July/August 2025
Before & After
What is neoadjuvant immunotherapy?
For many cancer patients, successfully removing their tumor is often just the first step. They will also be referred to a medical oncologist to discuss further treatment, such as immunotherapy (which helps the immune system identify and destroy hidden cancer cells) or chemotherapy (which kills fast-growing cancer cells, but can also affect healthy cells).
Why? Even after successful surgery, there's a risk of microscopic cancer cells being left behind or having spread locally. Medical oncology targets these cells to significantly reduce the chance of cancer returning.
But recently, for certain types of cancers, physicians have discovered an advantage in administering immunotherapy before surgery. This approach is called neoadjuvant immunotherapy ('neo' meaning new or preceding, 'adjuvant' meaning helpful or assisting).
"This treatment can often reduce the extent of the surgery needed to remove the tumor, and can help improve the surgical outcomes overall," explains medical oncologist J. Keegan Bakos, MD, of South Carolina Cancer Specialists. "In some cases, we can achieve our ultimate goal—to have the surgery completed and not see any evidence of cancer in the surgical specimen anymore.”
The Right Response
Traditionally, the procedure for many cancers involved surgery to remove the primary tumor, followed by adjuvant chemotherapy, radiation therapy or immunotherapy. However, the use of neoadjuvant immunotherapy has grown significantly in recent years. Besides potentially easing the burden of surgery, this approach also allows physicians to observe how the tumor responds in real time.
"We are looking for something called a pathologic response, which means a reduction in viable cancer cells in the tissue after surgery," Dr. Bakos says. "This shows us how effectively the neoadjuvant immunotherapy worked. In some cases, the specimen shows a pathologic complete response, or pCR, where there is no longer any evidence of cancer cells at all."
Currently, neoadjuvant immunotherapy has shown the most beneficial pathological responses in only some types of cancer, including non-small cell lung cancer and certain cases of breast cancer. Clinical trials have also proven this treatment to be effective for melanoma, a type of skin cancer.
“This is really starting to become the standard of care for melanoma treatment,” Dr. Bakos says. “Administering immunotherapy before surgery can shrink the tumor, leading to an improved surgical outcome, and we may find no or few living cancer cells. In some cases, the patient may not necessarily need immunotherapy or chemotherapy after the surgery.”
Candidates for neoadjuvant immunotherapy are identified through the multi-disciplinary teamwork of medical oncologists, surgeons and radiation oncologists who collaborate on certain cases at the Nancy N. and J.C. Lewis Cancer & Research Pavilion.
"There are many discussions with the surgery team, the radiation oncology team, and everyone that would be involved in a patient’s treatment plan," Dr. Bakos says. “We look closely at each case, and determine if a patient may be able to tolerate the therapy better if we use it before surgery instead of after. Then, ultimately, we want to see the pathologic complete response, which can lead to better overall survival and improved cure rates.”
Added Value
Some patients may be wary of adding another form of treatment to their plan, so Dr. Bakos discusses the potential risks and benefits of this approach during the treatment decision process.
"Some patients just want the tumor out of their body as soon as possible, which is understandable," he says. "They may worry about whether their cancer will get worse as the sequence of treatment changes. Part of my role is to explain the long-term improved outcomes and rate of overall survival that we have seen from this treatment.”
Dr. Bakos also notes how neoadjuvant immunotherapy can target what is known as micro-metastatic disease, meaning cancer cells that have spread from the primary tumor but are too few or too small to be detected by imaging.
“I think this will likely change the standard of care for some cancer types going forward,” he says. “Meanwhile, new clinical trials are looking at other cancer types as well. Providing this treatment at an earlier stage of cancer, before surgery, is a relatively new approach, but what we’ve seen gives us a strong reason to be optimistic.”