Co-occurrence in body site of malformations and cancer

Risk of Urological Cancer Among Boys and Men Born with Hypospadias: A Swedish Population-based Study

Background

Hypospadias is a common genital malformation among boys. Studies indicate that hypospadias is associated with a higher risk of testicular cancer. Other forms of urological cancer may be linked to hypospadias via a mutual aetiology, hormonal dysfunction, or hypospadias complications, but this has not yet been studied.

Objective

To investigate the association between hypospadias and testicular cancer and the risk of other urological cancers among individuals born with hypospadias.

Design setting and participants

The study used a population-based male cohort born in Sweden in 1964-2018. Exposure was hypospadias diagnosis in national registers. Outcomes were defined using the Swedish Cancer Register. An extended cohort born from 1940 was used to study cancers among older men. Biological brothers and fathers were linked to investigate familial coaggregation.

Outcome measurements and statistical analysis

Associations were assessed using Cox proportional-hazards regression analysis, with results presented as hazard ratios.

Results and limitations

We found that hypospadias was associated with a higher risk of testicular cancer (hazard ratio 2.04, 95% confidence interval 1.42-2.92), especially for proximal hypospadias, but did not observe any clear familial coaggregation of hypospadias and testicular cancer. Hypospadias was associated with Wilms' tumour in childhood. We also found an association between hypospadias and bladder and urethral cancers, but not prostate cancer. The number of cases with hypospadias was small and the results for cancers among older men may be impacted by limitations in register coverage.

Conclusions

Our study supports the hypothesis of a higher risk of testicular cancer for men with hypospadias, especially with proximal phenotypes. Hypospadias may also be associated with a higher risk of lower urinary tract cancers, although this requires further investigation in older cohorts.

Patient summary

Boys and men in whom the opening of the urethra is not at the end of the penis (called hypospadias) at birth are at higher risk of developing testicular cancer, although their overall risk is still low. They may also have a higher risk of developing other forms of cancer in the urinary tract.

A tumor profile in Edwards syndrome (trisomy 18)

Constitutional trisomy 18 causes Edwards syndrome, which is characterized by intellectual disability and a particular set of malformations. Although this condition carries high mortality during prenatal and early postnatal life, some of the rare infants who survive the first months develop benign and malignant tumors. To determine the tumor profile associated with Edwards syndrome, we performed a systematic review of the literature. This review reveals a tumor profile differing from those of Down (trisomy 21) and Patau (trisomy 13) syndromes. The literature covers 45 malignancies: 29 were liver cancers, mainly hepatoblastomas found in Japanese females; 13 were kidney tumors, predominantly nephroblastomas; 1 was neuroblastoma; 1 was a Hodgkin disease; and 1 was acute myeloid leukemia in an infant with both trisomy 18 and type 1 neurofibromatosis. No instances of the most frequent malignancies of early life-cerebral tumors, germ cell tumors, or leukemia--are reported in children with pure trisomy 18. Tumor occurrence does not appear to correlate with body weight, tissue growth, or cancer genes mapping to chromosome 18. Importantly, the most recent clinical histories report successful treatment; this raises ethical concerns about cancer treatment in infants with Edwards syndrome. In conclusion, knowledge of the Edwards' syndrome tumor profile will enable better clinical surveillance in at-risk organs (i.e., liver, kidney). This knowledge also provides clues to understanding oncogenesis, including the probably reduced frequency of some neoplasms in infants and children with this genetic condition. © 2016 Wiley Periodicals, Inc.

Genomic and functional overlap between somatic and germline chromosomal rearrangements

Genomic rearrangements are a common cause of human congenital abnormalities. However, their origin and consequences are poorly understood. We performed molecular analysis of two patients with congenital disease who carried de novo genomic rearrangements. We found that the rearrangements in both patients hit genes that are recurrently rearranged in cancer (ETV1, FOXP1, and microRNA cluster C19MC) and drive formation of fusion genes similar to those described in cancer. Subsequent analysis of a large set of 552 de novo germline genomic rearrangements underlying congenital disorders revealed enrichment for genes rearranged in cancer and overlap with somatic cancer breakpoints. Breakpoints of common (inherited) germline structural variations also overlap with cancer breakpoints but are depleted for cancer genes. We propose that the same genomic positions are prone to genomic rearrangements in germline and soma but that timing and context of breakage determines whether developmental defects or cancer are promoted.

Genetics of common malformations

Advanced technology has recently allowed us to study rare Mendelian disorders in an unprecedented manner. The same technology should allow us also to study more common malformations. Many of these are not caused by a variant in a single Mendelian gene but by interplay between series of genetic variants and exogenous influences. Likely the site from which the DNA is derived is of great importance in studying malformations as mosaicism may be much more common than earlier anticipated. Factors other than simple variants in our genomic DNA should be considered in the studies as well. Not only is recognition of someone's liability to disease important, but also determining exogenous factors involved in malformations should receive more attention as it may allow us decrease the burden of malformations in humans.