Letters to the Editor

CYCLOPHOSPHAMIDE AND THE PUBERTAL TESTIS

Immunosuppressive agents in childhood nephrotic syndrome: A meta-analysis of randomized trials.

Many children with steroid-sensitive nephrotic syndrome (SSNS) relapse frequently and receive immunosuppressive agents. In this systematic review of randomized controlled trials (RCTs), the benefits and harms of these immunosuppressive agents are evaluated.

RCTs with outcome data at six months or more that evaluated noncorticosteroid agents in relapsing SSNS were included. A summary relative risk for relapse at 6 to 12 months was calculated using a random effects model.

Seventeen trials involving 631 children were identified. Cyclophosphamide [3 trials; relative risk (RR) 0.44, 95% confidence interval (CI), 0.26 to 0.73] and chlorambucil (2 trials; RR 0.13, 95% CI, 0.03 to 0.57) significantly reduced the relapse risk at 6 to 12 months compared with prednisone alone. In the single chlorambucil versus cyclophosphamide trial, there was no observed difference in relapse risk at two years (RR 1.31, 95% CI, 0.80 to 2.13). Cyclosporine was as effective as cyclophosphamide (1 trial; RR 1.07, 95% CI, 0.48 to 2.35) and chlorambucil (1 trial; RR 0.82, 95% CI, 0.44 to 1.53), but the effect was not sustained when cyclosporine was ceased. During treatment, levamisole (3 trials; RR 0.60, 95% CI, 0.45 to 0.79) was more effective than steroids alone, but the effect was not sustained.

Cyclophosphamide, chorambucil, cyclosporine, and levamisole reduce the risk of relapse in children with relapsing SSNS compared with prednisone alone. Clinically important differences in efficacy among these agents are possible, and further comparative trials are still needed. Meanwhile, the choice between these agents depends on physician and patient preferences related to therapy duration and complication type and frequency.

Bilateral testicular biopsies were performed on 25 boys between 4 and 16 years old with the diagnosis of acute lymphocytic leukemia after the induction of regression with vincristine and prednisone, followed by cyclic maintenance therapy with a combination of 6-mercaptopurine, methotrexate, L-asparaginase, cyclophosphamide and doxorubicin for 2 years. These drugs were given in accordance with children’s cancer study group protocols. Only 3 boys had positive biopsies (12 per cent), although post-treatment testicular morphology was abnormal in the overwhelming majority. Interstitial fibrosis was present in 16 children (70 per cent), basement membrane thickening in 12 (50 per cent) and, most importantly, a reduction in the tubular fertility index of greater than 50 per cent in 20 (80 per cent). There was no relationship between the abnormal morphology encountered and the age of the patient when treated. Most of these changes may be reversible with time but only a biopsy at a later date can establish the long-term effects of treatment on testicular morphology and, perhaps, help to predict future fertility potential.

The effect of cyclical chemotherapy on fertility and gonadal function was investigated in seventy-four male patients who had been treated for advanced Hodgkin's disease. All patients were azoospermic after therapy, and, with a median follow-up period of 27 months (range 1-62 months), only four patients have regained spermatogenesis. Testicular biopsy showed an absence of germinal epithelium without other gross architectural changes. Despite this high degree of infertility, 60% of patients were practising contraception. A decline in libido and sexual performance with frequent long periods of sexual inactivity was noted by most men during therapy. Although some recovery was apparent once therapy was stopped, this was incomplete in approximately half of the patients. Follicle-stimulating-hormone levels were consistently raised after therapy at all periods of study. Median luteinising-hormone levels were at, or just above, the upper limit of normal, and median testosterone levels were normal. Increased prolactin levels were noted in 42% of patients, of whom about a half had an identifiable cause for hyperprolactinæmia. Return of spermatogenesis could not be predicted by serial hormone assessment. Because of the guaranteed infertility and the low frequency and unpredictability of recovery of spermatogenesis, sperm storage should be available for male patients undergoing cytotoxic therapy, since most of these patients may enjoy prolonged survival. Hormone-replacement therapy will usually be unnecessary. However, the probability of major changes in libido and sexual performance should be discussed with patients so that additional stress can be avoided. Contraceptive advice should be available to those who require it.