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Biomedical subjects

G DeBoer

Publications and source records attributed to G DeBoer.

At least 55 records · Page 3Linked to original sources
PubMed1985

Etoposide (VP-16) and cisplatin: an effective treatment for relapse in small-cell lung cancer.

Seventy-eight patients with evaluable small-cell lung cancer (SCLC) were treated with etoposide (VP-16) and cisplatin after their disease failed to respond to, or relapsed after, induction combination chemotherapy, consisting primarily of cyclophosphamide, doxorubicin (Adriamycin), and vincristine (CAV). Twenty-four patients had limited disease (LD) and 54 had extensive disease (ED). In six (8%) patients, a complete response (CR) was achieved and in 37 (47%), there was a partial response (PR). The median duration of response for responding patients was 22 weeks (range, 4 to 50 weeks) for patients with LD and 18 weeks (range, 4 to 49 weeks) for those with ED. Twelve percent of patients demonstrated stable disease, and 33% of patients had progressive disease on treatment. The median survival times of LD patients achieving a CR or PR were 59 and 34 weeks, respectively, whereas the comparable figures for ED patients were 45 and 23 weeks, respectively. Gastrointestinal toxicity was mild, but myelosuppression, predominantly leukopenia and thrombocytopenia, was common. Mild to moderate nephrotoxicity occurred in 11 patients, but was reversible in all cases. Two febrile episodes occurred during periods of drug-induced neutropenia, but no other significant toxicities were identified. These results provide further evidence that VP-16 and cisplatin is an effective and tolerable combination chemotherapy regimen for SCLC resistant to CAV.

Adult↗
PubMed1985

Carcinoembryonic antigen: a useful prognostic marker in small-cell lung cancer.

Plasma carcinoembryonic antigen (CEA) was determined in 180 patients with small-cell lung cancer (SCLC) before treatment. An abnormal level (greater than or equal to 6 ng/mL) was found in 34% of patients tested. Patients with extensive disease (39/83) had a significantly higher frequency of abnormal CEA (P = .001) than those with limited disease (22/97). There was a strong correlation between obtaining an objective response--particularly a complete response (P = .00003)--and the absence of an elevated CEA. Patients with an abnormal CEA also had a shorter survival time (P = .0007) and the difference remained statistically significant after logrank adjustment for extent of disease and ECOG (Eastern Cooperative Oncology Group) performance status. There was also a negative correlation between survival time and the quantitative level of CEA. In this series, only the group of patients with normal initial CEA levels included all survivors beyond 2.5 years. We conclude that CEA is a useful prognostic factor in SCLC.

Adult↗
PubMed1984

Ocular involvement in neuroblastoma: prognostic implications.

Neuroblastoma is one of the commonest childhood malignancies. The most important prognostic factor is age at diagnosis; early diagnosis, when the tumor is still localized and surgically resectable, is second in importance. On retrospective review of children seen at the Hospital for Sick Children, ophthalmic involvement was seen in 80 of 405 (20%). The three major eye signs of neuroblastoma, proptosis, Horner's syndrome and opsoclonus, are closely related to the site, stage of tumor, and outcome of the patient. Proptosis or periorbital ecchymosis due to orbital metastases was present in 60 of 80 children (bilaterally in 33). The 3-year survival rate was 11.2%. In 53 of 60 cases with orbital metastases the neuroblastoma originated in the abdomen. Unilateral Horner's syndrome occurred in 14 children, as the presenting sign in 9, related to localized disease in 11 and in a favorable location (cervical or thoracic neuroblastoma) in 8. The 3-year survival rate was 78.6%. Opsoclonus-myoclonus was the presenting sign of occult, localized neuroblastoma in all 9 children in whom it occurred. The 3-year survival rate was 100%. For all presentations, girls had a significantly better survival rate than boys (48.7% vs. 22.4%). Children presenting with any of these ophthalmological signs should undergo thorough and repeated investigations searching for neuroblastoma.

Child, Preschool↗
PubMed1984

Combined modality induction therapy without maintenance chemotherapy for small cell carcinoma of the lung.

One hundred fifty-three patients with limited and 167 with extensive small cell carcinoma of the lung (SCCL) were evaluable for response to treatment with six courses of chemotherapy (cyclophosphamide, doxorubicin, and vincristine), irradiation to intrathoracic disease, and prophylactic cranial irradiation (PCI). No maintenance chemotherapy was given. Fifty-two percent of patients with limited disease (LD) and 10% of extensive disease patients (ED) achieved a complete response. The median survival times for LD and ED patients were 49 and 34 weeks, respectively. These results were compared to a previous experience with 147 patients who were treated with three courses of similar induction chemotherapy and thoracic irradiation, as well as one year of maintenance chemotherapy (CCNU, procarbazine, and methotrexate) but without PCI. Although the use of PCI was found to reduce the frequency of brain metastases as the site of first relapse, detailed comparisons of response rates and survival showed no significant differences between the two study populations. Prolonged maintenance chemotherapy of the type used in the first study does not favorably influence outcome after intensive induction therapy for SCCL.

Adult↗
PubMed1984

Empiric therapy for infections in patients with granulocytopenia. Continuous v interrupted infusion of tobramycin plus cefamandole.

A combination of tobramycin sulfate and cefamandole nafate was used as initial empiric therapy for the treatment of 71 evaluable febrile (temperature greater than 38.5 degrees C) episodes in 64 (neutrophils, less than 1,000/microL) adult patients with cancer and granulocytopenia. Carbenicillin sodium or ticarcillin disodium was substituted for cefamandole in patients with Pseudomonas infections and in patients in whom the initial regimen was unsuccessful. Twenty-nine episodes were randomized to receive tobramycin by continuous infusion, while 42 were randomized to receive tobramycin by interrupted infusion. Twenty-seven (79%) of the 34 documented infections responded to the initial empiric antibiotic combination, ten (83%) of 12 being given continuous infusion and 17 (77%) of 22 being given interrupted infusion of tobramycin. Nephrotoxic reaction occurred in 7% of patients treated with continuous infusion and 15% treated with interrupted infusion, mostly patients older than 60 years. Tobramycin, by either continuous or interrupted infusion, plus cefamandole is safe and efficacious empiric therapy for infections in patients with cancer and granulocytopenia.

Adult↗
PubMed1983

Modulatory activity of chemotherapeutic agents on phagocytosis and intracellular bactericidal activity of human polymorphonuclear and mononuclear phagocytes.

Thirteen chemotherapeutic agents were tested for modulatory activity on phagocytosis by human granulocytes and monocytes. Phagocytosis, phagocytic index, and intracellular bactericidal activity were assessed using Staphylococcus aureus, smooth strain of Escherichia coli, and latex particles. Modulation of phagocytic activity depended on the type of particle used and the presence of serum in the medium. Testing granulocytes, only 1,3-bis(2-chloroethyl)-1-nitrosourea suppressed phagocytosis of all three types of particles used for ingestion. Other drugs suppressed either phagocytosis of E. coli and S. aureus or of one of the bacteria and latex particles. Three drugs enhanced ingestion of latex particles. The most pronounced modulation of phagocytosis was observed in conditions similar to those in vivo, namely, when serum was added to the medium and when the cells were exposed for longer time to the drugs. In the absence of serum, very little modulation of phagocytosis was observed, and only 1,3-bis(2-chloroethyl)-1-nitrosourea retained strong suppressive activity. Intracellular bactericidal activity was markedly suppressed by 7 of 13 drugs tested. Monocytes were less influenced by chemotherapeutic agents, their phagocytic activity being either suppressed or enhanced. The influence of chemotherapeutic agents on phagocytosis must be taken into consideration when assessing defense mechanisms and susceptibility to infection in patients with malignant diseases.

Antineoplastic Agents↗
PubMed1983

Modulation of phagocytosis and bactericidal activity of human polymorphonuclear and mononuclear phagocytes by antiarthritic agents.

The influence of 9 antiarthritic drugs on phagocytosis and intracellular bactericidal activity of human polymorphonuclear (PMN) and mononuclear phagocytes was investigated using gram-positive and -negative microorganisms and latex particles. With the exception of prednisone all the other agents suppressed phagocytosis and/or phagocytic index of PMN. Whereas naproxyn suppressed phagocytosis of all 3 particles used, other drugs had more pronounced inhibitory activity on phagocytosis of E. coli than of S. aureus or latex particles. Monocytes were less influenced by antiarthritic agents. Intracellular bactericidal activity was markedly suppressed by phenylbutazone, oxyphenbutazone, naproxyn and gold sodium thiomalate. In suboptimal conditions when serum was omitted from the assay, dual action of some drugs was observed. It may be concluded that antiarthritic agents may modulate phagocytosis and intracellular bactericidal activity. The modulation was most pronounced in conditions similar to those in vivo i.e., with added serum and when the cells were exposed to antiarthritic agents for longer time. It should be taken into consideration while assessing defense mechanisms and susceptibility to infection in rheumatic diseases.

Anti-Inflammatory Agents↗
PubMed1982

Herpes zoster in patients with carcinoma of the lung.

Herpes zoster was observed in only four of 250 (1.6 percent) patients with small cell carcinoma of the lung, who were treated in a prospective, combined modality therapy trial. Induction chemotherapy in this study consisted of six courses of cyclophosphamide, doxorubicin, and vincristine (CAV), followed by intrathoracic and cranial irradiation. Those with extensive disease also received single doses of upper half-body irradiation. Patients did not receive maintenance chemotherapy (CAV2 protocol). This contrasted with our previous study (CAV1 protocol), which consisted of three courses of the same induction chemotherapy, the same intrathoracic irradiation, but with one year of oral maintenance chemotherapy. During the CAV1 regimen, we observed that herpes zoster developed in 13 of 161 (8.1 percent) patients in association with their therapy. A retrospective analysis of 6,576 patients with lung cancer revealed that herpes zoster developed in 58 (0.9 percent). This complication developed in 10 of 622 (1.6 percent) patients with small cell carcinoma of the lung, as compared to 48 of 5,954 (0.8 percent) patients with non-small cell carcinoma of the lung. The risk of development of herpes zoster in the CAV1 group was significantly greater than the historical group (p = 0.007) and was also greater than the CAV2 group (p = 0.031). However, there was no significant difference between the historical group and the CAV2 group. Attempts to explain the differences in the rate of herpes zoster in our three studies and those in the literature suggest that the duration of therapy, the type of chemotherapy used, and the improving survival rate may be important contributing factors to this complication in patients aggressively treated for small cell carcinoma of the lung. The literature and our own studies suggest that procarbazine is the most likely chemotherapeutic agent predisposing to this complication.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1982

Results of treating Hodgkin's disease without a policy of laparotomy staging.

Results of the treatment of 780 primary patients with Hodgkin's disease at the Princess Margaret Hospital (PMH) between 1968 and 1977 are analyzed. Treatment decisions were based on the evaluation of the extent of disease by clinical methods. A marked improvement in relapse-free survival and overall survival was observed for 1973-1977 as compared to 1968-1972. This improvement did not result from differences in the distribution of important prognostic attributes (clinical stage, pathology, and age) between the two periods, and there was no improvement in our ability to rescue relapsed patients. Improved relapse-free and overall survival during the second period was observed for all stages in patients less than 50 years of age, but not in the older group. The improved survival of patients treated between 1973 and 1977 is attributed to more effective initial therapy, which reduced the fraction of patients who relapsed. These observations provide indirect evidence that relapse has a negative effect on prognosis, and that the initial treatment of patients with Hodgkin's disease should be designed to reduce the risk of relapse to a minimum without causing an unacceptable increase in late complications. The observed/expected incidence of acute leukemia and non-Hodgkin's lymphoma in the PMH series was increased to 41.9 and 13.9 respectively. The question of whether a policy of doing routine staging laparotomies improves the results of treatment of patients with Hodgkin's disease is considered only in general terms by comparing the total PMH series with the total Stanford Medical Center series of patients treated between 1968 and 1977. Relapse-free survival at 10 years is 48.9% and 66.8% respectively, at the two institutions, while overall survival at 10 years is identified.

Adult↗
PubMed1980

Second primary respiratory tract malignancies in glottic carcinoma.

Of 740 cases of glottic cancer, a second respiratory tract tumor developed in 48. Only 14 cases would have been expected in a sample of the same age and sex distribution drawn from the general population of Ontario. Of 25 patients with second tumors in the lung, 23 are dead. Of these 23, 17 had been cured of Stage T1 glottic cancer. An actuarial method for calculating the risk of developing a second respiratory tract tumor amongst the survivors of glottic cancer is described. Of the survivors, 12% will have a second respiratory tract tumor within ten years following initial diagnosis of glottic cancer. Of patients with Stage T1 glottic cancer, 7% will die of a second respiratory tract tumor within ten years. This rate is slightly more than that for those who die of laryngeal cancer in this stage grouping. Late recurrences and/or second primary tumors in the larynx following radiotherapy are rare. Methods for reducing the risk of death from a second respiratory tract tumor are discussed.

Canada↗
PubMed1980

Prognostic factors in T2 glottic cancer.

During a ten-year period from 1965 through 1974, 164 patients with T2N0M0 glottic cancer were seen at the Princess Margaret Hospital. These patients were treated by radiotherapy reserving surgery for salvage of recurrent or persistent disease. One hundred and fifty-four cases have been analyzed in detail with respect to two variables: impairment of mobility and surface extension of disease. Two end-points of analysis were used: actuarial local recurrence-free rates and corrected actuarial survival. The five-year corrected actuarial survival rate was 12% less in the T2N0M0 patients with impaired vocal cord mobility (75.2%) when compared to those cases with normal vocal cord mobility (86.8%) (P = 0.068). No difference in survival was seen with increasing degrees of surface extension of disease when correction for the effects of impairment of mobility was performed. There was a highly significant difference in local control rates with radiotherapy when comparing cases with normal vocal cord mobility (76.7% locally controlled) vs. impaired vocal cord mobility (51.1% locally controlled) (P = 0.015). Again, no significant trend in local control rates could be ascertained with increasing surface extension of disease. The number of patients with nodal disease was insufficient to permit meaningful analysis of the effects of the presence or absence of nodal disease on survival. On the basis of this analysis, we suggest that the Stage T2 grouping in glottic cancer be subdivided into Stage T2a for those tumors with normal vocal cord mobility and T2b for those with impaired vocal cord mobility.

Glottis↗
PubMed1980

Herpes zoster in patients with small-cell carcinoma of the lung receiving combined modality treatment.

Herpes zoster, a rare complication in patients with solid tumours, was observed in 13 of 161 (8.1%) patients with small-cell anaplastic carcinoma of the lung treated in a prospective combined modality therapy trial. Induction therapy consisted of three courses of cyclophosphamide, doxorubicin, and vincristine, followed by thoracic radiation. Maintenance chemotherapy with oral lomustine, procarbazine, and methotrexate was given for 1 year. Most herpes zoster cases (11) occurred while patients were on maintenance chemotherapy. Three patients developed nonfatal disseminated herpes zoster and one, postherpetic neuralgia. Herpes zoster may be a relatively frequent complication of prolonged aggressive treatment of small-cell carcinoma of the lung.

Antineoplastic Agents↗
PubMed1979

Carcinoma of the esophagus: pretreatment assessment, correlation of radiation treatment parameters with survival, and identification and management of radiation treatment failure.

Between January 1969 and February 1975, 344 patients with carcinoma of the esophagus were managed primarily at the Princess Margaret Hospital, Toronto. One hundred sixty-eight (168) of the patients were treated palliatively and 176 of the patients were treated by radical doses of radiation, surgical resection or both. Survival of the radical treatment group was biphasic, the steeper component being identical to the survival of the palliative treatment group, thereby representing a group of patients that did not respond to radical treatment. Analysis of pretreatment assessment parameters indicated that all patients with T1 lesions (length less than or equal to 5 cm, circumference incomplete) and all patients with Stage I disease responded to treatment. Patients who were female, age greater than or equal to 70 years, N0 or had well differentiated squamous cell histology, responded to treatment in at least 80% of cases. No patient with extralymphatic distant metastases responded to treatment. The presence of other major disease did not affect response to treatment. Thirty patients had surgical resections and their survival was not significantly greater than the 146 patients who had radical radiation alone. Survival analysis revealed an optimum range of nominal standard dose (NSD) of 1602--1714 rets (median 1679 rets) for patients treated by radiation alone. An optimum port size (area) of 100--140 cm2 was observed for patients receiving 5000 rads and supervoltage irradiation gave a significantly improved survival in comparison with megavoltage irradiation. Sixty-seven percent (67%) of patients treated by radical doses or radiation developed esophageal strictures postradiation and on the basis of radiological, endoscopic or histological evidence 75% of these strictures were considered to be associated with the persistence of malignancy. On the basis of postmortem examinations (32) and death certificates there was overall an 80% failure to control the disease locally and 95% of strictures were associated with persistence of malignancy in the esophagus. Thirty-one of the 146 patients receiving radical radiation alone had palliation for esophageal obstruction following radiotherapy. The construction of a physiological bypass (e.g., colon) resulted in a mean survival of 215 days which was much longer than the survival observed with rigid esophageal tubes (35 days) or gastrostomy tubes (58 days).

Aged↗
PubMedDate not supplied

Observer variation in abdominal CT.

Observer performance in radiologic interpretation has traditionally been based upon Receiver Operating Characteristic (ROC) analysis. A statistical method that evaluates the reproducibility or consistency of radiologic interpretation is presented. Since this method is not based upon pathologic verification, it cannot be used to assess accuracy of interpretation and is therefore not a substitute for ROC analysis. Rather, it can either supplement ROC analysis or be of use in situations in which the latter is not feasible or practical.

Humans↗