Combined modality therapy of operated astrocytomas grade III and IV. Confirmation of the value of postoperative irradiation and lack of potentiation of bleomycin on survival time: a prospective multicenter trial of the Scandinavian Glioblastoma Study Group

In a controlled, prospective, randomized investigation, started in 1974, 118 patients with supratentorial astrocytoma Grade III--IV were divided into three groups. Groups 1 and 2 received 45 Gy postoperatively to the whole supratentorial brain. Bleomycin in 15-mg doses and a total dose of 180 mg or placebo was given intravenously three times a week, one hour prior to radiotherapy, during weeks 1, 2, 4 and 5. Group 3 received conventional care but no radiotherapy or chemotherapy. Median survival rates of patients were 10.8 months in Groups 1 and 2, and 5.2 months in Groups 3, a statistically significant difference. With regard to performance, the patients in Group 3 deteriorated faster than patients in Groups 1 and 2. Bleomycin had no positive or negative influence on survival.

Comparison of conventional and split-course radiotherapy as primary treatment in carcinoma of the larynx

Based on our experience with conventional, daily irradiation, a split-course radiation schedule was introduced in 1978. The schedule, which was based on Cohen's models for squamous cell carcinoma and vascular damage respectively, predicted an improved tumour control and a reduced rate of late complications, e.g. late oedema, if the conventional, daily treatment was replaced by a split-course schedule. The schedule has later been abandoned, but the experience gained from split-course treatment at various dose levels has been analysed and the results compared with those obtained by conventional radiation. The data allowed construction of dose-response curves and estimation of iso-effect doses. Split-course treatment was associated with a significantly reduced therapeutic ratio because, disappointingly, it did not improve tumour control, and the severity of late complications grew. No late complications were avoided by introducing a 3-week pause in the radiation therapy regimen, nor was the tumour response improved despite a 12-Gy increase in total dose. This indicates a significant repopulation corresponding to more than 0.5 Gy/day, equivalent to an up to 100-fold increase of the number of clonogenic tumour cells during the pause--an increase that occurred despite the decrease, clinically, of the tumours during this period.

Selected novel flavones inhibit the DNA binding or the DNA religation step of eukaryotic topoisomerase I

Topoisomerases are involved in many aspects of DNA metabolism such as replication and transcription reactions. Camptothecins, which stabilize the covalent intermediate of topoisomerase I and DNA are effective, though toxic, drugs for cancer therapy. In this study, a new class of topoisomerase I inhibitors was identified, and their mode of action was characterized using recombinant human topoisomerase I preparations and human HL-60 leukemic cells. Quercetin and the related natural flavones, acacetin, apigenin, kaempferol, and morin, inhibit topoisomerase I-catalyzed DNA religation. In contrast to camptothecin, these compounds do not act directly on the catalytic intermediate and also do not interfere with DNA cleavage. However, formation of a ternary complex with topoisomerase I and DNA during the cleavage reaction inhibits the following DNA religation step. 3,3',4',7-Tetrahydroxy-substituted flavones stabilize the covalent topoisomerase I-DNA intermediate most efficiently. Enhanced formation of covalent topoisomerase I-DNA complexes was also demonstrated in human HL-60 cells. In contrast, synthetic 3,5'-dibromo- 4'-hydroxy-3-methylflavones bind selectively to topoisomerase I in its non-DNA-bound form and block the following DNA binding step. As a consequence, these synthetic flavonoids are capable of counteracting topoisomerase I-directed effects of camptothecin. Inhibition of DNA binding is obtained by voluminous hydrophobic substituents in 6-position of the flavone structure. Our data show that selective inhibitors of both half-reactions of topoisomerase I can be derived from the flavone structure.

Misonidazole combined with split-course radiotherapy in the treatment of invasive carcinoma of larynx and pharynx: report from the DAHANCA 2 study

Between October 1979 and May 1985, 626 patients with pharynx and larynx carcinoma were randomized to two different split-course radiation regimens and given either misonidazole (MISO; 11 g/m2) or placebo during the initial 4 weeks of treatment. Patients in the different treatment groups were evenly distributed among stages. The small number of females (136) gave an uneven distribution, thus making analysis difficult. The results show that females had a statistically better loco-regional control (45 vs. 33%; 5-year actuarial value). Overall, the MISO treated group did not have a significantly better control rate than the placebo groups (37 vs. 34%). However, a difference was found in patients with pharynx carcinomas (38 vs. 27%; p less than 0.05). The pre-irradiation hemoglobin (Hb) concentration was found to be a prognostic parameter. In females, loco-regional control for IIb values below or above 8 mmol/l were 37 and 47%, respectively. In males, the same values were below or above 9 mmol/l 26 and 38%. Hb influence on local control was only seen in supraglottic and pharynx tumors. This effect was independent of tumor size, which also was of prognostic value. In addition Hb concentration and MISO had an apparent additive effect. Thus in the male pharynx group, placebo patients with low Hb had a 14% disease rate compared to 40% in MISO treated patients with Hb above 9 mmol/l. MISO induced significant peripheral neuropathy in 26% of the treated patients, whereas other drug related side effects were minimal and tolerable.

Elevated serum CA 125 levels prior to diagnosis of ovarian neoplasia: relevance for early detection of ovarian cancer

To investigate the sensitivity of the CA 125 immunoradiometric assay for occult ovarian neoplasia, serum CA 125 levels were retrospectively determined "blind" in specimens collected from 105 women who subsequently developed ovarian neoplasia, and from 323 matched controls. The distribution of CA 125 levels was very different between the case and control populations (p = 0.0001) over the entire collection-to-diagnosis interval (range 1-143 months). Median CA 125 levels for all cases, and for those collected more than 24, 36 or even 60 months prior to diagnosis, were always 18 U/ml or greater, compared with a median of 10.9 U/ml for controls. Half of the cases collected within the 18 months preceding diagnosis had CA 125 levels of more than 30 U/ml and one-third had levels greater than 65 U/ml. About one-fourth of those collected prior to 60 months before diagnosis had levels above 30 U/ml. In contrast, approximately 7% and 0.9% of controls had levels in excess of 30 or 65 U/ml, respectively. Elevations occurred in cases eventually diagnosed with localized or advanced cancer, and with borderline or obviously malignant disease. These results provide an insight into the preclinical biology of ovarian neoplasia that may help in designing methods for early detection of this disease, and demonstrate the usefulness of the JANUS serum bank as a resource in evaluating serum tests.

Second primary cancer after treatment for cervical cancer. An international cancer registries study

BACKGROUND

The pattern of second cancers after treatment for cervical cancer provides important information on the risk of radiation-induced malignancies. Large numbers of women survive many years and can be studied for late effects.

METHODS

Incident second cancers in 86,193 patients with cervical cancer reported to 13 population-based cancer registries in 5 countries were evaluated to estimate the risk of second cancer among very long term survivors.

RESULTS

Overall, 7543 second cancers were observed versus 6015 cancers expected based on population rates (observed/expected = 1.2). Lung cancer accounted for nearly half of the excess cancers. Among the 49,828 women treated with radiation, 3750 survived 30 or more years and a two-fold risk of cancers of heavily irradiated organs was seen. Most of the excess cancers were of the rectum, vagina, vulva, ovary, and bladder. Patterns of risk over time since treatment were consistent with a radiation etiology. Significant increases of nonchronic lymphocytic leukemia and cancers of the bone and kidney were also linked to radiotherapy. Women treated surgically were also at significant risk of second cancers, in all likelihood related to cigarette smoking and risk factors similar to those of cervical cancer.

CONCLUSIONS

Curative therapy for cervical cancer results in large numbers of long term survivors who develop second cancers very late in life. Radiation is an important cause of this increase and there is no evidence that risk returns to normal levels.

Incidence of breast cancer in Norwegian female radio and telegraph operators

Exposure to electromagnetic fields may cause breast cancer in women if it increases susceptibility to sex-hormone-related cancer by diminishing the pineal gland's production of melatonin. We have studied breast cancer incidence in female radio and telegraph operators with potential exposure to light at night, radio frequency (405 kHz-25 MHz), and, to some extent, extremely low frequency fields (50 Hz). We linked the Norwegian Telecom cohort of female radio and telegraph operators working at sea to the Cancer Registry of Norway to study incident cases of breast cancer. The cohort consisted of 2,619 women who were certified to work as radio and telegraph operators between 1920 and 1980. Cancer incidence was analyzed on the basis of the standardized incidence ratio (SIR), with the Norwegian female population as the comparison group. The incidence of all cancers was close to unity (SIR = 1.2). An excess risk was seen for breast cancer (SIR = 1.5). Analysis of a nested case-control study within the cohort showed an association between breast cancer in women aged 50+ years and shift work. In a model with adjustment for age, calendar year, and year of first birth, the rate ratio for breast cancer associated with being a radio and telegraph operator--in comparison with all Norwegian women born 1935 or later--analyzed with Poisson regression, was 1.5 after adjustment for fertility factors. These results support a possible association between work as a radio and telegraph operator and breast cancer. Future epidemiologic studies on breast cancer in women aged 50 and over, should address possible disturbances of chronobiological parameters by environmental factors.

One year's treatment with propranolol after myocardial infarction: preliminary report of Norwegian multicentre trial

A prospective, randomised, double-blind study was performed to compare the effects of propranolol and placebo on sudden cardiac death in a high-risk group of patients who survived acute myocardial infarction. Altogether 4929 patients with definite acute myocardial infarction were screened for inclusion: 574 (11.6%) died before randomisation, and 3795 (77%) were excluded. Five hundred and sixty patients aged 35 to 70 years were stratified into two risk groups and randomly assigned treatment with propranolol 40 mg four times a day or placebo. Treatment started four to six days after the infarction. By one year there had been 11 sudden deaths in the propranolol group and 23 in the placebo group (p less than 0.038, two-tailed test analysed according to the "intention-to-treat" principle). Altogether there were 25 deaths in the propranolol group and 37 in the placebo group (P less than 0.12), with 16 and 21 non-fatal reinfarctions respectively. A quarter of the patients were withdrawn from each group. Withdrawal because of heart failure during the first two weeks of treatment was significantly more common among propranolol-treated patients than among the controls, but thereafter the withdrawal rate was the same. The significant reduction in sudden death was comparable with that after alprenolol, practolol, and timolol, which suggests that the mechanism of prevention is beta-blockade rather than any other pharmacological property of the individual drugs.

Birth defects among offspring of Norwegian farmers, 1967-1991

We investigated birth defects (N = 4,565) reported to the Medical Birth Registry of Norway among 192,417 births between 1967 and 1991 to parents identified as farmers in five agricultural and horticultural censuses between 1969 and 1989. The prevalences at birth of all and specific birth defects deviated little from those among 61,351 births to non-farmers in agricultural municipalities. We classified exposure indicators on the basis of information provided at the agricultural censuses. The main hypotheses were that parental exposure to pesticides was associated with defects of the central nervous system, orofacial clefts, some male genital defects, and limb reduction defects. We found moderate increases in risk for spina bifida and hydrocephaly, the associations being strongest for exposure to pesticides in orchards or greenhouses [spina bifida: 5 exposed cases, odds ratio (OR) = 2.76, 95% confidence interval (CI) = 1.07-7.13; hydrocephaly: 5 exposed cases, OR = 3.49, 95% CI = 1.34-9.09]. Exposure to pesticides, in particular in grain farming, was also associated with limb reduction defects (OR = 2.50; 95% CI = 1.06-5.90). We also saw an association with pesticides for cryptorchism and hypospadias. We found less striking associations for other specific defects and pesticide indicators, animal farming, and fertilizer regimens.

Second malignancies after treatment of Hodgkin's disease: the influence of treatment, follow-up time, and age

PURPOSE

In the period 1968 through 1988, The Norwegian Radium Hospital (NRH) treated an unselected population of 1,152 patients with Hodgkin's disease (HD) that comprised more older patients (mean age, 43 years) than most other institutions. We considered it important to evaluate these patients for development of second cancers (SCs).

PATIENTS AND METHODS

The Norwegian Cancer Registry identified previously untreated patients with HD treated at NRH who had developed a SC more than 1 year after diagnosis of HD. The relative risk ratio (RR) (observed/expected cases) and the cumulative risk were calculated.

RESULTS

Sixty-eight patients had developed a SC, including nine acute nonlymphocytic leukemias (ANLLs), eight non-Hodgkin's lymphomas (NHLs), and 51 solid tumors, including 11 lung cancers. The RR of SC and leukemia was 1.86 (95% confidence interval [CI], 1.4 to 2.4) and 24.3 (95% CI, 11.1 to 46.2), respectively. The RR of SC was highest in younger patients (< 41 years, RR = 3.8). No significant association between splenectomy and development of ANLL was found. The influence of treatment and follow-up time on the development of SC agrees with data from other large cancer institutions.

CONCLUSION

(1) The low RR of developing a SC in this study is probably due to the number of older patients included, who have a lower RR of developing a SC due to less aggressive treatment, shorter follow-up time, and higher incidence of cancer in the expected background population. (2) The low RR and cumulative risk of developing ANLL may be due to the limited use of extensive chemotherapy (CT) in our hospital in the earlier years.

Delayed gastrointestinal transit times in anorexia nervosa and bulimia nervosa

Anorectic and bulimic patients frequently report symptoms of constipation, bloating, and abdominal pain suggestive of abnormal gastrointestinal motility or transit. However, except for studies of gastric emptying, gastrointestinal motility and transit in these eating disorders have not been investigated. Ten anorectic and 18 bulimic inpatients were compared with 10 healthy controls. Whole-gut transit was tested by the radiopaque marker technique, and mouth-to-cecum transit time was assessed by the lactulose breath test. All anorectics and 67% of bulimics complained of constipation. Whole-gut transit time was significantly delayed in both anorectics (66.6 +/- 29.6 hours) and bulimics (70.2 +/- 32.4 hours) compared with controls (38.0 +/- 19.6 hours). Mouth-to-cecum transit time also tended to be longer in anorectics (109.0 +/- 33.5 minutes) and bulimics (106.2 +/- 24.5 minutes) than in controls (84.0 +/- 27.7 minutes), but these differences were not statistically significant. Delayed transit could contribute to or perpetuate the eating disorders by (a) causing the patient to feel bloated, thereby exacerbating fear of fatness, or (b) causing rectal distention, which may reflexly inhibit gastric emptying.

Exposure to nickel compounds and smoking in relation to incidence of lung and nasal cancer among nickel refinery workers

OBJECTIVES

To investigate the relation between occupational hazards among nickel refinery workers and their exposure to different forms of nickel over time and the interaction between smoking and total exposure to nickel.

METHODS

The cohort consisted of 379 workers with first employment 1916-40 and at least three years of employment and 4385 workers with at least one year of employment 1946-83. Data on smoking (ever or never) were available for almost 95% of the cohort. Two analyses were used, indirect standardisation from observed and expected numbers and Poisson regression.

RESULTS

During the follow up 1953-93, 203 new cases of lung cancer were observed v 68 expected (standardised incidence ratio (SIR) 3.0, 95% confidence interval (95% CI) 2.6-3.4) and 32 cases of nasal cancer were observed v 1.8 expected (SIR 18.0, 95% CI 12-25). The Poisson regression analysis showed an excess risk of lung cancer in association with exposure to soluble forms of nickel, with a threefold increase in relative risk (RR) (P < 0.001) and a multiplicative effect of smoking and exposure to nickel. The RRs were 1.1 (95% CI 0.2-5.1) for exposed workers who had never smoked and 5.1 (95% CI 1.3-20.5) for exposed workers who smoked.

CONCLUSION

It is not possible to state with certainty which specific nickel compounds are carcinogenic, but a significant excess risk was found for workers exposed to soluble nickel alone or in combination with other forms of nickel. The present study suggests a multiplicative effect of smoking and nickel exposure.

Smoking habits and risk of cancers other than lung cancer: 28 years' follow-up of 26,000 Norwegian men and women

The impact of tobacco smoking on lung cancer risk has been investigated thoroughly since the 1950s, but other types of cancer also have been associated with smoking. In the present study, the aim was to explore the variation in risk connected with cigarette, cigar, and pipe smoking of suspected smoking-associated cancers other than lung cancer. Data were obtained from a survey of a random sample of the Norwegian population. A self-administered mailed questionnaire, which included questions about smoking habits, was completed by 26,000 men and women in 1965 (response rate: 76 percent). The cohort was followed from 1966 through 1993, including registration of all incident cancer cases. A dose-response relationship of cigarette smoking to the risk of urinary bladder cancer and cancers of the upper digestive and respiratory tract was observed. For the latter forms of cancer, a dose-response relationship of pipe smoking also was observed. In cancer of the pancreas, a stronger association between cigarette smoking and cancer risk was observed when the analysis was confined to histologically confirmed cases only. Current cigarette smokers at baseline had a significantly higher risk of cervical cancer than those who never smoked cigarettes. In cancers of the stomach, colon, rectum, breast, corpus uteri, ovary, and prostate, and in leukemia, no association between smoking and cancer risk was observed.

Cellular effects of olomoucine, an inhibitor of cyclin-dependent kinases

Olomoucine (2-(2-hydroxyethylamino)-6-benzylamino-9-methylpurine) has been recently described as a competitive inhibitor (ATP-binding site) of the cell cycle regulating p34cdc2/cyclin B, p33cdk2/cyclin A and p33cdk2/cyclin E kinases, the brain p33cdk5/p35 kinase and the ERK1/MAP-kinase. The unusual specificity of this compound towards cell cycle regulating enzymes suggests that it could inhibit certain steps of the cell cycle. The cellular effects of olomoucine were investigated in a large variety of plant and animal models. This compound inhibits the G1/S transition of unicellular algae (dinoflagellate and diatom). It blocks Fucus zygote cleavage and development of Laminaria gametophytes. Stimulated Petunia mesophyl protoplasts are arrested in G1 by olomoucine. By arresting cleavage it blocks the Laminaria gametophytes. Stimulated Petunia mesophyl protoplasts are arrested in G1 by olomoucine. By arresting cleavage it blocks the development of Calanus copepod larvae. It reversibly inhibits the early cleavages of Caenorhabditis elegans embryos and those of ascidian embryos. Olomoucine inhibits the serotonin-induced prophase/metaphase transition of clam oocytes; furthermore, it triggers the the release of these oocytes from their meiotic metaphase I arrest, and induces nuclei reformation. Olomoucine slows down the prophase/metaphase transition in cleaving sea urchin embryos, but does not affect the duration of the metaphase/anaphase and anaphase/telophase transitions. It also inhibits the prophase/metaphase transition of starfish oocytes triggered by various agonists. Xenopus oocyte maturation, the in vivo and in vitro phosphorylation of elongation factor EF-1 are inhibited by olomoucine. Mouse oocyte maturation is delayed by this compound, whereas parthenogenetic release from metaphase II arrest is facilitated. Growth of a variety of human cell lines (rhabdomyosarcoma cell lines Rh1, Rh18, Rh28 and Rh30; MCF-7, KB-3-1 and their adriamycin-resistant counterparts; National Cancer Institute 60 human tumor cell lines comprising nine tumor types) is inhibited by olomoucine. Cell cycle parameter analysis of the non-small cell lung cancer cell line MR65 shows that olomoucine affects G1 and S phase transits. Olomoucine inhibits DNA synthesis in interleukin-2-stimulated T lymphocytes (CTLL-2 cells) and triggers a G1 arrest similar to interleukin-2 deprivation. Both cdc2 and cdk2 kinases (immunoprecipitated from nocodazole- and hydroxyurea-treated CTLL-2 cells, respectively) are inhibited by olomoucine. Both yeast and Drosophila embryos were insensitive to olomoucine. Taken together the results of this Noah's Ark approach show that olomoucine arrests cells both at the G1/S and the G2/M boundaries, consistent with the hypothesis of a prevalent effect on the cdk2 and cdc2 kinases, respectively.

Cancer in offspring of parents engaged in agricultural activities in Norway: incidence and risk factors in the farm environment

In this study of cancer in offspring we demonstrate that factors linked to horticulture and use of pesticides are associated with cancer at an early age, whereas factors in animal husbandry, in particular poultry farming, are associated with cancers in later childhood and young adulthood. Incident cancer was investigated in offspring born in 1952-1991 to parents identified as farm holders in agricultural censuses in Norway in 1969-1989. In the follow-up of 323,292 offspring for 5.7 million person-years, 1,275 incident cancers were identified in the Cancer Registry for 1965-1991. The standardized incidence for all cancers was equal to the total rural population of Norway, but cohort subjects had an excess incidence of nervous-system tumours and testicular cancers in certain regions and strata of time that could imply that specific risk factors were of importance. Classification of exposure indicators was based on information given at the agricultural censuses. Risk factors were found for brain tumours, in particular non-astrocytic neuroepithelial tumours: for all ages, pig farming tripled the risk [rate ratio (RR), 3.11; 95% confidence interval (CI), 1.89-5.13]; indicators of pesticide use had an independent effect of the same magnitude in a dose-response fashion, strongest in children aged 0 to 14 years (RR, 3.37; 95% CI, 1.63-6.94). Horticulture and pesticide indicators were associated with all cancers at ages 0 to 4 years, Wilms' tumour, non-Hodgkin's lymphoma, eye cancer and neuroblastoma. Chicken farming was associated with some common cancers of adolescence, and was strongest for osteosarcoma and mixed cellular type of Hodgkin's disease. The main problem in this large cohort study is the crude exposure indicators available; the resulting misclassification is likely to bias any true association towards unity.

Melanomas of the mucosa in the oral cavity and the upper respiratory passages

Thirty-eight patients with malignant melanoma of the mucosa in the nasal and oral cavity have been treated at the Radium Centres in Arhus, Copenhagen and Odense in the years from 1956 to 1978. Twenty cases were localized to the nasal cavity and the nasal sinuses, and 18 cases to the oral cavity and oropharynx. Twenty-nine patients had local tumors, eight had local lymph node metastases, and one patient had lung metastases. The primary treatment has been surgery, which was radical in 50% of the cases, whereas 14 patients received irradiation and combined treatment. Complete response was seen locally in five of six irradiated nasal tumors and in three of eight oral tumors. Only two patients with nasal and one patient with oral tumors had recurrence later. Active treatment for recurrence has had the result that 10 patients have survived for 2 additional years, and 1 patient for almost 5 additional years. Eight patients lived for more than 5 years; crude survival is 26%.

Incidence of cancer in Norwegian workers potentially exposed to electromagnetic fields

The risk of cancer was investigated in a cohort of 37,945 male Norwegian electrical workers for whom information on job description was collected from 1960 census data and linked to the 1970 census data. The standardized incidence ratio was calculated for all cancer sites in the overall cohort by comparison with national incidence rates for economically active men at the 1960 census. The standardized incidence ratios for cancers of the breast, pleura (mesothelioma), larynx, and bladder and for soft tissue sarcoma were elevated, while those for non-Hodgkins and Hodgkins lymphoma were lower. The standardized incidence ratio for leukemia for electrical workers with 10 or more economically active years was 1.41. The standardized incidence ratio for brain tumors in this subgroup of electrical workers was 1.14. These results from a large, national, population-based study at the Cancer Registry of Norway give support to previous findings of a possible association between electrical work and the risk of leukemia.

Long-term risk of second malignancy after treatment of Hodgkin's disease: the influence of treatment, age and follow-up time

BACKGROUND

To quantify the long-term risk of second cancers (SCs) up to 30 years after primary treatment for Hodgkin's disease (HD) Material and methods In the period 1968 to 1985, an unselected population of 1024 patients started treatment for HD at the Norwegian Radium Hospital (NRH) and were followed for SC from 1969 through 1998 by The Norwegian Cancer Registry. The median age at diagnosis of HD was 40 years, and the median time at follow-up was 14 years.

RESULTS

Of 197 SCs, 14 were acute non-lymphocytic leukemia (ANLL), 31 non-Hodgkin's lymphoma (NHL) and 152 solid cancers. The standardized incidence ratio (SIR) was significantly increased for SCs as a group, and for the subgroups ANLL, NHL, lung cancer, breast cancer, stomach cancer and melanoma. ANLL was related to heavy treatment with chemotherapy (CT) and combined CT and radiotherapy (RT), NHL was not treatment related, and solid tumors were related to radiotherapy only or combined RT and CT. The SIR of ANLL and NHL reached a peak between 5 and 10 years after treatment. Solid and non-solid tumors increased with young age at diagnosis of HD and solid tumors increased with follow-up time up to 28 years

CONCLUSION

In a long-term follow-up study of HD patients of all ages, the SIR of solid tumors was high in patients treated at young age and decreased with increasing age. Most solid tumors had started within or at the edge of the irradiated field, and SIR of solid tumors increased even 20-30 years after diagnosis.

Age at menarche, urine estrogens and breast cancer risk

In 511 nulliparous women aged 15-19 years and 347 aged 30-39, an analysis has been undertaken of the relationship of urine concentrations of the three principal estrogens to age, age at menarche and Quetelet's index of adiposity. The analysis was undertaken by means of multiple regression, controlling for each of the 12 centers from which the data originated, as well as for the other study variables. In the younger women, age was strongly and positively related to concentrations of E1 and E2 and less so to E3. In the age group 30-39, follicular phase specimens showed positive relationships with age for all three fractions but luteal specimens did not. Age at menarche showed inverse relationships to levels of E1 and E2 which were significant in the younger but not in the older age group. The associations of estrogens with Quetelet's index were weak and not statistically significant. The data suggest that women whose menarche occurs early not only have a longer duration of exposure to estrogens during years which are probably important in the initiation of breast cancer but, in addition, their exposures are at a higher level during those years and probably at later ages also. These observations support the hypothesis that the mechanism of the association of early menarche with breast cancer risk is via the association of both with estrogen stimulus.

The role of alcohol, tobacco, and dietary factors in upper aerogastric tract cancers: a prospective study of 10,900 Norwegian men

Previous knowledge on risk factors for oral, pharyngeal, laryngeal, and esophageal cancer has been based mainly on case-control studies. In the present study, the impact of alcohol consumption, tobacco smoking, and dietary factors on upper aerogastric tract cancer risk was studied in a cohort of 10,960 Norwegian men followed from 1968 through 1992, in which period a total of 71 upper aerogastric tract cancers occurred. The relative risk (RR) of cancer was 3.9 (95 percent confidence interval [CI] = 2.1-7.1) for the highest consumption group of alcohol and 4.7 (CI = 1.7-13.2) for the highest smoking level, compared with the respective reference groups. Among the dietary items, high consumption of oranges was associated with reduced cancer risk (RR = 0.5, CI = 0.3-1.0), as was high consumption of bread (RR = 0.2, CI = 0.1-0.5). Frequent consumption of beef and bacon increased relative cancer risk bordering on significance. The present results are largely in accordance with previous studies. The decreased risk associated with a high intake of bread deserves further investigation.

Postoperative irradiation of glioblastomas. Results in a randomized series

A material of 108 patients with glioblastoma is presented. The series was randomized in two groups: cases only operated upon and cases with postoperative irradiation in addition. Patients dead within 2 months after operation were excluded in estimating the real value of the postoperative irradiation. The irradiated cases had a 6-month survival rate of 64 per cent and a one-year survival rate of 19 per cent; the non-irradiated cases a 6-month survival rate of 28 per cent and a one-year survival rate of 0 per cent.

Risk of cancer and exposure to gasoline vapors

Until the introduction of self-service around 1970, service station workers in the Nordic countries were exposed to gasoline vapors. Based on measurements reported in the literature, the 8-hour time-weighted average benzene exposure was estimated to be in the range of 0.5-1 mg/m3. We studied the cancer incidence in a cohort of 19,000 service station workers from Denmark, Norway, Sweden, and Finland. They were identified from the 1970 censuses and followed through 20 years, where 1,300 incident cancers were observed. National incidence rates were used for comparison. The incidence was not increased for leukemia (observed = 28, standardized incidence ratio (SIR) = 0.9, 95% confidence interval (CI) 0.6-1.3) not for acute myeloid leukemia (observed = 13, SIR = 1.3, 95% CI 0.7-2.1). The incidence was slightly elevated for kidney cancer observed = 57, SIR = 1.3, 95% CI 1.0-1.7) and for pharyngeal, laryngeal, and lung cancer. A 3.5-fold risk of nasal cancer was found (observed = 12, SIR = 3.5, 95% CI 1.8-6.1). This cohort exposed to gasoline vapors with benzene levels estimated to be 0.5-1 mg/m3 showed no excess risk of leukemia or acute myeloid leukemia, a 30% elevated risk of kidney cancer, and a previously unnoticed risk of nasal cancer.

Second primary cancers among 109 000 cases of non-Hodgkin's lymphoma

An analysis of other primary cancers in individuals with non-Hodgkin's lymphoma (NHL) can help to elucidate this cancer aetiology. In all, 109 451 first primary NHL were included in a pooled analysis of 13 cancer registries. The observed numbers of second cancers were compared to the expected numbers derived from the age-, sex-, calendar period- and registry-specific incidence rates. We also calculated the standardised incidence ratios for NHL as a second primary after other cancers. There was a 47% (95% confidence interval 43-51%) overall increase in the risk of a primary cancer after NHL. A strongly significant (P<0.001) increase was observed for cancers of the lip, tongue, oropharynx*, stomach, small intestine, colon*, liver, nasal cavity*, lung, soft tissues*, skin melanoma*, nonmelanoma skin*, bladder*, kidney*, thyroid*, Hodgkin's lymphoma*, lymphoid leukaemia* and myeloid leukaemia. Non-Hodgkin's lymphoma as a second primary was increased after cancers marked with an asterisk. Patterns of risk indicate a treatment effect for lung, bladder, stomach, Hodgkin's lymphoma and myeloid leukaemia. Common risk factors may be involved for cancers of the lung, bladder, nasal cavity and for soft tissues, such as pesticides. Bidirectional effects for several cancer sites of potential viral origin argue strongly for a role for immune suppression in NHL.