Testicular tumors response to DES treatment

Carcinogenic effects of diethylstilbestrol in male Syrian golden hamsters and European hamsters, 1979


The tumorigenic effects of sc-implanted diethylstilbestrol (DES) on male Syrian golden hamsters and European hamsters were compared.

The adenohypophyses, kidneys, and testes of both species showed neoplastic responses to DES treatment.

European hamsters were more sensitive than were Syrian hamsters, in as much as the European hamsters had a higher tumor incidence.

The testicular tumors were all Leydig cell adenomas and seemed to depend on the coincident occurrence of hypophyseal neoplasms (all composed of gonadotropic cells).

Of the European hamsters tested, 29% also developed liver tumors (hepatocellular adenomas, carcinomas, and cholangiocarcinomas.


  • Carcinogenic effects of diethylstilbestrol in male Syrian golden hamsters and European hamsters, Journal of the National Cancer Institute, NCBI PubMed, PMID: 398263, 1979.
  • Featured image credit Ricky Kharawala.

The effects of exogenous female hormones on the fetus

DES has been proven a culprit in offspring malformations, 1979


The many side effects and sequelae of maternal ingestion of diethylstilbestrol (DES) during pregnancy are reviewed and the review focuses on the effects of female hormones on the fetus in terms of public health consequences.

DES affects female offspring in many ways: clear cell adenocarcinoma of the vagina and cervix; possible risks of uterine, ovarian, and breast cancers; infertility; and pregnancy complications.

In DES-exposed males analogous problems are surfacing: testicular cancer, congenital anomalies of the urogenital tract, and infertility.

Other effects of female hormones for which strong documentation exists are major malformations in general, cardiovascular malformations, and perhaps, limb reduction deformities. The public health consequences of intrauterine exposure to DES are considerable.

Congenital malformations in urogenital tracts of offspring will require long-term follow-ups and careful watching to avoid development of cancers and other malformations in the affected regions. The social cost of long-term follow-up might be computed monetarily or on another scale, such as the psychological impact. Either way, the cost is high.

Since DES has been proven a culprit in offspring malformations, the burden of proof that oral contraceptives in general do not provoke similar offspring changes is on the health community.


  • The effects of exogenous female hormones on the fetus, Epidemiologic reviews, NCBI PubMed, PMID: 398263, 1979.
  • Featured image credit medicalxpress.

Cryptorchidism and hypospadias as a TDS sign

Cryptorchidism and hypospadias as a sign of testicular dysgenesis syndrome (TDS): environmental connection, 2010


Cryptorchidism and hypospadias are common genital birth defects that affect 2-9% and 0.2-1% of male newborns, respectively.

The incidence of both defects shows large geographic variation, and in several countries increasing trends have been reported.

The conditions share many risk factors, and they are also interlinked to the risk of testis cancer and poor semen quality. Testicular Dysgenesis Syndrome (TDS) may underlie many cases of all these male reproductive health problems.

Genetic defects in androgen production or action can cause both cryptorchidism and hypospadias, but these are not common. A monogenic reason for cryptorchidism or hypospadias has been identified only in a small proportion of all cases. Environmental effects appear to play a major role in TDS. Exposure to several persistent chemicals has been found to be associated with the risk of cryptorchidism, and exposure to anti-androgenic phthalates has been shown to be associated with hormonal changes predisposing to male reproductive problems.

Despite progress in identification of endocrine-disrupting substances, we are still far from knowing all the risk factors for these birth defects, and advice for prevention must be based on precautionary principles.


  • Cryptorchidism and hypospadias as a sign of testicular dysgenesis syndrome (TDS): environmental connection, Birth defects research. Part A, Clinical and molecular teratology, NCBI PubMed, PMID: 20865786, 2000.
  • Featured image credit Sasha Freemind.

DES-induced testicular Leydigs cell tumours

image of transgenic mice

Changes in fine structure accompanying estrogen-induced tumorigenesis of Leydig cells in the mouse testis, 1975


The development of estrogen-induced Leydig cell tumors in cryptorchid BALB/c mice was studied with the electron microscope.

Changes in Leydig cell fine structure are apparent by 10 days after the s.c. implantation of a pellet of diethylstibestrol (DES). The smooth endoplasmic reticulum is diminished, and there is an increase in lipid droplets and free polysomes as compared with untreated cryptochid controls. These alterations persist as the Leydig cells proliferate to form focal areas of hyperplasia in the interstitial tissue. During this period of proliferation, activated macrophages containing large residual bodies appear among the Leydig cells. If DES treatment is continued for several months, malignant Leydig cell tumors, result. They are characterized by a nuclear and cytoplasmic pleomorphism of the Leydig cells and a decreased macrophage population. Virus-like particles are rarely seen within the cell during the period of tumorigenesis. Along with the reduction in smooth endoplasmic reticulum in the Leydig cells after DES treatment, evidence from the literature suggests that there is also a decrease in testosterone biosynthesis. However, it is not clear whether these two effect are correlated, since the level of the microsomal enzymes of steroid biosynthesis may vary independently of either the amount of smooth endoplasmic reticulum or the level of androgen secretion. The increase in lipid droplets seen in Leydig cells after DES treatment suggest the accumulation of precursors from the steroid biosynthetic pathway. The macrophages are though to represent scavenger cells, rather than a primary tumor cell population. The paucity of virus-like particles within altered Leydig cells implies that formed virus is not a prerequisite for tumorigenesis.


  • Changes in fine structure accompanying estrogen-induced tumorigenesis of Leydig cells in the mouse testis, Cancer research, NCBI PubMed, PMID: 236824, 1975.
  • Featured image credit wikimedia.

Genital-tract cancers in adolescents and young adults

Stilbesterol exposure possibly linked to cancers of the testis in the 20+ year old

1972 Study Abstract

In a review of the California Tumor Registry from 1950-1969, which records 1/3 of all cancer cases in California,

  • there was an increase in the number of cancers of the vagina, corpus uteri, prostate, testis, and bladder (male) for the 10-19 year old age groupThere was no increase in cancers of the vulva, ovary, cervix, breast, stomach, colon, rectum, and bladder (female).
  • However, for the 20-24 year old age group, cancer of the vulva and testis increased from 1962-1969.

The increases are compatible with other observations which indicate a possible association between stilbesterol and other cervical sites besides the vagina. There is a need for cancer surveillance to determine disease patterns and stimulate examination of existing data.



Testicular Leydig cell tumourigenesis by diethylstilbestrol in the BALB/c mouse

Histologic and histochemical study, European Journal of Cancer, 1966


The present study is dealing with an investigation on gross, histologic and histochemical changes in testes and adrenal cortex of BALB/c mice after subcutaneous implantation of a diethylstilbestrol pellet. The animals were serially killed 30, 60, 90, 120, 150 and 180 days after the implantation. They showed an initial marked loss of body weight, an increased testicular weight starting from the 90th day and a constant adrenal weight increase from the beginning of the experiment. Leydig cell hyperplasia was observed in the treated groups starting from the 60th day, and Leydig cell tumours from the 120th day. A marked regression of the spermatogenic elements was observed shortly after implantation; subsequently a partial revival of the seminal activity with final regression of spermiogenesis was found. The seminal vesicles-coagulating gland complex showed a persistent squamous metaplasia of the coagulation epithelium and evidence of initial atrophy of the seminal vesicles epithelium showing a functional revival in the later stages of the experiment.

The histochemical study carried out on testes and adrenal cortex gave useful information on some enzyme activities connected with steroidogenesis, i.e. 3β-hydroxysteroid dehydrogenase, glucose-6-phosphate dehydrogenase and NADPH diaphorase. The demonstration of the reported enzymes was obtained within normal, hyperplastic and tumoural Leydig tissues. A lack of enzyme activities was found in the inner zones of the adrenal cortex as well as in some Leydig cells where ceroid deposition was frequently found.


  • Testicular Leydig cell tumourigenesis by diethylstilbestrol in the BALB/c mouse: Histologic and histochemical study, Histologic and histochemical study, European Journal of Cancer, doi.org/10.1016/0014-2964(66)90056-9, 1966.
  • Featured image credit bbc news health.

Testicular Dysgenesis Syndrome and Testicular Germ Cell Cancer

Endocrine-Disrupting Chemicals: An Endocrine Society Scientific Statement, 2009


As discussed below, development of vaginal adenocarcinoma in women exposed fetally to DES and the association of carcinoma in situ in the fetal testis with the development of testicular cancer in adulthood (see Testicular dysgenesis syndrome: possible role of endocrine disrupters, 2006, and Pathways of endocrine disruption during male sexual differentiation and masculinization, 2006) are examples of links between the fetal environment and the occurrence of adult disease.

In the male, cryptorchidism, hypospadias, oligospermia, and testicular cancer have been proposed to be linked as the testicular dysgenesis syndrome (TDS) arising from disturbed prenatal testicular development. Such links are important because they could mean that several disorders occur at different periods throughout life in a single individual as a result of exposure to a given EDC (or mixture) at a particular period.

Testicular Dysgenesis Syndrome TDS

Skakkebaek et al. hypothesized that diminished semen quality, TGCC, and male urogenital tract anomalies may share a common causal pathway. They defined this triad as the TDS. The hypothesis invokes a common pathway by which EDCs, and other environmental chemicals and genetic factors, may lead to abnormal development of the fetal testis, producing testicular dysgenesis that can manifest as an increased risk of urogenital abnormalities in newborn males, as well as altered semen quality and TGCC in young men. As a cautionary note, the manifestations (or symptoms) of TDS have other causes apart from testicular dysgenesis.

It is hypothesized that TDS is due to prenatal Leydig and Sertoli cell dysfunction with secondary androgen insufficiency and impaired germ cell development. This should not be confused with the clinical diagnosis of dysgenetic testes, which is associated with genital ambiguity and a high risk of testicular malignancy. The existence of TDS as a distinct clinical entity and of possible associations with EDCs is an area of active research

Testicular Germ Cell Cancer TGCC

The earliest suggestion of epidemiological evidence related to prenatal estrogen exposure and increased risk of TGCC came from a (DES) study in 1979. However, other studies have not consistently confirmed these earlier results.


  • Full study (free access) : Endocrine-Disrupting Chemicals: An Endocrine Society Scientific Statement, Endocrine Reviews, PMC2726844, 2009 June.
  • Featured image credit tamassetmanagement.

Pre-natal and peri-natal exposures and risk of testicular germ-cell cancer

Exposure to maternal hormones (during pregnancy), particularly estrogen (DES), is associated with testicular germ‐cell cancer risk, 2000


The present case-control study was undertaken to investigate the association between exposure to maternal hormones and risk of testicular germ-cell cancer (TGCC) by histologic subgroups.

Cases were males, aged 16 to 59 years, diagnosed with testicular germ-cell cancer in Ontario between 1987 and 1989.

Histologic review was performed on all eligible cases for the purpose of categorizing cases as seminoma or non-seminoma (the latter classified 2 ways, with and without tumors containing seminoma). Risk factor data were collected on 502 cases, 346 case mothers, 975 age-matched controls, and 522 control mothers.

Exogenous hormone exposure was associated with elevated risk (OR = 4.9, 95% CI 1.7-13.9). Several additional risk factors were associated with risk of testicular cancer: bleeding and threatened miscarriage (OR = 0.6, 95% CI 0.3-1.0), maternal cigarette smoking (12+ cigarettes/day OR = 0.6, 95% CI 0. 4-1.0). pre-term birth (OR = 1.6, 95% CI 1.0-2.5), and treatment for undescended testicle (OR = 8.0, 95% CI 3.2-20.0). First births were associated with elevated risk (OR = 1.7, 95% CI 1.0-2.8) among mothers below the age of 24 years at conception. There was little evidence that risk factors differed by histologic subgroup. We found evidence that exposure to maternal hormones, particularly estrogens, is associated with testicular germ-cell cancer risk. Not only does exposure to elevated levels (exogenous hormone use, pre-term birth, and first births among young mothers) increase risk but also exposure to relatively lower levels (heavy cigarette consumption and, perhaps, bleeding and threatened miscarriage) may decrease cancer risk.


The early age at incidence of testicular germ‐cell cancer suggests that childhood exposures, possibly even those occurring in utero, may be important, including exposure to maternal hormones, from exogenous and endogenous sources.

A number of case‐control studies have interpreted results based on the hypothesis that exposure to maternal hormones elevates risk of testicular cancer (see 1980 study, 1983 study, 1986 study)  however, their results have not been entirely consistent with this hypothesis.

The present case‐control study was undertaken to examine the association of maternal hormone exposure, from both exogenous and endogenous sources, and risk of testicular germ‐cell cancer. The study also included histological review of all eligible cases, to further investigate the association according to the major histological subgroups, seminoma and non‐seminoma (the latter classified 2 ways, with and without tumors containing seminoma).

Definition of exposure variables

Exogenous hormone exposure was determined from the mother’s reported use of prescription hormones [e.g., diethylstilbestrol (DES) or premarin], prescription medication for conditions associated with threatened miscarriage, injections or pills to determine pregnancy, and use of oral contraceptives around the time of conception. Because reported exposures to exogenous hormones were uncommon, these exposures were combined into a dichotomous variable, coded “yes” if the mother reported exposure to any of the sources of exogenous hormones and “no” if she reported exposure to none of them.


Early population‐based case‐control studies reported that exogenous hormone exposure, in the form of pregnancy tests and hormone use for threatened miscarriage, elevated risk for testicular cancer (see 1979 study, 1980 study, 1983 study), while later studies failed to confirm the association (see 1986 study, 1988 study). Despite the fact that the present study provides evidence of an association in both histological subgroups, caution should be used in interpreting the results: DES has been associated with adverse health effects in both male and female offspring, exposure status was not validated in the current study, and participation rates among case mothers were higher than among control mothers. Potential recall bias has been reported in other studies, and such bias could be expected to operate in both histological subgroups.


In conclusion, our results support the hypothesis that exposure to maternal hormones, particularly estrogen, is associated with testicular germ‐cell cancer risk. Not only does exposure to elevated levels of maternal hormones (exogenous hormone use and pre‐term birth) appear to increase cancer risk, but exposure to relatively lower levels of maternal hormones (heavy cigarette consumption and, perhaps, bleeding and threatened miscarriage), as measured by indices of exposure to maternal hormones, appears to decrease cancer risk. Future studies should consider direct measurement of these exposures, to further explore the association between maternal estrogen exposure and risk of testicular germ‐cell cancer.

Evidence that risk factors differ by histological subgroup has been difficult to interpret. Our results support the conclusion of Møller and Skakkebæk that the causes of seminoma and non‐seminoma are likely the same. Furthermore, there is little convincing evidence to support the need to distinguish between non‐seminomatous tumors containing seminoma and those not containing seminoma. However, caution should be used in interpreting these results because small numbers in the histological subgroup analysis resulted in limited statistical power to detect differences. Since the evidence for possible differences comes from studies looking at maternal age and parity, an understanding of the mechanisms underlying histological differences may come with a better understanding of how maternal age and parity themselves are associated with risk of testicular germ‐cell cancer.



Case-control study of testicular cancer, 1988

Connecticut tumour registry data, International journal of epidemiology

1988 Study Abstract

This case-control study was designed to determine whether males who were exposed to diethylstilboestrol (DES) in utero are at increased risk of testicular cancer.

Questionnaires were completed for 79 residents of Connecticut, who were diagnosed with primary cancer of the testes between 1945 and approximately six months into 1980.

An equal number of matched controls drawn from birth certificate records available from the Connecticut State Department of Health Services also submitted questionnaires.

Information included data on past medical conditions of subjects and obstetrical history of mothers.

The major finding of this study was a statistically significant elevated risk for premature birth for the testicular cancer cases.

The study failed to show that DES increased the risk for testicular cancer.

However, in view of the findings from previous human and animal studies of such abnormalities as undescended and hypoplastic testes as well as the consideration that only the earliest exposed birth cohort has reached the age of substantial cancer risk, it would seem prudent for any male who has been prenatally exposed to DES to seek medical follow-up.


Since DES stopped being prescribed in 1971, and since testicular cancer takes time to develop, we believe it’s reasonable to think the study’s cases (diagnosed between 1945 and 1980) do not match DES Sons exact profiles / conditions .


  • A case-control study of testicular cancer using Connecticut tumour registry data, International journal of epidemiology, NCBI PubMed, PMID: 3225080, 1988 Dec.
  • Featured image credit patioyarddesign.

Prenatal and perinatal risk factors for testicular cancer

Cancer research, Clinical and Epidemiological Investigations, 1986


In an attempt to determine the risk factors responsible for the dramatic increases in testicular cancer incidence in young adults, mothers of testicular cancer cases and controls were questioned about in utero exposures, pregnancy-related conditions, and perinatal factors during their pregnancies with the 202 cases and the 206 controls.

  • The strongest risk factor was low birth weight with a greater than 12-fold risk (confidence interval = 2.8 to 78.1) for subjects weighing 5 lb or less at birth compared to those who weighed over 5 lb.
  • A statistically significant 2-fold increase in risk was associated with unusual bleeding or spotting during pregnancy, regardless of whether medication was taken for this condition.
  • Other exposures during pregnancy associated with a statistically significant increase in risk were:
    • use of “sedatives”;
    • alcohol consumption;
    • and exposure to X-rays.
  • No excess risk was associated with the use of hormones during pregnancy.

The findings for birth weight and abnormal uterine bleeding suggest that significant compromise of the normal maternal-fetal environment may be associated with subsequent increase in risk of testicular cancer. However, this increase in risk is not great enough to explain the dramatic increases in testicular cancer that have occurred in young adults.


  • Prenatal and perinatal risk factors for testicular cancer, Cancer research, NCBI PubMed, PMID: 3731127, 1986 Sep.
  • Featured image credit patioyarddesign.