PubMed Health⌕ Search

Biomedical subjects

R M Byers

Publications and source records attributed to R M Byers.

At least 19 recordsLinked to original sources
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↗
PubMed1990

DNA flow cytometry of acinic cell carcinomas of major salivary glands.

Fifteen acinic cell carcinomas from an equal number of patients were analysed for their DNA content and proliferative (S-phase) index by flow cytometry from archival tissues. Seven of the carcinomas manifested a diploid DNA content. None of the patients with diploid acinic cell carcinomas died of their carcinomas and none developed metastases in follow-up periods extending for 10 or more years. Four of eight patients with aneuploid acinic cell carcinomas have died because of their malignancies within a 10 year period after the first surgical removal of the carcinoma. Five of the eight patients exhibited metastases. Although the number of cases does not permit strong correlations between histopathological features, abnormalities in DNA content and outcome of patients, it was noted that carcinomas with prominent necrosis, tubuloductal differentiation and 'dedifferentiated' areas displayed more aggressive biological courses.

Adolescent↗
PubMed1989

Definitive radiotherapy for squamous cell carcinoma of the tonsillar fossa.

Between July 1968 and December 1983, 150 patients with previously untreated squamous cell carcinomas of the tonsillar fossa received megavoltage external beam irradiation with curative intent at U.T.M.D. Anderson Cancer Center. These patients were treated following a series of patients who had received radiotherapy between 1954 and May 1968. One hundred and thirty-seven patients were treated with conventional fractionation, the mean doses to the primary being 64.3 Gy, 67.8 Gy, 70.2 Gy, and 72.6 Gy for T1, T2, T3, and T4 lesions respectively. Thirteen patients were treated by altered fractionation schedules, 7 by hyperfractionation, and 6 by a concomitant boost to the primary. Elective bilateral neck irradiation was routine in all patients. A planned neck dissection was performed in 26 patients. The 5-year actuarial overall and disease-specific survival rates were 47% and 70%, respectively. Absolute local control rates with a minimum of 2 years follow-up after irradiation were 94%, 79%, 58%, and 50% for patients with T1, T2, T3, and T4 disease respectively. A total of 37 patients had local treatment failure; in 5 of 18 surgical salvage was successful. Only 4 patients with primary disease control developed failure in the neck and none of those with N0 or N1 disease did so when the primary was controlled. Twelve patients developed transient self-limited bone exposure, 7 developed osteoradionecrosis of the mandible, all requiring surgical resection. Most severe late complications occurred in patients with T3 and T4 lesions whose dose to the primary exceeded 67.5 Gy.

Adult↗
PubMed1989

Pulmonary thromboembolism after head and neck surgery.

In a retrospective study of all patients who had pulmonary embolism during a 37-year span at M. D. Anderson Hospital, we identified 502 patients, 30 of whom had a primary malignancy in the head and neck region. Only five of these patients had a clinically significant pulmonary embolus during the immediate postoperative period; these patients are the subject of a more detailed review with a case study as an example. Three of these patients died. Heart disease was identified as the most common predisposing factor. We review the results of this clinical study of pulmonary thromboembolism in patients having head and neck surgery as well as the natural history, diagnosis, and current treatment of pulmonary embolism.

Acute Disease↗
PubMed1989

Minor salivary gland tumors of the lip and buccal mucosa.

Between 1944 and 1985, 50 patients with minor salivary gland tumors of the lip and buccal mucosa were treated at M.D. Anderson Cancer Center: 19 with lip and 31 with buccal mucosa tumors. The male-to-female ratios were 2.8:1 for lip and 1:2.9 for the buccal mucosa tumors. Patient age at presentation ranged from 18 to 98 years with a median of 55 years. Treatment consisted of surgery alone for 28 patients, radiotherapy in 9 patients, and combined therapy for 13. Adenoid cystic carcinoma was the predominant histologic type, accounting for 21 (42%) tumors. Risk for recurrence was influenced by histology, the presence of perineural invasion, and the location of the primary tumor. Six patients developed recurrent disease; all six had adenoid cystic carcinoma. The therapeutic approach and the rationale for combined treatment of these neoplasms are discussed.

Adult↗
PubMed1988

The implication of tobacco use in the young adult with head and neck cancer.

To define the biologic characteristics of head and neck cancer in the young adult, the clinical course of 83 previously untreated patients less than or equal to 40 years of age with head and neck cancer was reviewed retrospectively. Their course was compared to that in a randomly chosen, concurrently treated, site-matched and stage-matched older head and neck cancer population (matched control). Patterns of recurrence as well as overall disease-free survival in each of the two populations were not significantly different. An important stratification factor, however, was related to tobacco usage. Thirty percent of the young patients denied using tobacco compared with only 9% of the controls (P less than 0.05). The 5-year disease-free survival rate of the young adults who did not use tobacco was 66% compared with 86% for their matched control group with a history of smoking. These differences were most significant in young adults with Stage II disease (P less than 0.05 by log-rank testing). The growth and progression of head and neck cancer in the young adults is characterized by tobacco use patterns; a family history of head and neck cancer in five of 17 nontobacco using young adults raises the issue of an inherent genetic determinant.

Actuarial Analysis↗