Biomedical subjects

R K Dodge

Publications and source records attributed to R K Dodge.

At least 19 recordsLinked to original sources

PubMed1995

Nitric oxide synthase inhibition irreversibly decreases perfusion in the R3230Ac rat mammary adenocarcinoma.

We examined the microvascular effects of competitive nitric oxide synthase (NOS) inhibition with NG-monomethyl-L-arginine (MeArg), followed by L-arginine, on R3230Ac mammary adenocarcinoma perfusion. In window preparations containing tumours, superfusion of 50 microM MeArg reduced diameters of central tumour venules by 13%, of peripheral tumour venules by 17% and of normal venules near tumours by 16% from baseline. MeArg reduced red blood cell (RBC) velocity in central tumour venules by 25%, and increased intermittent flow and stasis frequency by 20% in central tumour venules. Subsequent superfusion of 200 microM L-arginine did not restore diameters or RBC velocity of any tumour preparation venules, and decreased length density in both central tumour venules and peripheral tumour venules. In contrast, MeArg reduced control preparation venule diameter by 30% and RBC velocity by 66%, but did not decrease length density or increase intermittent flow or stasis frequency. Unlike tumour preparation venules, L-arginine restored control venule diameters and velocities. NOS inhibition reduces both tumour and control venule perfusion, but the effect is blunted in the vicinity of tumours, possibly because of increased NOS levels. Perfusion can be subsequently restored in control, but not tumour, venules with L-arginine. Tumour NOS inhibition, followed by normal tissue rescue with L-arginine, may provide a novel means to achieve the goal of selective tumour hypoxia.

Adenocarcinoma↗

PubMed1994

Differential immunoreactivity of transforming growth factor alpha in benign, dysplastic and malignant prostatic tissues.

Immunohistochemical examination of radical prostatectomy specimens from 57 patients was performed to determine the differential expression of transforming growth factor alpha in the human prostate. In addition, epidermal growth factor receptor (EGFr) immunoreactivity was assessed in each case. Stromal versus epithelial staining was determined for each histological subtype: benign prostatic hypertrophy (BPH), prostatic intra-epithelial neoplasia (PIN), and prostatic cancer (CaP) by a single pathologist reviewer. TGFa staining was predominant in stroma while EGFr was localized to the epithelial basal cell layer. Immunoreactivity of both TGFa (P = 0.002) and EGFr (P < 0.001) revealed a significant reduction in CaP compared to BPH or PIN. Autocrine stimulation of EGFr by TGFa or other unrecognized factors may be present in CaP. Conversely, altered stromal influence of CaP via TGFa may be present. These observations could form the basis for future cancer therapeutic strategies using antagonist factors.

Aged↗

PubMed1992

Clinical significance of the BCR-ABL fusion gene in adult acute lymphoblastic leukemia: a Cancer and Leukemia Group B Study (8762).

The Philadelphia (Ph1) chromosome, or its molecular counterpart, the BCR-ABL fusion gene, is a rare but important prognostic indicator in childhood acute lymphoblastic leukemia (ALL), but its impact on adult ALL has not been well ascertained. A prospective study of the BCR-ABL fusion gene was begun on patients entered on clinical trials conducted by the Cancer and Leukemia Group B (CALGB). All patients received intensive, multiagent chemotherapy that included daunorubicin. Over 2 years, 56 patients were studied for molecular evidence of a BCR-ABL gene using Southern blot and pulsed-field gel hybridization analysis. Results were compared with cytogenetic detection of a Ph1 chromosome, and clinical features were compared for the BCR-ABL-positive and -negative groups. Molecular methods detected the BCR-ABL gene in 30% of cases compared with cytogenetic detection of the Ph1 chromosome in only 23%. The majority of cases (76%) showed the p190 gene subtype similar to pediatric ALL; the BCR-ABL-positive cases displayed a more homogeneous immunophenotype than the BCR-ABL-negative cases and were predominantly CALLA positive (86%) and B-cell surface antigen positive (82%). The rate of achieving complete remission was similar in the BCR-ABL-positive and -negative groups (71% and 77%, respectively, P = .72). There were more early relapses in the BCR-ABL-positive group, resulting in a shorter remission duration that was especially marked in the CALLA-positive and B-cell antigen-positive populations. These preliminary data suggest that the impact of the BCR-ABL gene on clinical outcome in ALL may be on maintenance of complete remission (CR) rather than achievement of CR when aggressive, multiagent chemotherapy is used. This study identifies the BCR-ABL gene as an important factor in adult ALL and demonstrates the utility of molecular methods for its accurate diagnosis.

Adolescent↗

PubMed1992

The annual risk of melanoma progression. Implications for the concept of cure.

BACKGROUND: Melanoma may remain clinically dormant for years, and patients may have distant metastatic disease decades after the initial diagnosis is made. Because of this potential for late recurrence, the concept of "cure" for melanoma is not particularly meaningful. METHODS: To understand better the risks of future disease as a function of time elapsed after diagnosis, the clinical course of melanoma was reviewed in 5838 patients. Using conditional probability methods, the risk of recurrent disease and the risk of death were determined for 1-year and 5-year intervals during the first 15 years of follow-up. RESULTS: The estimated 5-year risk of recurrence declined from 44% at the time of diagnosis to 21% after 6 years. The 5-year risk of mortality decreased from 26% after 1 year to 16% after 9 years. Among patients with recurrent or metastatic disease, the annual risk of mortality was approximately 20% per year for 3 years; thereafter, the risk declined markedly. Among patients with thick primary lesions, the greatest risk was during the first few years after diagnosis, but in patients with thin lesions, the risk was distributed evenly over 15 years and did not decrease with time. CONCLUSIONS: Conditional probability methods permit estimation of future risks to address questions frequently asked by patients with cancer who want to know when they can be considered cured of cancer or when the risk of recurrent disease has decreased. These data on the future risk of recurrent disease and mortality can give a patient meaningful information on which to base life decisions.

Female↗

PubMed1992

Sensitive and specific detection of the 4B5 antigen in bronchial lavage specimens from patients with primary bronchogenic carcinoma.

The monoclonal antibody 4B5 binds to a mucin-like antigen elaborated by respiratory epithelium of patients with non-small cell bronchogenic carcinoma. Several immunoassay formats were used to determine the presence of the antigen in lavage specimens. A qualitative immunodrop binding assay showed immunoreactivity in 37 (64%) of 58 specimens from patients with non-small cell lung cancer. In contrast, only 11 (12%) of 93 specimens from patients with either metastatic carcinoma or benign pulmonary diseases exhibited 4B5 immunoreactivity. A quantitative radioimmunoassay using standardized amounts of mucin exhibited similar sensitivity and specificity. Positive immunoreactivity was associated significantly with tobacco use and the cytopathologic diagnoses of squamous metaplasia, atypia, or dysplasia. Conversely, no significant association was found between 4B5 immunoreactivity and age, gender, race, benign cytologic findings, frankly malignant cytologic findings, or stage of disease. The expression of 4B5 antigen in bronchial secretions from patients with bronchogenic carcinoma deserves additional evaluation as a potential marker of pulmonary carcinogenesis.

Adult↗

PubMed1992

Overexpression and mutation of p53 in endometrial carcinoma.

Immunohistochemical staining for the p53 protein was performed in 107 snap frozen primary endometrial adenocarcinomas and 15 benign uterine tissues using monoclonal antibody PAb1801. No staining was seen in benign samples, whereas intense nuclear staining of cancer cells consistent with overexpression of the p53 protein was observed in 22 of 107 cancers (21%). p53 overexpression was more frequent in advanced (Stage III/IV) cancers (41%) than in early (Stage I/II) cancers (9%) (P less than 0.001), and also was associated with nonendometrioid histology (P = 0.008), positive peritoneal cytology (P = 0.01), extrauterine metastases (P = 0.003), and negative progesterone receptor status (P = 0.04). To confirm the relationship between p53 overexpression and mutation, p53 mRNA from 8 cancers was reverse transcribed and amplified using the polymerase chain reaction. DNA sequencing revealed point mutations in each of the 5 cancers that overexpressed p53, whereas the wild-type sequence was found in 3 cancers that did not overexpress the protein. Each of the 5 mutations resulted in an amino acid substitution in a highly conserved region of the p53 gene where mutations have been found in other cancers. Further studies are warranted to determine whether the association between p53 overexpression and advanced stage disease is due to accumulation of genetic lesions during tumor progression or whether p53 alterations confer a more virulent phenotype.

Adenocarcinoma↗

PubMed1992

Use of nitroprusside to increase tissue temperature during local hyperthermia in normal and tumor-bearing dogs.

The present study investigates the effects of nitroprusside, a potent vasodilating agent, on tissue temperature during local hyperthermia in five normal and five tumor-bearing dogs. Caudal thigh muscles were heated in normal dogs and muscle temperatures were recorded during hyperthermia. Tumor-bearing dogs received two hyperthermia treatments during a course of radiation therapy. Temperatures were recorded in tumor and surrounding normal tissues. Mean arterial pressure was decreased by approximately 40-45% during nitroprusside infusion and was associated with a compensatory increase in heart rate and increases in tissue temperature. In normal dogs, muscle temperatures increased an average of 1.7 degrees C with nitroprusside administration. When nitroprusside was administered at the beginning of local hyperthermia to induce step-down heating, approximately 48% of the measured positions in caudal thigh muscle achieved a temperature greater than or equal to 43 degrees C, sufficient to induce step-down heating, during the hyperthermia episode. In tumor-bearing dogs, there was a significant increase in tumor and normal tissue temperatures during nitroprusside administration. Estimated T90 and T50 descriptors increased by 0.9 degrees C and 1.6 degrees C, respectively, for tumor tissue and by 0.4 degrees C and 1.2 degrees C, respectively, for normal tissue. Despite the increase in normal tissue temperatures no toxicity was observed in these dogs. Nitroprusside may be a useful agent for manipulation of tumor temperatures during the entire hyperthermia treatment or for a short time period at the initiation of treatment to induce step-down heating.

Animals↗

PubMed1992

Relationships among tumor temperature, treatment time, and histopathological outcome using preoperative hyperthermia with radiation in soft tissue sarcomas.

The lack of an unambiguous thermal dosimetry continues to impede progress in clinical hyperthermia. In an attempt to define better this dosimetry, a model based on the cumulative minutes during which arbitrary percentages of measured tumor temperature points exceeded an index temperature was tested in patients with soft tissue sarcomas treated with preoperative hyperthermia and conventional radiation therapy. Patients received 5000-5040 cGy at 180-200 cGy per fraction. Hyperthermia was delivered 30-60 minutes after radiation therapy and given for 60 minutes. Patients were randomized between one and two hyperthermia treatments per week for a total of five or 10 treatments, respectively. Lesions were excised 4-6 weeks after completion of hyperthermia/radiation therapy. Successful treatment outcome was considered to be the finding of greater than 80% necrosis of the sarcoma upon histopathologic examination of the resected specimen. Forty-five patients were eligible with thermometry data available in 44 patients. An average of 19 interstitial sites were monitored each treatment per tumor. Sixty percent of tumors had a successful histopathologic outcome. Univariate analysis demonstrated that several descriptors of the temperature distribution were strongly related to treatment outcome; more strongly than nonthermometric factors, such as the number of treatments per week, tumor volume and patient age and more strongly than the commonly used temperature descriptors Tmin and Tmax. Descriptors that incorporated both temperature and time were also superior to the more commonly used descriptors Tmin and Tmax. Multivariate stepwise logistic regression analysis revealed that a descriptor of both the hyperthermia treatment time and the frequency distribution of intratumoral temperatures was the strongest predictor of histopathologic outcome and that the best predictive model combined this time/temperature descriptor and one versus two treatment per week grouping. The more conventional temperature descriptor, minimum measured tumor temperature, did not significantly enhance the predictive power of treatment group. Based on these results, we recommend that descriptors based on both the frequency distribution of intratumoral temperatures and hyperthermia treatment time be tested for relationships with treatment outcome in other clinical data bases. Furthermore, we recommend that temperature descriptors that are less sensitive to catheter placement and tumor boundary identification than Tmin and Tmax (such as T90, T50, and T10) be tested prospectively along with other important thermal variables in Phase II trials in further efforts to define a thermal dosimetry for spatially nonuniform temperature distributions.

Combined Modality Therapy↗

PubMed1992

Histochemical staining of protein-tyrosine phosphatase activity in primary human mammary carcinoma: relationship with established prognostic indicators.

Protein-tyrosine phosphatase (PTPase) activity in frozen human mammary primary carcinoma tissue sections has been quantitated using a modified histochemical assay. The improved method features the assay of PTPase activity in 12-microns sections of air-dried unfixed tissues, and the use of [2-(N-morpholino)-ethanesulfonic acid] (MES) buffer to prepare stable reaction solutions. Tissue samples from 53 primary human mammary carcinomas were assayed for PTPase activity, and immunohistochemically stained for c-erbB-2 protein-tyrosine kinase expression. Elevated levels of PTPase activity were found in 68% of the tumors compared with the level of activity found in normal human mammary tissues. PTPase activity was co-localized with pathology definitive for carcinoma. Excessive activity was demonstrated throughout the cell, with high activity evident in the cell cytoplasmic membrane and the nucleus. Coexistence of elevated expression of c-erbB-2 and increased PTPase activity was present in 53% of the tumors. In contrast, 15% displayed low c-erbB-2 expression and high PTPase activity, and 24% displayed high c-erbB-2 expression and low PTPase activity. No statistically significant association was found between increased PTPase activity and either c-erbB-2 overexpression or grade and stage of disease in primary human mammary tumors.

Breast Neoplasms↗

PubMed1992

Impact of three methods of treatment intensification on acute lymphoblastic leukemia in children: long-term results of St Jude total therapy study X.

Long-term follow-up observations are reported on 427 patients who received one of three different intensified therapies in total therapy study X for acute lymphoblastic leukemia (ALL). In the trial for 'standard-risk' ALL, 154 of 309 patients in complete remission were randomized to receive high-dose methotrexate (HDMTX, 1 g/m2) periodically during the first 72 of 120 weeks of standard continuation therapy with 6-mercaptopurine and oral MTX; the remaining 155 patients received 1800 cGy cranial irradiation and intrathecal MTX, followed by 6-mercaptopurine/MTX therapy interrupted from week 36-71 for substitution of two other pairs of drugs. At 9 years of follow-up, significantly higher proportions of patients in the HDMTX group have maintained complete remissions (64 +/- 7%, SE, vs. 52 +/- 6%, p = 0.03), hematologic remissions (73 +/- 6% vs. 62 +/- 6%, p = 0.03), and testicular remissions (94 +/- 5% vs. 80 +/- 8%, p = 0.03); however, the proportion continuing in central nervous system remission has been lower (84 +/- 5% vs 93 +/- 4%, p = 0.02). In the evaluation of teniposide/cytarabine and delayed cranial irradiation for 'high-risk' ALL, 36 +/- 9% of 101 patients are predicted to be event-free survivors at 9 years. Altogether, 217 (51%) of the 427 patients are event-free survivors after at least 7 years of follow-up (median, 9 years); an additional 75 patients are alive and free of leukemia for a median of 6.4 years after successful remission retrieval therapy, boosting the total number of long-term survivors to 292 (68%). These results establish the efficacy of HDMTX for patients with standard-risk ALL and indicate the potential of teniposide/cytarabine for use in multiagent regimens for patients with high-risk disease. The overall survival figure, 68%, affords a benchmark for other studies assessing long-term outcome in ALL.

Child↗

PubMed1992

Relationship between quantitative tumor scintigraphy and time to metastasis in dogs with osteosarcoma.

Parameters that predict tumor aggressiveness or response to therapy are potentially useful in selecting the most appropriate treatment. In theory, the biologic aggressiveness of an untreated bone tumor may be reflected in bone scan parameters. The purpose of this study was to assess the usefulness of bone scintigraphy as a predictive indicator of subsequent metastasis in 25 dogs with primary osteosarcoma. Dogs received radiotherapy and/or intra-arterial cisplatin prior to limb-sparing surgery. Quantitative bone scintigraphy of the tumor was performed prior to treatment (25 dogs) and following treatment but prior to limb-sparing surgery (22 dogs). All dogs developed metastasis at a median time of 202 days (range, 41-444 days) after initiation of treatment. A statistically significant relationship was identified between time to metastasis and: (1) the radiographic tumor area, (2) the pretreatment ratio of mean counts per pixel in tumor-to-adjacent nontumor bone (T/NTT), and (3) the pre:post-treatment T/NTT. Larger tumor area and high pretreatment tumor activity were associated with earlier metastasis. Tumors characterized by greater decreases in scintigraphic uptake after treatment were associated with earlier metastasis. These data suggest that osteosarcomas with high pretreatment mean counts per pixel signify aggressive tumors subject to early metastasis.

Animals↗

PubMed1991

Overexpression and mutation of p53 in epithelial ovarian cancer.

We examined p53 expression in 107 epithelial ovarian cancers with immunohistochemical techniques using monoclonal antibody PAb1801. High level expression of nuclear p53 protein was detected in the malignant epithelium in 54 (50%) of these cancers. Expression of p53 protein was undetectable in 13 benign gynecological tissues. p53 mRNA from three cancers that overexpressed the protein were sequenced and point mutations which altered the coding sequence of the highly conserved region of the gene were found in each case. Three cancers with undetectable protein levels also were sequenced and were found to be wild-type through the same region of the gene. As in other cancers, overexpression of the p53 protein in ovarian cancer appears to correlate closely with the presence of mutation in the p53 gene. p53 overexpression did not correlate with stage, histological grade, or the ability to perform optimal cytoreductive surgery. A significant correlation (P = 0.04) was observed between p53 overexpression and aneuploidy in advanced stage (III/IV) disease. There was no significant relationship between overall survival and p53 expression. Since mutation and overexpression of p53 are common in epithelial ovarian cancers, further studies are warranted to clarify the role of p53 in ovarian tumorigenesis.

Amino Acid Sequence↗

PubMed1991

Overexpression of HER-2/neu in endometrial cancer is associated with advanced stage disease.

Prior studies have shown that overexpression of HER-2/neu occurs in one third of breast and ovarian cancers and that overexpression is associated with poor prognosis. We used a monoclonal antibody to assess immunohistochemically the level of HER-2/neu expression in normal and malignant endometrium. In 24 normal endometrial samples light to moderate (1+ to 2+) staining for HER-2/neu was seen in the glands, and there was no variation in intensity of staining during the menstrual cycle. Among 95 endometrial adenocarcinomas, nine (9%) were found to have heavier staining for HER-2/neu than was seen in normal endometrium (3+). High expression of HER-2/neu was found in 27% of patients with metastatic disease compared with 4% of patients with disease confined to the uterus (p less than 0.005). High HER-2/neu expression also was associated with absence of estrogen receptor (p less than 0.005) and with increased mortality from cancer. Further studies are needed to determine the significance of HER-2/neu overexpression in endometrial cancer.

Adenocarcinoma↗

PubMed1991

Epidermal growth factor receptor expression in normal ovarian epithelium and ovarian cancer. I. Correlation of receptor expression with prognostic factors in patients with ovarian cancer.

Previous studies in breast and bladder cancer have suggested that epidermal growth factor receptor is expressed by only a proportion of cancers and is associated with poor clinical outcome. We used a monoclonal antibody specifically reactive with the extracellular domain of the epidermal growth factor receptor to localize this receptor immunohistochemically in frozen sections of normal ovary and epithelial ovarian cancer. Normal ovarian epithelium was found to express epidermal growth factor receptor in all cases. Among 87 ovarian cancers, however, 23% did not express immunohistochemically detectable receptor. Epidermal growth factor receptor expression was not related to histologic grade or stage, but was associated with poor survival (p less than 0.05). The median length of survival of patients with tumors that did not express epidermal growth factor receptor was 40 months compared with 26 months in patients with tumors that did express epidermal growth factor receptor. As in breast and bladder cancer, expression of epidermal growth factor receptor in ovarian cancer appears to be a poor prognostic factor.

Antibodies, Monoclonal↗

PubMed1991

Risk of adverse events in children completing treatment for acute lymphoblastic leukemia: St. Jude Total Therapy studies VIII, IX, and X.

We studied the frequency, causes, and predictors of adverse events in 624 patients who had completed treatment for acute lymphoblastic leukemia (ALL) in three consecutive total therapy studies (VII, IX, and X, 1972 to 1983). Event-free survival in study X was significantly better overall than that in studies VIII and IX (P less than .0001 by the log-rank test). In study X, 75% of the patients were electively taken off therapy, compared with 54% in studies VIII and IX. However, the risks of having an adverse event during the first 5 years after completion of therapy were remarkably similar: 22% (95% confidence interval, 17% to 29%) in study X versus 24% (20% to 29%) in studies VIII and IX. Bone marrow, testicular, and CNS relapses accounted for the majority of failures in both groups (85% in study X and 92% in studies VIII and IX). Late adverse events consisted largely of hematologic relapses and the development of solid tumors. Black race (P = .001) and leukemia without an anterior mediastinal mass (P = .05) were associated with an increased risk of failure after completion of treatment in the two earlier clinical trials, whereas a lower leukemic cell DNA content (DNA index less than 1.16) was the only predictor of late treatment failure in the more recent trial (P = .019). None of the other presenting features that were examined (eg, age, leukocyte count, and sex) had value as predictors of late failure. Thus, improved treatment altered the impact of specific prognostic factors and the distribution of sites of relapse, but it did not significantly affect the risk of delayed failure.

Adolescent↗

PubMed1990

Delay in diagnosis and survival in testicular cancer: impact of effective therapy and changes during 18 years.

In an effort to determine the impact of a delayed diagnosis in testicular cancer the records of 148 patients with a known interval of delay were reviewed. The over-all mean symptomatic interval of this population was 21.1 weeks and did not change significantly during an 18-year review period. An increased symptomatic interval correlated with an increased presenting stage of disease for nonseminoma and a delay of greater than 16 weeks strongly (p equals 0.002) lowered survival for these patients during the study interval. However, the symptomatic interval was not significantly associated with stage for seminoma patients nor did the symptomatic interval influence survival for these patients. Further analysis of the nonseminoma patients revealed that delay strongly affected survival (p equals 0.001) in the pre-cisplatin era (1970 to 1978) but it was less pronounced (p equals 0.262) in the cisplatin era (1979 to 1987). Despite an attenuation of the effect of delay in the current era of effective chemotherapy, deaths still occur due to delay in diagnosis and programs to lessen delay, such as testicular self-examination, and patient and physician education, are strongly encouraged.

Adolescent↗

PubMed1990

Ifosfamide neurotoxicity is related to previous cisplatin treatment for pediatric solid tumors.

Neurotoxicity developed in 22 of 97 children and adolescents with malignant solid tumors treated within a phase II ifosfamide protocol. The occurrence of neurotoxicity was related to previous cumulative dosages of cisplatin. One third of the patients who had received more than 600 mg/m2 of cisplatin developed this complication. The relative risk increased 3.2-fold with previous cisplatin dosages above 301 to 600 mg/m2, and 4.1-fold with dosages of 601 to 1,340 mg/m2. The increased risk of neurotoxicity in patients who had received more than 600 mg/m2 of cisplatin may be related to either a decreased clearance of ifosfamide itself or of the drug's active metabolites.

Adolescent↗

PubMed1990

Presenting features and treatment outcome of adolescents with acute lymphoblastic leukemia.

Adolescents had lower rates of remission induction and shorter event-free survival than younger children in this study of consecutively treated patients with acute lymphoblastic leukemia (ALL). When compared to the younger patients (ages 1-9 years; n = 995), adolescents (ages 10-21 years; n = 338) were significantly more likely to have adverse prognostic features, including T cell phenotype, L2 blast cell morphology, higher serum lactate dehydrogenase level, higher leukocyte count, leukemic cell DNA index less than 1.16, and ploidy other than hyperdiploidy greater than 50. Within the adolescent group, outcome was worse for those older than 15 years. The increased frequency of unfavorable clinical and biologic features undoubtedly accounts in part for the poorer prognosis of adolescents with ALL. However, the independent prognostic significance of age greater than or equal to 10 years suggests that as yet unknown factors contribute to treatment failure in adolescent patients.

Adolescent↗