Tumor recurrence and survival in patients treated for thymomas and thymic squamous cell carcinomas: a retrospective analysis.
OBJECTIVE
Thymic epithelial tumors (TET) are rare epithelial neoplasms of the thymus with considerable histologic heterogeneity. This retrospective study focused on the correlation of WHO-defined TET histotypes with survival and tumor recurrence in a large cohort of patients receiving different modes of treatment.


METHODS
Two hundred twenty-eight patients were followed for up to 21 years (median, 60 months; range, 1 to 252 months) after primary surgery. Forty-two patients received adjuvant radiotherapy (mean dose, 53 Gy), and 33 patients received adjuvant chemotherapy.


RESULTS
Seventy-six (88%) of 86 patients with WHO type A, AB, and B1 thymomas were treated by surgery alone, with three tumor relapses after 3 to 10 years (median, 3.4 years). Twelve of 67 patients with WHO type B2 and B3 thymomas in Masaoka stages I and II were treated by adjuvant radiotherapy without evidence of tumor recurrence after 1 to 12 years (median, 4 years). Among 75 patients with B2 and B3 thymomas with incomplete resection or a tumor stage III or higher, the recurrence rate was 34% (n = 23) after 0.5 to 17 years (median, 5 years) in patients receiving adjuvant radiochemotherapy, compared to 78% (seven of nine patients) in patients without adjuvant radiochemotherapy. Incomplete tumor resection was associated with a high recurrence rate (65%) and a poor prognosis (P <.01).


CONCLUSIONS
The long-term outcome of TET patients is related to tumor stage, WHO histotype, completeness of surgical removal, and type of treatment. Prospective trials are warranted to formally address the efficacy of adjuvant therapy in the treatment of localized and advanced malignant TETs.
Ströbel
Philipp
P
Institute of Pathology, University of Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany. path036@mail.uni-wuerzburg.de
Bauer
Andrea
A
Puppe
Bernhard
B
Kraushaar
Til
T
Krein
Axel
A
Toyka
Klaus
K
Gold
Ralf
R
Semik
Michael
M
Kiefer
Reinhard
R
Nix
Wilfred
W
Schalke
Berthold
B
Müller-Hermelink
Hans Konrad
HK
Marx
Alexander
A
D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology*; D012189:Retrospective Studies; D015996:Survival Rate; D013945:Thymoma / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D013953:Thymus Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy