Posts tagged ‘pancreatic cancer’
Usually, we hate salmonella.
It’s the reason you’ve got to make sure your chicken is cooked through. These bacteria cause food poisoning so serious it can even be deadly to people with weakened immune systems.
We may yet learn to like salmonella if City of Hope virologist Don J. Diamond, Ph.D., has his way.
Diamond is leading studies to turn the household bug against diseases such as non-Hodgkin lymphoma. He plans to take advantage of a surprising trait of salmonella: The bacteria naturally seek out tumor cells.
Salmonella as a cancer-fighter isn’t a new idea. But Diamond has his own twist.
Using funds from his 2012–13 Tim Nesvig Lymphoma Fellowship, Diamond is improving a weakened, safe form of salmonella he says “performed beautifully in the laboratory, but had disappointing results in the clinic.” He and his team are amping up the bacteria’s natural cancer-finding ability.
So far, they’ve published exciting results in melanoma and pancreatic cancer. Ultimately, they hope to use the souped-up salmonella to help the body fight lymphoma. The plan: The bacteria travel to cancer cells and then push the body’s natural defenses to fight the cancer.
The scientists expect that a resulting treatment would be gentler on patients than the treatments of today.
That would be a good development coming from a bug that’s usually bad news.
Imagine a familiar scenario straight out of your favorite scary movie.
A relentless villain sets his sights on a bunch of carefree teens. As the terror mounts, they throw one obstacle after another in his path. But lock a door and he breaks through a window. Barricade a window and he busts through the wall.
No matter what, he finds a way to keep … on … coming.
Cancer has a lot in common with our cinematic slasher. That’s how it gets ahead. It’s got a lot of different tools it uses to grow, multiply and spread. When one gets shut down, it often can find ways around the roadblock.
So doctors like Vincent Chung, M.D., are trying to stop cancer in several ways at once.
Chung, clinical associate professor of medical oncology, is leading a national trial testing a strategy that uses two innovative drugs together to fight pancreatic cancer. These trials usually match a targeted therapy with traditional chemotherapy, but Chung’s is different. Could it also be better?
One of the reasons pancreatic cancer is so tough to beat is that it can survive the damage caused by radiation and chemotherapy. But City of Hope researchers figured out a way to make pancreatic cancer cells more vulnerable to therapy. They hope to push their studies into clinical trials in the near future.
“Pancreatic cancer patients are a special case of the particularly unlucky, and in many ways the most miserable. The drug and radiation resistance of this cancer is legendary,” says City of Hope physician-researcher Sanjay Awasthi, M.D., who leads the effort.
So the scientists adopted a unique strategy: Put a cork in cancer cells’ exhaust system.
Awasthi, professor in the departments of Medical Oncology & Therapeutics Research and Diabetes, Endocrinology and Metabolism, and his team study RLIP76, a protein naturally found in the body. “It pumps out the toxic chemicals that accumulate in the cancer cell as a result of chemo- or radiotherapy, before they can cause cell death,” he explains.
They wondered if taking away the protein might keep the toxins in the cells long enough to kill the cells. So they tried it in the lab.
When they dropped levels of RLIP76 in pancreatic cancer cells and tumors in mice, and then exposed the cells to radiation or chemotherapy, the therapies killed cancer better. An added bonus: dropping RLIP76 also reduced blood sugar, cholesterol and triglyceride levels in lab mice. So medications that use this strategy to fight cancer might also battle diabetes.
They presented their results at the American Association for Cancer Research’s Pancreatic Cancer: Progress and Challenges conference in mid-June.
City of Hope radiologists are using the NanoKnife, a medical tool that destroys tissue using electricity, to zap stubborn tumors that do not respond to chemotherapy or radiation and that lie in locations that are difficult to reach with traditional surgery.
John Park, M.D., chief of the Division of Interventional Radiology in City of Hope’s Department of Diagnostic Radiology, and several of his colleagues have started using the new unit. The NanoKnife consists of several probes wired to an electric source. While a patient sleeps under anesthesia, doctors carefully insert the probes into the patient’s body so they surround the tumor. The physicians know just where to place the probes because they use CT scans, real-time ultrasound or other imaging methods to see the tumor’s location and size.
Once the probes rest in place around the tumor, the physicians send pulses of electricity into the NanoKnife. Electrons jump from probe to probe, jolting the tumor and punching holes in the cancerous cells in their path. The electricity flows for as little as 30 seconds. When it’s over, the tumor cells are damaged beyond repair. The body’s immune system then steps in to clean up dead cells.
The NanoKnife also affects nearby healthy tissues, but unlike surgery and procedures that use extreme heat or cold to kill tumor cells, the NanoKnife leaves the basic structures necessary for the body to rebuild the area with healthy cells. Best of all, patients report little or no pain following the procedure. “Patients want to go home as soon as they wake up,” Park said.
According to Park, the NanoKnife is most commonly used to treat tumors in soft tissues, such as in lung, prostate, pancreatic and liver cancers. Because clinical researchers are testing how well the NanoKnife works for specific cancers, the device currently is used only for patients with no other options or as part of a clinical trial.
James V. Lacey, Jr., Ph.D., is an associate professor in City of Hope’s Division of Cancer Etiology. He recently commented on the American Cancer Society’s (ACS) “Cancer Facts and Figures 2012,” the latest report on cancer diagnoses and deaths throughout the country. The report showed that so many more people are now avoiding or surviving cancer that more than 1 million cancer deaths have been avoided over the past two decades.
The “War on Cancer” is now part of the national lexicon, but these new statistics from the ACS remind us of what a long battle it has been and will continue to be.
Each cancer site is different, but the overall message from these new statistics is positive: Death rates from the most common cancers among men, especially lung cancer, prostate cancer and cancers of the colon and rectum, are continuing to decline. For women, death rates from breast cancer and cancers of the colon and rectum are also declining, and the death rate from lung cancer, which had remained relatively constant from the early 1990s until the mid-2000s, might be on the decline.