What’s New in Colorectal Cancer Research?
Research is always going on in the area of colorectal cancer. Scientists are looking for causes and ways to prevent colorectal cancer, better ways to find it early, and ways to improve treatments. Here are some examples of current research.
Reducing colorectal cancer risk
Many studies are looking to identify the causes of colorectal cancer, in the hopes of using this knowledge to help prevent it.
Other studies are looking to see if certain types of diets, dietary supplements, or medicines can lower a person’s risk of colorectal cancer. For example, many studies have shown that aspirin and similar pain relievers might help lower the risk of colorectal cancer, but these drugs can sometimes have serious side effects. Researchers are now trying to determine if there are some groups of people for whom the benefits would outweigh the risks.
Early detection tests
Doctors are looking for better ways to find colorectal cancer early by studying new types of screening tests and improving the ones already being used.
Lab tests to help predict cancer recurrence risk
Lab tests (including Oncotype Dx® Colon Cancer Assay, ColoPrint®, and ColDx™)have been developed to help predict which patients have a higher risk of their colorectal cancer coming back after treatment. The tests do this by looking at the activity of many different genes inside colorectal cancer cells. So far, though, none of these tests have been shown to help predict which people could benefit from chemo or other treatments.
Researchers are constantly looking for better ways to treat colorectal cancer.
Newer surgery techniques
Surgeons are continuing to improve their techniques for operating on colorectal cancers.
Sometimes when colorectal cancer recurs (comes back), it spreads to the peritoneum (the thin lining of the abdominal cavity and of organs in the abdomen). These cancers are often hard to treat. Recently, some surgeons have been studying a procedure called hyperthermic intraperitoneal chemotherapy (HIPEC). First, surgery is done to remove as much of the cancer in the belly as possible. While still in the operating room, the abdominal cavity is bathed in heated chemotherapy drugs. This puts the chemo directly into contact with the cancer cells, and the heat is thought to help the drugs work better.
Some patients are living longer with this type of treatment, but more studies are needed to determine which patients it can help. It also requires well-trained doctors and nurses and specialized equipment, so it is not readily available.
Chemotherapy is an important part of treatment for many people with colorectal cancer, and doctors are constantly trying to make it more effective and safer. Different approaches are being tested in clinical trials, including:
- Testing new chemo drugs (such as trifluridine and tipiracil) or drugs that are already used against other cancers (such as cisplatin or gemcitabine).
- Looking for new ways to combine drugs already known to be active against colorectal cancer, such as irinotecan and oxaliplatin, to improve their effectiveness.
- Studying the best ways to combine chemotherapy with radiation therapy, targeted therapies, and/or immunotherapy.
Targeted therapy drugs work differently from standard chemotherapy drugs. They affect specific parts of cancer cells that make them different from normal cells. Several targeted therapy drugs are already used to treat colorectal cancer. Doctors continue to study the best way to give these drugs to make them more effective, as well as looking at new targeted therapy drugs.
Targeted therapies are currently used to treat advanced colorectal cancers, but newer studies are trying to determine if using them with chemotherapy in earlier-stage cancers as part of adjuvant therapy may further reduce the risk of recurrence.
An exciting area of research is the field of immunotherapy, which is treatment that uses the body’s own immune system to fight the cancer.
Immune checkpoint inhibitors: An important part of the immune system is its ability to tell between normal cells in the body and those it sees as “foreign.” This lets the immune system attack the foreign cells while leaving the normal cells alone. To do this, it uses “checkpoint” proteins on certain immune cells. These proteins act like switches, needing to be turned on (or off) to start an immune response. Cancer cells sometimes use these checkpoints to avoid being attacked by the immune system.
Newer drugs that target checkpoint proteins such as PD-1 hold a lot of promise as cancer treatments. Colorectal cancer cells that have specific gene changes, such as high levels of microsatellite instability (MSI-H), or changes in one of the mismatch repair (MMR) genes, tend to have a lot of other changes that make them different from normal colorectal cells. This might make them more visible to the immune system. Cancers with these changes may be helped by treatment with anti-PD-1 drugs such as pembrolizumab (Keytruda) or nivolumab (Opdivo).
Cancer vaccines: Researchers are studying several vaccines to try to treat colorectal cancer or prevent it from coming back after treatment. Unlike vaccines that prevent infectious diseases, these vaccines are meant to boost the person’s immune system to fight colorectal cancer more effectively.
Many types of vaccines are being studied. For example, some vaccines are created by removing some of the person’s own immune system cells (called dendritic cells) from their blood, exposing them in the lab to a substance that will make them attack cancer cells, and then putting them back into the person’s body. At this time, these types of vaccines are only available in clinical trials.