Primary neuroendocrine tumors of the thymus: a multicenter experience of 35 patients.
BACKGROUND
Primary neuroendocrine tumors of the thymus (NETT) are rare tumors and represent a distinct category of tumors collectively displaying morphologic and biological neuroendocrine features. We sought to evaluate factors influencing long-term survival in patients with primary NETT.


METHODS
From January 1990 to April 2011, 35 patients (27 male patients and 8 female patients) were surgically treated for primary NETT at 5 institutions.


RESULTS
No operative (30-day) mortality occurred. Morbidity was 37.14% (13/35 patients). All patients were followed for a total of 2,703 months. Fourteen patients had associated paraneoplastic syndrome. Twenty-four patients are alive, 19 of whom are free of disease and 5 of whom continue to have disease. The median overall survival was 153 months. The overall 5-year and 10-year actuarial survival rates were 84.34% and 60.82%, respectively. The 10-year survival was evaluated according to histologic type (typical carcinoid, 77.92%; atypical carcinoid, 54.55%; large-cell neuroendocrine carcinomas, 0%; Masaoka staging (stage I, 100%; stage II, 66.67%; stage III, 61.9%; stage Iva, 25%; stage IVb, 0%), presence of paraneoplastic syndrome (no = 70.67%; yes = 32.14%), postoperative radiotherapy (yes = 39.71%; no = 85.71.%), Surveillance, Epidemiology, and End Results (SEER) staging system (localized disease, 83.3%; regional disease, 53.3%; distant disease, 0%), tumor size (<7 cm = 90.9%; ≥7cm = 28.7%; p = 0.0007), and Ki67 expression, which was available in 23 patients (<10% = 85.71%; ≥10% = 0%; p = 0.0037).


CONCLUSIONS
The prognosis of primary NETT is statistically significantly related to tumor size >7 cm and to the proliferation index (evaluated by Ki67 expression >10%). The histologic type of the neoplasm, the presence of a paraneoplastic syndrome, the Masaoka staging, the evidence of distant disease, and postoperative radiotherapy also impact prognosis.
Department of Thoracic Surgery, Azienda Ospedaliera San Camillo Forlanini, Carlo Forlanini Hospital, Rome, Italy. gcardillo@scamilloforlanini.rm.it
Giuseppe
G
Cardillo
Federico
F
Rea
Marco
M
Lucchi
Marinus A
MA
Paul
Stefano
S
Margaritora
Francesco
F
Carleo
Giuseppe
G
Marulli
Alfredo
A
Mussi
Pierluigi
P
Granone
Paolo
P
Graziano
D018278:Carcinoma, Neuroendocrine / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018426:SEER Program; D015996:Survival Rate; D013953:Thymus Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*
D019394:Ki-67 Antigen