Debulking for Extensive Thymoma


Stage I

Macroscopically and miscroscopically completely encapsulated

Stage IIa

Microscopically transcapsular invasion

Stage IIb

Macroscopically invasion into surrounding fatty tissue or grossly adherent to but not through the mediastinal pleura or pericardium

Stage IIIa

Macroscopic invasion into pericardium or lung without great vessel invasion

Stage IIIb

Macroscopic invasion into pericardium or lung with great vessel invasion

Stage IVa

Pleural or pericardial dissemination

Stage IVb

Lymphatic or hematogenous metastasis



A debulking procedure is defined as a partial resection of an unresectable tumor with the intent of enhancing the efficacy of additional therapies. Debulking is useful in a limited number of malignancies, primarily gynecological ones. The value of debulking for advanced thymoma, defined as Masaoka stages III and IV, remains unclear, as there is no definitive evidence in the literature of survival benefit with this approach.



Search Strategy


The PICO criteria around which the literature search was conducted included patients with regionally advanced thymoma and compared debulking to no surgery, evaluating for survival and quality of life. A search of Medline database was performed with the keywords “debulking” or “tumor debulking” and “thymoma” or “thymic tumor” or “thymic carcinoma”. Studies in languages other than English were not included. Only papers that reported comparison of debulking versus non-surgical therapy – typically characterized as surgical biopsy alone – were included. All papers were published after 1981 (the year in which Masaoka staging system was established), and they classify the patient population based on this system. Using these criteria, only ten retrospective case series were identified, which provided the best evidence for this subject. The analysis of the results is presented in Table 56.2.


Table 56.2
Studies on debulking surgery for stage III and IV thymomas





















































































Author, date (n = no of patients)

Stage

Outcomes

Comments

Study type (quality of evidence)

Cohen et al. [3], (1984) (n = 23)

23 patients with stage III and IV

Complete resection is the most important factor affecting long-term survival. No difference in survival between group who received radiation post-operatively or not when complete resection obtained. No survival benefit in debulking

No difference in survival with cell type. Strong indicator gross invasion of tumor into adjacent structures

Retrospective, Evidence quality very low

Complete resection (n = 13)

5.3 years median follow-up showed 35 % survival

Irradiation may be value of local control

All followed by radiation, chemotherapy or nothing

Curran et al. [4], (1988) (n = 103)

Stage III (n = 36)

No difference between debulking and biopsy

Advantage of aggressive debulking is to reduce size of radiotherapy field

Retrospective, evidence quality very low

Stage IV (n = 4)

5 year survival 21 %

Debulking (n = 15)

Biopsy alone (n = 13)

Urgesi et al. [9], (1990) (n = 36)

Stage III debulking (n = 21)

Patients with debulking surgery in stage III had better survival than biopsy alone and marginally better survival for patients in stage IVa

Total resection showed better results

Retrospective, evidence quality very low

Stage IVa debulking (n = 15)

Stage III biopsy alone (n = 5)

Stage IVa biopsy alone (n = 4)

Ciernik et al. [5], (1994) (n = 31)

Stage III and IV (n = 31)

Tumor debulking did not improve survival

Radiation therapy for local tumor control is most effective treatment

Retrospective, evidence quality very low

Debulking (n = 15)

5-year survival: 61 % for stage III and 35 % for stage IV (no difference between stage IVa and IVb)

Biopsy alone (n = 16)

Liu et al. [7], (2002) (n = 38 with thymic carcinoma)

Stage III (n = 13)

Debulking did not improve survival. Median survival: complete resec – 35

Resectability and stage were the main predictors of survival

Retrospective, evidence quality very low

Stage IV (n = 22)

Median survival: complete resec – 35

Chemotherapy and radiation therapy had no significant impact in survival

Complete resect (n = 8)

Debulking (n = 7)

Biopsy alone (n = 23)

Akoum et al. [6], (2003) (n = 27)

Stage III (n = 14)

Better 5-year survival with complete resection (81 %), than bebulking or biopsy alone (44 %)

Resectability is the most important survival factor. Better survival in patients who present with myasthenia gravis (early diagnosis when tumor still resectable)

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Dec 30, 2016 | Posted by in CARDIOLOGY | Comments Off on Debulking for Extensive Thymoma
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