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Biomedical subjects

N Breslow

Publications and source records attributed to N Breslow.

72 records · Page 4Linked to original sources

Latent carcinoma of prostate at autopsy in seven areas. The International Agency for Research on Cancer, Lyons, France.

A world-wide comparative study of the frequency and characteristics of latent carcinoma of the prostate was undertaken in seven areas, using standardized methods and "blind" microscopic evaluation in order to reduce selection and observer bias. The morphological features of 350 latent carcinomas found in 1,327 prostates were examined. Two Chinese populations, from Hong Kong and Singapore, showed a low frequency of latent carcinoma in comparison with western Europeans in Sweden and the Federal Republic of Germany and negroes from Jamaica; an intermediate position was found for Israelis and black Ugandans. The frequency of small latent carcinomas was about 12% in all the areas investigated and did not vary with age. Rates for larger latent carcinomas increased sharply with age ans showed an area-to-area variation resembling that of clinical carcinoma of prostate. The small carcinomas were almost exclusively situated in the outer half of the prostate and latent carcinomas of all sizes were evenly distributed between the anterior and posterior halves of the prostate and the right and left sides of the outer prostatic shell. Certain disagreements in diagnosis were noted when the sections from each area were evaluated independently by a different pathologist. Most of these disagreements were resolved by re-reading the sections; their occurrence had no significant effect on the geographical comparisons.

Age Factors↗

Treatment of rhabdomyosarcoma in children with surgery, radiotherapy and chemotherapy.

From May, 1970 through December, 1972, Children's Cancer Study Group entered 112 patients on an amended treatment program for rhabdomyosarcoma and undifferentiated sarcoma in children. These patients had Group II disease with residual tumor remaining after surgery, or metastatic disease at onset. Another group consisted of patients who previously had treatment with surgery and radiotherapy and had recurrent disease. Cyclophosphamide was added to a previously used drug regimen which consisted of actinomycin D and vincristine. The drugs were given sequentially in repeated cycles for 18 months. Of 97 evaluable patients, there were 24 with microscopic residual disease, 37 with gross residual disease, 22 with metastatic disease at onset, and 14 patients who were treated with chemotherapy for the first time with recurrent or metastatic disease. All patients have been followed for 3 or more years. Survival in each group was 70.8%, 43.2%, 27.2%, and 28.2%, respectively. Although the number of complete remissions was greater than with two-drug therapy, survival with three-drug therapy was not significantly different than that seen in the earlier study.

Adolescent↗

Cancer of the oral cavity, pharynx/larynx and lung in North Thailand: case-control study and analysis of cigar smoke.

The unusually high relative frequency of cancer in the laryngeal region in males (18% of all histologically diagnosed cancers) and a sex ratio of unity for lung cancer in Northern Thailand were further explored in a hospital-based case-control study in Chiang Mai. This compared patients having cancers of the oral cavity (including oropharynx), larynx, hypopharynx and lung, with controls in relation to smoking and chewing habits. Statistical analysis indicated that chewing betel is strongly associated with the occurrence of oral cancer in both sexes, and with cancer of the laryngeal region in males. No factors were strongly linked to lung cancer in men, but, in women, urban residence and miang chewing were associated with lung cancer. Analysis of smoke from the two main types of cigars smoked in the region showed that both had high tar content, but there were marked differences in pH. Smoking cigars with alkaline smoke and high tar had an increased risk for laryngeal cancer in males, whereas other cigars with acid smoke and high tar together with manufactured cigarettes had increased risks for lung cancer. These increased risks were not, however, statistically significant.

Aged↗

The treatment of Wilms' tumor: Results of the national Wilms' tumor study.

The National Wilms' Tumor Study, initiated in 1969, tested competing treatment strategems for patients with tumors ranging from Group (Gp) I (tumors confined to the kidney and totally removed) to Gp IV (remote metastases present at diagnosis). Three hundred and fifty-nine of 606 registered patients were randomized in the trial. Gp I patients under 2 years of age fared well whether postoperative radiation therapy (RT) was or was not added to 15 months' maintenance actinomycin D (AMD). Their prognosis was better than that for older cohorts similarly treated, in whom the difference in relapse rates between treatment groups were suggestive of an RT effect. Combined AMD and vincristine (VCR) gave better results than either agent alone in patients with more advanced tumors (Gps II and III) still confined to the abdomen, all of whom received postoperative RT as well. Preoperative VCR given Gp IV patients in addition to postoperative RT, AMD, and VCR did not improve results. The frequency of mesoblastic nephroma (1%), of bilateral tumors (5%), and of incorrect preoperative diagnosis of Wilms' tumor (5%), the toxicities of the various regimens, and other ancillary data are presented and discussed.

Age Factors↗

Regression analysis of the log odds ratio: a method for retrospective studies.

Quantification of the dependence of the odds ratio on concomitant variables associated with each of several 2 X 2 tables, using a regression model proposed by Zelen [1971], is an important tool for retrospective studies in epidemiology, An "exact" analysis may be based on the conditional likelihood obtained by fixing all the marginal totals. A symptotically this approach is equivalent to use of an unconditional log-linear model. The method is used to reanalyze data reported by Kneale [1971] on the relationship between obstetric radiation and childhood cancer.

Biometry↗

BCG in the treatment of acute lymphocytic leukemia.

Children with acute lymphocytic leukemia, who were in remission after induction with prednisone and vincristine and consolidation with intravenous methotrexate, were randomized into three groups receiving (1) no further therapy, (2) BCG, and (3) chemotherapy with biweekly methotrexate and monthly prednisone and vincristine. Children continuing in remission after 8 mo on chemotherapy in group 3 were rerandomized into three similar groups, i.e., no therapy, BCG, and chemotherapy. In the primary randomization, the median duration of remission was identical in the groups receiving no therapy or BCG, (4 and 4.3 mo respectively), and both were significantly less than the median duration of remission on chemotherapy which had not been reached prior to secondary randomization at 8 mo. Results of secondary randomization were similar to those of primary randomization. As used in this study, BCG was ineffective in prolonging drug-induced remissions either early in remission or when the leukemic cell population might have been further reduced after 8 mo of maintenance chemotherapy.

Adolescent↗

Remarks on the conservatism of sigma(0 -- E)2/E in survival data.

This note presents theoretical and numerical calculations which investigate the adequacy of the sigma(0 -- E)2/E approximation (Peto and Pike [1973]) when applying the Mantel/Haenszel summary chisquare statistic to the comparison of r life tables in the manner suggested by Mantel [1966], Peto and Peto [1972], and Cox [1972]. These indicate that conservatism is mild unless there are marked differences in the withdrawal patterns in the r tables. Such differences may, however, be anticipated in the case of a generalization of the life table procedure suggested by Crowley [1973], Mantel and Byar [1974], and Turnbull, Brown, and Hu [1974], wherein individuals are moved from one life table to another according to changes in their treatment (or other) statuses.

Biometry↗

Negative association between type 1 diabetes and HLA DQB1*0602-DQA1*0102 is attenuated with age at onset. Swedish Childhood Diabetes Study Group.

HLA-associated relative risks of type 1 (insulin-dependent) diabetes mellitus were analysed in population-based Swedish patients and controls aged 0-34 years. The age dependence of HLA-associated relative risks was assessed by likelihood ratio tests of regression parameters in separate logistic regression models for each HLA category. The analyses demonstrated an attenuation with increasing age at onset in the relative risk for the positively associated DQB1*0201-A1*0502/B1*0302-A1*0301 (DQ2/8) genotype (P = 0.02) and the negatively associated DQB1*0602-A1*0102 (DQ6.2) haplotype (P = 0.004). At birth, DQ6.2-positive individuals had an estimated relative risk of 0.03, but this increased to 1.1 at age 35 years. Relative risks for individuals with DQ genotype 8/8 or 8/X or DQ genotype 2/2 or 2/X, where X is any DQ haplotype other than 2, 8 or 6.2, were not significantly age-dependent. An exploratory analysis of DQ haplotypes other than 2, 8 and 6.2 suggested that the risk of type 1 diabetes increases with age for DQB1*0604-A1*0102 (DQ6.4) and that the peak risk for the negatively associated DQB1*0301-A1*0501 haplotype is at age 18 years. There was also weak evidence that the risk for DQB1*0303-A1*0301 (DQ9), which has a positive association in the Japanese population, may decrease with age. We speculate that HLA-DQ alleles have a significant effect on the rate of beta cell destruction, which is accelerated in DQ2/8-positive individuals and inhibited, but not completely blocked, in DQ6.2-positive individuals.

Adolescent↗