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Biomedical subjects

T T Chen

Publications and source records attributed to T T Chen.

At least 145 records · Page 8Linked to original sources
PubMed1985

Treatment of non-small cell bronchogenic carcinoma with vinblastine and mitomycin: a Southwest Oncology Group Study.

Forty-five patients with stage III M1 non-small cell bronchogenic carcinoma were treated with vinblastine (1 mg/m2 by iv bolus twice a day on 2 consecutive days) plus mitomycin (10 mg/m2 on Day 1). This treatment was repeated at 3-week intervals for three courses. Consolidation therapy with doxorubicin and cisplatin at doses of 50 mg/m2 each was administered to responders every 4 weeks for two courses, with subsequent vinblastine and mitomycin maintenance therapy every 6 weeks. Eleven partial remissions (24%) were achieved, with a median duration of remission of 16 weeks (range, 8-32) and a median survival of 19 weeks. No differences were seen in median duration of remission or survival by cell type or performance status.

Adenocarcinoma↗
PubMed1985

Clinical results of pars plana vitrectomy in posterior-segment disorders.

From June 1981 to August 1983, a total of 142 eyes with posterior-segment disorders were treated with a pars plana vitrectomy technique using the Ocutome II system. The patients were 45 years old on average, with an average follow-up of six months. Simple vitrectomy was performed in 108 eyes, and additional retinal reattachment surgery was performed in the remaining 34 eyes. The lens was removed in 56 eyes and untouched in 65 eyes; the remaining 21 eyes were either aphakic or pseudophakic. All of the cases were divided into six main groups: two diabetic groups, two nondiabetic groups, a penetrating trauma group, and an endophthalmitis group. The two diabetic groups included 16 eyes with vitreous opacity, six of them complicated by retinal detachment. The two nondiabetic groups included a total of 91 eyes, with 31 of them complicated by retinal detachment. The group with penetrating trauma included 24 eyes, seven of which had been injured by intraocular foreign bodies. The endophthalmitis group included 11 eyes, of which six were the result of penetrating trauma and five the result of cataract operation. In this series, vision was maintained or improved in 78.9% of cases and improved in 51.4%. Eyes with vitreous opacities in conjunction with retinal detachment were complicated by proliferative vitreoretinopathy of moderate or severe degree. The reattachment rate was 50.0% in the diabetic group and 51.6% in the nondiabetic group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Surgical results of second-attempt radial keratotomy.

The safety, efficacy, and stability of second-attempt radial keratotomy were evaluated in 20 eyes of 12 patients from September 1, 1982, to August 31, 1983. The average amount of refractive error change was 1.89 diopters with 1.38 diopters of corneal curvature flattening. The effect of the second-attempt operation was about 60% that of the first-attempt operation. No significant surgical complications were observed in this study.

Adult↗
PubMed1984

Response of chronic myelogenous leukemia patients to COAP-splenectomy. A Southwest Oncology Group study.

Eighty-seven patients from 18 institutions with a confirmed diagnosis of chronic myelogenous leukemia were registered on a Southwest Oncology Group protocol for multiagent induction and single-agent maintenance chemotherapy, with randomization to an immunotherapy arm. Elective surgical splenectomy was performed for 42 patients at the completion of 3 months of induction therapy. Final analysis of the study revealed statistically significant survival advantages were correlated with age, splenectomy, the absence of hepatic leukemic infiltrate at the time of splenectomy, and race.

Adolescent↗
PubMed1984

Role of elective brain irradiation during combined chemoradiotherapy for limited disease non-small cell lung cancer.

We have studied the clinical impact of elective brain irradiation (EBI) in patients with locally advanced, non-small cell lung cancer (LA-NSC). All patients received combination chemotherapy (cyclophosphamide + doxorubicin (Adriamycin) + cisplatin = CAP) or CAP plus radiotherapy as the initial treatment for their active tumor or as an adjuvant therapy. Of 97 evaluable patients, 46 were randomized to receive EBI (3 000 rad in 10 fractions given over two weeks). The characteristics of both groups were comparable by sex, age, performance status, pretherapy weight loss, histologic cell type, clinical staging, and type of prior therapy. EBI significantly decreased the incidence of central nervous system (CNS) metastasis in the treated group compared to the control group (4% vs 27%, p = .002). CNS involvement occurred in the treated group after failure at other sites whereas 12 of 14 control patients had CNS metastases as the first site of relapse. EBI decreased the incidence of CNS metastasis in all prognostic categories. Using multivariate analysis, the beneficial effect was shown to be significant in females, patients with good performance status, weight loss less than 6%, squamous cell histology, state III disease or no prior therapy. EBI significantly increased CNS metastasis-free interval with a beneficial effect that was significant in males, patients with weight loss less than 6%, squamous cell histology or responders. Although no survival benefit was observed for the treated group because of the adverse effect from other relapses, EBI will become more important as better treatment programs are developed.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

Prognostic factors influencing survival of patients with advanced colorectal cancer: hepatic-artery infusion versus systemic intravenous chemotherapy for liver metastases.

In this study of 232 patients with histologically confirmed large bowel carcinoma, patient- and tumor-related characteristics were examined and their effect on prognosis was determined. Serum alkaline phosphatase and albumin concentrations, symptom duration prior to diagnosis of the primary tumor, and the status of the primary tumor showed the strongest relationship to survival after diagnosis of surgically noncurable disease. Patients who had normal serum alkaline phosphatase and albumin concentrations, patients whose symptoms lasted over 12 months before diagnosis, and patients whose primary tumor had been resected before diagnosis of noncurable disease had a good prognosis. Performance status, weight loss, sex, presence of liver metastasis, hemoglobin concentration, and absolute lymphocyte or monocyte counts in the peripheral blood, at time of diagnosis of surgically noncurable disease, were significant factors when examined individually. One hundred seventy-nine patients with metastatic colorectal cancer confined to the liver were selected from 601 patients who received chemotherapy for advanced colorectal cancer over 10-year periods to compare the efficacy of hepatic-artery infusion therapy with that of intravenous 5-fluoropyrimidine--containing chemotherapy. The two groups were similar with respect to prognostic factors. The hepatic-artery infusion chemotherapy produced a higher response rate than intravenous chemotherapy, but did not result in significant prolongation of survival.

Alkaline Phosphatase↗
PubMed1984

The natural history of gastric cancer and prognostic factors influencing survival.

This study of 783 patients with histologically confirmed gastric carcinoma has confirmed the importance of several previously recognized patient- and tumor-related characteristics related to prognosis and identified some new ones. Of the tumor-related factors, the ones that showed the strongest relationship to survival following curative gastric resection were tumor stage, histologic type, breach of lymph-node capsule, sinus histiocytosis, and gross appearance. Of the tumor- and patient-related factors, the ones that showed the strongest relationship to survival from time of diagnosis of surgically noncurable disease were status of primary, liver metastasis, serum bilirubin level, ascites, extent of tumor burden, and weight loss. The effect of treatment with 5-fluorouracil (5-FU) on survival duration was at best only minimal. Only those patients who received two or more cycles of 5-FU therapy had survival advantage over the remaining patients. The use of regression analysis has made it possible to make predictions of the prognosis of the patients. These predictions could be used in future studies to determine comparability of prognosis of various groups included in different studies and different arms of a randomized study.

Adenocarcinoma↗
PubMed1984

Drug combinations in the treatment of gastric adenocarcinoma: a randomized Southwest Oncology Group study.

The FAM combination with the simultaneous administration of 5-fluorouracil, doxorubicin, and mitomycin C is considered standard chemotherapy for gastric adenocarcinoma. This study was initiated to determine whether a kinetically designed sequential administration of these three drugs would be superior and whether the presence or absence of easily measurable tumor would imply differences in survival. To do so, the Southwest Oncology Group tested two schedules in a randomized study of 239 patients. Independent judgments of response were made by two authors with the same results. Equivalent response rates (23% of all eligible sequential and 30% simultaneous) and median survival durations (22 and 23 weeks, respectively) were seen. Patients with and without readily measurable tumors each lived a median of 22 weeks. Higher degrees of hematologic toxicity were associated with prolonged survival (median 27 weeks versus 20 weeks, p = 0.04). Patients treated by community oncologists were described as having higher response rates than those treated in major medical centers (64% versus 31%, p = 0.03). The meaning of this is questionable in that there were no statistical differences in survival or toxicity. Those with prior exposure to 5-fluorouracil had only a tendency, without statistical significance, for a slightly inferior response and survival.

Adenocarcinoma↗
PubMed1984

Combined modality treatment of extensive small cell lung cancer: a Southwest Oncology Group study.

The Southwest Oncology Group entered 453 patients with extensive small cell carcinoma into a combined modality treatment program, involving a randomized comparison of three different chemotherapy regimens for remission induction, and of maintenance chemotherapy alone versus maintenance treatment with cycles of reinduction added at six and 12 months. In addition, there was systematic comparison of diagnosis by institutional pathologist versus review panel pathologist. No difference was observed among the three different induction arms with respect to the incidence of response to treatment (61%), complete response (16%), or survival duration (median, 31 weeks). Neither overall response rate nor survival are superior to previous results. However, patients who achieved a complete response demonstrated significant survival benefit if they were in the group who received reinduction chemotherapy, as opposed to maintenance alone. This observation may apply most importantly to patients with small cell lung cancer of limited extent, for whom complete response is achieved in a majority. Agreement of institutional and review panel pathologists on the diagnosis of small cell lung cancer was observed in 94% of reviewed cases. A final observation is that the omission of chest irradiation results in a dramatic increase in the incidence of initial relapse at the primary tumor site. This suggests that future studies will need to use better therapy for local control in responding patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

Complications related to 234 staging laparotomies performed in the Intergroup Hodgkin's Disease in Childhood study.

This is a study of 234 children and young adult patients entered in the Intergroup Hodgkin's Disease in Childhood (stage I-II) Study from November 1975 to June 1981 and followed for a mean of 3.8 years after laparotomy. All patients had a staging laparotomy with total splenectomy, liver biopsy, and sampling of abdominal lymph node groups. Four patients (1.7%) have had documented sepsis, and three have had possible sepsis. There has been no sepsis-related death. Intestinal obstruction requiring operation was noted in four patients (no intestinal resection required). Urgent operation was necessary in two patients, one with ureteral obstruction and one with ovarian torsion, following a repositioning procedure, neither of these patients died. Organisms in the four patients with positive blood cultures were Streptococcus pneumoniae (two) and Haemophilus influenzae (two). Of the 234 patients in the study, 194 (83%) had received polyvalent pneumococcal vaccine, and 174 (74%) were taking prophylactic antibiotics. One of the two patients with pneumococcal sepsis had not been vaccinated, and the second was vaccinated only during radiotherapy. Only one of the four patients with positive blood cultures was on a prophylactic antibiotic treatment regimen at the time of the septic episode. The liabilities in employing laparotomy-splenectomy for the evaluation of pediatric patients with Hodgkin's disease include both general surgical complications and an increase in the risk of hyperacute infection, specifically related to encapsulated species. The latter appears to be modified to a major degree by current prophylactic measures or therapy.

Adolescent↗
PubMed1983

Leukemia and preleukemia after adjuvant treatment of gastrointestinal cancer with semustine (methyl-CCNU).

We evaluated the risk of acute nonlymphocytic leukemia, acute myelodysplastic syndrome, and preleukemia in 3633 patients with gastrointestinal cancer who were treated in nine randomized clinical trials. Among 2067 patients given semustine (methyl-CCNU) as adjuvant therapy, leukemic disorders developed in 14, whereas only one leukemic disorder (acute nonlymphocytic leukemia) occurred among 1566 patients given other therapies (relative risk = 12.4; 95 per cent confidence interval = 1.7 to 250). The six-year cumulative mean risk (+/- S.E.) of acquiring a leukemic disorder after treatment with semustine was 4.0 +/- 2.2 per cent; the incidence rate was 2.3 cases per 1000 persons per year. Risk increased significantly with time after treatment. The risk of leukemic disorders did not differ according to sex, race, age at treatment, or initial tumor type, nor was it enhanced by concomitant radiotherapy or immunotherapy. In addition, no excess of acute nonlymphocytic leukemia was seen in 44,370 patients treated for gastrointestinal cancer in Connecticut during the period 1935 to 1974, before the advent of nitrosourea chemotherapy. This study provides quantitative evidence that nitrosoureas are leukemogenic in human beings and confirms previous observations that adjuvant chemotherapy with alkylating agents may increase the risk of leukemia.

Acute Disease↗
PubMed1983

Randomized trial of 5-fluorouracil and mitomycin C with or without streptozotocin for advanced pancreatic cancer. A Southwest Oncology Group study.

A prospective randomized trial comparing streptozotocin, mitomycin C, and 5-FU (SMF) with mitomycin C and 5-FU (MF) in patients with advanced pancreatic cancer was performed. In patients with measurable disease the response rates were 34% (19/56) to SMF, and 8% (5/60) to MF (P = 0.009). Median survivals were similar, however, 18 versus 17 weeks (P = 0.356). Median survival of patients responding to chemotherapy was 33 weeks, and for nonresponders it was 17 weeks (P = 0.002). In patients with nonmeasurable disease, median survivals were 21 weeks (SMF) and 18 weeks (MF) (P = 0.797). Patients surviving greater than or equal to 48 weeks, however, appeared to be increased in the SMF arm (14 patients) compared to the MF (7 patients). Toxicity was moderate for both regimens, with SMF having greater gastrointestinal and renal toxicity. Chemotherapy with SMF appears to produce objective responses in patients with pancreatic cancer, but does not improve survival compared to MF.

Adult↗
PubMed1983

Management of adult acute leukemia. A Southwest Oncology Group study.

Five hundred forty three adult patients with acute leukemia were entered on the study designed to: (1) test efficacy of vincristine and prednisone used as primary drug therapy in patients with good prognosis as judged by a circulating blast cell count less than 30,000 cm2; (2) investigate the use of either simultaneously or sequentially administered Adriamycin plus cytosine arabinoside plus vincristine and prednisone; and (3) to assess the use of bacillus Calmette-Guerin (BCG) in the maintenance phase on both the response and duration of response. Complete remissions were seen in 21% of patients with the vincristine and prednisone arm. Complete remission rates were similar in both the simultaneously and sequentially administered chemotherapy with overall complete remission rates of 55%. Median durations of complete remission and survival were 35 and 62 weeks, respectively, for patients with AML; and 47 and 75, respectively, for patients with ALL. Toxicity was within acceptable limits. BCG administered during the maintenance phase of therapy caused no differences in duration of complete remission and survival. These results demonstrate an improved response and duration of response over previous studies done by this group.

Acute Disease↗
PubMed1983

Change in gonadotropin-binding sites in intracellular organelles and plasma membranes during luteal growth, development and regression.

Changes in the gonadotropin-binding sites in plasma membranes and several intracellular organelles of bovine corpora lutea of days 3, 13 and 19 of the cycle were investigated. These three times represent periods of rapid luteal growth (early luteal phase), maturity (mid luteal phase) and the onset of regression (late luteal phase), respectively. The 5'-nucleotidase activity was highest in the fraction possessing a predominance of plasma membranes. It was undetectable in nuclear fractions and detectable to a varying extent in fractions enriched with mitochondria-lysosomes, rough endoplasmic reticulum and Golgi. The gonadotropin-binding sites, as measured by 125I-human choriogonadotropin (hCG) specific binding, were found in all the subcellular organelles. Whereas the affinities remained about the same, the total number of available gonadotropin-binding sites in all the organelles increased from day 3 to 13 and then declined by day 19 of the cycle. Occupancy of binding sites by endogenous luteinizing hormone was not detectable and therefore was unlikely to be responsible for the changes in total number of available binding sites. Thus, binding site changes observed in all the organelles of early, mid and late luteal phase corpora lutea probably reflect actual changes in the steady-state turnover of binding sites. Morphometrically determined relative membrane counts of various subcellular organelles varied with the luteal phase. The relative total gonadotropin-binding sites, calculated from the relative membrane counts and the total number of available binding sites, increased in all the organelles from early to mid and then declined by late luteal phase. Plasma membranes of all three luteal phases contained greater relative total gonadotropin-binding sites than any other single intracellular organelle. However, all the intracellular organelles combined contained 59% of the total luteal cell gonadotropin-binding sites in early luteal phase which decreased to 43 and 28% by mid and late luteal phases respectively.

5'-Nucleotidase↗
PubMed1983

Phase II evaluation of MGBG in non-small cell carcinoma of the lung. A Southwest Oncology Group study.

One hundred and eight patients with non-small cell lung cancer were treated in a Phase II trial with MGBG at a dose of 600 mg/m2 i.v. weekly. Partial responses were noted in 3/43 patients with adenocarcinoma and 1/40 with squamous cell carcinoma. No responses were noted in 24 patients with large cell carcinoma. Overall, the drug was reasonably well-tolerated. At this dosage and schedule, MGBG has no substantial antitumor activity for patients with non-small cell lung cancer.

Drug Evaluation↗