iKNIFE DETECTS CANCER CELLS IN TUMOR OPERATIONS

When surgeons remove tumor tissue they try to leave a "margin" of healthy tissue to ensure all the cancer is removed. Sometimes this means the patient has to remain under general anaesthetic for another 30 minutes or so while tissue samples are sent for analysis to check if the margin is clear. Even then, it is still possible that some cancerous tissue remains, and the patient has to undergo further surgery to remove it.

Now, a new technique based on an "intelligent knife," called the "iKnife," promises to remove the need for lab analysis and the accompanying delay, and it also helps avoid repeat surgeries.

The iKnife sniffs the "smoke" created by the electrosurgical removal of cancerous tissue and tells the surgeon almost immediately if the tissue it has come from is healthy or cancerous.

This first study appears online this week in Science Translational Medicine, in which the iKnife is tested in the operating room.

In tissue samples from 91 patients, researchers at Imperial College London using the iKnife achieved 100% accuracy in diagnosing whether the samples were cancerous or not.

Study author Dr. Zoltan Takats is the inventor of the iKnife. Asked if his new surgical tool would be confined to use in only certain types of cancer, he told Medical News Today:

"It is a generally applicable tool, we believe it will be useful for many different types of cancer surgeries."

On the question of cost-effectiveness, Dr. Takats told us:

"We believe that it will be a cost-saver - due to elimination of intraoperative histology, shorter intervention times and lower rate of re-operations."

iKnife combines electrosurgery with new mass spectrometry techniques

The iKnife is a combination of an established technology called electrosurgery that was invented in the 1920s and a new technology that is still emerging, called rapid evaporative ionization mass spectrometry (REIMS).

In electrosurgery, the surgeon's knife delivers an electric current that heats the target tissue and cuts through it while causing minimum loss of blood.

The heat from the current vaporizes the tissue, which gives off a smoke that is normally sucked away with an extractor.

The mass spectrometer technology behind REIMS almost instantly identifies the chemicals present in human tissue by analyzing the smoke that is released during electrosurgery.

Cells produce thousands of metabolites in various concentrations, depeding on their cell type. So once the REIMS technology is primed with the profiles of healthy and cancerous cells, it can rapidly use these to screen the sample of smoke and inform the surgeon whether it is from a tumor or healthy tissue.

Results delivered in under 3 seconds

By comparing the chemical profile of the tissue it is sampling to the reference library, the iKnife can deliver a result in under 3 seconds, say the researchers.

But for this study, the surgeons carrying out the procedures were not allowed to see the nearly instant readings from the iKnife.

The researchers now hope to run a clinical trial that tests whether giving surgeons access to iKnife readings during operations improves outcomes for patients.

Dr. Takats says in a statement:

"These results provide compelling evidence that the iKnife can be applied in a wide range of cancer surgery procedures."

As the technology delivers almost instant results, it allows "surgeons to carry out procedures with a level of accuracy that hasn't been possible before", he adds, noting that they "believe it has the potential to reduce tumor recurrence rates and enable more patients to survive."

Source: Medical News Today

NEW TASK FORCE RECOMMENDATIONS FOR BRCA MUTATION SCREENING

Updated recommendations issued by the United States Preventive Services Task Force (USPSTF) state that primary care physicians should screen women who have a family history of either breast, ovarian, tubal, or peritoneal cancers as they may be carriers of a mutation in one of the breast cancer susceptibility genes—BRCA1 or BRCA2. Screening should be done with one of several screening tools available and included in the current update. 

The task force recommends against testing for women who have an average risk of being diagnosed with breast cancer. 

“The goal of the recommendation is to encourage clinicians to assess a woman’s family history of BRCA-related cancers, so as to identify those women who may benefit from further evaluation,” Douglas K. Owens, MD, professor and director of the Center for Health Policy at the Stanford University School of Medicine and one of the USPSTF members, told Cancer Network in an email. 

The current update from the task force, which is chaired by Virginia A. Moyer, MD, MPH, reaffirms the last update of these recommendations made in 2005. 

“The main change is that there is now evidence to support the use of screening tools that clinicians can use to screen women and identify those who are candidates for genetic counseling and further evaluation,” said Owens. “The grades of the recommendation have not changed.” 

The updated recommendations are published in the Annals of Internal Medicine. 

Those women who have one or more family member with a potentially harmful BRCA mutation should be offered genetic counseling and testing. 

The tools listed in the recommendation include the Ontario Family History Assessment Tool, Manchester Scoring System, Referral Screening Tool, Pedigree Assessment Tool, and the FHS-7 tool. All are questionnaires that add up risk factors for these cancers such as the number of family members with a history of breast or ovarian cancer and the age of onset. The tools are a way to help clinicians discuss whether there are factors present that make it more likely their patient is a BRCA mutation carrier. The task force estimates that the tools are more than 85% sensitive. No one test was recommended for use over another. 

The two most simple and quickest to use, according to the task force, are the Referral Screening Tool and FHS-7. 

Use of these structured screening tools to assess the need for more in-depth genetic counseling may be relatively new for some clinicians, Owens noted. 

BRCA mutation testing should only be done for those patients who have either a personal or family history that suggests a role of inherited cancer susceptibility. Testing for these mutations are now more widely available following a June 2013 decision by the Supreme Court. 

In the United States, approximately 12.3% of women will develop breast cancer during their lifetime and 2.7% will die of their disease according to the National Cancer Institute. About 1.4% will develop ovarian cancer and 1% will die of their disease. 

Analyses of the penetrance of BRCA1 and BRCA2 genes suggest that a woman’s risk of a breast cancer diagnosis jumps from 45% to 65% by the age of 70 if she is a carrier of a deleterious BRCA mutation. A mutation in the BRCA1 gene increases ovarian cancer risk to about 39% by age 70 and to 10% to 17% for those who are BRCA2 mutation carriers. 

Between 1 in 300 and 1 in 500 women carry a BRCA mutation (between 0.2% and 0.3% of the population) with a higher prevalence (about 2.1%) for the general Ashkenazi Jewish women population. 

Understanding the chance of being diagnosed with breast cancer is important. A recent survey and analysis of more than 2,500 adults published in Genetics in Medicine shows that despite the recent coverage of breast cancer risk and Angelina Jolie’s decision to undergo a double mastectomy, women still do not have a better understanding of breast cancer risk including how rare Angelina Jolie’s decision was and what to do if one is positive for a deleterious mutation that confers an increased cancer risk. 

The study also showed that many did not understand the relationship of overall cancer risk and risk in the context of a family history of cancer. “Perhaps even more striking and worrisome is that about half of all individuals aware of the story and without a family history of cancer rated their cancer risk as lower than the population average relative to those without a family history and unaware of the story,” said the authors. 

This type of analysis points to a greater need for primary care physicians to discuss cancer risk with patients to guide their education and awareness about the issue, particularly as the genetics of cancer is increasingly an important factor in diagnosis and treatment. 

The endorsement of family history screening tools to identify candidates for testing could be problematic because the correct threshold for testing is still not resolved, noted Mark Robson, MD, an oncologist who specializes in identifying and managing women with inherited breast cancer risk and the director of the clinical genetics service at the Memorial Sloan-Kettering Cancer Center in New York. 

“The limitation here is that USPSTF has not provided guidance about testing for affected women, who should be the first ones tested in a family,” said Robson in an email. “The USPSTF has not really provided much in the way of endorsement for the screening and prevention interventions that would follow from testing.” 

Source: cancernetwork.com

MAJOR DECLINE IN LUNG CANCER REPORTED

“Eliminating tobacco use is the most important thing we can do to prevent lung and other cancers, as well as the many other diseases its use causes. Today’s news confirms that we are making progress. However, the global health challenges from tobacco are still growing.

“This new CDC report shows how far we’ve come in the U.S. as we approach the 50th anniversaries of both the Surgeon General’s first report on tobacco and ASCO’s founding. Having shown that we can make substantial progress, we must continue to do everything possible to expand tobacco control programs in the United States and especially overseas, where tobacco use is taking an even greater toll.

“ASCO believes it is our responsibility as cancer doctors to help our patients quit and oppose tobacco use in all its forms. We are deeply committed to proactive tobacco control globally and have set an aggressive agenda for slashing tobacco use, deploying every public health, policy, and legal approach available.”

—Clifford A. Hudis, MD, FACP

Source: ASCO post 

POTENTIAL NEW TARGET IDENTIFIED IN PANCREATIC CANCER

Researchers have identified a potential new method for treating pancreatic cancer, using calcium to overload pancreatic cancer cells and, thus, induce cell death in cancerous cells while sparing healthy cells. 

The key to this discovery, made by Jason Bruce, PhD, from the Physiological Systems and Disease Research Group at the University of Manchester, and colleagues, was identifying the “power source” for calcium pumps in the cancer cells that keep calcium levels low, assisting in cell survival. 

According to background information in the study, maintaining a low concentration of calcium is key to cell survival. Plasma membrane Ca²⁺ ATPase (PMCA) is a protein in the plasma membrane of cells that removes calcium from the cell. PMCA is fueled using adenosine triphosphate (ATP). 

Prior research has shown that many cancer cells, including pancreatic cancer, shift from ATP produced from mitochondria metabolism to a glycolysis ATP. Mitochondria generate approximately 90% of a cells’ energy in normal healthy cells. However, in pancreatic cancer cells it is thought that PMCA may have its own supply of glycolytic ATP, and it is this fuel supply that gives cancer cells a survival advantage over normal cells. 

“Designing drugs to cut off this supply to the calcium pumps might be an effective strategy for selectively killing cancer cells while sparing normal cells within the pancreas,” said Bruce in a prepared statement. 

In order to determine whether pancreatic cells were fuelled by mitochondrial or glycolytic ATP, the researchers used pancreatic tumor cells to test the effect of mitochondrial and glycolytic inhibition on cell death. The results of the study were published in the Journal of Biological Chemistry. 

Mitochondrial inhibition had no effect on cell death compared with control experiments. However, the researchers found that glycolysis inhibition induced ATP depletion, an irreversible increase in calcium, and ultimately cell death. 

“Collectively, the present study suggests that glycolytic ATP synthesis is critically important for maintaining PMCA activity and low resting Ca2+, in human pancreatic ductal adenocarcinoma cell lines,” the researchers wrote. “Furthermore, these findings are translational and provide insights into a potentially new therapeutic avenue for the treatment of pancreatic ductal adenocarcinoma.” 

Source:  cancernetwork.com