A. K. Zamora1, M. J. Zobel1, N. M. Shillingford2, S. Zhou2, E. S. Kim1,3 1Children’s Hospital Los Angeles,Pediatric Surgery,Los Angeles, CA, USA 2Children’s Hospital Los Angeles,Pathology,Los Angeles, CA, USA 3University Of Southern California,Surgery,Los Angeles, CA, USA
Introduction: Pleuropulmonary blastoma (PPB) is the most common primary lung cancer in children. While rare, these tumors are highly aggressive and often present as massive intrapleural tumors. Tumor recurrence and overall survival is dependent on extent of surgical resection, and neoadjuvant chemotherapy may help facilitate a complete resection. We sought to examine our institutional experience with PPB and determine the effect of incomplete versus complete tumor resection on patient outcomes and recurrence.
Methods: After IRB approval, a retrospective chart review of all patients diagnosed with PPB was performed at Children’s Hospital Los Angeles from 1/1998 to 8/2018. Cases were identified by histologic confirmation and Dehner graded from I to III: grade I being purely cystic and the more advanced grade III purely solid. Data collection included age, gender, location of tumor, use of chemotherapy and radiation, extent of resection, recurrence and overall survival.
Results: Eight cases of PPB were identified in 7 patients (4 females: 3 males) that underwent surgical resection. The median age at diagnosis was 2.3 years (1 day to 4 years). Neoadjuvant chemotherapy was utilized in 3 of 8 cases (38%) prior to attempted surgical resection, while 5 cases (62%) proceeded straight to surgery. The operative goal was to achieve gross total resection (>95%), and to this end, 3 partial lobectomies/wedge resections, 4 lobectomies, and 1 pneumonectomy were performed. Histologically, 3 cases were Type I, 1 was Type II, and 4 were poor prognosis Type III PPB. The average length of follow up was 4.4 years with an overall survival of 71%. Six of 8 cases (75%) underwent complete resection with negative gross and microscopic margins (R0). One of these six (17%), who had Type III disease, recurred locally and eventually died, while all of the other patients survived. Two of the 8 cases had incomplete resections; one patient underwent re-excision on post-operative day 4 to achieve negative margins, and the other patient, who received neoadjuvant chemotherapy, had a positive hilar microscopic margin (R1) which was not amenable to further excision. This R1 resection patient, who had Type III disease, subsequently developed a brain metastasis, which was surgically removed. Both patients are alive, and currently disease-free. None of the patients experienced any other post-operative complications.
Conclusion: Our data shows that PPB patients who achieve gross total resection with or without neoadjuvant chemotherapy have good overall survival with minimal morbidity. Further large-scale studies are needed to determine the benefit of surgical resection margins on tumor recurrence and survival to guide future surgical protocols.