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Biomedical subjects

R M Byers

Publications and source records attributed to R M Byers.

At least 37 records · Page 2Linked to original sources
PubMed1994

Prognostic factors in mucoepidermoid carcinomas of major salivary glands: a clinicopathologic and flow cytometric study.

Mucoepidermoid carcinomas (MEC) of the major salivary glands from 48 patients who received their treatment at a single institution were studied for prognostic indicators. Uni- and multivariate statistical analyses were performed on several clinicopathologic factors and also on flow cytometric (FCM) DNA content data of the carcinomas. Clinical prognostic factors associated with decreased survival included age > 60 years (P = 0.01), male gender (P = 0.002), symptoms at diagnosis (P = 0.03), stage of disease (P < or = 0.0001), type of surgery (P = 0.0006), and recurrence (P = 0.0001). Histopathological prognostic factors associated with decreased survival included MEC tumour grade (P = 0.0001), tumour size > 3.0 cm (P = 0.02), lymph node involvement (P = 0.0004) and positive surgical margins (P = 0.007). DNA FCM factors associated with decreased survival included aneuploid tumours (P = 0.08) and proliferative activity (S+G2M > 5%, P = 0.07). Multivariate analysis indicated that histological grade, proliferative activity, symptoms at diagnosis, clinical stage of disease and type of surgery were significant (P < or = 0.05) prognostic/survival factors in the biological assessment of this neoplasm.

Adolescent↗
PubMed1993

Evaluation of the dose for postoperative radiation therapy of head and neck cancer: first report of a prospective randomized trial.

PURPOSE: This study was designed to determine in a prospective randomized trial the optimal dose of conventionally fractionated postoperative radiotherapy for advanced head and neck cancer in relation to clinical and pathologic risk factors. METHODS AND MATERIALS: Between January 1983 and March 1991, 302 patients were enrolled on the study. This analysis is based on the first 240 patients entered through September 1989, of whom 221 (92%) had AJC Stage III or IV cancers of the oral cavity, oropharynx, hypopharynx, or larynx. The patients were stratified by postulated risk factors and randomized to one of three dose levels ranging between 52.2 Gy and 68.4 Gy, all given in daily doses of 1.8 Gy. Patients receiving > 57.6 Gy had a field reduction at this dose level such that boosts were only given to sites of increased risk. RESULTS: The overall crude and actuarial 2-year local-regional recurrence rates were 25.4% and 26%, respectively. Patients who received a dose of < or = 54 Gy had a significantly higher primary failure rate than those receiving > or = 57.6 Gy (p = 0.02). No significant dose response could be demonstrated above 57.6 Gy except for patients with extracapsular nodal disease in the neck in whom the recurrence rate was significantly higher at 57.6 Gy than at > or = 63 Gy. Analysis of prognostic factors predictive of local-regional recurrence showed that the only variable of independent significance was extracapsular nodal disease. However, clusters of two or more of the following risk factors were associated with a progressively increased risk of recurrence: oral cavity primary, mucosal margins close or positive, nerve invasion, > or = 2 positive lymph nodes, largest node > 3 cm, treatment delay greater than 6 weeks, and Zubrod performance status > or = 2. Moderate to severe complications of combined treatment occurred in 7.1% of patients; these were more frequent in patients who received > or = 63 Gy. CONCLUSION: With daily fractions of 1.7 Gy, a minimum tumor dose of 57.6 Gy to the whole operative bed should be delivered with a boost of 63 Gy being given to sites of increased risk, especially regions of the neck where extracapsular nodal disease is present. Treatment should be started as soon as possible after surgery. Dose escalation above 63 Gy at 1.8 Gy per day does not appear to improve the therapeutic ratio.

Adult↗
PubMed1993

Predicting occult lymph node metastasis in parotid cancer.

To determine the factors predictive of occult cervical metastases, we retrospectively reviewed the charts of 99 previously untreated patients with a primary parotid malignancy who underwent elective neck dissection between 1960 and 1985. Univariate and multivariate analyses were performed to determine the predictive value of 11 factors. The univariate study found facial nerve paralysis, extraparotid extension, and perilymphatic invasion statistically significant. In the multivariate analysis of preoperative factors, facial nerve paralysis was most predictive of occult disease. If the variable pool was expanded to include a fine-needle biopsy, tumor grade became the most important preoperative variable. When the analysis was further expanded to include a parotidectomy, the most influential factors were patient age, perilymphatic invasion, and extraparotid tumor extension. This report identifies the variables predictive of occult neck disease in parotid cancer.

Adolescent↗
PubMed1993

Effectiveness of combined induction chemotherapy and radiotherapy in advanced nasopharyngeal carcinoma.

PURPOSE: This prospective trial was conducted with the goal of achieving an improvement in both overall and progression-free survival in previously untreated patients with stage IV nasopharyngeal carcinoma who received an induction chemotherapy regimen of fluorouracil (5-FU) and cisplatin followed by radiotherapy. PATIENTS AND METHODS: From January 1985 to January 1990, 47 patients with T1-4N2-3M0 squamous cell carcinoma of the nasopharynx were treated at The University of Texas M.D. Anderson Cancer Center with two to three cycles of 5-FU (1,000 mg/m2 continuous infusion per day x 5 days) plus cisplatin (100 mg/m2 continuous infusion on day 1 only) followed by radiotherapy using the conventional time/dose schedule. RESULTS: The response rate to chemotherapy was 93.2% (20.5% complete response [CR]; 72.7% partial response [PR]), and the overall CR rate after radiotherapy was 86%. With a median follow-up period of 53 months, the 2-, 4-, and 6-year survival rates were 80%, 71.6%, and 67.4%; the overall treatment failure rate was 27%. Treatment was well tolerated and without significant acute or chronic toxic effects. CONCLUSION: The results of this prospective study demonstrate that 5-FU plus cisplatin followed by radiotherapy can induce a durable remission in a high proportion of patients with poor-prognosis stage IV nasopharyngeal carcinoma.

Adolescent↗
PubMed1993

Congenital hemangiopericytoma. An ultrastructural, immunocytochemical, and flow cytometric study.

Congenital (infantile) hemangiopericytoma is a rare soft-tissue tumor that has been described as a distinct subtype of the classic hemangiopericytoma. We report the ultrastructural, immunocytochemical, and flow cytometric features of a case diagnosed in a male neonate 3 days after birth. The tumor appeared structurally similar to its adult counterpart, meriting the designation hemangiopericytoma, but the improved prognosis that has been reported in young children supports according the infantile form the status of an entity rather than merging it with its adult counterpart.

Cytoskeletal Proteins↗
PubMed1993

Functional parathyroid cyst and hypocalciuric hypercalcemia.

Parathyroid cysts are uncommon. They can be divided into functional and nonfunctional cysts depending on whether or not they are associated with hypercalcemia. Functioning cysts are very rare with less than twenty reported cases. We report a case of functioning parathyroid cyst associated with hypocalciuric hypercalcemia. We have been unable to find a similar case previously reported in the literature.

Adult↗
PubMed1992

Ampicillin-sulbactam vs clindamycin in head and neck oncologic surgery. The need for gram-negative coverage.

This study was undertaken to assess whether gram-negative antimicrobial coverage is required in patients undergoing head and neck oncologic surgery. Ampicillin sodium-sulbactam sodium and clindamycin phosphate were compared in a prospective, randomized, parallel, double-blind trial of 212 patients undergoing head and neck procedures involving clean-contaminated wounds. Both antibiotics were given up to 1 hour before surgery and continued at 6-hour intervals after surgery for an additional eight doses. Fourteen infections occurred in the ampicillin-sulbactam-treated group (13.3%) and 29 infections in the clindamycin-treated group (27.1%). From patients receiving clindamycin, 29 gram-negative organisms were isolated, compared with six from those patients receiving ampicillin-sulbactam. This finding supports the need for gram-negative coverage in patients undergoing clean-contaminated head and neck oncologic surgery.

Adult↗
PubMed1992

Squamous carcinoma of oral tongue: prognostic significance of flow-cytometric DNA content.

Thirty-eight squamous carcinomas of the mobile tongue were flow cytometrically analyzed for their DNA content, and the results correlated with clinicopathologic parameters and patient survival. Tumor size (p = 0.01), depth of invasion (p = 0.05), histologic differentiation (p = 0.03), ploidy pattern (p = 0.01), and S-phase (p = 0.001) showed significant correlation with patients' clinical outcomes in univariate analyses. A multifactorial regression analysis of all significant parameters indicated that S-phase percentage and depth of tumor invasion were independent prognostic factors in this cohort.

Adult↗
PubMed1991

Prognostic variables in parotid gland cancer.

We performed a retrospective review of 178 previously untreated patients with primary malignant neoplasms of the parotid gland treated at our institution between 1960 and 1985. Patients were followed up for a median of 7.5 years. Fifty-nine percent underwent surgery alone, and 40% underwent surgery and radiation therapy. Univariate and multivariate analyses established the prognostic influence of cancer stage, cancer grade, histologic type, presence of lymphatic invasion, perineural invasion, tumor size, extension beyond the parotid gland fascia, cervical adenopathy, quality of margins, and patient age and gender. Survival was influenced most by tumor grade, tumor size, presence of positive cervical lymph nodes, and facial nerve invasion. The risk of local-regional recurrence was most affected by cervical adenopathy and tumor size. Distant metastases were predicted by tumor grade and size. At last contact, 39% of patients were alive and free of disease, while 26% had died of the disease. We analyzed the optimal surgical procedure and the rationale for the selection of combined treatment.

Adolescent↗
PubMed1991

Metastatic adenocarcinoma to the neck from an unknown primary source.

We report a retrospective review of 223 patients who presented to the Department of Head and Neck Surgery from 1970 through 1987 with a diagnosis of metastatic adenocarcinoma of unknown primary origin. Multivariate analysis was performed using the following parameters: age, sex, initial side and site of nodal involvement, involvement of other body sites, degree of differentiation, treatment modality, outcome, and survival. Follow-up was obtained in all patients, with a minimum of 2 years for survivors. Average age was 55 years, with an approximately equal male:female ratio. The most common site of presentation was the supraclavicular fossa (76%). The initial side of presentation was the left neck in 53% of patients, right neck in 33%, and bilateral in 14%. Metastatic disease to other body sites was present in 86% of patients, with the most common sites being mediastinum (35%), lung (21%), and bones (19%). Increased survival was associated with unilateral neck involvement (p = 0.001) and disease limited to nodes above the cricoid cartilage (p = 0.007). Mean survival was 17 months, with a median of 8 months. Death was due to the index cancer in all but four patients; three of these four patients died of treatment-related causes. Survival was 20% at 2 years and 9% at 5 years. Length of survival was not affected by age, sex, initial side of neck disease, location of other metastatic sites, histologic appearance, or treatment modality. Our current algorithm for the work-up and treatment of this lethal disease is explained.

Adenocarcinoma↗
PubMed1991

The prognostic implications of location for scalp melanoma.

The clinical and pathologic records of 95 patients with primary cutaneous melanoma isolated to the scalp and regional lymph nodes treated at the MD Anderson Cancer Center between 1976 and 1985 were reviewed to assess the effect of lesion location on the prognosis of scalp melanoma. The scalp was defined as an area bounded by the supraorbital ridges, superior nuchal line, zygoma, and mastoid, thereby including a large non-hair-bearing area. Patients were grouped according to lesion location: hair-bearing or non-hair-bearing; anterior or posterior to the mid-tragal line; and parietal versus frontal, temporal, or occipital. There was a similar distribution of prognostic factors between the anatomic subsites. Analysis by univariate and multivariate methods demonstrated that, in a hair-bearing area, in an area posterior to the mid-tragal line, or in the parietal region, lesion location was highly predictive of the patient's survival. For example, the 5-year, melanoma-specific survival rate was 65% overall, 86% for patients with lesions located in non-hair-bearing regions and 47% for those with lesions in hair-bearing regions (p = 0.0019).

Female↗
PubMed1991

Intraoral soft tissue reconstruction after cancer ablation: a comparison of the pectoralis major flap and the free radial forearm flap.

We compared, by retrospective chart review, the free radial forearm flap and the pectoralis major flap in repairing intraoral soft tissue defects resulting from tumor ablation. Statistical significance of differences was determined using Fisher's exact test and chi-square analysis. Fifty-one free flap and 126 musculocutaneous flap transfers were analyzed. The former were used more often for defects in the anterior part of the oral cavity, whereas the latter were used more frequently in the posterior part. Significantly more patients with pectoralis major flap transfers had late-stage (T3 and T4) disease than did those in the free radial forearm flap group (p = 0.004). Also, the complication rate was significantly higher in the pectoralis major flap group (p = 0.01); this was due to differences in the rates of dehiscence, fistula formation, and flap loss. We thus conclude that, despite the need for microsurgery, the free radial forearm flap is at least as reliable as the pectoralis major flap and that the choice of flap should be based on defect considerations rather than on the perceived reliability of the reconstructive method.

Chi-Square Distribution↗
PubMed1990

Prevention of second primary tumors with isotretinoin in squamous-cell carcinoma of the head and neck.

BACKGROUND: Patients with head-and-neck cancers who are free of disease after local therapy remain at high risk for both recurrent and second primary tumors. Retinoids have proved efficacious in the treatment of premalignant oral lesions and are promising agents for the prevention of epithelial carcinogenesis. METHODS: We prospectively studied 103 patients who were disease-free after primary treatment for squamous-cell cancers of the larynx, pharynx, or oral cavity. After completion of surgery or radiotherapy (or both), these patients were randomly assigned to receive either isotretinoin (13-cis-retinoic acid) (50 to 100 mg per square meter of body-surface area per day) or placebo, to be taken daily for 12 months. RESULTS: There were no significant differences between the two groups in the number of local, regional, or distant recurrences of the primary cancers. However, the isotretinoin group had significantly fewer second primary tumors. After a median follow-up of 32 months, only 2 patients (4 percent) in the isotretinoin group had second primary tumors, as compared with 12 (24 percent) in the placebo group (P = 0.005). Multiple second primary tumors occurred in four patients, all of whom were in the placebo group. Of the 14 second cancers, 13 (93 percent) occurred in the head and neck, esophagus, or lung. CONCLUSIONS: Daily treatment with high doses of isotretinoin is effective in preventing second primary tumors in patients who have been treated for squamous-cell carcinoma of the head and neck, although it does not prevent recurrences of the original tumor.

Adult↗
PubMed1990

Regional radiotherapy as adjuvant treatment for head and neck malignant melanoma. Preliminary results.

From 1983 through 1988, 83 patients with high-risk cutaneous malignant melanoma (primary lesion thicker than 1.5 mm or palpable lymphadenopathy) of the head and neck region were enrolled in a study designed to assess the efficacy of a few large doses of radiation (24 to 30 Gy in 4 to 5 fractions). The actuarial 2-year locoregional control rates for the three groups were 95%, 90%, and 83%, respectively. Corresponding survival rates were 80%, 71%, and 69%. The majority of failures were due to distant metastases. Locoregional control rates were better than those reported earlier with surgery alone for comparable patients. The treatment morbidity was minimal.

Adolescent↗
PubMed1990

Submandibular gland tumors. Adverse histologic factors and therapeutic implications.

We reviewed our 41-year experience with tumors of the submandibular gland to determine what factors influence outcome and their implications for treatment. The most common benign neoplasm was pleomorphic adenoma (21), while among malignant tumors the adenoid cystic variety (37) predominated. For the 86 patients who had malignant tumors, the 2- and 5-year survivals by the life table method were 82% and 69%, respectively. For patients with malignant tumors, histology, size, perineural invasion, and prior treatment did not affect overall survival. Factors adversely affecting outcome were extraglandular soft-tissue extension and lymph node metastasis. Local-regional control was enhanced in patients with soft-tissue extension if they were treated by surgery followed by radiotherapy rather than by surgery alone.

Adenocarcinoma↗
PubMed1990

Primary radiotherapy in the treatment of stage I and II oral tongue cancers: importance of the proportion of therapy delivered with interstitial therapy.

From January 1963 through December 1979, 103 patients with Stage T1N0 and T2N0 squamous cell carcinomas of the oral tongue were treated with definitive radiotherapy. The primary was Stage T1 in 18 patients and T2 in 85 patients. Therapy to the primary consisted of interstitial therapy only in 18 patients, 16-37 Gy in 2.4-4.0 Gy fractions followed by interstitial therapy to doses of 38-55 Gy in 31 patients, external therapy of 40-50 Gy with interstitial therapy of 20-40 Gy in 46 patients, and external beam only to doses of 45-82 Gy in 8 patients. Follow-up ranged from 2 to 290 months (median 159 months). Five of the 8 patients treated with external therapy alone and 6 of the 18 patients treated with interstitial therapy failed at the primary site. In those patients treated with a combination of external and interstitial therapy the 2-year local control rate was 92% for patients treated with external therapy to doses of less than 40 Gy combined with a moderately high dose of brachytherapy, compared with 65% for patients who received external therapy to doses of greater than or equal to 40 Gy with lower brachytherapy doses (p = .01). Conversely the risk of failure in the neck was directly related to the dose delivered by external beam therapy. In field recurrence occurred in 44% of patients receiving no therapy to the neck. 27% in those receiving less than 40 Gy, and 11% in those patients with neck treatment to greater than or equal to 40 Gy. Eleven of 87 (13%) of patients who were at risk for complications for greater than or equal to 24 months developed severe complications; severe complications were more likely to occur in the group who received most of their therapy with external beam irradiation. These data show that a high dose of interstitial therapy is necessary to secure optimum local control of early primary tongue cancer. Because of the high frequency of moderate to severe late complications in this series we have adopted a policy of initial surgery for most oral tongue cancers with postoperative radiotherapy if indicated by pathological features predictive of a high rate of local-regional failure.

Adult↗