**5. Staging**

There are several different staging systems for thymoma and thymic carcinoma, but the Masaoka-Koga staging system [32] and the American Joint Committee on Cancer (AJCC) the eighth edition of the TNM prognostic staging system [33] are the most commonly used.

Both staging systems are based on the extent of the primary tumor, invasion of adjacent structures and dissemination. In contrast to other thoracic cancers, both lymph node and distant metastases are considered stage IV disease. The Masaoka-Koga staging system (**Table 2**) is a surgical-pathological system that can only be definitely ascertained after surgery is performed. Historically this has been the most widely used staging system, so most data supporting treatment options is based on patients staged according to the Masaoka-Koga system.


#### **Table 2.**

*Masaoka-Koga staging system.*


**81**

**Table 4.**

*Thymoma and Thymic Carcinoma*

**6. Management**

*DOI: http://dx.doi.org/10.5772/intechopen.87132*

there are different options, as discussed below.

**Treatment thymoma and thymic carcinoma according to stage**

Consider PORT in WHO type B2/3

Consider neoadjuvant chemotherapy in IIIA tumors. Neoadjuvant chemotherapy in IIIb tumors Complete resection or, when not feasible during

IVB chemotherapy or individual approach

*Treatment thymoma and thymic carcinoma according to stage.*

Stage III **Resectable or potentially resectable disease:** Multimodality approach

surgery, maximum debulking

**Unresectable disease** Chemoradiation

**6.1 Treatment thymoma**

Stage II Complete resection

PORT

Stage IV IVA same as stage III

*6.1.1 Resectable disease*

AJCC TMN stage

with prognosis, we would advise the AJCC TNM staging system.

In 2018, the AJCC published the eighth edition of the TNM staging system (**Table 3**). They incorporated a proposal from the International Association for the Study of Lung Cancer (IASLC) and the International Thymic Malignancy Interest Group (ITMIG) for the staging of thymoma and thymic carcinoma based on the anatomical extend of the tumor combined with prognostic factor. Survival data of 10,808 patients was used [33]. Because of this larger dataset, the addition of nodal metastasis and a better correlation

There are no phase III randomized, clinical trials on the treatment of thymoma and thymic carcinoma. Although they are two different entities, the general management per stage is almost the same. Surgery aimed at complete resection is the cornerstone of thymoma and thymic carcinoma management and should always be pursued. All patients should be managed by a multidisciplinary team with experience in the management of thymoma and thymic carcinoma. The choice of treatment depends on resectability, stage, and whether or not myasthenia gravis is present. In all stages of thymoma and thymic carcinoma, resectability should be considered. When deemed possible in stages IIIb and IVa, surgery is part of a multimodality approach [25, 34–37]. An example of management according to stage could be as shown in **Table 4**. One should realize though that there is no advise based on phase III randomized controlled trails available and every case should be considered individually and

Once complete resection of a thymoma is deemed possible, complete resection of the thymus, the tumor, and the invaded structures (including resection of the lung parenchyma or pericardium and vena cava reconstruction if necessary) is

Complete resection and PORT

Multimodality approach

**Unresectable disease** Chemoradiation

IVA same as stage III IVB chemotherapy

tumors

PORT

**Resectable or potentially resectable disease:**

Consider neoadjuvant chemotherapy in IIIA tumors. Neoadjuvant chemotherapy in IIIb

Complete resection or, when not feasible during surgery, maximum debulking

Thymoma Thymic carcinoma

Stage I Complete resection Complete resection

#### **Table 3.**

*TNM staging AJCC eighth edition.*

#### *Thymoma and Thymic Carcinoma DOI: http://dx.doi.org/10.5772/intechopen.87132*

In 2018, the AJCC published the eighth edition of the TNM staging system (**Table 3**). They incorporated a proposal from the International Association for the Study of Lung Cancer (IASLC) and the International Thymic Malignancy Interest Group (ITMIG) for the staging of thymoma and thymic carcinoma based on the anatomical extend of the tumor combined with prognostic factor. Survival data of 10,808 patients was used [33]. Because of this larger dataset, the addition of nodal metastasis and a better correlation with prognosis, we would advise the AJCC TNM staging system.
