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Biomedical subjects

H O Adami

Publications and source records attributed to H O Adami.

At least 73 records · Page 4Linked to original sources
PubMed1999

Variants of squamous cell carcinoma of the anal canal and perianal skin and their relation to human papillomaviruses.

High-risk types of human papillomaviruses (hrHPVs) may be a necessary cause in cervical cancer and in some subtype of anal, vulvar, and penile cancers. Large studies aimed at characterizing hrHPV-associated and non-hrHPV-associated subtypes of anal carcinomas are, however, lacking. We searched for human papillomavirus type 16 and 13 other hrHPVs in tumor tissue by PCR and performed a systematic histological evaluation of specimens from 386 patients with anal cancer (86% invasive; 302 women and 84 men). Cancers in women and homosexual men were more often hrHPV positive (P < 0.01) and located in the anal canal (P < or = 0.01) than were cancers in heterosexual men. In both women and men, anal canal cancers contained hrHPV clearly more often than did perianal skin cancers, and increasing hrHPV positivity was seen with higher localization in the anal canal. Indeed, 95 and 83% of cancers involving the anal canal in women and men, respectively, were hrHPV positive versus 80 and 28% of perianal skin cancers (P-trend < 0.001). Basaloid feature, adjacent anal intraepithelial neoplasia, poor or absent keratinization, and a predominance of small or medium neoplastic cells were all strongly positively associated with hrHPV status. Like cancer of the uterine cervix, the development of cancer of the anal canal may require infection with hrHPV, whereas a dual etiology of perianal skin cancers bears parallels to vulvar and penile cancers.

Age Factors↗
PubMed1999

The role of reproductive factors and use of oral contraceptives in the aetiology of breast cancer in women aged 50 to 74 years.

It is unclear whether age at menarche is causally involved in breast-cancer aetiology, or serves a correlate of other early-life exposures. Other aspects of reproductive life, including cycle length and regularity, climacteric symptoms, reproductive history and oral contraceptive use, are also incompletely investigated. We examined these issues in a population-based case-control study, including 3,016 women aged 50 to 74 years with invasive breast cancer, and 3,263 controls of similar age. Mailed questionnaires and telephone interviews were used to collect information on menstrual and reproductive characteristics as well as use of oral contraceptives. We found a statistically significant negative association between increasing age at menarche and breast-cancer risk in women born before 1925 but not after. Length of the menstrual cycle at age 30 seemed to be adversely related to breast-cancer risk, with OR for women with cycle lengths < 24 days and > 30 days being 0.76 and 1.18, as compared with women with a cycle length of 28 days. There was a strong trend of decreasing breast-cancer risk with increasing parity (OR per borne child 0.85, 95% CI 0.80-0.90). Lactation, menopausal symptoms or past use of oral contraceptives did not appear associated with breast-cancer risk. Our findings provide some evidence of a role of environmental correlates of early menarche in breast-cancer aetiology, and underline the importance of childbirth, especially early in life, in the prevention of breast cancer. Our data are not readily compatible with an important influence of former oral contraceptive use on post-menopausal breast-cancer risk.

Aged↗
PubMed1999

Is there a healthy worker effect for cancer incidence among women in Sweden?

BACKGROUND: Our aim was to evaluate whether there is a healthy worker effect (HWE) for cancer incidence among women. HWE is a bias found in occupational studies that compare rates of disease among employed people to disease rates for the general population, which includes unemployed people (who may be less healthy than those who are employed). METHODS: Data from the 1960 and 1970 Swedish censuses were used to identify all 1,659,940 Swedish women who were employed in either year. They were followed during 1971-1989 through linkages to the national cancer and death registers. Standardized incidence ratios (SIRs) were computed comparing employed women to the 1,627,873 women who were not employed in either 1960 or 1970. RESULTS: For the 545,857 women employed in both 1960 and 1970, the SIR for all cancers combined was 1.05 (1.04-1.06). When specific cancer sites were analyzed separately, the highest cancer risks were for cancers of the lung and bladder (SIR = 1.2) and reproductive organs (breast, ovary, endometrium, and cervix SIR = 1.1). Overall cancer risks were highest among full-time workers, younger workers, urban workers, and workers with the highest socioeconomic status (based on the woman's job title). CONCLUSIONS: These results show no general HWE for cancer incidence among employed Swedish women.

Adult↗
PubMed1999

The role of diabetes mellitus in the aetiology of renal cell cancer.

To investigate the relation between diabetes mellitus and the risk of renal cell cancer we carried out a population-based retrospective cohort study. Patients identified in the Swedish Inpatient Register who were discharged from hospitals with a diagnosis of diabetes mellitus between 1965 and 1983 formed a cohort of 153852 patients (80005 women and 73847 men). The cohort members were followed up to 1989 by record linkage to three nation-wide registries. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) were computed using age-specific sex-specific and period-specific incidence and mortality rates derived from the entire Swedish population. After exclusion of the first year of observation, a total of 267 incidences of renal cell cancer (ICD-7:180.0) occurred in diabetic patients compared with the 182.4 that had been expected. Increased risks were observed in both women (SIR = 1.7, 95% confidence interval, CI = 1.4-2.0) and men (SIR = 1.3; 95 % CI = 1.1-1.6) throughout the duration of follow-up (1-25 years). A higher risk was seen for kidney cancer (ICD-7:180) mortality (SMR = 1.9; 95% CI = 1.7-2.2, women; SMR 1.7, 95% CI = 1.4-1.9, men). In comparison with the general population, patients with diabetes mellitus have an increased risk of renal cell cancer.

Age Factors↗
PubMed1999

Diet and benign prostatic hyperplasia: a study in Greece.

OBJECTIVES: To evaluate the nutritional etiology of benign prostatic hyperplasia (BPH) by conducting a case-control study in Athens, Greece. Despite the high morbidity and substantial human suffering produced by BPH, little research has been undertaken concerning the nutritional etiology of this disease. METHODS: The study sample consisted of 184 patients with histologically confirmed BPH and 246 control patients without clinical evidence of prostate disease. All patients and controls were permanent residents of the greater Athens area. The data were modeled through unconditional logistic regression. RESULTS: Among the food groups, fruits were inversely related to BPH risk, with a logistic regression-derived odds ratio of 0.79 per quintile increase and 95% confidence interval 0.67 to 0.93. Increased consumption of both butter and margarine was positively associated with BPH risk, and a marginally significant positive association was also evident for seed oils. No overall association was found with respect to consumption of olive oil. In analyses evaluating the role of nutrients rather than foods, zinc, an element selectively concentrated in the prostate gland, was significantly positively associated with BPH risk. CONCLUSIONS: Our study provides evidence that, among added lipids, butter and margarine may increase the risk of BPH, and fruit intake may reduce this risk. Dietary zinc may play an important role in the etiology of BPH.

Case-Control Studies↗
PubMed1999

Occupational physical activity and risk for breast cancer in a nationwide cohort study in Sweden.

OBJECTIVE: Our purpose was to investigate effects of physical activity on risk for breast cancer. METHODS: From the Swedish nationwide censuses in 1960 and 1970 we defined three partly overlapping cohorts of women whose occupational titles allowed reproducible classification of physical demands at work in 1960 (n = 704,904), in 1970 (n = 982,270), or with the same demands in both 1960 and 1970 (n = 253,336). The incidence of breast cancer during 1971-89 was ascertained through record linkage to the Swedish Cancer Register. We used Poisson regression to estimate relative risks (RR). RESULTS: A total of 20,419, 22,840, and 8261 breast cancers, respectively, were detected in the three cohorts. In all three cohorts the risk for breast cancer increased monotonically with decreasing level of occupational physical activity and with increasing socioeconomic status. Among women with the same estimated physical activity level in 1960 and 1970 the RR was 1.3 for sedentary as compared with high/very high activity level (95% CI 1.2-1.4; p for trend < 0.001). Adjustment for socioeconomic status virtually eliminated this association (RR 1.1; 95% CI 0.9-1.2; p for trend 0.12) leaving a statistically significant 30% gradient only among women aged 50-59 years at follow-up. The association between socioeconomic status and breast cancer risk was largely unchanged after adjustment for occupational physical activity. CONCLUSION: The protective effect of occupational physical activity on breast cancer risk, if any, appears to be confined to certain age groups.

Activities of Daily Living↗
PubMed1999

Use of oral contraceptives and endometrial cancer risk (Sweden).

OBJECTIVES: To estimate the magnitude and persistence of the protective effect of use of combined oral contraceptives (COCs) and endometrial cancer risk. METHODS: We performed a nation-wide, population-based case-control study among postmenopausal women aged 50-74 years in Sweden, which included 709 subjects with incident, histopathologically verified endometrial cancer, and 3,368 controls with an intact uterus. We used unconditional logistic regression to calculate odds ratios as estimates of relative risks. RESULTS: Use of any sort of oral contraceptive decreased risk for endometrial cancer by 30%, while progestin-only pills reduced risk more markedly. For COCs the reduction in risk was noticeable following 3 or more years of use (OR 0.5, 95% CI 0.3-0.7), and increased with duration of intake, reaching 80% lower risk after 10 years of use. The protective effect of COC use was similar for all degrees of tumor differentiation and invasiveness, and remained for at least 20 years after cessation of use. Subsequent use of hormone replacement did not modify these protective effects. CONCLUSIONS: We conclude that COC use confers a long-lasting protection against endometrial cancer risk which is particularly marked for long-term users.

Age Distribution↗
PubMed1999

Maternal pregnancy hormone levels in an area with a high incidence (Boston, USA) and in an area with a low incidence (Shanghai, China) of breast cancer.

Characteristics probably associated with the fetal hormonal milieu have recently been shown to increase (birth size indicators, prematurity, neonatal jaundice) or decrease (pregnancy toxaemia) breast cancer risk in the female offspring. However, it is unknown whether differences in pregnancy hormone levels may contribute to the marked geographical variation in breast cancer incidence. We have compared, in a highly standardized manner, pregnancy hormone levels in a population with high incidence and one with low incidence of breast cancer. Three hundred and four pregnant Caucasian women in Boston and 334 pregnant Chinese women in Shanghai were enrolled from March 1994 to October 1995. Levels of oestradiol, oestriol, prolactin, progesterone, human growth hormone, albumin and sex hormone-binding globulin were measured in maternal blood at weeks 16 and 27 of gestation and compared between the two study sites using non-parametric Wilcoxon's rank-sum test. Demographical, anthropometrical and pregnancy characteristics were ascertained through interview, and relevant variables concerning delivery and the newborn were abstracted from medical records and paediatric charts. During the first visit, median serum levels of all studied hormones were statistically significant, and in most instances substantially, higher among Chinese women, who have a low incidence of breast cancer, compared with American women, who have a high incidence of breast cancer. An analogous pattern was evident during the second visit, although the relative differences tended to be smaller. Further research is needed to identify lifestyle or other exogenous determinants of pregnancy hormone levels, as well as possible mechanisms by which they may influence carcinogenic processes in the breast and possibly other organs.

Adult↗
PubMed1999

Trends in cancer of the cervix uteri in Sweden following cytological screening.

Trends in cervical cancer incidence following the introduction of screening have mostly been studied using cross-sectional data and not analysed separately for squamous cell cancer and adenocarcinomas. Using Swedish nationwide data on incidence and mortality, we analysed trends during more than 3 decades and fitted Poisson-based age-period-cohort models, and also investigated whether screening has reduced the incidence of adenocarcinomas of the cervix. The incidence of reported cancer in situ increased rapidly during 1958-1967. Incidence rates of squamous cell cancer, fairly stable before 1968, decreased thereafter by 4-6% yearly in women aged 40-64, with a much smaller magnitude in younger and older women. An age-cohort model indicated a stable 70-75% reduction in incidence for women born 1940 and later compared with those born around 1923. The incidence of adenocarcinomas doubled during the 35-year study period. The mortality rate increased by 3.6% before 1968 and decreased by 4.0% yearly thereafter. Although a combination of organized and opportunistic screening can reduce the incidence of squamous cell cancer substantially, the incidence of adenocarcinomas appears uninfluenced by screening.

Adenocarcinoma↗
PubMed1999

On the scientific inference from clinical trials.

We have not been able to describe clearly how we generalize findings from a study to our own 'everyday patients'. This difficulty is not surprising, since generalization deals with how empirical observations are related to the growth of scientific knowledge, which is a major philosophical problem. An argument, sometimes used to discard evidence from a trial, is that the patient sample was too selected and therefore not 'representative' enough for the results to be meaningful for generalization. In this paper, we discuss issues of representativeness and generalizability. Other authors have shown that generalization cannot only depend on statistical inference. Then, how do randomized clinical trials contribute to the growth of knowledge? We discuss three aspects of the randomized clinical trial (Mant 1999), First, the trial is an empirical experiment set up to study the intervention on the question as specifically and as much in isolation from other -- biasing and confounding -- factors as possible (Rothman & Greenland 1998). Second, the trial is set up to challenge our prevailing hypotheses (or prejudices) and the trial is above all a help in error elimination (Popper 1992). Third, we need to learn to see new, unexpected and thought-provoking patterns in the data from a trial. Point one -- and partly point two -- refers to the paradigm of the controlled experiment in scientific method. How much a study contributes to our knowledge, with respect to points two and three, relates to its originality. In none of these respects is the representativeness of the patients, or the clinical situations, crucial for judging the study and its possible inferences. However, we also discuss that the biological domain of disease that was studied in a particular trial has to be taken into account. Thus, the inference drawn from a clinical study is not only a question of statistical generalization, but must include a jump from the world of experiences into the world of reason, assessment and theoretical judgement.

Biometry↗
PubMed1999

Survival after rectal cancer: differences between hospital catchment areas. A nationwide study in Sweden.

BACKGROUND: The quality of rectal cancer surgery at small units has been debated. No national studies of this issue have been undertaken and most studies have been based on insufficient data to clarify the controversy. It has been claimed that observed differences in outcomes between specialised centres and smaller hospitals are confounded by differences in stage/severity. AIM: To compare survival after rectal cancer between hospital catchment areas. PATIENTS: All patients with rectal cancer notified to the Swedish Cancer Register in 1973-1992 (n = 30 811) were followed up by record linkage to the nationwide Death Register. METHODS: Relative survival-that is, ratio of observed to expected survival-was computed as a measure of excess mortality attributable to rectal cancer. Multivariate analysis was then performed to estimate the independent effects of hospital catchment area categories and age, year of diagnosis, and duration of follow up. RESULTS: One year relative survival among rectal cancer patients residing in catchment areas of large regional hospitals was 76%, compared with 72% for small local hospitals (p<0.001). A difference was already noted after 30 days and remained five years after diagnosis. Relative survival improved considerably overall, but the differences between catchment area categories persisted. These were not reduced by adjustment for age, time after diagnosis, or time period in multivariate models. CONCLUSION: The differences in outcome between catchment area categories could not be explained by differences in age, time period, or duration of follow up after diagnosis. They are unlikely to be explained by differences between catchment area populations with regard to the average stage of the disease at which symptoms lead to diagnosis. The differences may therefore be attributable to different strategies for diagnosing and managing patients with rectal cancer.

Aged↗
PubMed1999

10-Year results after sector resection with or without postoperative radiotherapy for stage I breast cancer: a randomized trial.

PURPOSE: To study the long-term effectiveness of postoperative radiotherapy after sector resection for breast cancer in a randomized trial in which mammography is a major pathway to diagnosis. PATIENTS AND METHODS: Three hundred eighty-one women with a unifocal breast cancer < or = 20 mm in diameter on the preoperative mammogram and without histopathologic signs of axillary metastases were treated by sector resection plus axillary dissection. Of these patients, 184 women were randomized to receive postoperative radiotherapy to the breast (XRT group), and 197 women received no further treatment (non-XRT group). RESULTS: The local recurrence rate was 8.5% (95% confidence interval [CI], 3.9% to 13.1%) in the XRT group and 24.0% (95% CI, 17.6% to 30.4%) in the non-XRT group (P =.0001). Survival free from regional and distant recurrence was 83. 3% in the XRT group (95% CI, 77.5% to 89.1%) and 80.0% in the non-XRT group (95% CI, 73.9% to 86.1%) (P =.23). Overall survival was 77.5% in the XRT group (95% CI, 70.9% to 84.1%) and 78% in the non-XRT group (95% CI, 71.7% to 84.3%) (P =.99). A subgroup analysis suggested that women older than 55 years of age without comedo or lobular carcinomas had a low risk of local recurrence of 6.1% (95% CI, 0.1% to 9.1%) in the XRT-group and 11.0% (4.0% to 18.0%) in the non-XRT group (P =.16). CONCLUSION: Sector resection plus radiotherapy resulted in an absolute reduction in local recurrence of 16% at 10 years compared with surgery alone. Women older than 55 years of age without comedo or lobular carcinomas may have a low risk of local recurrence. Postoperative radiotherapy was not shown to reduce distant recurrences or improve overall survival.

Breast Neoplasms↗
PubMed1998

[Sexually transmitted infection as a cause of anal cancer].

Interviews were carried out with 423 women and 93 men with invasive or in situ anal cancer in Denmark and Sweden in a search for clues to the aetiology of this neoplasm. Patients with rectal adenocarcinoma (n = 534) and persons drawn from the background population (n = 554) served as controls. Multivariate logistic regression analyses confirmed previous observations of a strong association between either male homosexual experience or a history of anogenital warts and the risk for anal cancer. Moreover, hitherto unknown, but strong and consistent associations were observed between measures of high heterosexual activity and the risk for anal cancer among both sexes. Polymerase chain reaction analysis revealed human papilloma-virus DNA in the majority (88%) of anal cancer specimens but in none of 20 examined rectal adenocarcinomas. It is concluded that most anal cancers appear to be caused by sexually transmitted types of human papillomaviruses and, consequently, that anal cancer is a potentially preventable neoplasm.

Adenocarcinoma↗