356 children below 16 yrs of age with CS/PS IA, IB, and IIA were treated in the studies HD-78, HD-82, HD-85, HD-87, and OEPA-pilot 87 between June 1978 and Sept 1990. All patients received combined modality treatment (CMT) with 2 courses of chemotherapy (CT). In HD-78 and HD-82, the MOPP-derived drug combination OPPA (ADR instead of mechlorethamine) was applied. Extended-field radiotherapy (RT) was given in HD-78 using 36-40 Gy to involved-fields (IF) and 36-40 Gy vs. 18-20 Gy to adjacent fields. In HD-82 only IF-RT was applied using 35 Gy. When gonadotoxic effects of procarbazine (PC) in boys was detected in follow-up examinations, this drug was eliminated in studies HD-85 and HD-87 (OPA). Dosages of IF-RT were 35 Gy in HD-85 and 30 Gy in HD-87. With HD-87 a simultaneous pilot study was initiated to test the new combination OEPA (E = etoposide) together with 25 Gy IF-RT.
Results: (May 1993): Rates for event-free survival and survival are HD-78 (73 patients): 0.90 and 0.97 at 10 yrs; HD-82 (100 patients): 0.98 and 1.0 at 10 yrs; HD-85 (53 patients): 0.85 and 0.98 at 8 yrs; HD-87 (104 patients): 0.85 and 0.99 at 6 yrs; OEPA-pilot (26 patients): 0.96 and 0.96 at 5 yrs. No secondary leukemias, MDS, or solid tumors were observed in 14-yr observation time. After 2 OPPA, elevated FSH levels indicating impaired spermatogenesis were found in 29% of male patients. In contrast, after 2 OPA (without PC) only normal FSH levels were observed. In female patients, no gonadal dysfunction was found. Subclinical hypothyroidism was seen only after RT doses of > 30 Gy to the neck. Cardiomyopathies were not observed.
Conclusion: 2 OPPA plus IF-RT using < 30 Gy can presently be considered optimal therapy for girls with localized HD. 2 OEPA plus 25 Gy IF-RT are being evaluated for boys in a phase III study (HD-90). In summary, there are good reasons to use CMT in early stages of HD in children, provided a highly effective CT of short duration and low long-term toxicity with low-dose IFI is applied.