The predominant sites of viable and nonviable tumor were determined in the primary lesions of 50 patients with osteosarcoma after initial treatment with preoperative chemotherapy. The degree of tumor destruction was classified as good, fair, and poor and a map of the sites revealing viable and nonviable tumor was constructed. The study revealed several preferential sites where viable tumor was likely to persist: soft tissues, cortex, subcortex, ligaments, and areas in contact with cartilage (growth plate and/or articular cartilage). Localized areas of hemorrhage and necrosis, designated "lacunae," were noted within the tumor. They were frequently surrounded by bundles of viable tumor and appeared to correlate with open surgical biopsies. Factors responsible for this phenomenon and the persistence of viable tumor are discussed. The findings have important implications in the design of surgical treatment and in the use of needle biopsies to determine the effects of preoperative treatment.

Between January 1970 and December 1988, 174 consecutive patients under the age of 20 years with curatively resected primary osteosarcoma were treated at our institute; 72 in the years of 1970 to 1981 and 102 in the years 1982 to 1988. In the latter period, adjuvant chemotherapy was replaced by neoadjuvant programs, and new criteria were adopted for the management of lung metastases, consisting in early bilateral surgical staging and lung resection through median sternotomy for all patients with purely intrathoracic relapse. Follow-up was updated in December 1989. During the last period, the overall 5-year survival improved significantly from 35% to 58% (P less than .001). The disease-free survival rose from 38% to 45% at 5 years, with median values of 15 months versus 33 months, while the frequency of isolated lung metastases dropped from 58% to the actuarial 48%. The proportion of patients who underwent complete resections of their pulmonary metastases rose from 17% (seven of 42) to 55% (27 of 49), without operative mortality. Due to such a high proportion of patients eligible for salvage surgery, the overall survival from detection of lung metastases improved from 0% to 28% at 5 years (P less than .001). Contralateral occult metastases were resected in three of 15 subjects with monolateral clinical lesions, and five patients underwent subsequent lung resections. These data indicate that systematic bilateral pulmonary resection plays an important role in improving the final cure rate of childhood osteosarcoma, beyond the benefit resulting from neoadjuvant chemotherapy.

Forty-three fresh tumor specimens of human neuroblastoma belonging to different clinical stages were analyzed for the expression of 2 proto-oncogenes: trk, which encodes a tyrosine-kinase receptor for nerve growth factor (NGF) and ret, another receptor-type tyrosine kinase whose ligand is unknown. The mRNA expression of the trk gene was detected in 67.4% of cases, with increased frequency in I, II and IVs Evans' stages and in patients with favorable prognosis according to the Shimada classification. Moreover, trk expression inversely correlated with Nmyc-gene amplification. ret mRNA was found in 36.8% of cases and equally distributed in the different stages. In addition, ngfR (low-affinity NGF receptor)-gene expression was present in 9 out of 25 cases. The simultaneous presence of mRNA related to both forms of the NGF receptor, while not proving the presence of a functional receptor, indicates the existence of a sub-set of neuroblastoma cells potentially responsive to NGF.

Tumour-infiltrating lymphocytes (TIL) of paediatric tumours obtained from 37 lesions of different histotype (12 osteosarcomas, 5 Wilms' tumours, 7 soft-tissue sarcomas, 5 neuroblastomas and 8 miscellaneous) were studied to establish their potential for therapy. Fresh isolated TIL were cultured for the first 2 weeks with low doses of interleukin-2 (IL-2) (20 Cetus U/ml) to select for "tumour-specific" lymphocytes potentially present in the neoplastic lesion, followed by culture with high doses of IL-2 (1000 Cetus U/ml) to achieve TIL expansion. TIL were grown with more than 10-fold expansion in only 9 cases (mean expansion: 58-fold, range 13.5-346). In 17 cases no viable cells were obtained. After 30 days of culture with IL-2 the proliferative ability of TIL declined sharply in the majority of cases and TIL became refractory to any further stimulus, including addition of IL-4, tumour necrosis factor alpha (TNF alpha) or interferon gamma, and activation with OKT3 in solid phase. In 20 out of 37 cases TIL were available for phenotypic and functional analysis. TIL after long-term culture were predominantly CD3+ but 2 cases of osteosarcoma showed a predominance of CD3+TcR gamma/delta cells. The CD4/CD8 ratio was more than 1 in 10 cases, without correlation with tumour histology, site of lesion or TIL growth. The number of CD16+ and CD25+ lymphocytes decreased progressively during culture, the latter concomitantly with a reduction of TIL growth rate. The lytic pattern of TIL against allogenic and autologous tumour (Auto-Tu) cells was variable, but specific lysis of Auto-Tu was seen in only one case (Wilms' tumour) after culture with TNF alpha and irradiated Auto-Tu cells. The immunohistochemical analysis of tumour lesions revealed a limited lymphocyte infiltrate, a low expression of histocompatibility leukocyte antigens (HLA) class I and of the adhesion molecules ICAM1, LFA3, and a significant production of transforming growth factor beta (TGF beta). These data indicate that TIL obtained from paediatric patients are difficult to expand at levels required for immunotherapy and lack a significant number of tumour-specific T lymphocytes. A low expression of immunomodulatory molecules on tumour cells or the production of suppressive factors may prevent activation and expansion of TIL in paediatric tumours.

A total of 20 children (median age 11 years) were treated for primary thyroid carcinoma from 1976 to 1990. Papillary adenocarcinoma was diagnosed in 19 and follicular in one case. Nineteen of 20 patients were considered amenable to surgery, which consisted of total thyroidectomy in 14 and partial thyroidectomy in 5. Only one patient with extensive perithyroid soft tissue infiltration was treated with external beam radiotherapy. Monolateral or bilateral cervical nodal dissection was performed in eight and six children, respectively; in nine cases without clinical evidence of metastatic nodes. Pathological examination showed that tumor extent was greater than that clinically assessed: Multiple tumor foci within the thyroid were assessed in 8/19, unilateral positive nodes in 8, and bilateral in 6, and soft tissue infiltration in 7. Subsequently 10 patients received thyroid-stimulating hormone (TSH) suppressive hormonotherapy. Relapses occurred in 7/20 at 2-48 months (median 18) from primary treatment: Four in cervical nodes, two in cervical nodes and lungs, and one in lungs. These seven patients were salvaged with node dissection and radioiodine therapy for lung metastases. All the 20 children are alive and disease-free after a median follow-up of longer than 10 years. The incidence of relapse was greater in the group of patients not given TSH-suppressive hormonotherapy. Total thyroidectomy produced permanent hypoparathyroidism in 5/14 (36%). Thyroid carcinoma in children of this series frequently presented with multiple tumor foci within the thyroid and cervical node metastases. Prognosis was favourable even after relapse and was not related to the extent of surgical treatment. Limited surgery and suppressive hormonotherapy may be adequate therapy for thyroid carcinoma in children.