What`s new in kidney cancer research and treatment?

There is always research going on in the area of kidney cancer. Scientists are looking for causes of and ways to prevent renal cell carcinoma. Doctors are working to improve treatments as part of a major effort to lower the number of people who die from this cancer. In addition to finding new medicines and looking at the best way to combine and sequence existing ones, a major area of research lies in finding better ways to select therapy for an individual. That is, finding factors about a person's cancer that make it more likely to respond to a certain medicine. This is a major area of research in many cancers, as doctors want to be able to individualize therapy as much as possible to increase a person's chance of benefiting from a therapy.

Research on the treatments for renal cell carcinoma is now being done at many medical centers, university hospitals, and other institutions across the nation. The American Cancer Society supports research into the detection, diagnosis, and treatment of kidney cancer.

Genetics

Scientists are studying several genes that may play a part in changing normal kidney cells into renal cell carcinoma.

For example, problems with the von Hippel-Lindau tumor suppressor gene are found in most clear cell kidney cancers. This allows other genes such as the hypoxia-inducible factor (HIF) gene to be activated when they shouldn't be, which drives a cell toward being cancerous. Newer treatments focus on attacking this cellular pathway.

Researchers now also have a better idea of the gene changes responsible for some other forms of kidney cancer. Doctors are now trying to determine which treatments are most likely to be effective for certain types of kidney cancer. This information can also be used to develop new treatments.

New approaches to local treatment

High-intensity focused ultrasound is a fairly new technique that is now being studied for use in kidney cancer. It involves pointing very focused ultrasound beams from outside the body to destroy the tumor.

Ablation with cryotherapy or radiofrequency ablation is sometimes used to treat small kidney cancers. Research is now under way to determine how useful these techniques are in the long term and to refine them further.

Targeted therapies

Because chemotherapy drugs have not been very effective against advanced kidney cancer, targeted therapies are now usually the first-line option to treat kidney cancers that cannot be removed by surgery. At this time they are usually given separately. Clinical trials are now under way to try to determine if combining these drugs, either with each other or with other types of treatment, might be better than using them alone. Several new targeted therapies are now being tested as well, with cediranib and linifanib showing promise.

The potential roles of giving these drugs before and after surgery (called neoadjuvant and adjuvant therapy, respectively) are also being studied.

Immunotherapy

Kidney cancer is one of a handful of cancers that may respond to immunotherapy. Clinical trials of new immunotherapy methods are being tested. Basic research is now being directed toward a better understanding of the immune system, how to activate it, and how it reacts to cancer.

Researchers are studying the use of cytokines to stimulate immune system cells that have been removed from circulating blood. The cells are treated with cytokines and exposed to killed tumor cells to make cells called dendritic cells. These cells are injected into lymph nodes in the hope that this will stimulate the immune system to fight the cancer. Early results have been promising, but more studies are needed.

Vaccines

Several types of vaccines for boosting the body's immune response to kidney cancer cells are being tested in clinical trials. Unlike vaccines against infections like measles or mumps, these vaccines are designed to help treat, not prevent, kidney cancer. One possible advantage of these types of treatments is that they seem to have very limited side effects.

There are several ways to create vaccines that might stimulate the immune system. In one approach, cancer cells (removed during surgery) are altered in the lab to make them more likely to cause an immune response and are then returned to the body. In another approach, a special virus is altered so it is no longer infectious, but it carries a gene for a protein often found on cancer cells. Once the virus is injected into the body, the hope is that the protein will cause the immune system to react against cancer cells anywhere in the body. Combining vaccines with targeted agents or other agents to help them work better is also being studied.

At this time, these vaccines are only available in clinical trials.

Bone marrow or peripheral blood stem cell transplant

In people with advanced kidney cancer, the person's own immune system is not effectively controlling the cancer. Another approach to immunotherapy is to try to use someone else's immune system to attack the cancer cells.

First, very primitive immune system cells (called stem cells) are collected from a compatible donor, either from their bone marrow or their blood. The person with cancer is then treated with chemotherapy drugs, either in lower doses (called a mini or non-myeloablative stem cell transplant) to suppress the immune system or in higher doses to cause more severe damage to the immune cells and other components of the bone marrow. They are then given the stem cells to try to build a new immune system that will be more likely to attack the cancer cells.

Some early studies of this technique have been promising, finding that it may help shrink kidney cancers in some people. But it can also cause major complications, and side effects can be severe. Until more is known about its safety and usefulness, it will probably only be available in clinical trials.