What are the treatment options for metastatic ACC patients?
Two key factors tend to frame decisions for most patients with advanced disease:
- Tumor growth rate – Is the disease stable or do imaging studies show clear growth over the past 3-6 months?
- Tumor extent and location – How numerous and large are the tumors? Are they near vital structures such as the spine, bronchus, brain or heart?
The following table provides a framework for thinking about the options patients may choose in consultation with their physicians.
|Tumor Growth Rate|
|Tumor Extent and Location||Few, small and not near vital structures||Watchful Waiting (SBRT or Interventional Radiology if patient prefers)||SBRT, Interventional Radiology, Systemic Therapy or Surgery|
|Numerous, large or near vital structures||Watchful Waiting||Systemic Therapy|
ACC growth rates can be highly variable. Patients with lung metastases may go years without experiencing any recognizable growth. There are even rare cases of spontaneous regression where metastases have disappeared without treatment.
Given the limited effectiveness and potential side effects of surgery, radiation and systemic therapies, many doctors will recommend that ACC patients with stable disease follow a strategy of “watchful waiting”. Such patients are closely monitored until such time as there is progressive disease (clear tumor growth or new metastases) at which point new treatments will be considered.
A patient’s personal preferences may lead to a more aggressive strategy if there are only one or a few tumors (oligometastatic disease). In such cases, patients may consider stereotactic body radiation therapy (SBRT) or interventional radiology (such as radiofrequency ablation or brachytherapy).
Systemic therapy (chemotherapy and targeted drugs) often is not chosen in stable patients because no drugs have yet been found to shrink tumors consistently in a significant subset of ACC patients. Extensive research is underway that may provide attractive options in the future for patients with stable disease.
Patients with tumors that are clearly growing face a journey with few signposts and even more potential paths to follow. The extent and location of the ACC tumors will help guide the decisions.
If the tumors are few, well-defined and don’t encroach on vital organs, then the options of stereotactic body radiation therapy (SBRT), interventional radiology or, in some cases, surgery may be appropriate. The treatments may not be curative, but they may lead to disease stabilization.
In many situations, physicians recommend to patients with many growing recurrences that systemic therapy is necessary to address the evident and as-yet-unidentified tumors. This is particularly the case if the tumors are near vital structures that limit the scope of radiation, interventional radiology or surgery to address the problem.
Given the generally limited effectiveness of chemotherapy in most ACC patients, doctors often point to the option of clinical trials of targeted drugs or immunotherapy. Of course, the attractiveness of any clinical trial will depend upon the scientific promise of the drug as well as the patient’s ability to travel, insurance coverage, prior treatments and personal preferences. ACCRF maintains a list of open ACC clinical trials for patients to consider with their physicians.
In all cases, it is prudent for patients to consult with a multi-disciplinary team of ACC specialists (surgeons, radiation oncologists, interventional radiologists and medical oncologists) before selecting the best course of action.