Tumor-Infiltrating Lymphocyte (TIL) Therapy

Many cancers hold immune cells called tumor-infiltrating lymphocytes (TILs). TILs are white blood cells made in bone marrow that have migrated from the blood to the tumor(s).

TIL infusion therapy is a promising experimental type of cancer immunotherapy that harnesses the potential of these TILs to help fight cancer.

Experts at UPMC Hillman Cancer Center are creating personalized TIL therapy plans to treat metastatic cancer, or cancer that has spread in the body. This therapy uses cancer-fighting T cells from the person’s own tumor to create a treatment to eliminate their cancer.


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What Is Tumor-Infiltrating Lymphocyte (TIL) Therapy?  

Your body’s immune system plays an important role in fighting off disease. But sometimes it is not strong enough on its own.

Immunotherapy can help boost the body’s natural defenses and enhance the immune response to fight off different diseases, including cancer.

One experimental type of cancer immunotherapy is tumor-infiltrating lymphocyte (TIL) infusion therapy. It uses the cancer-fighting T cells from a patient’s own tumor to create a treatment to eliminate the cancer.

TILs are white blood cells made in bone marrow that have migrated from the blood to the tumor. People with cancer still have TILs, but either there aren't enough of them, or they’ve become too depleted over time to destroy their cancer.

Adoptive cell transfer of autologous tumor-infiltrating lymphocyte therapy – or TIL therapy for short – is a complex, personalized therapy for certain types of solid tumor cancers.

Why Do You Perform Tumor-Infiltrating Lymphocyte Therapy?

TIL therapy is an advanced form of immunotherapy for solid tumor metastatic cancer, or cancer that has spread. It can sometimes help where other cancer treatments have failed.

While its full benefits are being studied, there are several advantages to TIL therapy, including:

  • It treats large volumes of tumors.
  • It can successfully treat cancers when other therapies haven’t been effective.
  • TIL therapy can result in long-lasting responses.

How does TIL therapy work?

In tumor-infiltrating lymphocyte (TIL) therapy, a person's tumor is removed during surgery.

Later, in the lab, the tumor’s fighter T cells are isolated and multiplied to recognize the person’s cancer-specific mutations. Typically, it takes two to three weeks to grow and assess the suitability of the T cells for future infusion.

If they are suitable, doctors then infuse the lab-grown T cells back into the person’s bloodstream to destroy their tumors. Once infused, the new TILs have the same tumor-infiltration traits as the person’s original immune cells.

Researchers are evaluating TIL therapy in various clinical trials against many different types of cancer. Unlike chemotherapy and other treatments that are mass-produced for many patients, TILs are made specifically for you. They are a true form of personalized cancer care.

Because TIL therapy is made from each person’s unique immune cells, it can often fight that person’s unique cancer.

Tumor-Infiltrating Lymphocyte (TIL) Therapy diagram.

What types of cancer can be treated with TIL therapy?

TIL therapy has shown promising results in bile duct, breast, and colorectal cancers as well as melanoma, a type of skin cancer. Studies also are being conducted using TIL therapy to treat other cancers, including ovarian and pancreatic cancers.

Because TIL therapy is considered an experimental treatment, it is performed as part of a clinical trial. Clinical trials enable people with cancer to access the latest treatments as they’re developed.

What types of TIL therapy clinical trials are available at UPMC Hillman?

To enroll in a TIL therapy clinical trial, you would first be enrolled in a tumor procurement clinical trial. This first trial allows the study team to analyze your tumors post-operatively and attempt to separate and grow the TILs.

If the expanded TILs are acceptable for infusion, you can then enroll in one of our clinical trials.

We offer clinical trials specialized for patients with the following types of cancer:

Is Tumor-Infiltrating Lymphocyte Therapy Right for Me?

TIL therapy is being tested on many different cancer types in clinical trials.

Who’s eligible for TIL Therapy?

To be a candidate for TIL therapy through a clinical trial, you must meet certain criteria:

  • You must have metastatic cancer, or cancer that has spread in the body.
  • Your tumor must be large enough to be removed surgically and provide enough tissue to grow the cells.
  • You should have received standard first-line therapy before our clinical trials.
  • You should have exhausted other conventional therapy options for your cancer.

You'll also need to complete:

  • Screening medical questionnaire — To determine if you’re eligible for one of our clinical trials. It will ask about your cancer and health history to help us determine if our trials would be a good fit for you.
  • Medical records review — If you pass the screening, you'll need to provide additional medical records and radiographic scans, including bloodwork and pathology reports.
  • Immunotherapy Tumor Review Board — A group of specialists will review these medical records to determine your clinical trial eligibility and evaluate your recent radiographic studies to identify a tumor for removal.

If you’re eligible, you'll be contacted for an in-person consultation at UPMC Hillman in Shadyside or a telemedicine evaluation.

During the consultation, we'll discuss a detailed history of your cancer course, treatments, and your general health, plus perform a physical exam. Then, we'll discuss TIL therapy in detail, including published clinical results from recent trials, expected toxicities, and logistics.

Finally, we'll discuss whether your condition is suitable for enrollment. If it is, you will be contacted by the clinical trial team and receive informed consent documents to sign, indicating that you fully understand the therapy.

What’s the difference between TIL therapy and CAR T-cell therapy?

TIL therapy is similar in some ways to CAR T-cell therapy in that both use the person’s own immune cells to fight cancer. However, unlike CAR T-cell therapy – which modifies T cells to target cancer – TIL therapy selects and enhances natural T cells already present in the tumor.

Six different CAR T-cell therapies have been approved by the Food and Drug Administration (FDA) for various types of blood cancers, but none has yet worked safely or effectively for solid tumors.

TIL therapy uses the person’s T cells that are already fighting against their cancer. Rather than genetically modifying these cells, scientists simply multiply their numbers so that the person’s immune system has more tumor-infiltrating cells ready to go to work against their tumor.

What are TIL therapy risk factors and complications?

According to the National Cancer Institute, TIL therapy doesn't cause any severe side effects.

Potential mild and manageable side effects may occur for up to two weeks following TIL infusion, including:

  • Chills.
  • Fever.
  • Shortness of breath.  

Call your doctor if you experience any of these issues.

What happens during TIL therapy?

The first step of TIL therapy is for you to have surgery to remove the tumor from your body.

After the tumor is removed, it’s taken to the lab where it’s dissected to find the most potent tumor-fighting T cells. Interleukin-2 (IL-2), a naturally occurring protein that promotes TIL growth, is then added to those cells.

Some growth is typically seen within one week. In two weeks, there’s usually enough for a sample to test the potency of the cells. If the cells are determined to be favorable, it takes another two weeks for the cell numbers to grow to several billion.

Before receiving the T cell reinfusion, you’ll go through a chemotherapy regimen, which will temporarily wipe out your existing immune system to make it more likely for the new T cells to work.

Finally, the enhanced cancer-fighting TILs are infused back into your body. We monitor your progress as the infused TILs attack your cancer.

How long does it take to recover?  

Recovery from TIL therapy can take up to 10 weeks, starting with recovery from the tumor-removal surgery. Preparation of the TIL infusion in the lab may take up to two weeks, and it may take another two weeks to adequately expand the number of cells for infusion. After TIL cell infusion, you may be able to return to normal activities shortly, but it will take several more weeks for your immune system to recover.

Why Choose UPMC for Tumor-Infiltrating Lymphocyte Therapy Care?

Our team is one of only a few in the world conducting pioneering studies on TIL therapy. People from across the United States seek out UPMC Hillman Cancer Center for this breakthrough treatment for advanced cancer.


By UPMC Editorial Staff. Last reviewed on 2025-07-08.