Aggregate Data IPACTR Phase 2 – Highlights



We recently amended the IPACTR protocol to study genetic and molecular components of pediatric adrenocortical tumors (ACT). To study these aspects, we have collected, stored, and processed biological samples according to established procedures and country-specific guidelines. We developed a translational program that includes screening for TP53 mutations and polymorphisms, interrogating pathways involved in tumor initiation and progression, performing gene expression analysis, and establishing cell lines and xenograft models for drug testing.


Demographics and Clinical Findings

We have enrolled 73 pediatric adrenocortical tumor patients and 3 relatives who developed cancer since the protocol amendment. As observed in the first IPACTR study, more girls than boys enrolled. The median age at diagnosis of ACT was 4.3 years, ranging from 5 to 217 months; 46% of cases were 2.5 years old or younger. Fewer than 7% were 13 years or older at diagnosis. We observed a bilateral lesion in only 1 (1.5%) case. Most ACT cases are sporadic cases. However, we found an association between familial predisposition to ACT and LFS in 9 patients and LFL in 2 patients. As noted in our previous analysis, about 90% of patients had signs and symptoms associated with increased adrenal cortex hormone production. The most common presenting endocrine syndrome was virilization alone or in combination with hypercortisolism (Cushing syndrome). Two (3%) cases presented with aldosteronism (Conn syndrome). In 7 patients with non-functioning tumors (11%), the initial symptoms included abdominal pain, fever, weakness, and weight loss. Only 1 patient was asymptomatic. Two children had clinical manifestations consistent with a diagnosis of BWS.


Pathologic Findings and Disease Stage

Of these cases, tumor weight was ≤200 g in 68.7% of cases. At diagnosis, 43% of cases were stage I, 24% were stage II, 24% were stage III, and 9% were stage IV (with metastases). The most frequent sites of metastasis were the lungs, liver, and distant lymph nodes. Tumor spillage during surgery occurred in 11 cases; 7 of those were localized disease (stage I or II) and 4 were stage III.


Treatment

The primary physicians for all ACT patients enrolled on the study made the treatment decisions. In 79% of cases, surgical excision at the time of initial evaluation and no adjuvant chemotherapy was reported. Patients with a high risk of relapse were treated with chemotherapy, including mitotane. Survival analysis is not available at this time.