Jørn Müller

Germ cell cancer and disorders of spermatogenesis: An environmental connection?

Why is there a small peak of germ cell tumours in the postnatal period and a major peak in young age, starting at puberty? And, paradoxically, small risk in old age, although spermatogenesis is a lifelong process? Why is this type of cancer more common in individuals with maldeveloped gonads, including undescended testis, gonadal dysgenesis and androgen insensitivity syndrome? Why has there, during the past 50 years, been a quite dramatic increase in testicular cancer in many developed countries? These are just a few of many questions concerning testicular cancer. However, the recent progress in research in the early stages of testicular cancer (carcinoma in situ testis (CIS)) allows us to begin to answer some of these questions. There is more and more evidence that the CIS cell is a gonocyte with stem cell potential, which explains why an adult man can develop a non‐seminoma, which is a neoplastic caricature of embryonic growth. We consider the possibility that CIS cells may loose their stem cell potential with ageing. Along these lines, a seminoma is regarded a gonocytoma where the single gonocytes have little or no stem cell potential. The Sertoli and Leydig cells, which are activated postnatally and during and after puberty, may play a crucial role for both the development of the CIS gonocyte and progression of the neoplasm to invasiveness. The reported increase in testicular cancer is not the only sign that male reproductive health is at risk. There are reports that undescended testis and hypospadias have become more common. Also semen quality has deteriorated, at least in some countries. The epidemiological evidence suggests that environmental factors may play a role. Are the environmental hormone disrupters (e.g. DDT, PCB, nonylphenol, bisphenol A) to be blamed for the apparently synchronised deterioration in these aspects of male reproductive health?

Developmental arrest of germ cells in the pathogenesis of germ cell neoplasia

Clinical observations and epidemiological evidence suggest that important aetiopathological events that cause neoplastic transformation of the male germ cell may occur in fetal life or early infancy. The incidence of germ cell neoplasia is high in individuals with various disorders of gonadal development and sexual differentiation, such as gonadal dysgenesis or androgen insensitivity syndrome. Increased risk has also been noted in individuals with trisomy 21, idiopathic infertility and low birth weight. Infertility is sometimes associated with small aberrations of sex chromosomes (e.g. low frequency mosaicism XY/XO) which can also be found in patients with testicular cancer. The variety of conditions that predispose to testicular neoplasia and the rise in its incidence in many countries speaks for the influence of environmental factors which may affect genetically predisposed individuals. We hypothesise that if the development of the testis is disturbed or delayed, primordial germ cells or gonocytes undergo maturation delay or differentiation arrest which may render them susceptible to neoplastic transformation. Morphologically homogenous premalignant carcinoma in situ (CIS) cells have the potential to differentiate into a variety of histological forms of overt testicular tumours. Analysis of cell surface antigens expressed by CIS cells found in the vicinity of pure and mixed tumours demonstrates that CIS cells are phenotypically heterogeneous. Comparison of the phenotypes of CIS cells, primordial germ cells, human embryonal carcinoma cells and closely related primate embryonal stem cells reveals various similarities but also differences. We speculate that phenotypical heterogeneity of CIS cells may be associated with their potential to give rise to different tumour types, and may be related to the developmental stage of the early germ cell which has undergone malignant transformation.

Radiotherapy at a young age reduces uterine volume of childhood cancer survivors

Background.  In contrast to chemotherapy, previous irradiation of the uterus carries an increased risk of an adverse pregnancy outcome. Conflicting results exist as regards the ability of the uterus to increase in volume following radiotherapy‐induced damage. We measured uterine volume in a cohort of childhood cancer survivors, and assessed uterine response to a high‐dose estrogen replacement regimen.

Cryptorchidism and testis cancer. Atypical infantile germ cells followed by carcinoma in situ and invasive carcinoma in adulthood

Atypical germ cells closely resembling carcinoma in situ (CIS) cells of the adult testis were found in a biopsy specimen from an undescended testis of a 10‐year old prepubertal boy who was admitted for orchiopexy. The atypical cells were distributed as normal infantile germ cells in the seminiferous tubules, but in successive postpubertal biopsies an adult CIS pattern developed. Microspectrophotometric DNA measurements showed aneuploidy of both the prepubertal and postpubertal atypical germ cells, and the malignant potential of these cells was proven as small foci of invasive germ cell carcinoma in addition to widespread CIS were found when an orchiectomy was performed at the age of 20 years. Thus, premalignant changes in the testis may be found before puberty, and may precede a clinically detectable tumor by more than 10 years.

Carcinoma in situ of the testis in children with 45,X/46,XY gonadal dysgenesis

The frequency of gonadal tumors in intersex patients with a karyotype including a Y chromosome is very high. In other at-risk groups, testicular germ cell tumors have been shown to be preceded by carcinoma in situ (CIS) changes. We investigated gonadal tissue from four children, aged 1 month to 18 years, with 45,X/46,XY gonadal dysgenesis, and with male or ambiguous genitalia, for the presence of CIS germ cells. Twelve gonadal biopsies and gonadectomy specimens were analyzed by means of conventional histology and densitometric DNA measurements. CIS changes were detected in specimens from all four patients, and aneuploid DNA distributions of the CIS germ cells confirmed the malignant potential of these cells. In one case, electron microscopic analysis revealed the same ultrastructural features of the CIS germ cells as previously described in seminoma cells. These observations indicate that in all patients with 45,X/46,XY gonadal dysgenesis and a male phenotype, gonadal biopsies should be considered as soon as the syndrome is diagnosed. We believe that the finding of CIS warrants gonadectomy.

Ultrasound B-mode changes in the uterus and ovaries and Doppler changes in the uterus after total body irradiation and allogeneic bone marrow transplantation in childhood

Internal genitalia and uterine blood flow were assessed by ultrasound in 12 females 4.0–10.9 years after total body irradiation and allogeneic bone marrow transplantation for childhood leukaemia or lymphoma. Median age of the participants was 12.7 years (range 6.1–17.6) at bone marrow transplantation and 21.5 years (11.6–25.6) at the follow-up study. At follow-up all had entered puberty and 11/12 females had experienced the menarche. Eight females received sex steroid replacement therapy, three had spontaneous pubertal development and one woman experienced symptoms of estrogen deficiency. Median uterine and ovarian volumes were significantly reduced to −2.6 standard deviation scores (SDS) (−6.3 to −0.6), P = 0.002, and −2.6 SDS (−4.8 to −0.5), P = 0.002, respectively, compared with normal controls. Follicles were only detectable in two individuals. Uterine blood flow was impaired, as a systolic blood flow could be measured in 6/9 individuals, and a diastolic blood flow in 1/9 females. Our results indicate that the prescribed dosage of hormone replacement therapy, which was sufficient to induce bleeding and suppress other stigmata of premature menopause, was inadequate to generate normal uterine growth. In order to achieve uterine growth higher doses of hormone replacement therapy may be required. Our results confirm pelvic ultrasound as a reliable tool for investigation of internal female genitalia; however, in an infertility setting further tests are indicated.

Prevalence of carcinoma in situ and other histopathological abnormalities in testes from 399 men who died suddenly and unexpectedly.

To determine the prevalence of carcinoma in situ of the testis and other testicular histopathological abnormalities in the general male population, we examined gonads from 399 men 18 to 50 years old who died suddenly and unexpectedly. No sign of malignancy was found in any of these gonads. However, 3 of the 399 men had been previously treated for testicular tumor or carcinoma in situ. Thus, the over-all prevalence of testicular neoplasia in the population studied was 0.8% (95% confidence limits 0.2 to 2.2%). This frequency is of the same magnitude as the lifetime risk of testicular cancer in the Danish male population. The median weights of the left and right testes were 19.3 and 19.7 gm., respectively. This difference was statistically significant (p = 0.00003). Thus, our study confirmed that on average the left testis is smaller than the right testis. The median weight of the gonads collected in our study was 0.9 gm. lower than the weight of testes examined 40 years earlier at the same department of forensic medicine. However, this difference was not statistically significant (p = 0.17). Microscopic examination of the gonadal specimens revealed that 83% of the men exhibited complete spermatogenesis, including late spermatids in all tubules. In the age group studied we found no age-related changes in testicular weight or in the proportion of tubules with degenerative changes, such as spermatogenic arrest, the Sertoli-cell-only syndrome or hyalinization.

Bone Mass After Treatment for Acute Lymphoblastic Leukemia in Childhood

PURPOSETo study bone mass after childhood acute lymphoblastic leukemia (ALL) and determine if reduced bone mass is related to previous therapy or endocrine status at follow-up.PATIENTS AND METHODSWe studied 95 survivors of childhood ALL who were in first remission a median of 11 years (range, 3 to 23 years) after diagnosis and who had never been irradiated outside a cranial field. The bone mass was measured by dual-energy x-ray absorptiometry. The results were compared with data on 396 local controls.RESULTSAdjusted for sex and age, the mean whole-body bone mineral content (BMC) and bone mineral areal density (BMDA) were both significantly reduced (0.4 SDs less than the predicted mean value). This was mainly caused by reduced bone mass in the 33 participants who were aged 19 years or older at follow-up. In these young adults, the mean height for age, bone area for height, and BMC for bone area were all significantly reduced. This indicated that the reduced whole-body bone mass was caused by both reduced b...

Heterogeneity of gonadoblastoma germ cells: similarities with immature germ cells, spermatogonia and testicular carcinoma in situ cells

Gonadoblastoma is defined as a neoplasm containing nests of germ cells and cells resembling Sertoli cells or granulosa cells. Gonadoblastomas arise almost exclusively in dysgenetic gonads. They are associated with an increased risk of developing germ cell tumours. Testicular germ cell tumours in adults are preceded by carcinoma in situ cells, which are characterized by their morphology, by their immunohistochemical expression of placental‐like alkaline phosphatase, the proto oncogene c‐kit and/or epitopes for the monoclonal antibodies M2A, 43–9F and TRA‐1–60, and by their aneuploid DNA content. In order to elucidate if gonadoblastomas are in situ neoplasms from the beginning, showing similarities with carcinoma in situ cells in otherwise normal testes, we investigated the germ cells in gonadoblastomas for their expression of the immunohistochemical markers of carcinoma in situ cells from six patients aged 812 months to 20 years and 4 months. In addition, the DNA content of the germ cells from five of the six patients was also determined by densitometric measurement on Feulgen stained specimens. The germ cell populations were heterogeneous both within the same patient and between the patients. Expression of the testicular carcinoma in situ markers was detected in specimens from all the patients and germ cells with an aneuploid DNA distribution pattern in accordance with testicular carcinoma in situ cells were detected. However, apparently normal immature germ cells were also present in four of the patients of whom two also had germ cells with a morphology similar to normal spermatogonia. Thus, gonadoblastoma is most likely an in situ germ cell neoplasia from the beginning. It seems probable that the germ cell tumours associated with gonadoblastomas originate from the carcinoma in situ cells inside the gonadoblastoma. Our findings of carcinoma in situ cells in gonadoblastomas from children support the theory that the cells arose prenatally.

Bone mineral status in 134 patients with cystic fibrosis

AIM To investigate bone mineral status in patients with cystic fibrosis (CF). PATIENTS AND METHODS Whole body bone mineral content (BMC), projected bone area, and bone mineral density (BMD) were determined by dual energy x ray absorptiometry in 134 patients with CF and compared with 396 healthy controls. RESULTS In patients ⩽ 19 years of age, BMD for age was normal in boys and marginally reduced in girls, whereas BMC for age was significantly reduced in both sexes. Height for age and bone area for height were significantly reduced, indicating “short” and “narrow” bones, whereas BMC for bone area was increased, indicating increased size corrected BMC. In patients > 19 years of age, BMD and BMC for age were significantly reduced. CONCLUSION Short and narrow bones were the main reasons for reduced BMC for age in patients ⩽ 19 years of age, indicating that treatment to prevent osteoporosis in younger patients should be directed at increasing bone size, whereas conventional treatment with calcium and vitamin D supplementation alone might not be as effective. Because of the significant decrease in BMD and BMC in adult patients, we fear that these patients may develop osteoporotic fractures prematurely.