Antibody levels against tetanus and diphtheria after polychemotherapy for childhood sarcoma: a report from the Late Effects Surveillance System.

BACKGROUND It is known that antineoplastic treatment may induce secondary immunodeficiency, but studies after childhood sarcoma are rare. Since 1998, the Late Effects Surveillance System (LESS) of the German Society for Paediatric Oncology and Haematology (GPOH) prospectively registers late effects in soft tissue-, osteo- and Ewing's sarcoma patients treated within the therapy trials EICESS-92/EURO-E.W.I.N.G.-99, CWS-96/CWS-2002P, COSS-96 in Austria, Germany and Switzerland. PATIENTS AND METHODS Antibody levels (AL) against diphtheria and tetanus were used as markers for immunity and classified according to established guidelines for protective AL values. There were 47 eligible relapse-free patients<21 years of age (31 males; 10 osteosarcoma, 12 Ewing's and 25 soft tissue sarcoma patients). Median age at diagnosis was 9.6 (interquartile range: 4.4-14.7) years. RESULTS A median 7.2 (3.7-12.2) months after end of antineoplastic therapy, in 28% (13/47; 95% CI 16-43%) of patients there were no protective AL (<0.1 IU/ml) against diphtheria and/or tetanus. Diphtheria and tetanus AL were positively correlated (r=0.39; p=0.007). In multivariable analysis, the type of treatment had no effect on AL, similar to tumour type and time of examination after treatment end. Younger patients had significantly lower AL against tetanus (p=0.009) and girls had significantly lower AL against diphtheria than boys (p=0.015). CONCLUSION Lack of protective AL against tetanus and/or diphtheria is frequent after childhood sarcoma treatment. Prospective surveillance of immunity and, if indicated, re-immunization is warranted in patients treated for childhood cancer.