“How am I doing?”, asked one of my colorectal patients.
Ten years ago, I first met John (name changed for privacy), a warm and spirited individual diagnosed with stage 3 colon cancer. After undergoing surgical resection of the primary colon tumor and six months of standard adjuvant chemotherapy with mFOLFOX, John and I optimistically looked forward to a future free of cancer. However, life took an unexpected turn when, within a few years, John developed new limited lung nodules, indicating Stage IV metastatic disease.
Throughout my years of practice, I have come to appreciate the uniqueness of each patient’s journey and the profound impact that personalized care can have on their lives. Most patients that developed recurrent metastatic cancer most often will have widespread disease that is best treated with systemic therapy. John’s case was a bit different as he only had limited 2-3 lung nodules that were all amenable to local treatments such as surgery, ablation or radiation.
With John’s best interests at heart and consensus at tumor board, I had recommended a series of local wedge resections with the cardiothoracic surgeon. Each treatment modality, whether it be resection, ablation, radiation therapy, has its own pros and cons, which are most often discussed at a tumor board if more than one option is considered with or without systemic therapy. Certain malignancies may have good systemic treatment options to consider especially with hormonal therapy, targeted therapies or immunotherapy. In colon cancer, 5FU or FOLFOX are the only regimens that have been shown to prevent recurrent tumors in patients with high-risk colorectal malignancies who are in remission which John already had when he was initially diagnosed. Chemotherapy such as FOLFIRI, VEGR, EGFR inhibitors and TKIs have not shown or failed to demonstrate the prevention of recurrent disease in large, randomized trials.
During this time, John and his loving wife understandably questioned the potential benefits of further systemic chemotherapy. Seeking a second opinion at another institution, John received a brief course of chemotherapy using FOLFIRI, only for another lung nodule to develop within a year. When John returned to me, I continued to advocate for local treatment. As a physician, my deepest commitment is to my patients’ well-being, and I believed that local therapies could offer John the best quality of life by simply avoiding the known risks and side effects of systemic chemotherapy. It was a challenging decision, but one driven by compassion and trust. As a medical oncologist, it would be easy for me to simply write for chemotherapy at any point in time. The good news was that this new lung nodule was easily treatable with CT guided ablation and again I was hoping to avoid months of chemotherapy. Probably within another 1-2 years, John developed another lung nodule that was deep into the lungs not so easily treatable with resection or ablation however most amenable with SBRT (stereotactic body radiotherapy). Despite these recurrences, each local treatment saved this patient years of drug therapy and the potential loss in the “window of opportunity” as we say to treat with local options.
A decade has passed since John’s initial diagnosis, and after numerous varied local treatments for his metastatic lung nodules, he now finds himself in complete remission, embracing life with energy and enthusiasm. Eight years have elapsed since his Stage IV diagnosis, and it’s been two years since we addressed his last lung nodule. When I saw John this past week, he looked at me with a hopeful gaze and asked, “How am I doing?”. With a heart filled with pride and admiration, I met his eyes and confidently replied, “You are doing well.”
The decision to pursue local therapies for oligometastatic disease depends on several factors, including the tumor type, extent of disease, patient performance status, and the availability of effective systemic therapies. Are metastasis synchronous meaning we are seeing both the primary tumor and metastatic tumor at the same time implying the first of many metastatic tumors. Or is metastasis metachronous meaning the primary tumor was treated years prior and we are now dealing with a new metastatic tumor by itself which often implies it is the one and only tumor. Local treatments are best considered for metachronous tumors. It is essential to consider each patient individually when making these decisions.
Some types of cancers where the oligometastatic approach might be more effective include:
- Colorectal cancer: In select cases, resection or local ablative therapies for liver or lung metastases may be considered to prolong survival or even achieve a cure.
- Non-small cell lung cancer (NSCLC): Stereotactic body radiation therapy (SBRT) or surgery may be used to treat a limited number of metastatic lesions in the lung, liver, adrenal glands, or brain, especially when there is a good response to systemic therapy.
- Breast cancer: Some patients with limited metastatic disease, particularly in the liver or bone, may benefit from local therapies in addition to systemic treatment.
- Prostate cancer: Patients with oligometastatic prostate cancer, typically involving the bone or lymph nodes, may be candidates for local therapies such as SBRT or surgical resection.
- Renal cell carcinoma: Patients with limited metastatic disease, especially in the lung, bone, or liver, may benefit from local therapies such as surgery or radiofrequency ablation.
- Melanoma: Local therapies like surgery or radiotherapy may be useful for patients with a limited number of metastases, particularly in the lung, liver, or brain.
Some cancers are less likely to benefit from local therapies for oligometastatic disease, either because they tend to be more aggressive, have a high likelihood of widespread micrometastatic disease, or do not respond well to local treatments. It is important to remember that each case is unique, and treatment decisions should be made in close consultation with a multidisciplinary team.
Cancers that are generally less likely to benefit from local therapies for oligometastatic disease include:
- Small cell lung cancer (SCLC): SCLC is an aggressive cancer that often has widespread micrometastases even when it appears to be oligometastatic. Systemic chemotherapy and immunotherapy are the mainstays of treatment for metastatic SCLC.
- Pancreatic cancer: Pancreatic cancer is typically aggressive, with a high likelihood of micrometastatic disease even when a limited number of metastases are visible. Systemic chemotherapy is the primary treatment for metastatic pancreatic cancer.
- Glioblastoma: Glioblastoma is a highly aggressive brain cancer that rarely metastasizes outside the central nervous system. Even with limited metastatic lesions, the primary treatment remains focused on the brain, including surgery, radiotherapy, and chemotherapy.
- Gastric cancer: Gastric cancer tends to disseminate widely, and even oligometastatic disease may represent the tip of the iceberg. Systemic chemotherapy and targeted therapies are the main treatments for metastatic gastric cancer.
- High-grade neuroendocrine carcinomas: These aggressive tumors often spread rapidly and are associated with a high likelihood of micrometastatic disease. Systemic chemotherapy is the primary treatment option for metastatic high-grade neuroendocrine carcinomas.
These are just a few examples, and it is important to note that exceptions may exist. In some cases, local therapies might be considered for symptom control, palliation, or to delay the need for systemic therapy. As always, treatment decisions should be individualized, and patients should be involved in the decision-making process.
There are several local modalities used to treat oligometastatic disease. Here’s a list of the common approaches along with their pros and cons:
Surgery
Pros:
- Offers the potential for complete removal of the metastatic lesion
- Can provide a definitive diagnosis through histopathology
- Can be curative in select cases
Cons:
- Invasive procedure with associated risks, such as bleeding, infection, and damage to surrounding structures
- Requires anesthesia and a recovery period
- May not be feasible in all cases, depending on the location, size, or number of metastases
Stereotactic Body Radiation Therapy (SBRT)
Pros:
- Non-invasive treatment with high precision in targeting metastatic lesions
- Can treat multiple lesions simultaneously
- Short treatment course (typically 1 to 5 sessions)
Cons:
- Risk of radiation-induced side effects or damage to nearby healthy tissue
- Limited effectiveness for large, radioresistant, or hypoxic tumors
- Not suitable for all locations due to the risk of damage to critical structures
Microwave Ablation (MWA)
Pros:
- Minimally invasive procedure with fast ablation times
- Less affected by the heat-sink effect compared to RFA
- Can be performed percutaneously under image guidance
Cons:
- Limited to small lesions, typically less than 3-4 cm in size
- Risk of complications such as bleeding, infection, and damage to nearby structures
- Limited data on long-term outcomes compared to other modalities
Cryoablation
Pros:
- Minimally invasive procedure that uses extreme cold to destroy tumor cells
- Can be performed percutaneously under image guidance
- Lower risk of damage to adjacent structures due to the formation of an ice ball
Cons:
- Limited to small lesions, typically less than 3-4 cm in size
- Risk of complications such as bleeding, infection, and damage to nearby structures
- May not be suitable for all tumor locations due to the risk of freezing critical structures
Let me know what you think? Ask a question or leave a comment!
About the author
Dr. Sajeve Thomas is a distinguished medical professional and a compassionate guide in the field of oncology. With over a decade of dedicated experience as a board-certified medical oncologist/internal medicine specialist, Dr. Thomas has become a trusted expert in the treatment of melanoma, sarcoma, and gastrointestinal conditions. Currently practicing at the renowned Orlando Health Cancer Institute, he brings a wealth of expertise to the complex and challenging world of oncology.
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