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Biomedical subjects

B Cummings

Publications and source records attributed to B Cummings.

At least 55 records · Page 3Linked to original sources
PubMed1991

Functional outcome in patients treated with surgery and irradiation for soft tissue tumours.

One hundred five consecutive patients underwent surgical resection and adjuvant irradiation in treatment of soft tissue sarcoma or aggressive fibromatosis. All patients were entered in a prospective study evaluating functional outcome and 88 patients were examined at 12 months following surgery. Outcome was characterized using the Enneking system as well as documenting employment/recreational status and limb edema. Sixty-eight of 88 patients had functional scores of 21 or better (out of a possible total of 35). Forty-four patients were serially evaluated at 12 and 24 months and there was no difference in their outcome at the 2 time points. Univariate analysis demonstrated that large tumour size, postoperative complications, and neural sacrifice were associated with poor functional outcome.

Adolescent↗
PubMed1991

Preoperative and postoperative irradiation of soft tissue sarcomas: effect of radiation field size.

For the treatment of soft tissue sarcomas it has frequently been staged but not quantitatively demonstrated, that the volume irradiated is smaller when irradiation is given preoperatively as compared to postoperatively. In this study the field size used for preoperative irradiation was compared with that necessary in the same patient had the radiation been given postoperatively. Twenty-six patients with soft tissue sarcomas of the extremity, groin, and shoulder girdle who had received preoperative irradiation were resimulated following surgery to determine the size of the postoperative field. The simulation was performed by a physician not involved in the preoperative treatment planning. Preoperatively a radial margin of 5 cm around the tumor was used for low and intermediate grade and 7 cm for high grade sarcomas. Postoperatively the same margins were used but around the surgical field. Twelve patients underwent a wide resection and 14 patients a resection followed by vascularized tissue transfer to the surgical bed. The median follow-up was 22 months (range 13-46). No local recurrences and two cases of distant metastasis were observed. Independently of surgical procedure and tumor grade, the size of the preoperative radiation field and number of joints included in the field were significantly smaller than that of postoperative radiation (p less than 0.001). In two patients preoperatively and four patients postoperatively, the radiation field involved the whole circumference of the limb. Provided that equivalent radiation time-dose-fraction parameters are used and that the complication rate is proportional to the radiation field size, late complications may be less after preoperative irradiation than after post-operative irradiation.

Adolescent↗
PubMed1991

Fractures following limb-salvage surgery and adjuvant irradiation for soft-tissue sarcoma.

In a prospective study, consecutive patients were treated for soft-tissue sarcoma (STS) by wide resection and adjuvant irradiation. Twelve patients had resection of bone to achieve a tumor free margin; five of these patients were left with lower extremity open segmental cortical defects in the high-dose radiation field. Four of the five patients with cortical defects suffered a fracture through the defect more than six months after surgery. Only one of 71 patients not treated with bony resection suffered a late fracture. Patients requiring bony cortex resection for STS of the lower extremity should be considered at risk for late fracture if adjuvant irradiation is prescribed.

Adult↗
PubMed1989

The surgical margin in soft-tissue sarcoma.

In a retrospective review of 231 patients who were referred to Princess Margaret Hospital because of a soft-tissue sarcoma in an extremity, 100 patients were identified who had no metastases when they were first seen and who had been treated by local resection and adjuvant radiation therapy. Complete data were collected for each patient for the following variables: age; sex; location of the tumor and its size, grade, depth, and compartmental status; chemotherapy; and dose of radiation. The surgical margins were characterized as positive or negative for histological evidence of disease on the basis of an independent review of the pathological and operative reports by a surgeon and a radiation oncologist who were experienced in the management of sarcoma. Cox multivariate analysis was used to determine which of these variables contributed to local recurrence and evidence of systemic disease. Adequacy of the margin of resection was the only variable that was associated with local relapse (p = 0.0004). The size of the tumor (p = 0.0008) was the major determinant of the risk of systemic disease.

Adolescent↗
PubMed1988

Low dose postoperative adjuvant radiation therapy for rectal cancer is ineffective.

Ninety-seven patients with rectal cancer which had either penetrated through the rectal wall or involved regional lymph nodes received postoperative adjuvant radiation therapy of 24 Gy in 12 fractions or 25 Gy in 10 fractions in 2 weeks. The crude pelvic recurrence rate was 48/97 (49%) and the actuarial local relapse-free rate at 5 years was 41%. The radiation doses used produced no late morbidity, but had no discernible effect on the risk of local recurrence, and may have compromised the subsequent use of radiation for symptomatic pelvic recurrence.

Adenocarcinoma↗
PubMed1987

Sequential chemotherapy and radiation for nasopharyngeal cancer: absence of long-term benefit despite a high rate of tumor response to chemotherapy.

Between April 1981 and December 1983, patients with locoregional carcinoma of the nasopharynx were treated with two courses of chemotherapy administered before radiation therapy. Chemotherapy consisted of methotrexate, bleomycin, and cisplatin, which were administered at 3-week intervals, and radiation therapy was scheduled to commence 3 weeks after the start of the second course. Forty-nine of 51 consecutive patients were treated; only one patient progressed on chemotherapy, and of 36 patients with measurable neck nodes, eight had complete and 19 had partial clearance (greater than 50% decrease in cross-sectional area) of these nodes when assessed before initiation of radiotherapy. Despite the high rate of tumor response (75%; 95% confidence limits, 59% to 91%), the actuarial survival and disease-free survival curves were almost identical to those recorded for a consecutive group of 140 historical controls of similar stage distribution treated with radiation alone. This chemotherapy provided a high rate of tumor remission, but did not appear to convey long-term benefit to patients when used before radiation therapy.

Actuarial Analysis↗
PubMed1985

Carcinoma of the extrahepatic bile ducts: results of an aggressive surgical approach.

Ninety patients with adenocarcinoma of the extrahepatic bile ducts were treated between 1969 and 1984. Fifty-four tumors involved the upper third, 15 the middle third, and 21 the lower third of the common duct. Twenty-two patients had gallstones and five had inflammatory bowel disease. Forty-three patients had operations before definitive treatment; the diagnosis was made in only 18. Resection was accomplished in 30 patients (33%): 12 of 54 in the proximal third, six of 15 in the middle third, and 12 of 21 in the distal third. The mean survival in patients who underwent resection was 32 months (proximal third, 28 months; middle third, 32 months; lower third, 37 months). Surgical bypass was performed in 28 patients (mean survival 10 months) and intubation alone was performed in 24 patients (mean survival 8 months). Recurrent cholangitis occurred in 56% of intubated patients compared with 26% of patients treated without tubes. Radiation was used with resection and for palliation. Responses were observed, but the complication of radiation duodenitis has limited the dose. An aggressive approach to resection of bile duct tumors is possible with a low operative mortality rate and offers the best opportunity for cure as well as good palliation. Internal bypass is preferable to chronic intubation. The role of radiation therapy in this disease is still not clear.

Adenocarcinoma↗
PubMed1984

Results and toxicity of the treatment of anal canal carcinoma by radiation therapy or radiation therapy and chemotherapy.

The results of treating anal canal carcinoma by radical external beam radiation alone (RT) or by combined 5-fluorouracil, mitomycin C and radiation (FUMIR), were compared in nonrandomized groups of patients treated in a single center. In each treatment regimen, surgery was reserved for those patients with residual carcinoma. The uncorrected 5-year survival rate in each group was approximately 70%, but primary tumor control was achieved in 93% (28/30) with FUMIR compared to 60% (15/25) treated with RT. Acute hematologic and enterocolic toxicity with uninterrupted external beam radiation courses of 5000 cGy in 4 weeks plus chemotherapy led to the adoption of split-course treatment. Serious late toxicity requiring surgical intervention occurred in 3 of 25 following RT, and in 5 of 30 following FUMIR. Colostomies were needed as part of treatment for residual carcinoma or for the management of treatment-related toxicity in 11 of 25 treated by RT and have been required to date in 4 of 30 treated by FUMIR. The improvement in the primary tumor control rate and the reduction in the number of patients requiring colostomy when compared with the results of RT favor combined chemotherapy and radiation as the initial treatment for anal canal carcinoma.

Actuarial Analysis↗
PubMed1982

Beryllium toxicity. The selective inhibition of casein kinase 1.

1. Cyclic AMP-independent casein kinase 1 in liver cytoplasm and nuclei was inhibited by Be2+ in vitro (Ki 2.5 microM and 29 microM respectively). Casein kinase 2 (phosvitin kinase) and cyclic AMP-dependent protein kinase were unaffected. 2. The inhibition of casein kinase 1 by Be2+ was competitive with respect to the protein substrate; at non-saturating concentrations of casein, inhibition was non-competitive with respect to ATP. 3. In rats given LD50 doses of Be2+ 24 h before death, the activities of cytoplasmic and nuclear casein kinase 1 in livers from partially hepatectomized animals were diminished approx. 50%; with intact rats, nuclear casein kinase 1 was inhibited at concentrations of casein less than the Km.

Animals↗
PubMed1982

Combination chemotherapy used prior to radiation therapy for locally advanced squamous cell carcinoma of the head and neck.

Thirty-three patients with locally advanced squamous cell carcinoma of the head and neck were scheduled to receive two courses of chemotherapy prior to radical radiotherapy. Chemotherapy consisted of moderate-dose methotrexate with leucovorin rescue, bleomycin by infusion, and cisplatin. Loss of body weight and the duration of membrane formation at a specified region of the oral cavity during radiation therapy were used as indices of radiation toxicity: there was no excessive loss of body weight or mucosal reaction in patients who received combined treatment compared to patients in a nonrandomized control group who received radiotherapy alone. Twenty patients (60%) had a greater than or equal to 50% decrease of measurable disease prior to starting irradiation, but only eight patients (24%) are alive and disease-free at a median followup of 16 months. Aggressive chemotherapy does not prevent delivery of subsequent full-dose radiotherapy for squamous cell carcinoma of the head and neck, but this study does not suggest that chemotherapy has a great beneficial effect on long-term survival.

Antineoplastic Agents↗
PubMed1980

Radiotherapy of early glottic cancer.

Patients (383) with stage Tis, Tla and Tlb NoMo glottic cancer are reviewed. Radiotherapy cured 93% of Tis patients and 86% of Tla and Tlb cases. Of all recurrences, 63% were cured. No patient with stage Tis died as a result of tumor and only 5% of stage Tla and Tlb died from tumor. Involvement of the anterior commissure or both vocal cords did not influence control rates by radiotherapy. Mobility of the vocal cord and size of radiotherapy field were significant factors influencing control by radiotherapy. Late recurrences and/or second primaries in the larynx following radiotherapy are rare. Second primaries in the respiratory tract (especially lung) are common and are as important a cause of death as laryngeal cancer in T1 cases. It is concluded that moderate dose radiotherapy with surgery for salvage is a highly effective method of management for early glottic cancer.

Evaluation Studies as Topic↗
PubMed1980

Differences in the lipid constituents of sebum from pre-pubertal and pubertal subjects.

Significant differences have been reported in the composition of skin surface lipid in pre-pubertal subjects when compared to pubertal subjects. Analytical studies were performed to determine whether group mean changes in the fatty acid composition of the triglyceride and wax ester fractions of sebum could be detected in pre-pubertal versus pubertal subjects. Twenty males (ages 6-9), twenty females (ages 6-9) and twelve teenagers (ages 11-16) were studied. Skin surface lipid was examined by densitometry and gas chromatography. There were significant changes in the fatty acid composition of the wax fraction of sebum in the 11-16-year-old children when compared to the 6-9-year-old group. As wax is of sebaceous gland origin, this may represent a change in sebum composition probably in response to the hormonal stimulus. Changes in the fatty acid fraction of triglycerides were also noted with age, but this may be due to the change in source of triglyceride from predominantly epidermal origin to sebaceous gland origin.

Adolescent↗