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Biomedical subjects

J T Flannery

Publications and source records attributed to J T Flannery.

At least 55 records · Page 3Linked to original sources
PubMed1985

Prenatal x-ray exposure and childhood cancer in twins.

We conducted a case-control study to investigate the relation between prenatal exposure to x-rays and childhood cancer, including leukemia, in over 32,000 twins born in Connecticut from 1930 to 1969. Twins as opposed to single births were chosen for study to reduce the likelihood of medical selection bias, since twins were often exposed to x-rays to diagnose the twin pregnancy or to determine fetal positioning before delivery and not because of medical conditions that may conceivably pre-dispose to cancer. Each of 31 incident cases of cancer, identified by linking the Connecticut twin and tumor registries, was matched with four twin controls according to sex, year of birth, and race. Records of hospitals, radiologists, and private physicians were searched for histories of x-ray exposure and other potentially important risk factors. Documented prenatal x-ray exposures were found for 39 per cent of the cases (12 of 31) and for 26 per cent of the controls (28 of 109). No other pregnancy, delivery, or maternal conditions were associated with cancer risk except low birth weight: 38 per cent of the cases as compared with 25 per cent of the controls weighed under 2.27 kg at birth. When birth weight was adjusted for, twins in whom leukemia or other childhood cancer developed were twice as likely to have been exposed to x-rays in utero as twins who were free of disease (relative risk, 2.4; 95 per cent confidence interval, 1.0 to 5.9). The results, though based on small numbers, provide further evidence that low-dose prenatal irradiation may increase the risk of childhood cancer.

Adolescent↗
PubMed1985

A population-based study of survival after scrotal carcinoma.

In previous reports on scrotal carcinomas, overall 5-year survival rates have varied from 18% to 70% without explanation. In this study, survival was determined through the active follow-up of the Connecticut Tumor Registry for 65 cases of scrotal carcinoma diagnosed in the state from 1935 to 1980. The overall actuarial probability of surviving 5 years was 0.57. Stage and age at diagnosis were statistically significant predictors of survival (P less than 0.001 and P = 0.016, respectively). Survival varied progressively with combinations of these two variables with subjects younger than age 65 years and localized at diagnosis having 5-year survival of 0.75, compared to 0.17 for subjects age 65 years and older with regional or distant spread; these survival outcomes encompassed those of previous reports. With the passage of more than four decades, no improvement in survival was detectable. Initial radiotherapy, given to nine cases, also bore no detectable relationship to survival after adjustment for other variables. The 30 men in metalworking occupations previously shown to be associated with this cancer were not more frequently diagnosed with the cancer in localized stage, and showed a survival similar to that for the 29 men in other occupations.

Actuarial Analysis↗
PubMed1985

Astrocytomas in childhood: a population-based study.

A population-based study of astrocytomas occurring in children is reported. A population-based study eliminates referral bias and the bias of a series based on the experience of a given medical center or a particular surgeon. In a 42-year period, 179 such cases were diagnosed. The average age at diagnosis was 8.9 years. Over one-half of the astrocytic tumors were located in the cerebellum. A peak in the number of astrocytomas was noted between 1965 and 1970. Cumulative probability of survival of children with intracranial astrocytomas at 6 months and at 1, 2, and 5 years was 0.824, 0.752, 0.732, and 0.667; by 10 years and 20 years the cumulative probability of survival had fallen to 0.607 and 0.538. The shortest survival was observed with brainstem tumors, with an average survival of 19 months. Longer survivals were noted with tumors of the cerebral hemispheres: 0.779, 0.748, 0.678 and 0.628 at 1, 2, 5, and 10 years, respectively. The longest survivals were in those children with cerebellar astrocytomas: at 1 year they had an 0.837 probability of survival and at 20 years, 0.675.

Adolescent↗
PubMed1985

Survival with localized carcinoma: radical prostatectomy vs radiation therapy.

The charts of all patients receiving radical surgery and radiation therapy for cancer localized to the prostate in the years 1950 to 1977 in the State of Connecticut were reviewed. Long-term survival rates at ten and fifteen years were considerably better in those patients treated with radical surgery.

Actuarial Analysis↗
PubMed1985

Time period compared to birth cohort in Connecticut incidence rates for twenty-five malignant neoplasms.

Out of necessity and convenience many reports on population-based rates for cancer are limited to analyses by time period of diagnosis, and just how often cohort effects are important in cancer data has not been fully explored. To address this question, Connecticut cancer incidence rates for the years 1940-79 were fitted to the model: Log (incidence rate) = constant + age effect + period effect + birth cohort effect + error term. Data for each cancer site and sex were categorized into 10-year intervals by time period and age group. Significance testing for the curvilinear effects (which are estimable functions) of age (A), period (P), and cohort (C) in the 44 data sets led to no clear choice of model for three data sets; an APC model for 20, an AP model for 7, and an AC model for 14. These choices were corroborated by the RA2 index. Limitations in the interpretation of the results were enumerated. Presentation of population-based cancer rates by implicitly assuming an AP model is valuable (e.g., for studying age distribution in different regions or for age-adjustment in examining international variation or time trends). However, the assumption of an AP model may often be incorrect, as was shown to be the case for most of these 44 data sets. The implications for monitoring trends and generating etiologic hypotheses were discussed in light of the results for cutaneous malignant melanoma and cancers of the cervix, breast, ovary, lung, and bladder.

Adult↗
PubMed1985

Second cancers following radiation treatment for cervical cancer. An international collaboration among cancer registries.

The numbers of second cancers among 182,040 women treated for cervical cancer that were reported to 15 cancer registries in 8 countries were compared to the numbers expected had the same risk prevailed as in the general population. A small 9% excess of second cancers (5,146 observed vs. 4,736 expected) occurred 1 or more years after treatment. Large radiation doses experienced by 82,616 women did not dramatically alter their risk of developing a second cancer; at most, about 162 of 3,324 second cancers (approximately equal to 5%) could be attributed to radiation. The relative risk (RR = 1.1) for developing cancer in organs close to the cervix that had received high radiation exposures--most notably, the bladder, rectum, uterine corpus, ovary, small intestine, bone, and connective tissue--and for developing multiple myeloma increased with time since treatment. No similar increase was seen for 99,424 women not treated with radiation. Only a slight excess of acute and non-lymphocytic leukemia was found among irradiated women (RR = 1.3), and substantially fewer cases were observed than expected on the basis of current radiation risk estimates. The small risk of leukemia may be associated with low doses of radiation absorbed by the bone marrow outside the pelvis, inasmuch as the marrow in the pelvis may have been destroyed or rendered inactive by very large radiotherapy exposures. There was little evidence of a radiation effect for cancers of the stomach, colon, liver, and gallbladder, for melanoma and other skin cancers, or for chronic lymphocytic leukemia despite substantial exposures. An excess of thyroid cancer possibly was related to the low dose received by this organ. Ovarian damage caused by radiation may have been responsible for a low breast cancer risk (RR = 0.7), which was evident even among postmenopausal women. A substantial excess of lung cancer (RR = 3.7) largely may be due to misclassification of metastases and the confounding influence of cigarette smoking. Women who were under 30 or over 50 years of age when irradiated were at greatest absolute risk for developing a second cancer. The RR, however, was higher among those under age 30 years at exposure (RR = 3.9) than among older women. The expression period for radiation-induced solid tumors appeared to continue to the end of life.

Abdominal Neoplasms↗
PubMed1985

Cancer registration in Connecticut and the study of multiple primary cancers, 1935-82.

The Connecticut Tumor Registry (CTR) was established in 1941 and is the oldest population-based cancer registry in the world. Since 1935, all malignant tumors have been registered, and cancer patients are followed annually for vital status. Reporting by hospitals of all cancers diagnosed in Connecticut residents became mandatory in 1971. The reporting physician or hospital makes the initial determination as to whether a tumor is an independent primary cancer, recurrent tumor, or metastatic lesion. In addition, the Registry maintains stringent quality control procedures to avoid duplication of cancer reports. The Registry reviews reports of new cancers developing in patients with a previous primary cancer to rule out the possibility of misdiagnosed metastases. Microscopic confirmation of the diagnosis has improved from 49% in 1935-39 to 94% in 1980-82. Cancers reported only from death certificates currently account for only 1% of all registrations. Between 1935 and 1979, cancer rates in Connecticut almost doubled among males and increased by more than one-third among females; notable increases were seen for cancers of the lung and prostate in males and cancers of the lung and breast in females. In recent years, rates for malignant melanoma of the skin have increased dramatically among both sexes. Stomach cancer has decreased over time in both sexes, as has cervical cancer in females. Although the CTR has used several revisions of the International Classification of Diseases to code the primary site of cancers, rules for the coding of multiple primary cancers have remained essentially the same. Among 253,536 individuals diagnosed between 1935 and 1982 with an invasive cancer, 16,727 (6.6%) nonsimultaneous second cancers were evaluated and are discussed in subsequent chapters of this monograph. Simultaneous cancers were diagnosed in 4,107 individuals and accounted for approximately 20% of all multiple cancers reported in Connecticut. The most frequent simultaneous tumors were cancers of the colon, rectum, prostate, lung, breast, and bladder. Some simultaneous cancers (chronic lymphocytic leukemia, testis, prostate, rectum, uterine corpus, and liver and biliary tract) occurred almost as frequently as the number of subsequent nonsimultaneous tumors, which suggests that the patterns of risk over time for certain sites may be distorted when diagnoses are advanced in time and removed from analysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1985

Summary: multiple primary cancers in Connecticut, 1935-82.

The risk of developing a second primary cancer was evaluated in over 250,000 persons reported to the Connecticut Tumor Registry (CTR) during 1935-82. The CTR has collected data on cancer incidence longer than any other population-based tumor registry and thus provided researchers with a unique opportunity to investigate the occurrence of second cancers among persons followed for long periods, in some cases for more than 40 years. When compared with the general Connecticut population, cancer patients had a 31% increased risk of developing a subsequent cancer overall and a 23% elevated risk of second cancer at a different site from the first. Little variation in risk was seen for the first 20 years of follow-up, although the risk for females averaged twice that for males (41% vs. 18%). Persons who survived more than 20 years after the diagnosis of their first cancer were at highest risk: 51% for females and 45% for males. Over 1 million person-years of observation were recorded, and the excess risk of developing a new cancer was 3.5 per 1,000 persons per year. Common environmental exposures seemed responsible for the excess occurrence of many second cancers, particularly those related to cigarette smoking, alcohol consumption, or both. For example, persons with epithelial cancers of the lung, larynx, esophagus, buccal cavity, and pharynx were particularly prone to developing new cancers in the same or contiguous tissue throughout their lifetimes. A notable finding was the high risk of cancers of the lung, larynx, buccal cavity, and pharynx observed among cervical cancer patients, which suggested a common etiology involving cigarette smoking. The intriguing association previously reported among cancers of the colon, uterine corpus, breast, and ovary was confirmed in our data, which indicated the possible influence of hormonal or dietary factors. Incidental autopsy findings were largely responsible for the observed excesses of second cancers of the prostate and kidney, and heightened medical surveillance of cancer patients likely resulted in ascertainment bias and elevated risks for some tumors during the early period of follow-up, most notably cancers of the thyroid. Interestingly, patients with prostate cancer were the only ones found to be at significantly low risk for second cancer development. However, this might be an artifact of case-finding because advanced age at initial diagnosis of prostate cancer was associated with an underascertainment of second cancers.(ABSTRACT TRUNCATED AT 400 WORDS)

Connecticut↗
PubMed1985

Introduction to the study of multiple primary cancers.

To lay the groundwork for subsequent chapters in this monograph of multiple primary cancers in Connecticut and Denmark, we present a description of the historical significance of previous studies, focusing on key surveys that have enhanced our understanding of the origins of multiple cancers. Case reports, hospital series, and cancer registry studies have progressively sharpened our perspective on the patterns and causes of multiple cancers. These findings in turn have generated hypotheses about host and environmental determinants of various combinations of cancer and have provided clues to the actual mechanisms of carcinogenesis. The registries of Connecticut and Denmark which began in the 1930s and 1940s, respectively, afford investigators a unique opportunity to analyze the cancer experience of well-defined populations, followed for long periods. The major contribution of this monograph is the evaluation of second cancer risks among long-term survivors of cancer, including relatively rare tumors about which little information currently exists. For patients with a particular cancer, the number of observed second cancers are tabulated over time and compared with those expected if the patients experienced the same rates prevailing in the corresponding general population. We have discussed problems in distinguishing statistical artifacts from biologically plausible associations in light of the potential biases inherent in follow-up surveys of cancer patients; for example, heightened medical surveillance and mistaken metastases could result in false indications of elevated risk. Several differences in the reporting, follow-up, and coding practices between the Connecticut and Denmark registries are described and probably account for many differences in the reported findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Connecticut↗
PubMed1984

Cancer in relatives of children with central-nervous-system neoplasms.

We compared the occurrence of cancer in parents, siblings, and offspring of 643 patients who had central-nervous-system tumors in childhood (cases), as recorded in the Connecticut Tumor Registry, with the occurrence in parents, siblings, and offspring of 360 controls selected according to birth certificate and matched for sex, birth date, and birthplace. Overall cancer incidence was comparable in the two groups. However, 11 nervous-system tumors occurred in relatives of cases, whereas none occurred in relatives of controls (P = 0.0005). Nine relatives of cases but no relatives of controls had cancer of the hematopoietic-lymphatic system (P = 0.003). Nine siblings of cases but only one sibling of a control had cancer as children. Medulloblastoma and glioblastoma multiforme were overrepresented in the group of children whose relatives had central-nervous-system tumors. We compared the actual number of cancers of the central nervous system or hematopoietic-lymphatic system in relatives of cases with the number expected on the basis of known incidence rates and found a fivefold excess. We conclude that the occurrence of a brain tumor in a child is a marker for an increased likelihood of central-nervous-system tumors, leukemia, and childhood tumors in the family.

Adolescent↗
PubMed1984

Secular and age distribution of scrotal cancer in Connecticut and a review of United States literature.

In contrast with the expectations of the authors and with reports suggesting a decline in risk for scrotal cancer, Connecticut Tumor Registry data neither showed detectable decrease in risk over the 45-year-period for all 95 scrotal malignancies nor for the 71 epithelial cancers. The age distribution of scrotal cancer in Connecticut was similar to that of the more common tumors thought to be caused by exogenous agents. The risk increased up to age 75 in a geometric fashion, followed by a plateau and decline in risk among the very elderly. United States literature on scrotal cancer points to a change in occupational risks; this literature and recent occupational data from Connecticut suggest that metalworking may have been associated with a high proportion of cases in recent decades. Evidence is lacking that scrotal cancer and its most recent marker of carcinogenic risk have been fully eliminated.

Adolescent↗
PubMed1984

Second primaries in children with central nervous system tumors.

Among 670 children diagnosed with central nervous system tumors before age 20 and recorded in the Connecticut Tumor Registry, nine had a second neoplasm as well. From known age-specific and year-specific cancer incidence figures for Connecticut, the expected number of second neoplasms for the series of 670 is 0.99; therefore the relative risk is 9.1 (95% confidence limits: 4.0, 17.3). Three patients developed two central nervous system tumors, while 0.16 were expected, giving a relative risk of 19 (95% confidence limits: 3.8, 55). Six patients developed two neoplasms in childhood, versus 0.66 expected; the relative risk of this event is 9.1 (95% confidence limits: 3.3, 20). In four cases of lapse in time between the diagnosis of the first and second tumor, the first tumor had been treated with radiation. Five cancers occurred in parents or siblings of these nine patients, versus 0.91 expected; the relative risk is 5.5 (95% confidence limits: 1.2, 10.0). Three of these relatives had leukemia, while only 0.04 cases were expected (relative risk = 75). We conclude that not only is a child with CNS cancer at increased risk for other cancers, but such a child with two cancers is often part of a familial cluster with increased risk of cancer.

Adenoma, Chromophobe↗
PubMed1984

Multiple primary breast and thyroid cancer.

The occurrence of breast and thyroid multiple primary cancers was evaluated using data from the Connecticut Tumor Registry. The study population consisted of 1618 women with primary thyroid cancer and 39,194 women with primary breast cancer diagnosed between 1935 and 1978. Thirty-four thyroid cancer patients subsequently developed breast cancer and 24 breast cancer patients later had thyroid cancer. A significantly elevated risk of thyroid cancer following breast cancer (SIR = 1.68) and breast cancer following thyroid cancer (SIR = 1.89) was demonstrated. The finding was even more notable when compared with the risks obtained for other sites. The elevated risk was particularly evident in women under 40 years of age at time of diagnosis of the first cancer. Analysis by histologic type revealed that the highest risk of second primary breast cancer was found among patients with follicular or mixed papillary-follicular thyroid cancer. Women under age 40 with follicular carcinoma had a 10-fold risk of developing breast cancer (4 observed, 0.4 expected). An enhanced risk of second primary tumours was evident for the entire period after treatment of the first primary, although it was highest within one year after diagnosis of the first primary. This may be due to the close medical surveillance of cancer patients which would increase early diagnosis of second tumours. Our findings suggest that breast and thyroid cancer may share common aetiologic features.

Adult↗
PubMed1984

Medulloblastoma in childhood: an epidemiological study.

The authors have reviewed 143 cases of medulloblastoma in children aged 19 years or younger who were treated in a 42-year period and reported in the Connecticut Tumor Registry. About 20 cases have occurred in each 5-year period since 1950, but 31 were seen between 1955 and 1959. Correspondingly, an excessive number of children born in the period 1954 to 1958 have developed medulloblastomas. A relationship to polio vaccine contaminated with SV40 virus may exist. Children with medulloblastomas had an increased number of immediate family members with brain tumors, leukemia, and childhood cancer when compared to controls. In this series, the male to female ratio was 1.33:1. Average age at diagnosis was 6 1/2 years, with most children being diagnosed at 3 years old and fewer cases appearing in each successive hemidecade from birth to 20 years of age. Probability of survival at 6 months was 0.687; at 1 year, 0.444; at 2 years, 0.314; and at 5 years, 0.222. Survival probability was statistically significantly better in the years 1968 to 1977 than in previous decades, in part due to fewer autopsy diagnoses and lowered operative mortality, but also due to a decreased mortality rate in children several years after diagnosis. Fifty-one percent were treated with operation and irradiation, 17% with operation alone, 12% with irradiation alone, and 5% with operation, irradiation, and chemotherapy. Fifteen percent were not treated. One- and 5-year survival rates in patients with operation and irradiation were, respectively, 0.615 and 0.307; with operation, 0.125 and 0.042; with irradiation, 0.688 and 0.277; and with operation, irradiation, and chemotherapy, 0.857 and 0.643. All seven children who received chemotherapy were diagnosed after 1968, and five are still alive. Perhaps due to short follow-up time, the course and mortality rate of children treated with all three modalities were not statistically significantly different from those of children treated since 1968 with operation and radiation therapy.

Adolescent↗
PubMed1984

Tumors of the central nervous system in adolescents.

In a series of 144 central nervous system tumors found in adolescent patients, 133 occurred intracranially. Astrocytomas comprised 27 percent, glioblastoma multiforme 12 percent, medulloblastomas 11 percent and craniopharyngiomas 8 percent. The most common symptoms were headache and vomiting. Papilledema was the most frequent neurologic finding. Supratentorial and infratentorial lesions were nearly equal in occurrence. Rapidly growing tumors, such as medulloblastoma, were less frequent in these patients than in younger children.

Adolescent↗