Primitive neuroectodermal tumors (PNETs) are rare, rapidly progressive, small- round cell tumors with a poor prognosis despite multimodal therapy, including surgery and chemoradiotherapy. The treatment of choice was unknown since no clinical series with surgical therapy had been reported. We evaluated the impact of multimodal treatment in patients with PNETs located in the thoracic region.
Between 1998 and 2006, 25 patients with PNETs in the thoracic region were treated in 3 tertiary-care hospitals. The patients consisted of 15 males and 10 females with a mean age of 27.2 years (range, 6-60). The tumor was in the chest wall in 20 (involving the costovertebral junction in 9), the lung in four, and the heart in one patient. Twelve patients received neoadjuvant chemotherapy (54.5%), and 22 of 25 patients underwent surgery.
In patients who received neoadjuvant treatment, the mean regression rate was 65.4% (range, 30-100%). Eighteen (82%) patients underwent chest wall resection, while 7 (32%) had vertebral resections, and the remaining 4 (16%) had pulmonary resections. A complete resection was possible in 18 of 22 patients (82%). Patients with incomplete and complete resections had 25% and 56% 5-year survival rates, respectively (p = 0.13). The progression-free 3-year survival rate was 36% and the median survival time was 13 months. The complete resection rate was significantly higher in patients receiving neoadjuvant therapy (p = 0.027). The 5-year survival rate of the patients with or without neoadjuvant therapy was 77% and 37%, respectively (p = 0.22) although it prolonged the disease-free survival (p = 0.01). The 5-year survival rate of patients without costovertebral junction involvement was 66%, whereas patients with PNETs involving the costovertebral junction had a 21% 3-year survival. The difference was statistically significant (p = 0.01). The 5-year progression-free survival rate of patients without costovertebral junction involvement was 58%, whereas patients with PNETs involving the costovertebral junction had a 14% 1-year progression-free survival (p = 0.004).
PNET is an aggressive malignancy that often requires multimodal therapy. Induction chemotherapy leads to a greater complete resection rate and better disease-free survival, while involvement of the costovertebral junction indicates a poorer survival.