The Challenges of Managing Thymic Cancers

An Expert Interview With James Huang, MD, and Gregory J. Riely, MD, PhD

Shira Berman; James Huang, MD; Gregory J. Riely, MD, PhD


May 11, 2012

In This Article

Does Induction Therapy Improve Outcomes?

Medscape: For patients who have more aggressive tumors, what is the role of induction or neoadjuvant chemotherapy? Is it starting to move into more common practice?

Dr. Riely: Time and again we've found that complete surgical resection is the best prognostic factor for patients with thymomas, and the goal of induction therapy is to improve the odds of a complete surgical resection. We are advocates of using induction chemotherapy. That said, we don't have any randomized data to support it, but it's the sense of many investigators that it likely does improve the chance of complete surgical resections. Other investigators are exploring not only chemotherapy but also radiation in the preoperative setting, with a goal of doing the best job they can to shrink the cancer and to make surgical resection more feasible.[8]

Dr. Huang: There have been studies looking at radiation combined with chemotherapy as a primary definitive treatment in unresectable patients.[9] If the tumor is resectable, however, surgery should be the primary approach. Nonoperative therapies are options for patients who are unable or unwilling to undergo surgery.

Dr. Riely: This question comes up in patients with stage IV-A disease. When you look at thymoma, the most common site of disease is the anterior mediastinum, and the most common site of spread is the pleura. It's sufficiently common and has sufficiently different prognosis that it's referred to as stage IV-A vs stage IV-B, which indicates metastasis to another organ.

In general, unlike in the treatment of most other stage IV cancers, many institutions believe it is feasible -- and a good thing for the patient -- to resect pleural-based disease if it's resectable.

Dr. Huang: Particularly in this situation, many experts would say that combination or multimodality therapy incorporating induction chemotherapy along with surgery is a helpful approach.

Proper management of a case in which you have pleural metastases but not distant metastases has been a particularly vexing problem. The International Thymic Malignancy Interest Group (ITMIG) is an international coalition or consortium of people of all disciplines -- basic scientists, clinicians, surgeons, oncologists, radiation oncologists, pathologists -- who have an interest in this disease. The goal of the group is to leverage this international collaboration by collecting data in a global, accessible database and to pioneer collaborative translational studies.[10] There have been recent discussions within the group about standardizing the approach to management of stage IV-A disease, so there may be a forthcoming study from these discussions.

Dr. Riely: Remember, these tumors are extraordinarily uncommon. Surgical resection of thymomas is unlike surgical resection of lung cancer and is unlike coronary bypass procedures. This is a unique surgical procedure. It's hard. It's complicated. And if your center is not doing it frequently, you're not going to have the same comfort of resecting the different structures that thymomas can invade.

Medscape: And because complete resection is the most important prognostic factor, that's critical.

Dr. Riely: Exactly.

Dr. Huang: Taking a multidisciplinary approach for the more advanced cases is important, too. These cases could very conceivably require a medical oncologist, a surgeon, a radiation oncologist, and possibly even a neurologist, because many patients with thymoma have associated myasthenia gravis that may need to be managed.

Dr. Riely: And a pathologist who sees these routinely.

Dr. Huang: Agreed. The pathology of these tumors can be quite confusing, so having an experienced pathologist is very important as well.


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