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Biomedical subjects

A J Coldman

Publications and source records attributed to A J Coldman.

At least 73 records · Page 4Linked to original sources
PubMed1986

Childhood and recent eating patterns and risk of breast cancer.

A case-control study was done to examine the relationship between childhood and recent eating practices and risk of breast cancer. Eight hundred forty-six cases and 862 controls returned questionnaires indicating their menopausal status. In premenopausal women, breast cancer risk was increased with recent consumption of foods high in fat content (gravy, beef, pork) and reduced with foods low in fat content (fish); in postmenopausal women, risk was increased with pork consumption only. Regarding carotene sources, risk was reduced with carrot consumption in postmenopausal women only. Similar trends in risk were not found for childhood eating practices. Body weight influenced the breast cancer risk differently for pre- and postmenopausal women: Heavier weight in childhood and teens reduced the risk of premenopausal breast cancer, and heavier weight in adulthood increased the risk of postmenopausal breast cancer. We conclude that fat consumption is associated with breast cancer, especially in premenopausal women.

Adult↗
PubMed1985

Radiation dose and second breast cancer.

Amongst 14,000 women with breast cancer treated between 1946 and 1982, 194 developed a second primary tumour in the contralateral breast more than one year after diagnosis of the first primary. The radiation dose to the contralateral breast was calculated for each member of this group and also for members of a control group matched for age, year of diagnosis and survival time. Comparison of the groups provides no evidence for radiation induced carcinogenesis on the contralateral breast in these patients.

Adult↗
PubMed1985

Reproductive factors, oral contraceptives and risk of malignant melanoma: Western Canada Melanoma Study.

A study of 361 female melanoma patients and age matched controls was conducted in the four western provinces of Canada. Analysis of reproductive factors showed a significant negative association between number of livebirths and risk of melanoma. The relationship persisted for superficial spreading melanomas after adjustment for host pigmentation factors, freckling, and educational status. An inverse association between bilateral oophorectomy and risk of superficial spreading melanoma was also seen. No association was found between risk of melanoma and age at first birth, age at menarche and age at natural menopause. No association was found between risk of superficial spreading or nodular melanoma and use of either oral contraceptives or menopausal oestrogens.

Adult↗
PubMed1985

Meat consumption as a risk factor in enteritis necroticans.

The association between the consumption of animal protein and enteritis necroticans (EN) was investigated in a case-control study of 60 proven cases of acute surgical EN. A very high risk of EN was found in association with the recent ingestion of pork and other meats with the exception of tinned fish. The control group was characterized by the more frequent and regular ingestion of animal protein (predominantly in the form of tinned fish) suggesting a protective effect. No conclusions about the causality of the observed associations could be drawn but the implications for preventive intervention are discussed.

Adult↗
PubMed1985

Role of mathematical modeling in protocol formulation in cancer chemotherapy.

The origin of drug resistance is discussed and the spontaneous mutation model is presented. The general implications of this model for the use of chemotherapy are considered and are found to agree with the broad range of experience from treating human malignancy. The large amount of information required to use this model to create detailed protocols does not permit its utilization at present, but it is hoped that such information will become available in the future.

Animals↗
PubMed1984

Breast self-examination: importance of technique in early diagnosis.

Shortly after diagnosis of breast cancer 416 patients were interviewed about their use of screening procedures and the method of tumour detection. Although 72% reported that they performed breast self-examination (BSE), only 12% actually inspected and palpated their breasts monthly. BSE was not significantly associated with tumour size or involvement of the lymph nodes; however, thorough inspection was associated with smaller tumours, and careful palpation with the absence of palpable nodes. Of those who no longer or never had examined their breasts 40% reported having annual breast examinations by their physician and had significantly smaller tumours than did the others. Most of the women (86%) reported having detected their own tumours, and BSE did not significantly increase the likelihood of self-detection. The frequency of use of screening procedures was similar in a sample of women without breast cancer.

Adult↗
PubMed1984

Second primary cancers of the breast: incidence and risk factors.

Between 1946 and 1976 over 9,000 women with breast cancer were seen within one year of diagnosis at the A. Maxwell Evans Clinic (AMEC) in Vancouver, British Columbia. By 1978, 275 had a subsequent diagnosis of a second primary in the contralateral breast: 100 were diagnosed within 1 year, and 175 after 1 year of the first primary. Two separate comparison groups of AMEC patients with unilateral breast cancer were selected to identify risk factors for bilateral breast cancer and to determine the incidence. The average annual incidence rates for a second primary in the contralateral breast were 5.0, 4.1 and 3.0 per 1,000 women for women less than 45 years, 45-54 years, and over 55 years of age at diagnosis of first primary breast cancer, respectively. These rates remained stable for at least 15 years after the diagnosis of the first primary. Two risk factors were found for bilateral cancer within 1 year of the first primary, histologic diagnosis of lobular carcinoma and absence of pathologic involvement of axillary nodes; one risk factor was found for bilateral breast cancer after 1 year of the first primary, family history of breast cancer.

Adult↗
PubMed1984

Cancer and aplastic anemia in British Columbia farmers.

For evaluation of occupational mortality in agriculture, age-standardized proportional mortality ratios (PMR) were calculated for 28,032 male farmers with the use of British Columbia (B.C.) death registrations collected from 1950 to 1978. Farmers had significantly elevated risks of death from cancer of the lip (PMR = 191, P = .05), stomach (PMR = 119, P less than .0001), and prostate gland (PMR = 113, P less than .001). In addition, leukemia was higher than expected (PMR = 122, P less than .01), as was aplastic anemia (PMR = 174, P less than .01). The elevated risks were fairly consistent over the 29-year period for stomach, prostate gland, and lip cancer, as well as for leukemia. The PMR for aplastic anemia was highest for the years 1950-59 and declined over the next 19 years. Farmers also showed significant mortality deficits for several important cancer sites, including esophagus (PMR = 59, P less than .0001), colon (PMR = 84, P less than .001), larynx (PMR = 62, P less than .01), and lung (PMR = 66, P less than .0001) for the period 1950-78. More detailed studies in B.C. will be necessary to confirm and extend these cancer-agriculture associations.

Adult↗
PubMed1984

The genetic origin of drug resistance in neoplasms: implications for systemic therapy.

Drug resistance continues to be a major factor in limiting the effectiveness of cancer chemotherapy. Evidence from a variety of sources implicates a genetic basis for most drug-resistant phenotypes. Assuming a random spontaneous origin for these resistant cells, it is possible to develop mathematical and computer-based models of the drug treatment of tumors. These can provide a more intuitive understanding of the basis of treatment success or failure. This in turn may lead to the development of more rational and effective treatment protocols. Studies of phenomena such as pleiotropic drug resistance are providing insights into how multiple levels of drug resistance occur and are yielding information on how certain types of drug resistance may be prevented or overcome.

Animals↗
PubMed1983

Quantitative model for multiple levels of drug resistance in clinical tumors.

A mathematical model to examine the effect of cellular differentiation on phenotypic drug resistance in neoplasms is proposed. Attention is restricted to the maintenance of stem cell proliferative capacity. For fixed mutation rates, tumors in which loss of stem cell capacity occurs with high frequency will have a higher proportion of resistant stem cells than those in which such loss is infrequent. The acquisition of multiple levels of drug resistance will proceed at a disproportionately accelerated pace, which leads to greater degrees of incurability for tumors with a stem cell compartment of a given size. This model directly predicts that the phenotypic heterogeneity of slow-growing advanced clinical tumors will be very great. However, as this heterogeneity depends on both the size and the age of the tumor, there will be a period early in the development of the tumor when it should be susceptible to drug-induced cure. This potential for curability at an early stage may not be reflected in the pattern of drug responsiveness of the advanced tumor.

Antineoplastic Agents↗
PubMed1982

Sports activities and risk of testicular cancer.

The relationship of testicular seminoma with several factors was explored using a case-control study. Previously recognized associations with cryptorchidism and infantile inguinal hernia were confirmed and relationships were also found with cycling and horse-riding. These findings represent the first relationships of testicular cancer with well-defined postnatal risk factors.

Animals↗
PubMed1981

Breast cancer prognosis and the sex of the patient's children.

To verify a report that the prognosis of breast cancer was better in women whose first child was male, we analyzed the survival of 233 consecutive breast cancer patients diagnosed in 1969 and 1970 in terms of the sex of the first and last children, and of the number and proportion of males among the first four live births. No association between survival and any index of the sex of children was found. Similar negative findings for both survival and time to first recurrence were found in an independent series of 113 patients.

Birth Order↗
PubMed1981

Water composition in the etiology of anencephalus.

This case-control study was based on 468 deaths from anencephalus and a random sample of 4129 livebirths occurring during 1969 to 1972 to mothers resident in 142 localities of over 10,000 population in Canada. Anencephalus risk was associated with the previous pregnancy history of the mother, with legitimacy, year of birth and with the longitude of the mother's residence, but after adjusting for these there was no significant association seen with locality population size, mean income, the proportion of women employed, latitude, or with the concentrations in drinking water of any of 14 elements: calcium, magnesium, copper, lithium, zinc, nickle, lead, selenium, mercury, chromium, silver, cobalt, cadmium and molybdenum.

Anencephaly↗
PubMed1981

Clinical indicators of prognosis in unresected lung cancer.

A prognosis estimate in palliative treatment for inoperable lung cancer is thought to be of value. Performance status is now recognized as being of major importance, but only recently has been consistently available. We examined other simple information not requiring clinical or laboratory tests that is available in the clinical histories of a series of 1,839 patients with unresected lung cancer. Actuarial survivals at 1, 2, and 5 years were 21.9, 7.8, and 2.0 percent, respectively. The median survival rate was 24 weeks. Squamous cell histology and an increasing interval between the first symptoms and diagnosis were associated with a better prognosis. The number of symptoms recorded at the time of assessment had strong negative association with survival; asymptomatic patients had a two-year survival of 26 percent compared with 6 percent or less with four or more symptoms. A similar discrimination is given by Feinstein's index, which combines information on the number and type of symptoms and on the interval between first symptom and diagnosis. The clinical stage was strongly related to survival. Additional statistical analysis showed that the prognostic value of each of the most powerful prognostic factors, the number of symptoms, and Feinstein's index was little altered by the use of data on stage and histology in addition. The data show a range of median survival of 18 to 60 weeks for Feinstein's indices from 6 to 1, suggesting that the symptom index is useful particularly in the relatively well patients and the performance status particularly in those more ill. The combination may be better than either alone, and it is recommended that such information be recorded for all lung cancer patients.

Adenocarcinoma↗