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Biomedical subjects

F L Wong

Publications and source records attributed to F L Wong.

At least 19 recordsLinked to original sources
PubMed1997

Cancer incidence after retinoblastoma. Radiation dose and sarcoma risk.

CONTEXT: There is a substantial risk of a second cancer for persons with hereditary retinoblastoma, which is enhanced by radiotherapy. OBJECTIVE: To examine long-term risk of new primary cancers in survivors of childhood retinoblastoma and quantify the role of radiotherapy in sarcoma development. DESIGN: Cohort incidence study of patients with retinoblastoma followed for a median of 20 years, and nested case-control study of a radiation dose-response relationship for bone and soft tissue sarcomas. SETTING/PARTICIPANTS: A total of 1604 patients with retinoblastoma who survived at least 1 year after diagnosis, identified from hospital records in Massachusetts and New York during 1914 to 1984. RESULTS: Incidence of subsequent cancers was statistically significantly elevated only in the 961 patients with hereditary retinoblastoma, in whom 190 cancers were diagnosed, vs 6.3 expected in the general population (relative risk [RR], 30 [95% confidence interval, 26-47]). Cumulative incidence (+/-SE) of a second cancer at 50 years after diagnosis was 51.0% (+/-6.2%) for hereditary retinoblastoma, and 5.0% (+/-3.0%) for nonhereditary retinoblastoma. All 114 sarcomas of diverse histologic types occurred in patients with hereditary retinoblastoma. For soft tissue sarcomas, the RRs showed a stepwise increase at all dose categories, and were statistically significant at 10 to 29.9 Gy and 30 to 59.9 Gy. A radiation risk for all sarcomas combined was evident at doses above 5 Gy, rising to 10.7-fold at doses of 60 Gy or greater (P<.05). CONCLUSIONS: Genetic predisposition has a substantial impact on risk of subsequent cancers in retinoblastoma patients, which is further increased by radiation treatment. A radiation dose-response relationship is demonstrated for all sarcomas and, for the first time in humans, for soft tissue sarcomas. Retinoblastoma patients should be examined for new cancers and followed into later life to determine whether their extraordinary cancer risk extends to common cancers of adulthood.

Adolescent↗
PubMed1997

Longitudinal trends in total serum cholesterol levels in a Japanese cohort, 1958-1986.

The 28-year follow-up of a Japanese cohort, having collected vast amounts of data collected on total serum cholesterol (TC), provided an exceptional opportunity to examine TC temporal trends. The longitudinal statistical method of growth-curve analysis was used to elucidate the age-related changes in TC levels and to characterize these trends in relation to sex, birth cohort, time period, place of residence, and body mass index (BMI). Japanese TC levels at initial examination were remarkably lower than those in western countries. During the study period from 1958 to 1986, TC levels increased dramatically with age in both sexes. The slope of the cholesterol growth curve was steeper for women than for men, with the difference growing larger after age 40 years. Drastic changes in Japanese behavior and lifestyle, especially westernization of the diet, are thought to have affected the TC values as time-period effects. As a result of this temporal change, which affected different cohorts at different ages, TC values were higher in members of the younger cohort. The increase of the TC values as time-period effects were larger in earlier period than in later period. These time-period effects appeared to be almost similar in men and women. The TC growth curves also varied by city of residence. Subjects in urban areas had higher TC values than subjects in rural areas. Changes associated with BMI from 1958 to 1986 were only partially responsible for the increased steepness of the TC growth curve.

Adult↗
PubMed1996

Benign thyroid tumors: general risk factors and their effects on radiation risk estimation.

The authors examined risk factors for benign thyroid nodules and their influence on radiation effects among 544 subjects who were exposed to childhood radiation treatment for benign head and neck conditions at a Chicago, Illinois hospital during 1939-1962. In follow-up through 1991, benign thyroid nodules were diagnosed in 131 patients. The risk of benign nodules was elevated in women (relative risk (RR) = 2.2, 95% confidence interval (CI) 1.6-3.2), Jews (RR = 1.7, 95% CI 1.2-2.5), college graduates (RR = 1.8, 95% CI 1.2-2.8), and subjects whose mother had cancer (RR = 1.7, 95% CI 1.2-2.5). There were increasing trends for risk with increasing body mass index in women and decreasing height in men. Risk was increased for women who never married (RR = 3.7, 95% CI 1.6-7.3) or who never had a full-term pregnancy (RR = 2.0, 95% CI 1.1-3.3). A significant radiation dose-response relationship was observed that was not modified by sex, education, Jewish religion, or reproductive factors. The data suggest that there are genetic, life-style (including ascertainment), and hormonal factors associated with the development of benign thyroid nodules.

Cohort Studies↗
PubMed1995

Incidence of benign gastrointestinal tumors among atomic bomb survivors.

Using the Hiroshima and Nagasaki tumor and tissue registries, benign tumors of the stomach, colon, and rectum were identified among members of the Life Span Study cohort of atomic bomb survivors. During the period 1958-1989, a total of 470 cases with histologically confirmed benign gastrointestinal tumors (163 stomach, 215 colon, and 92 rectum) were identified among approximately 80,000 Life Span Study members with known radiation doses, who were alive in 1958. Restricting the analysis to adenomatous tumors not detected at autopsy, a dose-response relation was observed for stomach tumors (excess relative risk at 1 sievert (ERR1Sv) = 0.53; 95% confidence interval (CI) -0.01 to 1.43). However, there was little evidence of a dose response for colon tumors (ERR1Sv = 0.14; 95% CI -0.20 to 0.76), and no evidence was present for rectal tumors (ERR1Sv = -0.25; 95% CI undetermined to 0.80). The excess relative risk (ERR) for benign tumors of the stomach is consistent with the excess found for stomach cancer. For cancer of the rectum, the dose response was not significant, but the point estimate of the excess relative risk was positive. The excess relative risk for benign colon tumors is less than that reported for colon cancer (ERR1Sv = 0.72). The authors observed a dramatic increase in colon tumors detected after 1985, suggesting that the relatively recent introduction of colonoscopy may be influencing these results.

Cohort Studies↗
PubMed1995

Relationship between cataracts and epilation in atomic bomb survivors.

Among 1713 atomic bomb survivors who underwent ophthalmological examinations from 1963-1964, the risk of cataract formation per unit dose of radiation was significantly greater for those who reported hair loss of 67% or more after exposure (the epilation group) than for those who reported less or no hair loss (the no-epilation group) (P < 0.01). Such an epilation effect has also been associated with leukemia mortality and the frequency of chromosome aberrations. Although this might be interpreted as indicating differential sensitivity to radiation between the epilation group and the no-epilation group, it could also be explained by imprecision in dose estimates. We have calculated that a 48% random error in DS86 dose estimates could be in accordance with the dose-response relationship for the prevalence of cataracts in the epilation group or the no-epilation group. Possible mechanisms for variation in radiosensitivity are discussed.

Alopecia↗
PubMed1994

Endometrial adenocarcinoma presenting as an isolated calcaneal metastasis. A rare entity with good prognosis.

A 59-year-old woman presented with progressive pain, swelling, and erythema of her right foot. Biopsy of a destructive calcaneal lesion revealed a metastatic adenoacanthoma with focal adenosquamous carcinoma consistent with an endometrial origin. This was confirmed on hysterectomy. Postoperative treatment consisted of systemic chemotherapy, hormonal therapy, and local radiotherapy to the foot. She has now experienced 5 years of complete remission. This is a case of an endometrial adenocarcinoma presenting as an isolated calcaneal metastasis with an excellent outcome.

Adenocarcinoma↗
PubMed1994

The efficacy of sucralfate suspension in the prevention of oral mucositis due to radiation therapy.

PURPOSE: The purpose of this study was to assess the value of sucralfate suspension in prevention of oral mucositis and for reduction of oral pain in patients who develop mucositis during radiation therapy. METHODS AND MATERIALS: The study was a double-blind, placebo-controlled, randomized prospective trial of a sucralfate suspension in the prevention and management of oral mucositis during radiation therapy. Oral mucositis was assessed using a quantitative scale and symptoms were assessed using visual analogue scales. The statistical model was developed to detect a 40% reduction in mucositis. RESULTS: No statistically significant reduction in mucositis was seen. Early during radiation therapy less oral pain was reported in the sucralfate group, but as treatment progressed all patients experienced pain. Patients in the sucralfate group were prescribed topical and systemic analgesics later in the course of radiation therapy. CONCLUSION: Prophylactic oral rinsing with sucralfate did not prevent oral ulcerative mucositis. Sucralfate may reduce the experience of pain during radiation therapy.

Adult↗
PubMed1993

Mortality from second tumors among long-term survivors of retinoblastoma.

BACKGROUND: Children diagnosed with retinoblastoma, a rare cancer of the eye, tend to develop and die of second primary cancers in childhood and adolescence, but few investigations have followed patients into adulthood. Retinoblastoma is frequently caused by inherited mutations of the RB1 tumor suppressor gene. Most patients with germline (hereditary) mutations have bilateral disease. PURPOSE: We sought to quantify the mortality from second malignancies among long-term survivors of retinoblastoma and to identify factors that predispose to these deaths. METHODS: A retrospective cohort study examined mortality among 1603 patients enrolled at 1 year after diagnosis of retinoblastoma during the period 1914-1984. Data on demography, family history, and retinoblastoma treatment were collected by medical chart review and questionnaire interview. Number of deaths, by cause, was compared with the corresponding expected figure based on U.S. mortality data for the general population for 1925-1990. RESULTS: Follow-up was complete for 1458 patients (91%) for a median of 17 years after retinoblastoma diagnosis. A total of 305 deaths occurred, 167 of them from retinoblastoma. There were 96 deaths from second primary tumors (relative risk [RR] = 30), 21 from other known causes (RR = 1.0), and 21 from ill-defined or unknown causes. Statistically significant excess mortality was found for second primary cancers of bone, connective tissue, and malignant melanoma and benign and malignant neoplasms of brain and meninges. Among 919 children with bilateral retinoblastoma, 90 deaths from second primary tumors occurred (RR = 60). Deaths from second tumors were more frequent among females (RR = 39) than males (RR = 22) (P = .007). The cumulative probability of death from second primary neoplasms was 26% at 40 years after bilateral retinoblastoma diagnosis, and additional cancer deaths occurred thereafter. Radiotherapy for retinoblastoma further increased the risk of mortality from second neoplasms. An excess of mortality from a second cancer, not seen in prior studies, was found among the 684 children with unilateral disease (RR = 3.1; 95% confidence interval = 1.0-7.3). CONCLUSIONS: These findings implicate germinal mutations in the retinoblastoma gene in second cancer mortality. Radiotherapy treatment for retinoblastoma appears to further enhance the inborn susceptibility to development of a second cancer. IMPLICATIONS: Patients with retinoblastoma, particularly bilateral retinoblastoma, should have careful follow-up, and interventions should be developed to reduce mortality from a second cancer.

Adolescent↗
PubMed1993

Hyperbaric oxygen and postradiation osteonecrosis of the mandible.

The clinical and dental records of 26 patients with the clinical diagnosis of postradiation osteonecrosis (PRON) managed with hyperbaric oxygen (HBO) were reviewed to determine the efficacy of HBO. 19 patients were male and 7 were female; age at the first HBO session ranged from 28 to 80 years (median 57.5 years). All but 8 patients reviewed had some form of surgical management; 7 had mandibulectomy for PRON. As part of management, a total of 9-84 HBO sessions (median 35 sessions) was administered. 18 of the 26 patients ultimately achieved persistent mucosal and cutaneous coverage 1-84 months (median 24 months) after the first HBO session. 13 of the 26 patients met strict criteria for resolution of their disease; fully 21 of 26 patients had improved PRON status following HBO therapy. HBO treatment as part of a comprehensive management plan is safe and effective in the management of PRON.

Adult↗
PubMed1993

Noncancer disease incidence in the atomic bomb survivors: 1958-1986.

Using the longitudinal data of the Adult Health Study (AHS) cohort collected during 1958-1986, we examined for the first time the relationship between exposure to ionizing radiation and the incidence of 19 nonmalignant disorders in the A-bomb survivors. Affected individuals were ascertained through the three-digit codes of the International Classification of Diseases which are encoded in the AHS database subsequent to diagnoses made on the basis of general laboratory tests, physical examinations, and history-taking conducted during biennial AHS examinations. The disease onset time was estimated using the mid-point between the AHS examination data when the disease was initially reported and the previously attended disease-free examination date. Dosimetry System 86 organ doses judged to be most appropriate were used. Tests of dose effects were performed assuming a linear relative risk model with stratified background incidence. For the entire study period, significant excess risk was detected for uterine myoma (P < 0.001), chronic liver disease and cirrhosis (P = 0.006), and thyroid disease (P < 0.0001), defined broadly as the presence of one or more of certain noncancerous thyroid conditions. The incidence of myocardial infarction was shown to be increased (P = 0.03) in later years (1968-1986) among the younger heavily exposed AHS subjects, confirming the results of the recent Life Span Study (LSS) noncancer mortality report on coronary heart disease. The findings for uterine myoma may serve as additional evidence indicating benign tumor growth as a possible consequence of radiation exposure. Our results indicating the involvement of radiation in the development of liver diseases are consistent with the report of increased mortality from liver cirrhosis with radiation dose in the LSS cohort. An effect of age at exposure was detected for nonmalignant thyroid disease (P = 0.02), with an increased risk for those exposed who were under 20 years of age, but not for older survivors. Thus the AHS data suggest that thyroid glands in the young are more radiosensitive not only to the development of malignancies, but also to the development of nonmalignant disorders as well. The findings hold independently of the dose effects observed for thyroid cancer. This study also shows that for the period 1958-1986 new occurrences of lens opacity are not increased with radiation dose (P = 0.39) in the AHS subjects.

Adult↗
PubMed1992

Longitudinal study of the association between ABO phenotype and total serum cholesterol level in a Japanese cohort.

The relationship between ABO blood phenotype and total serum cholesterol (TC) level was examined in a Japanese population to determine whether an elevated TC level is associated with phenotype A, as has been demonstrated in many West European populations. Such studies in nonwhite populations are scarce, and findings generally failed to demonstrate the relationship. Inconsistent results from cross-sectional studies of various racial groups with widely varying ages raised an age effect as a possible explanatory factor. It was also suggested that the ABO-TC association may not be apparent in populations with low fat intake or low mean cholesterol level. These hypotheses are addressed by examining long-term TC data collected serially from the unexposed controls of the atomic bomb survivors in Hiroshima and Nagasaki who were participants of the Adult Health Study program at the Atomic Bomb Casualty Commission-Radiation Effects Research Foundation between 1958 and 1986. The statistical method of growth curve analysis, through the mixed effect model of Laird and Ware [1982], was used to model age-dependent changes in cholesterol levels within individuals. The effects of the ABO polymorphism in modifying the resultant growth curve are examined. We demonstrate that TC levels are elevated on average by about 4 mg/dl in phenotype A compared to non-A in the Japanese (P < 0.00001), and that this relationship is maintained from early to late adulthood, independent of sex, body mass index, cohort status, or city of residence. Thus, phenotype A individuals may be more predisposed to cardiovascular disease through one of its major risk factors. This is the first study of the ABO-cholesterol association in the Japanese, and the first based on a cohort with longitudinally collected TC data.

ABO Blood-Group System↗
PubMed1990

Surveillance of severe pediatric undernutrition: conceptual and practical issues.

Despite a high level of concern among health professionals and the general public, data are inadequate to define and monitor the prevalence of severe pediatric undernutrition (SPUN). The Centers for Disease Control is supporting four state health departments to test the feasibility of surveillance mechanisms for SPUN. These efforts will seek to develop workable case definitions, define prevalence estimates, identify high-risk populations and describe specific demographic, social and medical risk factors. Initial experience with SPUN surveillance indicates that a variety of approaches may prove feasible but that these require attention to issues such as measurement error, data collection burden, confidentiality and data management. SPUN surveillance may prove too costly to be practical for general application, but it can serve as a means to identify needy children and estimate the prevalence of undernutrition in specific high-risk populations.

Centers for Disease Control and Prevention, U.S.↗
PubMed1990

Methodological issues in nutrition surveillance: the CDC experience.

Nutrition surveillance systems serve to provide state- and locality-specific data that are useful for the management of public health nutrition programs. Current systems, such as the Pediatric and Pregnancy Nutrition Surveillance Systems coordinated by the Centers for Disease Control (CDC), collect program-based data focused on nutrition problems in infants, children, and pregnant women. These systems provide highly useful information, but also present significant methodological challenges relating to representativeness, quality control, and indicator sensitivity/specificity. As the importance of nutritional risk factors for chronic disease is increasingly recognized, the concept of nutrition surveillance must be expanded beyond maternal and child nutrition to include nutrition-related behaviors and risk factors in adolescents and adults. The Behavioral Risk Factor Surveillance System (BRFSS), coordinated by CDC, collects telephone survey data that include information on nutrition-related issues such as overweight, weight-loss practices, and cholesterol screening. In addition, a school-based surveillance system is being established by CDC in coordination with state education agencies to assess adolescent health behaviors, including nutrition. The operation of these nutrition surveillance systems presents significant methodological issues that must be considered in interpreting and using the data for public health purposes.

Adolescent↗
PubMed1989

Clinical results in carcinoma of the cervix: radium compared to caesium using remote afterloading.

In 1979 the Cancer Control Agency of British Columbia changed from radium to remote controlled afterloaded caesium in the treatment of carcinoma of the cervix. In the 3 years prior to the change, 139 patients received radium as part of their treatment and in the 3 years after the change, 158 patients received caesium. Overall referral patterns, patient and cancer demographics, and treatment policies were stable throughout the 6-year period. Radiotherapy technique, dose, dose distribution and dose rate were comparable for both radium and caesium treated patients. The results of treatment in the two time periods showed no difference in survival, local tumour control or complications. The use of afterloading has not compromised treatment results and has allowed better nursing care for patients and protection from radiation for all staff.

Brachytherapy↗
PubMed1987

Osteoradionecrosis: clinical experience and a proposal for classification.

Osteoradionecrosis is a severe complication of radiation therapy for cancer. Prevention of osteoradionecrosis is most important as the condition may be chronic, progressive and lead to pathologic fracture. The clinical experience at the Cancer Control Agency of British Columbia with 26 cases in approximately 1000 patients treated with radical radiation therapy to the head and neck region is presented and discussed. A clinical classification system is proposed to provide a guide for treatment selection, and to allow classification for research purposes.

Adult↗