Abstract P4-12-02: Serum-triglycerides among triple negative breast cancer patients as a biomarker of poor outcome

Backgound: Obesity and related metabolic imbalances, including increased activity of free fatty acids, may promote tumor growth and metastasis. Fatty acids are mainly stored as triacylglycerols. Yet, the role of serum-triglycerides on breast cancer prognosis is still undefined.

Methods: A population based survival study among 575 breast cancer patients identified within the Tromsø study during 1979-2008, was conducted. Pre-diagnostic serum triglycerides, high density lipoprotein-cholesterol, total cholesterol, height and weight were measured. Histopathological and clinical data were obtained from medical records, and hormone receptor, HER2 status, and Ki-67 were re-analyzed on tissue microarray blocks. Multivariate Cox proportional Hazard regression models were used to study the associations between patient characteristics including s-triglycerides, and breast cancer survival.

Results: Among 575 women with invasive breast cancer (stage 1-3), a total of 87 women were diagnosed with triple negative breast cancer (TNBC). Patients diagnosed with TNBC, compared to non-TNBC, were likely to be younger at diagnosis (55.3 vs 57.9 years, p=0.061), they had larger tumors (29.7 mm vs 22.5 mm, p=0.001), and higher Ki-67 (31.1% vs 15.9%, p<0.001). After a mean follow-up of 8.4 years, TNBC patients with above median levels of s-triglycerides (> 0.98mmol/L) compared to TNBC patients with below median levels of s-triglycerides (≤ 0.98mmol/L) had 3.0 times higher risk for breast cancer recurrence or breast cancer specific death (HR 3.02, 95% CI 1.21-7.55), and 3.4 times higher overall mortality risk (HR 3.41, 95% CI 1.38-8.45). Among the TNBC patients, women with above median s-triglycerides had 15% lower 5-year disease-free survival (76% vs 91%) and 18% lower 5-year overall survival (74% vs 92%) compared to women with below median s-triglycerides.

Conclusions: Our results strongly support s-triglycerides as an important biomarker for breast cancer outcomes among triple negative breast cancer patients.

Table 1: Multivariable adjusted Hazard Ratios (HRs) for incidence breast cancer recurrence or breast cancer specific death, and incidence overall mortality by pre-diagnostic serum-triglycerides among non-triple negative breast cancer (TNBC) and TNBC patients  Non-TNBC, n=488 TNBC, n=87  Recurrence or breast cancer specific death (n=90)Overall mortality (n=104) Recurrence or breast cancer specific death (n=24)Overall mortality (n=33) nHR (95% CI)HR (95% CI)nHR (95% CI)HR (95% CI)s-Triglycerides      Median      ≤ 0.98 mmol/l2571.001.00431.001.00> 0.98 mmol/l2310.87 (0.56-1.35)1.06 (0.70-1.62)443.02 (1.21-7.55)3.41 (1.38-8.45)       Tertiles      ≤ 0.82 mmol/l1731.001.00261.001.000.83 – 1.22 mmol/l1660.74 (0.44-1.23)0.81 (0.49-1.36)311.37 (0.38-4.98)0.98 (0.31-3.08)≥ 1.23 mmol/l1490.88 (0.50-1.54)1.17 (0.66-1.96)306.63 (1.64-19.3)3.87 (1.52-12.0)p-trend 0.4950.357 0.0050.007       Multivariate Cox proportional Hazard regression model. Adjusted for BMI and age at attendance (continuous), age at diagnosis (continuous), breast cancer stage at diagnosis (categorical), and current smoking (categorical). Abbreviation: CI, confidence interval; n, number of cases; TNBC, triple negative breast cancer

Citation Format: Lofterød T, Mortensen ES, Nalwoga H, Wilsgaard T, Frydenberg H, Risberg T, Eggen AE, McTiernan A, Aziz S, Wist EA, Reitan JB, Akslen LA, Thune I. Serum-triglycerides among triple negative breast cancer patients as a biomarker of poor outcome [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-12-02.

Osteosclerotic myeloma with polyneuropathy

Five cases of histologically verified plasma cell myeloma in sclerotic skeletal foci and polyneuropathy are reported. Thirty similar cases were collected from the literature. They illustrate a special form of plasma cell neoplasia. The characteristic features are osteosclerosis, polyneuropathy resembling polyradiculitis, approximately normal hemoglobin concentration, bone marrow smears and ESR, low concentration of M-protein, and absence of Bence-Jones' proteinuria. Slow progesssion of the disease is a possible additional feature. It is hypothesized that autoimmune mechanisms are involved in the pathogenesis. This hypothesis is based on the observation of circulating immune complexes, positive Waaler's reaction and relative increase in the number of circulating B-lymphocytes.

Cancer incidence among Norwegian airline cabin attendants

BACKGROUND

Cabin crews are exposed to cosmic radiation at work and this may increase their incidence of radiation-induced cancers. Former studies indicate an increased risk of breast cancer.

METHODS

A retrospective cohort study was performed. The cohort was established from the files of the Civil Aviation Administration and included people with a valid licence as a cabin attendant between 1950 and 1994. The cohort was linked to the Cancer Registry of Norway. Observed number of cases was compared with expected, based on national rates. Breast cancer incidence was analysed, adjusting for individual fertility variables.

RESULTS

A group of 3693 cabin attendants were followed over 72 804 person-years. Among the women, 38 cases of breast cancer were observed (standardized incidence ratio (SIR) = 1.1, 95% CI : 0.8-1.5). Among men excess risks were found for cancers in the upper respiratory and gastric tract (SIR = 6.0, 95% CI : 2.7-11.4) and cancer of the liver (two cases, SIR = 10.8, 95% CI : 1.3-39.2). For both sexes elevated risks were found for malignant melanoma and non-melanoma skin cancer; for men these were SIR = 2.9 (95% CI : 1.1-6.4) and SIR = 9.9 (95% CI : 4.5-18.8) respectively, while for women these were SIR = 1.7 (95% CI : 1.0-2.7) and SIR = 2.9 (95% CI : 1.0-6.9) respectively. For no cancer site was a significant decreased risk found.

CONCLUSIONS

An increased risk of radiation-induced cancers was not observed. The excess risks of some other cancers are more probably explained by factors related to lifestyle.

Hatching in zebrafish (Danio rerio) embryos exposed to a 50 Hz magnetic field

Zebrafish embryos were exposed intra ovo to a 50 Hz AC magnetic field of 1000 microT rms, and the progress of asynchronous hatching was monitored. A statistically significant delay was observed when field exposure started 48 h after fertilization. In contrast, when exposure started 2 h after fertilization, no statistically significant effect was seen. When field exposure was administered together with submaximal doses of progesterone at 48 h postfertilization, the two treatments appeared to delay hatching in an additive manner. Evaluating the progress of hatching in zebrafish embryos seems relevant for exploration of EMF effects on reproduction.

Cancer incidence among Norwegian airline pilots

OBJECTIVES

In this retrospective cohort study, the cancer incidence of commercial pilots was studied to determine whether exposure at work has any influence on the incidence of cancer.

METHODS

The cohort was established from the files of the Civil Aviation Administration and included people who had valid licenses as commercial pilots between 1946 and 1994. Basic data about their flight careers were recorded, and exposure to cosmic radiation was estimated. The cohort was linked to the Cancer Register of Norway. The observed number of cases was compared with that expected based on national rates.

RESULTS

A group of 3701 male pilots was followed over 70 560 person-years. There were 200 cases of cancer versus 188.8 expected, with a standardized incidence ratio (SIR) of 1.06 and a 95% confidence interval (95% CI) of 0.92-1.22. No significant decreased risk was found for any cancer site. Excess risks were found for malignant melanoma (22 cases SIR 1.8, 95% CI 1.1-2.7) and nonmelanoma skin cancer (14 cases, SIR 2.4, 95% CI 1.3-4.0). For malignant melanoma, there was a significant trend for the SIR by cumulative dose.

CONCLUSIONS

For most cancer sites, the incidence among pilots did not deviate from that of the general population and could not be related to block hours of flight time or dose. It seems more likely that the excess risks of malignant melanoma and skin cancer are explained by factors related to life-style rather than by conditions at work.

[Patient treatment in radiation accidents]

Accidental human injury due to ionizing radiation is rare. Industrial accidents are comparatively the most common. Life saving procedures should always have priority to any concern about radiation injury or contamination. The personal risks for emergency medical personnel is negligible when simple measures are taken. Repeated clinical examinations and blood lymphocyte counts should be performed on all patients with suspected radiation injury to allow a diagnosis. The radiation syndrome develops within days or weeks depending on total radiation dose, dose rate and dose distribution. Damage to the bone marrow and gut are the most important. Local radiation injuries to the hands are common in industrial accidents. The Norwegian Radiation Protection Authority should always be called when a potential ionizing radiation accident takes place within Norway.

[Effects of sunscreening agents and reactions with ultraviolet radiation]

The use of sunscreens is extensive. During the last few years there have been indications that UV radiation causes breakdown of the sunlight absorbing filters in the sunscreens, i.e. the sunscreens are not photostable. We describe briefly UV propagation in skin, the chemical and physical properties of sunscreens, and how these may react during UV irradiation. We have studied the stability of several sunscreens in vitro. The stability tests were performed by applying a thin film of the sunscreen preparation to the wall of a quartz window, irradiating it with a sun simulator, and measuring the absorbance with spectrophotometry before and during irradiation. The sunscreen agent studied most thoroughly was the UVB filter octyl methoxy cinnamate, but other UVA and UVB filters and some commercial products were also tested. Considerable breakdown of most filters was observed after doses of irradiation equivalent to moderate sun exposure. It can be questioned whether the breakdown products of sunscreens also possess other physical or biological properties. General practitioners should be able to advise their patients on sun protection and the proper use of sunscreens, considering the extensive use of sunscreens and the fact that sunbathing may be a health hazard.

Chromosome analysis of peripheral lymphocytes from persons exposed to radioactive fallout in Norway from the Chernobyl accident

Chromosome analysis of peripheral lymphocytes from two Norwegian populations (44 reindeer herding South samis from Røros and Snåsa, 12 sheep farmers from Valdres) exposed to fallout from the Chernobyl accident were made. The doses from caesium through the years 1987-1991 were calculated based on whole-body measurements 134Cs and 137Cs giving a total cumulative mean internal dose of 5.54 mSv for the total group of 56 persons. Chromosome aberrations were within the normal range when compared with historical controls with the exception of dicentrics (0.3% per cell, which is a 10-fold increase) and rings (0.07% per cell). A dose-dependent increase in dicentrics and rings based on caesium exposure was not observed.

Skin treatment with bepanthen cream versus no cream during radiotherapy--a randomized controlled trial

In several radiotherapy departments, dexpanthenol cream (Bepanthen 'Roche') has been used extensively to ameliorate acute radiotherapy skin reactions. The evidence base for this practice is obscure as no randomized trials have been performed. In the present clinical prospective study of 86 patients we have compared Bepanthen cream with no topical ointment at all. The cream was applied on randomly selected parts of treatment fields in laryngeal and breast cancer patients, and so each patient acted as his own control. Seven patients were withdrawn from analysis. Scoring of skin reactions in 16 laryngeal and 63 breast cancer patients was performed without knowledge of which area that had been given cream or not. Endpoints were a modified skin reaction grading according to EORTC/RTOG, and itching/pain in treated fields. The study did not indicate any clinically important benefits of using Bepanthen cream for ameliorating radiogenic skin reactions under the conditions applied.

High-voltage overhead power lines in epidemiology: patterns of time variations in current load and magnetic fields

In epidemiological studies of electromagnetic fields and health effects, exposure classification is crucial. There is no generally accepted biophysical interaction mechanism, but many studies are based on the hypothesis of a causal relationship with the strength of magnetic field. Some definition of the magnitude of exposure must be used, e.g., mean magnetic flux density, the integral of magnetic flux and time, or a peak value. Magnetic fields around a particular power line depend on the current load. The aim of the present study was to follow variations in line current load in the power supply system of the largest Norwegian city on a yearly, monthly, daily and diurnal basis. Fairly large variations in load were found, but increases in consumption were not necessarily reflected in current load on high voltage lines. The correlation between outdoor temperature and current load varied widely, depending on the type of power station feeding the line in question. The registered time variations are large enough to interfere with epidemiological classification of residences and testing of epidemiological hypotheses.

Relationship between intestinal fibrosis and histopathologic and morphometric changes in consequential and late radiation enteropathy

Intestinal fibrosis is a marked feature of late radiation enteropathy. This study assessed the time dose fractionation relationships of radiation-induced fibrosis in order to elucidate possible pathogenetic mechanisms. In 290 male Sprague-Dawley rats, a loop of small bowel was transposed to the left side of the scrotum. Three weeks later, the transposed segment was irradiated with either single dose or various fractionated regimens. The animals were observed for radiation-induced intestinal complications and killed in groups, 2 and 26 weeks after completion of irradiation. A semiquantitative histopathologic radiation injury score, morphometry of the submucosa, submucosal arterioles, intestinal surface area, and relative collagen content were used as endpoints. Fibrosis, measured by collagen assay and radiation injury score, increased with total dose, increasing fraction size and reduction in overall treatment time. This paralleled the results of morphometric assessment of mucosal surface area. Differences in vascular morphometry were only statistically significant in response to changes in total dose and fraction size and not with changes in overall treatment time. We conclude that fibrosis increases with increasing observation time, increasing fraction size, increasing total dose, and reduction of interfraction interval. Consequential injury, occurring as a result of disruption of mucosal integrity, seems to be an important mechanism for development of intestinal fibrosis. In contrast, vascular injury is relatively independent of this mechanism.

Incidence of cancer among workers in Norwegian hydroelectric power companies

OBJECTIVES

The goal of this study was to examine whether exposure to electric or magnetic fields is related to cancer.

METHODS

The study cohort consisted of 5088 men who had worked for at least one year between 1920 and 1991 for any of eight participating companies which produce and distribute hydroelectric power in Norway. The occupational exposure of these workers included extremely low-frequency electromagnetic fields. Incident cancer cases identified from the Cancer Registry of Norway were analyzed on the basis of the standardized incidence ratio with the Norwegian male population as reference.

RESULTS

The incidence of cancer was close to unity for the cohort. The standardized incidence ratio for lymphoma was below unity, whereas those for leukemia and brain tumors were similar to those expected. Calculated cumulative exposure to electric or magnetic fields was not associated with the incidence of leukemia or brain tumors, but an excess of malignant melanoma was shown for the highest category of magnetic field exposure. An analysis of combined possible exposure to oils containing polychlorinated biphenyls and exposure to magnetic fields or possible exposure to electric sparks gave standardized incidence ratios of 265 and 280, respectively, for the higher exposure category.

CONCLUSIONS

These results do not support the assumption of a possible association between exposure to electromagnetic fields and leukemia and brain tumors. The possible association between exposure to polychlorinated biphenyls or magnetic fields and risk of malignant melanoma should be further evaluated in future studies.

Influence of fractionation schedule on development of intestinal complications following localized irradiation. An experimental study in the rat

This study examined the relationship among time-dose-fractionation, development of intestinal complications, and histopathologic radiation injury in rat small bowel. In 177 rats, a functional loop of rat ileum was surgically transposed to the left scrotum. Three weeks later, fractionated irradiation was delivered to the transposed intestine as 2.8 Gy or 5.6 Gy daily fractions, or as 2.8 Gy twice daily with 12 hours' interval. Eleven experimental groups received total doses ranging from 28 Gy to 90 Gy. The animals were observed for intestinal complications, and groups of animals were killed 2 and 26 weeks after completion of irradiation for assessment of injury. Radiation injury was assessed by a semiquantitative histopathologic scoring system and by the frequency of lethal intestinal complications. Both increased fraction size and reduced overall treatment time increased the severity of subacute and chronic radiation injury, as well as frequency of intestinal complications. We conclude that rapidly proliferating cells (mucosal epithelium) play a pivotal role in the pathogenesis of radiation enteropathy and mechanisms other than radiation-induced mitotic cell death are pathogenetically involved.

[Radiation accidents and radiation disasters]

Accidents and disasters involving ionizing radiation are rare. Such accidents may occur not only at nuclear power stations but also in medicine and in industry. Only fairly large radiation doses can give acute medical effects. Symptoms and signs depend on the actual dose, and on what parts of the body are irradiated. In connection with a radiation accident, the main points are to recognize in the first place that radiation may be involved, and to have some knowledge of the actual source. Risk of localized irradiation from industrial sources, especially of hands, is a problem that is often overlooked. The paper reviews the principles for action by local health officers, the pathogenesis of radiation injury and early medical management. Some information is also given on the Norwegian system of contingency preparedness against nuclear accidents.

Influence of interferon and radiation on serotonin content in primary carcinoid cell cultures

Carcinoids are in general thought to be radioresistent, and have not been subjected to radiation therapy, except for palliative purposes. Clinical experience has indicated that interferons might enhance radiation effect and toxicity. In order to examine the effect of radiation, the combination of radiation and interferon, and the usefulness of the main metabolic product of primary cell cultures--serotonin--as a response indicator, we exposed primary carcinoid cell cultures with and without interferon pretreatment to radiation (2 Gy and 8 Gy). Irradiation alone had no effect on the serotonin content of the medium at the low dose (2 Gy) and even at the high dose (8 gy) the effect was not significant. When cells were preincubated with 1,000 IU/ml alpha-interferon, however, irradiation with 8 Gy induced a significant reduction of the hormone concentration in the medium on day 12 to 54.9 +/- 8.0% of the control value (p = 0.026). We think our model may provide a useful tool for further exploration of these mechanisms.

Birth defects in Norway by levels of external and food-based exposure to radiation from Chernobyl

In Norway, external doses of radiation resulting from fallout from the Chernobyl nuclear accident were estimated from detailed measurements, including soil deposition patterns. Internal doses were estimated from measurements of radioactive cesium in meat and milk supplies. The doses were calculated as average monthly doses for each of 454 municipalities during 36 consecutive months after the accident in spring 1986. Prospectively collected data on all newborns listed in the Medical Birth Registry of Norway who were conceived in the period May 1983-April 1989 were used to assess possible dose-response relations between estimated external and food-based exposures and congenital malformations and some other conditions. A positive association was observed between total radiation dose (external plus food-based) and hydrocephaly, while a negative association was observed for Down's syndrome. However, an important conclusion of the study was that no associations were found for conditions previously reported to be associated with radiation, i.e., small head circumference, congenital cataracts, anencephaly, spina bifida, and low birth weight. Potential sources of bias, including exposure misclassification and incomplete ascertainment of cases, are discussed.

Tolerance of rat small intestine to localized single dose and fractionated irradiation

The tolerance of rat small intestine to localized single-dose and fractionated irradiation was assessed. In 168 rats, bilateral orchiectomy was performed and a loop of small intestine was transposed to the left part of the scrotum. Beginning 3 weeks postoperatively, single dose (18-24 Gy) or fractionated (4.2 Gy or 5.6 Gy per fraction) x-irradiation was delivered to the transposed intestine. The animals were observed for complications, and groups of animals were killed 2 and 26 weeks after completion of irradiation for assessment of injury. Mortality (i.e. the occurrence of lethal intestinal complications) and a semiquantitative histopathologic scoring system were used as endpoints to assess the degree of radiation injury. The most frequent intestinal complications were enterocutaneous fistula formation and intestinal obstruction. Logistic regression analysis ov complications data was used to estimate LD50 values and the alpha/beta ratio. There was good correlation between histopathologic scores and the incidence of lethal complications. The estimated LD50 values were 22.1 +/- 0.5 Gy, 37.0 +/- 4.4 Gy and 51.0 +/- 5.3 Gy for the single dose regimen and the fractionated regimens of 5.6 Gy and 4.2 Gy respectively. The estimated alpha/beta ratio was 10.7 +/- 2.4 Gy. The goodness of fit of the linear-quadratic isoeffect model to our data was satisfactory. Our results indicate that acute mucosal damage may be pathogenetically involved in the development of intestinal complications.

Pregnancy outcome in Norway after Chernobyl

Pregnancy outcome has been studied in terms of legal abortions, early spontaneous abortions and total number of pregnancies (in an ad hoc study covering 6 counties) as well as various perinatal health problems (on the basis of routinely recorded data for epidemiological surveillance from the Medical Birth Registry of Norway). Apparently, no effects were observed in terms of an increased occurrence of legal abortions, while spontaneous abortions increased from 7.2% of all pregnancies during the last 12 months before the accident to 8.3% after the accident [corrected]. At the same time, the total number of pregnancies somewhat decreased. Based on monthly measurements in each municipality of external and internal (food-based) doses, dose-response associations were assessed for a number of perinatal health problems. No associations were observed.

Single-strand breaks in the DNA of human cells exposed to visible light from phototherapy lamps in the presence and absence of bilirubin

Clinical evidence indicates that phototherapy of hyperbilirubinaemia in newborn infants is a safe and efficient form of therapy. The short-term side effects are not serious and seem to be well controlled. There are few long-term follow-up studies of phototherapy-treated infants. Therefore one cannot completely exclude the possibility that side effects can be found in future studies. With this background we undertook the present study of possible genotoxic effects of phototherapy. Human cells of the established glioblastoma cell line TMG-1 were used. The cells were exposed to visible light in the presence of different concentrations of bilirubin or in the absence of bilirubin. DNA was unwound in alkaline solution and the induction of strand breaks was assayed by a method taking advantage of the fluorescence from the dye Hoechst 33258. Blue light induced single-strand breaks in the DNA of cells in culture in the absence of bilirubin. During irradiation of bilirubin solutions with blue and green phototherapy light, long-lived toxic photoproducts were formed under in vitro conditions. At high and clinically relevant bilirubin concentrations, the effects of blue and green light were relatively similar. At low concentrations, there was a smaller effect of green light as expected from the absorption spectrum of bilirubin. It remains to be seen whether the genotoxic effect observed in the present studies can occur in vivo.

[Health protection after the Chernobyl accident. The relation of costs and reduction of radioactive dosage level]

This article describes the nutritional measures introduced to protect health after the Chernobyl accident, and the associated costs. The total value of the reindeer meat, mutton, lamb and goat meat saved as a result of such measures in 1987 amounted to approx. NOK 250 million. The measures cost approx. NOK 60 million. The resulting reduction in the radiation dose level to which the population was exposed was 450 manSv. In 1988, mutton/lamb and goat meat valued at approx. NOK 310 million was saved from condemnation by similar measures, which cost approx. NOK 50 million. The resulting dose level reduction was approx. 200 manSv. The relationship (cost/benefit ratio) between the overall cost of the measures taken to reduce radioactivity levels in food and the dose level reduction achieved was acceptable.

Limited short term effects on number of nuclei after electron irradiation of mouse bladder urothelium. A morphometric study

By use of morphometry the number of urothelial nuclei per mouse bladder on days 1 and 7 after electron irradiation with 0, 10, 20 and 30 Gy was calculated. The results indicate only limited cell loss.

Characterization of bladder tumours by multiparameter flow cytometry with special reference to grade II tumours

Sixty-three human transitional cell carcinomas of the urinary bladder were studied by multiparameter flow cytometry (FCM). The cellular DNA content, the cellular protein content, the fraction of cells in S phase, and the nuclear size were registered and correlated to histological grade (WHO) and histologically determined infiltration through the basement membrane. Aneuploidy was found in the great majority of grade III tumours, but in only 24% of grade II tumours. A new, combined variable, viz. the cellular DNA to protein ratio, indicated a possibility for further subdivision of the tumours. Grade II tumours, which constitute a rather heterogeneous group with regard to prognosis, could be classified in two subgroups: One group of diploid tumours with the FCM characteristics of grade I tumours, and another group of diploid and aneuploid tumours with the characteristics of grade III tumours. Infiltration was most frequently seen in the latter subgroup. The putative prognostic relevance of such a subdivision will be the subject of a future study. Compared to FCM measurement of DNA alone, multiparameter FCM, including measurement of the total cellular protein content, has given additional information that may be of prognostic value.

Life with an ileal conduit in cystectomized bladder cancer patients: expectations and experience

Before total cystectomy for bladder cancer 59 patients answered a questionnaire dealing with the "quality of life" they expected after performance of an ileal conduit. Forty-nine relapse-free patients filled in a comparable questionnaire after a median of 36 months following total cystectomy. In the majority of patients the overall "quality of life" was considered as good after total cystectomy though moderate changes of the daily, professional and social life were frequent. Information to the patient before cystectomy must be improved, especially concerning post-operative sexual problems and necessary modifications of social activities (sport, hobbies, travelling). A social worker, a urostomy patient group and a stoma-therapist should all be put in contact with any patient in whom an ileal conduit is planned.

An epidermal proliferative unit-like structure in the epithelium of mouse bladder observed by backscattered electron imaging

The simultaneous use of a silver-staining technique, backscattered electron imaging and stereo-tilts has made it possible to visualize the spatial distribution of cell nuclei in the stretched epithelium of the bladder of mice. This study has led to the observation that a structural organization resembling the epidermal proliferative unit, previously found in the skin exists also in bladder epithelium. However, the proliferative unit in the bladder was different in that it contained a higher number of cells per unit, and an absence of columns of inactive squamous cells. These findings may indicate that epidermal proliferative unit-like structures represent a common form of organization in some epithelia.

Some long-term cell kinetic effects of ionizing radiation on mouse bladder urothelium

The cell kinetics of the mouse bladder urothelium were followed with tritiated thymidine pulse labelling and flow cytometry for one year after irradiation with electrons. No perturbations were registered after 10 Gy. Three to four weeks after 20 Gy an elevation of the labelling index with a subsequent return to normal was seen. Flow cytometry revealed some increase in the proportion of octaploid nuclei at the same time. From about six months after irradiation the normal polyploidization decreased. The urothelium turned into a mainly diploid cell population. The proportion of diploid S phase cells also increased. The data give some support to the model hypothesis of reactive proliferation in a 'flexible' tissue, according to Wheldon et al. (1982).

Late radiation enteropathy following split-dose irradiation of rat small intestine

In female Wistar rats roentgen irradiation of a 10 cm long exteriorized mid small intestinal segment was performed. The radiation dose was 23 Gy, given as a single exposure or divided in two equal fractions separated by intervals of 4 to 96 hours. Radiation injury was assessed 2, 8 and 26 weeks following irradiation using a semiquantitative histopathologic scoring system. An increased fractionation interval led to a reduced degree of radiation injury at all 3 observation times. The greatest difference was found between the single dose and 4 hour groups, indicating a relatively large capacity for repair of sublethal damage. The degree of radiation injury also decreased significantly when the interval between fractions was increased from 4 hours to 96 hours. This suggests that the phenomenon of slow repair may occur in cells involved in the development of late radiation enteropathy. However, an indirectly protective effect due to mucosal repopulation between fractions may also explain some of the differences.

Value of hydroxyproline measurements in the assessment of late radiation enteropathy

In female Wistar rats roentgen irradiation of a 10 cm long temporarily exteriorized mid small intestinal segment was performed. Hydroxyproline, proline, aspartic acid and threonine were measured in intestinal samples 2 to 44 weeks after single or fractionated irradiation, and compared with a histopathologic radiation injury score in order to determine their value as assays of late radiation enteropathy. Two to 4 weeks after irradiation there was good correlation between the histopathologic injury score and the content of hydroxyproline. During the late observation period, there was no difference in hydroxyproline concentration between irradiated and sham-irradiated animals. There was no difference in hydroxyproline concentration in samples from the 1, 2 or 3 fractions groups, although the relative amount of non-collagen protein seemed to increase with fractionation. Determination of the hydroxyproline concentration may be used as an assay of early radiation injury, but it seems to be less suitable for late radiation enteropathy assessment.

Some cell kinetic effects of combined injury with ionizing radiation and cyclophosphamide on mouse bladder urothelium

Cyclophosphamide was given intraperitoneally to groups of eight female mice 48 h after local electron irradiation to the bladder with 0, 10 and 20 Gy respectively. The reactions in the urothelium were monitored by histology, incorporation of tritiated thymidine and flow cytometry. A wave of increased thymidine incorporation combined with an increase in the proportion of diploid S-phase cells was seen in the unirradiated bladders 24 h after the drug treatment, followed by normalization after 1 week. This response was significantly less pronounced in the irradiated animals. In the unirradiated animals a similar wave characterized by an increased proportion of octaploid cells was also seen, but this wave occurred later in the irradiated animals. Severe injury was observed in the rectum of the 20 Gy-irradiated animals. Irradiation prior to drug treatment led to only small effects, but a decreased ability for regenerative DNA synthesis after drug injury seems to persist. This affects both proliferation and the building up of polyploidy.

Some short-term cell kinetic effects of ionizing radiation on mouse bladder urothelium

Early morphological changes and the pattern of reactive proliferation of the hairless mouse urinary bladder urothelium after irradiation are reported. Groups of female hairless mice were anaesthetized with sodium pentobarbital and irradiated over the bladder region with 0, 10, 20 and 30 Gy. Control groups were sham-treated. Short-term cell kinetic changes were monitored using incorporation of tritiated thymidine and flow cytometry. Only minor radiation-induced alterations in the cell kinetic pattern were recorded, and no significant histomorphological changes were seen. However, a marked increase in the thymidine incorporation was seen in the control animals on the first day after anaesthesia. Radiation proctitis induced early deaths in the 30 Gy irradiated animals. The present results are in accordance with commonly accepted radiobiological theories, but not in agreement with results previously published by others.

Prognostic factors in liposarcoma

In a series of 99 liposarcomas, the prognostic impact of the various diagnostic and therapeutic factors was analyzed. The analysis indicated that the tumor size, histologic subtype, and x-ray density are important prognostic factors. The prognosis is also influenced by operability and treatment modalities employed. Treatment strategy should be radical, irrespective of the actual prognostic factors.

Cell numbers and ploidy classes in the normal bladder urothelium in hairless mice. Based on an improved method for dispersion and preparation of cells for flow cytometry

A simple method for obtaining high-yield single cell suspensions from mouse urothelium is reported. The yield of cells per bladder is about 5 X 10(5), or more than twice that of previously published methods. The method gives a satisfactory coefficient of variation and regularly low levels of debris when used for flow cytometry.

Prediction of tumour progression in superficial bladder carcinoma

In a retrospective study, prognostic factors have been analyzed in 45 patients with superficial bladder carcinoma (Tis, Ta, T1) with subsequent progression to invasive (T2, T3, T4) and/or metastatic (M+) disease. The findings are compared with those from a control group of 17 patients with no subsequent invasive or metastatic disease. In a single-parameter analysis the following parameters were significantly associated with a high risk of developing invasive disease: tumour multiplicity; tumour invasion of blood and/or lymph vessels; increasing histological grade, and the history of previous surgical treatment. In a multivariate analysis, multifocality, small vessel infiltration and previous treatment per time (TPT factor) were significantly related to the risk of subsequent progression. An arbitrary score system revealed that progression could be predicted significantly in patients with a high score.

Radiotherapy of liposarcomas

A review of the literature of time-dose relationships of liposarcoma is given. The radiotherapeutic data on 15 measurable liposarcoma sites, together with 45 sites collected from the literature, are subjected to a Strandqvist plot analysis using the modified Ellis' formula TSD = D.T-alpha. The recovery coefficient alpha is thought to be rather high, of the order alpha = 0.5. This suggests that the use of a few large fractions in therapy may be beneficial.