601
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Holt VL, Daling JR, Voigt LF, McKnight B, Stergachis A, Chu J, Weiss NS. Induced abortion and the risk of subsequent ectopic pregnancy. Am J Public Health 1989; 79:1234-8. [PMID: 2764199 PMCID: PMC1349695 DOI: 10.2105/ajph.79.9.1234] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This study assessed the effect of legal induced abortion on ectopic pregnancy risk by using a comparison group of reproductive-age women who were at risk of becoming pregnant during the same time period the women with ectopic pregnancy conceived. Cases were members of Group Health Cooperative of Puget Sound who were hospitalized for ectopic pregnancy from October 1981 through September 1986 (N = 211). Controls were randomly selected members matched to cases on age and county of residence (N = 457). All subjects in this analysis had had one or more prior pregnancies. Eighty-eight cases (41.7 per cent) and 177 controls (38.7 per cent) had a history of one or more induced abortions. The relative risk of ectopic pregnancy associated with one abortion was 0.9 (95 per cent confidence interval 0.6, 1.3), adjusted for age, county, reference date, religion, gravidity, age at first pregnancy, lifetime number of sexual partners, and miscarriage history. Among women with two or more prior pregnancies, the risk associated with two or more abortions was 1.2 (0.6, 2.4). Controlling for pelvic inflammatory disease and use of intrauterine devices did not alter these risks. We conclude that legal abortion as performed in the US since 1970 has little or no influence on a woman's risk of ectopic pregnancy in subsequent pregnancies.
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602
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Verreault R, Chu J, Mandelson M, Shy K. A case-control study of diet and invasive cervical cancer. Int J Cancer 1989; 43:1050-4. [PMID: 2731999 DOI: 10.1002/ijc.2910430616] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A population-based case-control study was conducted to assess the relation of diet, especially intake of vitamins A, C and E and of folic acid, to the risk of invasive cervical cancer. Cases were 189 women diagnosed with cervical carcinoma between 1979 and 1983 in 3 counties of the Seattle area. Controls (N = 227) were selected through random digit dialling. Diet during the year preceding diagnosis was assessed by interview, using a food frequency questionnaire covering the intake of 66 food items. After adjustment for known risk factors, frequent consumption of dark green or yellow vegetables and of fruit juices was related to a reduced risk of cervical cancer. Similarly, high dietary intake of carotene was associated with a lower risk of the disease, especially of the squamous-cell type. There was an inverse relationship between vitamin C intake and the risk of cervical carcinoma. The adjusted relative risk (RR) was 0.5 (95% confidence interval: 0.2-1.0) for the highest quartile of intake compared to a RR of 1.0 for the first quartile. High vitamin E intake was also related to a reduced risk, the risk for women in the highest quartile being only one-third of the risk for those in the first quartile. Intake of pre-formed vitamin A and of folic acid was not related to the risk of cervix cancer. Thus, our study suggests that the risk of invasive cervical carcinoma might be influenced by some aspects of diet.
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603
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Chu J, Solin L, Hwang C, Kessler H, Hanks G. Three dimensional dosimetric comparison of radiation therapy treatment techniques for carcinoma of pancreas. Int J Radiat Oncol Biol Phys 1989. [DOI: 10.1016/0360-3016(89)90684-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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604
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Carmalt HL, Gillett DJ, Chu J, Evans RA, Kos S. Prospective comparison of radionuclide, ultrasound, and computed tomography in the preoperative localization of parathyroid glands. World J Surg 1988; 12:830-4. [PMID: 3074593 DOI: 10.1007/bf01655489] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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605
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Harlow BL, Weiss NS, Roth GJ, Chu J, Daling JR. Case-control study of borderline ovarian tumors: reproductive history and exposure to exogenous female hormones. Cancer Res 1988; 48:5849-52. [PMID: 3167840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Borderline ovarian tumors possess many of the same morphological features as their malignant counterparts, but they do not destructively invade the ovarian stroma, and the women in whom they develop generally have a favorable prognosis. Female residents of three urban counties of western Washington diagnosed with serous and mucinous borderline ovarian tumors between 1980 and 1985 (n = 116) were interviewed regarding past reproductive events. A random sample of women from the same counties (n = 158) was identified through random digit dialing and were interviewed. The risk of these ovarian tumors among women who had given birth to 1 or 2 children and to 3 or more children was, respectively, 0.7 and 0.4 that of nulliparous women. There was no consistent influence of increasing age at first live birth. Adjusting for parity, a history of lactation was associated with a 50% reduction in risk. Among nulliparous women, a further increase in risk was present in those who reported a history of infertility. Use of oral contraceptives was associated with a 60% reduction in risk. However, the size of the association was not dependent on duration, age at first use, or years since last usage. In conclusion, borderline tumors appear to have similar epidemiological patterns with regard to reproductive events as their more malignant counterparts.
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606
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Firth PA, Chu J, Bell MA, Bailey GA, Soderstrom RM. Changing practice habits of King County obstetricians. Obstet Gynecol 1988; 72:419-22. [PMID: 3405558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In 1987, all practicing King County, Washington obstetricians (N = 181) were surveyed to determine the impact of rising malpractice premium rates and the threat of litigation on their obstetric practices. Six percent of respondents anticipated closing their practices over the next year, which means an additional 520 deliveries will have to be absorbed into existing obstetric practices. Of the 71% who increased their professional fees in 1986, 90% attributed the increase to higher malpractice premiums and increased risk of litigation.
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607
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Chu J. Motor unit analysis--comparison between concentric and monopolar needles. Am J Phys Med Rehabil 1988; 67:190. [PMID: 3401369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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608
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Feigl P, Glaefke G, Ford L, Diehr P, Chu J. Studying patterns of cancer care: how useful is the medical record? Am J Public Health 1988; 78:526-33. [PMID: 3354736 PMCID: PMC1349332 DOI: 10.2105/ajph.78.5.526] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Records of hospital inpatients were abstracted for 5,000 newly diagnosed cancer patients admitted in 1982-83 to 17 Comprehensive Cancer Centers and 17 Community Hospital Oncology Programs. Generally available data items (silent record rate less than 5 per cent for the typical institution) included: age, race, sex, dates of hospitalization, zip code of residence, pathological stage, dates of biopsy and surgery, numbers of nodes examined and positive, certain diagnostic procedures, and some radiotherapy descriptors. For other data items, there was enormous variability in completeness and high institution-to-institution variation. Record completeness did not differ consistently between comprehensive and community cancer centers. We conclude that the hospital patient record is useful for tracking the frequency of surgical and related events. However, studies of diagnostic and therapeutic procedures should not rely solely on the hospital medical record due to the high rates of silent records.
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609
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Abstract
Postoperatively, vulvar cancer patients visit the physician's office frequently until the incision is healed completely. Follow-up visits are then continued biannually and eventually annually. Postoperative mortality is directly related to the extensiveness of the disease at the time of diagnosis. If the lymph nodes are negative at the time of surgery, the five-year survival rate approaches 90%; however, if lymph nodes are positive, the five-year survival rate drops to about 33%. Because most women diagnosed with invasive cancer of the vulva are elderly, many die of noncancer related diseases while tumor free. Recurrence, if it should occur, may be distant or local. Local recurrence usually occurs at the margins of the resection and distant recurrence in the deep pelvic nodes. The radical vulvectomy procedure with bilateral groin node dissection poses a significant challenge to the perioperative nursing team. This team plays an important role in helping the patient and her partner adjust to this extensive procedure.
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610
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Sherman KJ, Daling JR, Chu J, McKnight B, Weiss NS. Multiple primary tumours in women with vulvar neoplasms: a case-control study. Br J Cancer 1988; 57:423-7. [PMID: 3390379 PMCID: PMC2246562 DOI: 10.1038/bjc.1988.96] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We sought to determine whether women with in situ or invasive squamous cell vulvar cancer were more likely than other women to have had a previous or concurrent tumour at other anogenital sites. One hundred and fifty-eight women with vulvar cancer were identified who were first diagnosed during 1980-1985, were ages 18-79 years at that time, and were residents of one of three counties in western Washington. Two control groups were selected: (1) from records of hospital pathology departments, a sample of 113 women with certain benign conditions of the vulva; (2) through random digit dialing, a sample of 212 women from the general population of these counties. Information on a history of other cancers, and on sexual, reproductive, medical, and demographic characteristics was collected from cases and controls in at-home interviews. Cases were more likely to report a history of other anogenital cancers than were controls, with relative risks of 3.5-29.8, depending on the type of case group and type of control. These associations were not explained by case-control differences in demographic characteristics or frequency of cervical screening. On the other hand, prior or concurrent non-anogenital cancers were equally common in cases and controls. These results support the hypothesis that the different anogenital cancers have at least one aetiology in common.
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611
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Abstract
Although the overall incidence of invasive cervical cancer is decreasing, there is concern that the disease might be increasing in younger women. Analysis of data from the Cancer Surveillance System, a population-based cancer registry in western Washington, shows a decreasing incidence of cervical cancer in women of all ages.
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612
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White E, Daling JR, Norsted TL, Chu J. Rising incidence of breast cancer among young women in Washington State. J Natl Cancer Inst 1987; 79:239-43. [PMID: 3474456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The prevalence of several known or suspected risk factors for breast cancer is changing among young women. The time trend in incidence of breast cancer among young women in western Washington was analyzed as a possible predictor of trends in future incidence rates. Data were from the Seattle-Puget Sound Surveillance, Epidemiology, and End Results cancer registry. For women age 25-44 years (n = 1,869 cases), the incidence of breast cancer increased by 22% (P less than .001) between the time periods 1974-77 and 1982-84. The estimated annual increase was 2.5% (P less than .001). The increase in incidence over time appeared to be greater among those residing in low-income census tracts of urban counties and among black women. Possible relationships between the observed increase in rates and trends of risk factors for breast cancer are discussed.
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613
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Florin T, Chapuis P, Bokey L, Chu J, Newland R. Pre-operative isotope liver scanning in clinicopathological staging of patients with large bowel cancer. THE AUSTRALIAN AND NEW ZEALAND JOURNAL OF SURGERY 1987; 57:451-4. [PMID: 3475059 DOI: 10.1111/j.1445-2197.1987.tb01396.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Isotope liver scanning is an accurate technique for detecting liver metastases from large bowel cancer. In this retrospective study of patients who had a resection for bowel cancer, the accuracy of liver scanning was 95%. However, the scan accuracy as defined by median survival time was insufficient to detect liver metastases missed by the surgeon at operation and did not alter the clinicopathological stage of the patient's disease.
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614
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Chu J, Diehr P, Feigl P, Glaefke G, Begg C, Glicksman A, Ford L. The effect of age on the care of women with breast cancer in community hospitals. JOURNAL OF GERONTOLOGY 1987; 42:185-90. [PMID: 3819344 DOI: 10.1093/geronj/42.2.185] [Citation(s) in RCA: 106] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We studied the process of care received by 1,680 female breast cancer patients treated in 17 community hospitals. The probability of receiving various diagnostic, consultation, therapy, or rehabilitation services was almost always significantly associated with patient age for one or more disease stages. Most often there was a linear trend for older patients to receive fewer services (e.g., biopsies prior to definitive treatment, number of lymph nodes examined, chemotherapy, radiation therapy) but other age patterns also were found. Age was not significantly associated with clinical staging or estrogen receptors.
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615
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Huang PH, Chu J, Bjärngard BE. The effect of collimator backscatter radiation on photon output of linear accelerators. Med Phys 1987; 14:268-9. [PMID: 3587153 DOI: 10.1118/1.596137] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The field-size dependence of the photon output of linear accelerators in air has been attributed in part to changes in the amount of radiation backscattered from the collimator jaws into the dose monitor chamber. This possible effect was investigated for a variety of accelerators with energies from 4 to 15 MV by measuring the monitor unit rate (MU/min) for different collimator openings. This measurement was made without dose rate feedback control, i.e., with constant electron beam current in the accelerator. The monitor unit rate was independent of collimator setting for all machines tested. Hence, it is concluded that backscattered radiation from the collimator jaws into the dose monitor chamber does not contribute to the variation of output with field size.
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616
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Shy K, Chu J, Mandelson M, Figge D, Greer B. Papanicotaou (Pap) smear screening interval and risk of cervical cancer (CXCA). Gynecol Oncol 1987. [DOI: 10.1016/0090-8258(87)90044-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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617
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Chu J, Chan RC, Bruyninckx F. Progressive teflon denudation of the monopolar needle: effects on motor unit potential parameters. Arch Phys Med Rehabil 1987; 68:36-40. [PMID: 3800622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This paper reports on the effects of an increase in size of the recording surface of monopolar needles on motor unit potentials (MUPs). The teflon coating of the TECA monopolar needles MG37 and MF37, commonly used in clinical electromyography, was progressively denuded to increase the length of the recording tip to 2, 3, 5, and 10 times the normal exposure, with resultant increase in the area of the recording portion. Low threshold MUPs obtained on minimal contraction from the tibialis anterior were analyzed for amplitude, duration, area, phases, turns, peak duration, and index. The amplitude and area of the MUP showed the most change, both decreasing with progressive denudation. The number of turns and phases were also reduced, more for the MF than for the MG needle. Duration, peak duration, and index showed insignificant changes. These findings give further support to the use of duration for representation of the MUP, since this is the most stable parameter even under poor recording conditions.
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618
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Chu J, Chan RC, Bruyninckx F. Effects of the EMG amplifier filter settings on the motor unit action potential parameters recorded with concentric and monopolar needles. ELECTROMYOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1986; 26:627-39. [PMID: 3830043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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619
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Solin LJ, Fowble B, Miller-Wilson P, Chu J, Goodman RL. A practical method of delivering the posterior axillary boost for the treatment of patients with breast cancer. Int J Radiat Oncol Biol Phys 1986; 12:2041-3. [PMID: 3771320 DOI: 10.1016/0360-3016(86)90144-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A practical technique for delivery of the posterior axillary boost is reported. A standard breast board is modified to allow for treatment of all fields in a single clinical set-up, and the posterior boost is delivered through a cut-out in the breast board. This technique is simple, is efficient, and eliminates problems of patient positioning and daily reproducibility.
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620
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Chu J, Solin L, Larsen R, Fowble B, Goodman R. A new method of determining treatment depth for electron breast boosts. Int J Radiat Oncol Biol Phys 1986. [DOI: 10.1016/0360-3016(86)90637-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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621
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Chu J, Bruyninckx F, Chan RC. Significance of motor unit action potential parameters in normal and neurogenic situations. ELECTROMYOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1986; 26:465-79. [PMID: 3816664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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622
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Coia L, Chu J, Larsen R, Myerson R. Spinal cord protection during radiation therapy. Int J Radiat Oncol Biol Phys 1986; 12:1697-705. [PMID: 3093419 DOI: 10.1016/0360-3016(86)90299-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Treating intrathoracic malignancies to high doses, particularly those of lung and esophagus, requires limiting the radiation dose delivered to the spinal cord. Several factors are important in determining the cord dose. These are: The distance from the block or collimator edge to the cord, the variation of dose with distance from the block or collimator edge and, the expected variation of this distance for clinical set-up from day-to-day. When treating with an oblique beam, the position of the cord may be difficult to identify. A technique for localizing the spinal cord on a simulator film at an arbitrary gantry angle is presented. The technique requires determination of distances from the central axis of the beam to the medial aspect of the pedicle and posterior vertebral body. These can readily be obtained from measurements on orthogonal, AP/PA and lateral isocentric simulator radiographs. A mathematical transformation is applied to determine the corresponding cord locations on the oblique radiographs for any arbitrary gantry angle. The accuracy of cord localization was within 2-3 mm with a precision of 2 mm for five physicians who used this technique. The beam edge characteristics for 60Co, 6 MV, and 10 MV teletherapy unit were measured for various depths and field sizes. For the 6 and 10 MV units, the beam penumbra is nearly independent of the field size, depth and field defining devices (inner and outer collimator jaws, trimmer bars, and shielding blocks). Because the beam penumbra is dependent on the design of the linear accelerator, its measurement should be made individually for each linear accelerator. Our preliminary data on patient positioning uncertainty did not exceed the 6-8 mm limit documented in the literature.
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623
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Thomas DB, Chu J. Nutritional and endocrine factors in reproductive organ cancers: opportunities for primary prevention. JOURNAL OF CHRONIC DISEASES 1986; 39:1031-50. [PMID: 3539966 DOI: 10.1016/0021-9681(86)90138-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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624
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Prentice RL, Omenn GS, Goodman GE, Chu J, Henderson MM, Feigl P, Kleinman GD, Thomas DB, Hutchinson ML, Lund B. Rationale and design of cancer chemoprevention studies in Seattle. NATIONAL CANCER INSTITUTE MONOGRAPH 1985; 69:249-58. [PMID: 3914621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Three cancer prevention trials are currently in their early phases at The Fred Hutchinson Cancer Research Center, the University of Washington School of Public Health and Community Medicine, and the Swedish Hospital. All 3 studies are randomized and placebo controlled. One large-scale study involves the daily administration of retinoids to persons with asbestos-related lung disease in an attempt toward reduction of their high risk for bronchogenic carcinomas and mesotheliomas. A second study involves administration of the same agents to long-term heavy smokers; a substantial feasibility and toxicity pilot study will precede a full-scale prevention trial. In the third trial, folic acid administration is evaluated in relation to the progression and regression of cervical dysplasia among women with abnormal Pap smears. We report here the rationale and the design for these 3 studies.
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625
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McTiernan A, Chu J, Thomas DB. Cancer incidence in Caucasians living in the Pacific Basin. NATIONAL CANCER INSTITUTE MONOGRAPH 1985; 69:65-72. [PMID: 3834348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Variations in cancer incidence among whites in 1973-77 in 8 geographic areas of the Pacific Basin were compared. Substantial differences were found for the occurrences of lung cancer, cancer of the corpus uteri, and malignant melanoma. White women living in New Zealand and Australia had the lowest risk of developing lung cancer, whereas white men living in the western United States had the highest risk. Cancer of the corpus uteri occurred more commonly in the western United States than elsewhere in the Pacific Basin. Geographic areas located closest to the equator experienced the highest incidence of malignant melanoma. In all areas, the incidence rates of cancers of the lung and corpus uteri and malignant melanoma increased significantly between 1960-66 and 1973-77; after the mid-1970s, rates of cancer of the corpus uteri declined. The incidence of stomach cancer decreased in all areas. Although cervical cancer decreased in incidence over time for most women, it increased noticeably in young women. The incidence of breast cancer also rose during the 17-year period. In at least 1 geographic area, the observed increases in breast cancer incidence were confined to women under age 40.
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