Thymoma medical therapy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Amr Marawan, M.D. [2]

Overview

Chemotherapy and radiotherapy are used as adjuvant or neoadjuvant therapies. Neoadjuvant therapy may be administered prior to surgery to make the tumor resectable. Radiotherapy is used in the treatment of unresectable thymoma. Radiotherapy may be used to decrease the size of the tumor and improve resectability, before surgery is attempted.

Medical Therapy

Resectable

Resection of primary tumor & isolated metastasis

Consider postoperative radiotherapy

Locally advanced

Chemotherapy

Re-evaluate for surgery

Unresectable

Radiotherapy +/- chemotherapy

Chemotherapy

Thymoma

Isolated solitary metastasis

Surgery

Consider chemotherapy or radiotherapy

Evidence of distant metastasis

Chemotherapy

Adopted from the NCCN treatment algorithm^[1]

Chemotherapy is used in locally advanced thymomas, after which patients are re-evaluated for resectability.
In cases of isolated solitary metastasis, surgery may be attempted before chemotherapy administration.
Chemotherapy is also used if there is evidence of distant metastasis.
Most of the chemotherapy regimens used are based on cisplatin and anthracyclines.

Corticosteroids may be used in unresectable tumors that are refractory to radiation therapy, leading to transient partial responses.^[2]
Similar to the effects of aging and stress, steroids increase thymic fat and connective tissue and decrease corticomedullary differentiation.
Therefore in WHO sub-types A and B thymomas, corticosteroids cause tumor size reduction mainly through lymphocyte depletion.^[3]

Radiotherapy is used in unresectable thymoma or incompletely resected invasive thymoma.
The dose and fraction schemes of radiotherapy depend on the indication of the radiation and the completeness of surgical resection.^[4]

References

Overview