obtained in 147 women (age range, 18-73 years; mean age, 47.9 years +/- 10.2 [standard deviation]) with 153 lesions that warranted breast biopsy (102 lesions) or fine-needle aspiration cytologic analysis (51 lesions). There were 113 palpable and 40 nonpalpable lesions. Lesion size on mammograms was 0.8 x 0.6 cm to 15.0 x 11.0 cm (mean, 2.82 cm +/- 1.71 x 2.39 cm +/- 1.56). RESULTS: Scintimammographic findings were true-positive in 47 biopsy-confirmed carcinomas, true-negative in 91 benign lesions, false-positive in 11 lesions with benign histopathologic findings (fibrocystic disease [n = 8] or fibroadenoma [n = 3]), and false-negative in four lesions of infiltrating ductal carcinoma. The sensitivity of scintimammography was 92.2%; specificity, 89.2%; positive predictive value, 81.0%; and negative predictive value, 95.8%. CONCLUSION: The authors conclude that scintimammography is a sensitive test that can improve the detection of breast carcinoma.

Biopsy, Needle↗
PubMed1994

Appendiceal mass: conservative therapy followed by interval laparoscopic appendectomy.

BACKGROUND: Current therapy of patients with appendiceal abscess or phlegmon is in evolution. Controversial areas include initial conservative therapy, drainage of periappendiceal abscesses, and the role of interval appendectomy. OBJECTIVE: To evaluate the safety and efficacy of conservative therapy and of interval laparoscopic appendectomy (ILA). PATIENTS AND METHODS: Patients with signs and symptoms of acute appendicitis and a palpable right lower quadrant mass were included. Abscess/phlegmon was documented with ultrasound or computerized tomography. After initial therapy with antibiotics, patients were discharged to home. ILA was performed 6 to 12 weeks later. RESULTS: Twelve patients were included. Four patients had phlegmonous appendicitis and eight had an abscess, but only four had percutaneous drainage. All patients improved without surgical exploration and were subjected to ILA. ILA was successful in 11 of 12 patients; a median hospital postoperative stay of 1 day was required, and no perioperative morbidity was encountered. All patients returned to routine activities within 2 weeks of surgery. CONCLUSIONS: 1) Initial conservative management of patients with appendiceal abscess/phlegmon is prudent, safe, and effective. 2) Interval laparoscopic appendectomy can be performed safely and effectively.

Abscess↗
PubMed1992

Immunohistochemical determination of the estrogen receptor content of gastrointestinal adenocarcinomas.

Recently there have been several reports documenting the presence of estrogen receptors (ERs) in human gastrointestinal (GI) malignancies, raising the possibility that these cancers may be hormonally manipulated. To test this hypothesis, 68 frozen GI tissue specimens were examined for the presence of ERs within the cell nuclei by immunohistochemical staining. There were 51 cancers (25 gastric, 26 colon) and 17 normal tissue specimens (six gastric, 11 colon). Tissue sections 4 to 6 microns thick were incubated with monoclonal antibody H222SP psi, then stained by the peroxidase-antiperoxidase technique for visualization of the ER. The staining was semiquantitatively graded from 0 to 3+ depending on both the intensity of staining and the percentage of cell nuclei stained. A breast cancer specimen known to be strongly positive for the ER was used as a positive control. The 30 male and 21 female cancer patients had a median age of 59 years. All tumors were adenocarcinomas. Eight per cent of the gastric cancers were poorly differentiated, while 94 per cent of the colon cancers were moderately well to well differentiated. Using weak staining of at least 20 per cent of the cell nuclei as the minimum requirement for an ER positive tumor (1+, 0/51 tumors and 0/17) normal specimens were positive for ER. Only three out of 25 (12%) gastric tumors, and two out of 26 (8%) colon tumors demonstrated any staining; each exhibited weak staining of only five to ten per cent of the tumor nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1991

MR and CT imaging of ethanol-treated liver tumors in an animal model.

To characterize the radiographic appearance of liver lesions over time following ethanol injection, seven New Zealand white rabbits underwent surgical implantation of small fragments of VX-2 carcinoma within the liver. Upon reaching 1 cm in diameter, a tumor nodule was directly injected with absolute ethanol. Another nodule in the same animal was injected with saline as a control. Imaging was performed 6-24 days after the injections by high resolution CT and MRI, and correlation obtained with the pathologic specimens. Long TR spin-echo MR sequences were found to characterize the ethanol-treated regions of liver most accurately. Liver tissue infarcted by alcohol could be differentiated from tumor and necrosis by virtue of its short T2 relaxation value. There were no distinguishing features by other imaging techniques between the ethanol-treated and control tumor nodules. Peripheral contrast enhancement was demonstrated in both, corresponding to fibrous tissue around the ethanol-injected regions, and to viable tumor in the case of controls.

Animals↗