Recurrent Thymoma and Thymic Carcinoma
Patients with recurrent thymomas who undergo re-resection of recurrent disease may have prolonged survival when complete resection is attained. However, only a minority of patients may be candidates for resection.
In a review of 395 patients who underwent resections for thymic epithelial tumors, 67 had tumor recurrence and 22 underwent a re-resection procedure. The 10-year survival rate was 70%. In a second series, 30 of 266 patients initially treated by total resection of the tumor had a recurrence, and in all 30 patients surgical resection had been attempted. Complete resection of the recurrent tumor was obtained in ten cases. Overall 5-year and 10-year survival rates for the 30 patients with recurrent thymomas were 48% and 24%, respectively.
Of note, patients in these series may have received chemotherapy and/or radiation therapy in addition to surgery.
A number of studies have demonstrated that certain chemotherapy drugs can induce tumor responses as single agents or in combination. In general, higher response rates have been reported with combinations; however, no randomized trials have been conducted to date.
A phase II trial of cisplatin (50 mg/m2) reported an objective response rate of 10% among 21 patients. Six of 13 patients treated with single-agent ifosfamide had objective responses. Octreotide with or without prednisone may induce responses in patients with octreotide scan-positive thymoma. Six of 16 patients achieved objective responses to octreotide (1.5 mg/day subcutaneously) associated with prednisone (0.6 mg/kg/day orally for 3 months, 0.2 mg/kg/day orally during follow-up).
In a second study, 2 complete (5.3%) and 10 partial responses (25%) were observed among 42 patients.
In general, combination chemotherapy produces complete and partial remissions; some of the complete remissions have been pathologically confirmed at subsequent surgery.
In a series of 30 patients with stage IV or locally progressive recurrent tumor following radiation therapy, the PAC regimen (cisplatin, doxorubicin, cyclophosphamide) achieved a 50% response rate, including three complete responses. The median duration of response was 12 months, and the 5-year survival rate was 32%.[Level of evidence: 3iiiDiv]
In another study, the ADOC regimen (doxorubicin, cisplatin, vincristine, cyclophosphamide) produced a 92% response rate (34 of 37 patients), including complete responses in 43% of patients.
One study of combined chemotherapy with cisplatin and etoposide produced responses in 9 of 16 patients treated, with a median response duration of 3.4 years and a median survival of 4.3 years.
Nine of 28 patients with invasive thymoma or thymic carcinoma who received four cycles of etoposide, ifosfamide, and cisplatin (VIP) at 3-week intervals had partial responses. The median duration of response was 11.9 months (range, <1–26 months), and the median overall survival (OS) rate was 31.6 months. The 1-year and 2-year survival rates were 89% and 70%, respectively.[Level of evidence: 3iiiDiv] Nine of 34 patients treated with VIP had partial responses (32%; 95% confidence interval, 16%–52%). The median follow-up was 43 months (range, 12.8–52.3 months), the median duration of response was 11.9 months (range, <1–26 months), and the median OS rate was 31.6 months. Based on Kaplan-Meier estimates, the 1-year and 2-year survival rates were 89% and 70%, respectively. These results appear to be inferior to other combinations.
Standard treatment options:
- Repeat surgical resection, particularly for local recurrences and, in some cases, pleural and pericardial implants. Postoperative radiation therapy has been used for patients with incomplete resections and has been employed in selected patients following complete resection of recurrent thymoma.
- Radiation therapy (when possible, based on previous treatment).
- Corticosteroids in unresectable tumors that have not responded to radiation therapy.
Treatment options under clinical evaluation:
Areas of active clinical evaluation for patients with recurrent thymoma or thymic carcinoma include:
- New drug regimens.
- Variation of drug doses in current regimens.
- New radiation therapy schedules.
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with recurrent thymoma and thymic carcinoma. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.
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