Case report: cystic fibrosis and embryonal carcinoma of the testis

Rational approach to genetic testing of cystic fibrosis (CF) in infertile men

Male infertility as a result of isolated congenital bilateral absence of the vas deferens (CBAVD) is one primary genital form of cystic fibrosis (CF) and occurs in 1-2% of infertile men. Assisted fertilization in patients with CBAVD increases the risk of transmitting mutations in the CF gene. We developed a rational approach to genetic CF testing in infertile men. A total of 282 infertile male patients were screened for the most common CF mutations (DeltaF508, R117H, IVS8-5T). Clinical data including medical history, examination, semen analysis, sweat tests, karyotypes and hormonal values were analysed. We identified 23 patients carrying mutations in the CF gene (DeltaF508: 10 patients; R117H: six patients; IVS8-5T: 11 patients). Two patients were compound heterozygote for DeltaF508/R117H, two others for DeltaF508/IVS8-5T. Correlating these molecular analyses with the clinical data pertaining to serum follicle-stimulating hormone concentration, semen pH, sperm count and total testicular volume, we were able to develop a score with a high specificity (98.4) for the presence of a cystic fibrosis transmembrane conductance regulator (CFTR) mutation, but only with a low sensitivity (positive post-test likelihood: 62.5%; negative post-test likelihood: 6.3%). With regard to the low sensitivity and the high number of CFTR mutations found in this heterogeneous group of infertile men, we still recommend genetic CF testing before assisted fertilization.

Bilateral carcinoma in situ of the testis and cystic fibrosis transmembrane conductance regulator (CFTR) mutation in an azoospermic patient with late-onset 21beta-hydroxylase deficiency

Testicular cancer can impair spermatogenesis. In addition, chemotherapy or radiotherapy used for its treatment further damage testicular function mainly affecting highly proliferating germ cells. The multifaceted etiology of male infertility includes, among others, alterations of male reproductive tract differentiation such as monolateral or bilateral congenital absence of vas deferens and perturbations in adrenal steroid synthesis on a genetic basis such as 21beta-hydroxylase deficiency. Herein, we report the case of a male patient with primary infertility, probably related to a combination of genetic and acquired factors with different expressions over time.

Cancer risk in nontransplanted and transplanted cystic fibrosis patients: a 10-year study

BACKGROUND

Cancer in patients with cystic fibrosis (CF), the most common genetic disorder in Caucasians, has been a rare event. However, more patients now reach adulthood, and more patients undergo organ transplantation-factors associated with an increased cancer risk. Our aim was to assess the risk of cancer in nontransplanted and transplanted CF patients.

METHODS

We followed 28 858 patients whose data were reported to the Cystic Fibrosis Foundation patient registry from 1990 through 1999 and compared the number of cancers observed in transplanted and nontransplanted patients to the number expected from population-based cancer incidence data. All statistical tests were two-sided.

RESULTS

In 202 999 person-years of observation of nontransplanted CF patients, 75 cancers were observed, but 69.7 were expected (standardized incidence ratio [SIR] = 1.1, 95% confidence interval [CI] = 0.8 to 1.4). Twenty-three digestive tract tumors were observed, but 4.5 were expected (SIR = 5.1, 95% CI = 3.2 to 7.6). More cancers than expected were observed of the small bowel, colon, and biliary tract but not of the stomach or rectum. We found that the deficit of non-digestive tract tumors was not statistically significant (52 observed versus 65.2 expected; SIR = 0.80, 95% CI = 0.6 to 1.0; P =.055). In 2725 person-years of observation of 1063 transplanted patients, 13 cancers were observed, but 2.05 were expected (SIR = 6.3, 95% CI = 3.4 to 10.8), and more digestive tract tumors (four observed versus 0.19 expected; SIR = 21.2, 95% CI = 5.8 to 54.2) and lymphomas (seven observed versus 0.16 expected; SIR = 44.0, 95% CI = 17.7 to 90.7) were observed than expected.

CONCLUSIONS

We observed an increased risk of digestive tract cancers among adult CF patients, particularly of the small bowel, colon, and biliary tract. This increased risk appeared to be more pronounced in patients who had had an organ transplantation.