Virtual Library

Start Your Search

Robert Korst



Author of

  • +

    MS08 - Management of Thymic Carcinoma (ID 71)

    • Event: WCLC 2019
    • Type: Mini Symposium
    • Track: Thymoma/Other Thoracic Malignancies
    • Presentations: 1
    • Now Available
    • +

      MS08.02 - Induction Therapy for Locally Advanced Thymic Carcinoma (Now Available) (ID 3482)

      14:00 - 15:30  |  Presenting Author(s): Robert Korst

      • Abstract
      • Presentation
      • Slides

      Abstract

      Thymic carcinoma (TC) is a rare mediastinal malignancy that occurs in approximately 10% of all patients with thymic epithelial tumors. There are several different histologic subtypes of TC with squamous cell carcinoma predominating. TC is an aggressive lesion, and frequently presents in more advanced stages and metastasizes to other organs compared to thymoma. This biologic behavior is reflected in the survival rates associated with TC, which are significantly shorter than that of thymoma. Clinical trials conducted exclusively in TC patients have been scarce with only a handful of studies reported in the literature, all focused on advanced, nonsurgical patients.

      Locally advanced, nonmetastatic disease is a common presentation of TC. In the largest retrospective series reported to date, locally advanced disease was the most common stage at presentation, accounting for 45% of patients in whom pathologic stage was recorded1. The importance of complete resection for patients with locally advanced TC cannot be overemphasized. Virtually all reported series of exclusively TC patients that undergo surgical resection have determined that the ability to perform a complete resection is an independent favorable prognostic factor. Despite this, the rate of complete resection in the large, aforementioned series for locally advanced TC was only 64%.

      Given that thymic epithelial tumors (thymoma and TC) are sensitive to both chemotherapy and radiotherapy, an approach that has been favored for patients with locally advanced disease is to administer one or both of these agents preoperatively (neoadjuvant therapy). This strategy is thought to increase the chances of performing a complete resection for marginally resectable or unresectable tumors. Although no clinical trials have been reported exclusively for TC patients using the neoadjuvant strategy, two retrospective reports in TC patients utilizing neoadjuvant chemotherapy or chemoradiation demonstrated complete resection rates of 86% and 69% in marginally resectable or unresectable locally advanced disease2,3. In a phase II clinical trial of neoadjuvant chemoradiotherapy for locally advanced thymic tumors, the complete resection rate for the seven patients that had thymic carcinoma was 71%4. Despite these data, the ability of neoadjuvant therapy to definitively enhance the resectability of locally advanced TC has not been demonstrated due to the absence of randomization and a control group in these studies.

      Some published data have also suggested that TC may respond better to neoadjuvant therapies when compared to the thymoma histotypes. In the previously described phase II trial of neoadjuvant chemoradiotherapy, the patients with TC not only had a better radiographic response to treatment, they were more likely to have a near complete pathologic response (<10% viable tumor) than the patients with thymoma (57% versus 8%)4. Similarly, in a retrospective pathologic analysis of 49 patients with unresectable thymic tumors that underwent neoadjuvant therapy followed by surgical resection at a single institution, the median percent viable tumor in the surgical specimen was significantly less in the TC specimens compared to thymoma (20% versus 91%)5. These two studies also suggest that TC may respond better to chemoradiotherapy than chemotherapy alone.

      Whether targeted or immune therapies can be used successfully in the neoadjuvant setting for TC remains to be determined. Active targeted agents against this disease have remained elusive and immunotherapy may be associated with autoimmune toxicities that may preclude their use in this approach6.

      In summary, the use of induction therapy for locally advanced TC is based on the premise that this approach may enhance resectability of these aggressive tumors, which is an overwhelmingly positive prognostic indicator. However, no published data has conclusively determined that this strategy is effective in enhancing resectability due to a lack of controlled studies. TC may respond better to induction therapy when compared to thymoma, and chemoradiotherapy may induce more radiographic and pathologic responses than chemotherapy alone, but these data are preliminary.

      References.

      Ahmad U, Yao X, Detterbeck F, et al. Thymic carcinoma outcomes and prognosis: Results of an international analysis. J Thorac Cardiovasc Surg 2015;149:95-101.

      Kawasaki H, Taira N, Ichi T, et al. Weekly chemotherapy with cisplatin, vincristine, doxorubicin and etoposide followed by surgery for thymic carcinoma. Eur J Surg Oncol 2014;40:1151-1155.

      Shintani Y, Masayoshi I, Tomohiro K, et al. Multimodality treatment for advanced thymic carcinoma: outcomes of induction therapy followed by surgical resection in 16 cases at a single institution. Gen Thorac Cardiovasc Surg 2015;63:159-63.

      Korst RJ, Bezjak A, Blackmon S, et al. Neoadjuvant chemoradiotherapy for locally advanced thymic tumors: A phase II, multi-institutional clinical trial. J Thorac Cardiovasc Surg 2014;147:36-46.

      Johnson GB, Aubry MC, Yi ES, et al. Radiologic response to neoadjuvant treatment predicts histologic response in thymic epithelial tumors. J Thorac Oncol 2016;12:354-67.

      Giaccone G, Kim C, Thompson J, et al. Pembrolizumab in patients with thymic carcinoma: a single-arm, single-centre, phase 2 study. Lancet Oncol 2018;19:347-355.

      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.