Living with cancer is different from living after cancer. And it’s becoming more common every day due to advances in treatment procedures, equipment and scientific research

‘local recurrence’ means that the cancer has come back in the same place as the original cancer or very close to it. The primary tumor site is often treated successfully (normally with surgery and radiation) and approximately 80% of patients do not experience a local recurrence.

‘Distant recurrence’ means that the cancer has spread to organs or tissues far from the original cancer; also called metastasis. These new tumors are also called ‘mets’. Approximately, 50% of ACC patients will develop distant metastasis most commonly to the lungs (then the liver, bones). When cancer spreads, it is still the same type of cancer. For example, if you have ACC, it may spread to the liver but it is still called ACC (not liver cancer).

ACC metastasis can develop 3-10 years (and sometimes earlier/later) after the initial diagnosis. It’s also important to know that even after achieving clean margins to the initial primary tumor with no local recurrence, there is a likelihood of ACC spreading to other areas of the body. For these reasons, it requires a regimen of lifelong monitoring.

How does ACC spread

Perineural Invasion (PNI) – ACC has a high tendency to microscopically infiltrate the adjoining nerve tissues around the tumor site, which is called perineural invasion (PNI). This microscopic invasion of cancer cells into the linings of connected nerve tissue follows the ‘path of least resistance’ and can be difficult for a surgeon to detect during surgery. Due to its microscopic size, it may not show up on any imaging scans. Major nerves that lead back to the brain should always be inspected with scans and monitored closely.
Even when achieving clean margins, it has been reported that this cancer can ‘skip’ areas and can infiltrate nerves which may reach a significant distance from the primary tumor.

Bloodstream (hematogenous dissemination) – Like many cancers, cells from the primary tumor can break off; penetrate the walls of blood vessels, after which they are able to circulate through the bloodstream. Due to the high level of blood supply, the lungs and liver are the most common sites for ACC metastatic spread.

It is relatively rare for ACC to infiltrate nearby lymph nodes although this can happen in about 10% of all cases. Research has also shown that lymphatic involvement may be an indicator of a more aggressive form of ACC.

Remember, ACC is typically slow growing with a gradual growth pattern, but over time can become progressive.

Studies have shown that surgery for a ‘local’ recurrence (head/neck area) has been associated with significantly increased long-term survival. However, the overall uncertainty about the role of local treatments for ‘distant recurrence/metastasis’ (i.e., lungs) still remains. Only recently are studies being conducted to measure a patient’s overall survival rate after treating a distant recurrence with local treatments such as surgery, radiation, etc. For this reason, physicians do not have a clear standard of care when treating ACC metastasis.

Treatment choices and decisions for metastatic tumors can be varied and complex when taking into account the tumor size, growth rate, location, number of tumors, adjoining critical organs, recommendations from different specialists (radiation oncologists vs surgeons), and the knowledge and comfort level of the patient.

It’s also important to know that most ACC patients who have just been diagnosed with a recurrence (local or distant) are not initially treated with systemic therapy or drugs. As the cancer is normally slow growing, doctors may delay the start of systemic therapy with local treatments (i.e., surgery, external or internal radiation), in the hopes that better drugs become available. Furthermore, there are no FDA-approved systemic therapy options available for ACC

While there has been much progress in research, currently, there is limited effectiveness in the use of systemic therapy (chemotherapy and targeted drugs). For this reason, systemic therapy often is not chosen in patients with stable disease. For example, ACC does not normally respond to chemotherapy unless the cancer becomes fast growing. Chemotherapy enters and leaves the body before these slow growing ACC cells divide making little impact in ridding the cancer.

If the cancer is stable or tumors are few, small (nodules) and not near critical structures (heart, brain, spine) some doctors may recommend a strategy of “watchful waiting” and these patients are closely monitored. For instance, patients with lung metastasis can go on for years without experiencing recognizable growth, however, metastasis in the liver may be addressed more quickly. 

On the other hand, doctors may suggest a more aggressive approach if there are only a handful of tumors (oligometastatic disease). This may be described as an intermediate stage of cancer between localized and widely spread. Again, patients may pursue conventional treatments in the hopes of delaying progression of the cancer. While surgically removing a tumor has historically been the preferred treatment for limited metastasis, stereotactic body radiation therapy (SBRT), brachytherapy (internal radiation) or interventional radiology (radiofrequency ablation, microwave ablation or cryoablation) are a number of less invasive procedures being performed today. 

Interventional Radiology (IR) procedures can be used to treat cancer in a number of areas in the body such as the lung, liver and kidney. Recent studies have also shown positive results in the effectiveness of treating ACC metastasis. Ironically, this procedure does not involve radiation. The method involves placing a needle into the tumor and delivering heat (radio-frequency ablation) or cold (cryoablation) to destroy the tumor. More recently, doctors have started to use IR to treat the head and neck area, and its role in this context continues to expand. Like brachytherapy, IR procedures are less invasive and be repeated over time if necessary. Most patients can return home the day of the procedure.

Patients may often work with a medical oncologist to explore systemic therapy (or drugs) if the tumors show significant growth throughout an organ or the body. Additionally, systemic therapy may be suggested if tumor growth has the potential to compromise organ function and palliative therapy (as those listed above) are no longer an option.

Because of the rarity of ACC and limited benefit of chemotherapy, doctors might suggest a clinical trial. Many clinical trials are researching the use of targeted drugs or a combination of drugs such as immunotherapy.

Throughout each stage of their cancer journey, patients should seek the advice of a multidisciplinary team of surgeons, radiation oncologists and medical oncologist.