Electronic Noses Sniff Out Cancer

Earlier this year, I speculated that electronic “noses” would someday be able to detect cancer. Now, I can report that we are getting closer (although trained dogs still seem better at the task!).

Background: It’s the second most common cancer for men worldwide, but prostate cancer remains difficult to diagnose, with standard blood tests criticized for delivering a high rate of false positives. But in a study presented in May this year, trained detection dogs were able to identify prostate cancer from a few sniffs of a urine sample with a staggering 98% accuracy, with few false positives. Although the study is by no means conclusive, it joins a growing body of research suggesting dogs could be able to smell out cancers.

However, there are numerous practical problems in using dogs to detect cancers in a medical setting (not least training, consistency and identifying exactly which chemicals the dogs are detecting), which is why scientists are seeking to harness the potential detection ability of man’s best friend through the development of an “electronic nose” capable of making a diagnosis.

Finnish researchers are using a device that conducts molecular analysis of the atmosphere in the “headspace” above urine samples, and tests it for the volatile organic compounds associated with prostate cancer. In a study published earlier this year, the method had a detection rate of 78%, and a specificity (the probability of the test being negative when cancer is absent) of 67%.

Researchers continue to refine the method, such as through removing impurities for cleaner sample analysis, but he believes the principle is reliable and can be applied to many other cancers.

“We have found there are over 30 molecule compounds in a tumor that are very smelly and easily sniffed. Eventually this can be used as a test for every cancer in the Western world,” he added.

Around the world, similar approaches are being applied to offer simple diagnosis for the world’s greatest killers. In 2011, the Gates Foundation announced funding for a battery-operated electronic nose prototype in India that functions as a breathalyzer test for tuberculosis.

The “NaNose” is being developed by the Israeli Technion Institute, claiming 90% accuracy in detecting lung cancer from a breath test, and providing enough information to distinguish between subtypes of the disease.

My Take: Dogs are still better, but I am confident that they will help to recognize diseases based on body odors. A dog recognizes thousands of odors at a time, so machines have a bit of learning to do to catch up. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: http://www.cnn.com/2014/07/16/tech/innovation/electronic-noses-sniff-out-disease/index.html?hpt=hp_bn5

FAST MRI: A 3-minute MRI for Breast Cancer Screening

What You Need to Know: An MRI screening protocol for breast cancer that takes just 3 minutes is as good as a regular MRI that takes 21 minutes, and more accurate than digital mammography, according to a proof-of-concept study published in the August 1 issue of the Journal of Clinical Oncology.

What: The accelerated MRI was as good as regular MRI for detecting 11 invasive breast cancers that had escaped detection on regular mammography, report Christiane A. Kuhl, MD, and colleagues from the University Hospital of Aachen in Bonn, Germany.

“MRI is the technique of the future [for screening]. Ionizing radiation is not involved. Compared with digital mammography, it is highly sensitive, and overdiagnosis is less of a problem, contrary to current notions,” Dr. Kuhl told Medscape Medical News.

How: Dr. Kuhl’s team “stripped down MRI to the essential part that makes for fast acquisition,” she explained. For the 3-minute protocol, the radiologist reads the first postcontrast subtracted (FAST) and maximum-intensity projection images; for the full diagnostic protocol, all the images are read. The screening accuracy of the accelerated MRI is similar to that of a full diagnostic MRI, she added.

The accelerated protocol “is a huge step forward in breast cancer screening,” writes Elizabeth A. Morris, MD, chief of breast imaging services at the Memorial Sloan Kettering Cancer Center in New York City, in an accompanying editorial. “Data clearly demonstrate that FAST breast MRI could be the standard for breast cancer screening: it is safe, does not induce cancers, and can find more cancers than mammography,” she explains.

The study consisted of 443 asymptomatic women at mild to moderate risk for breast cancer. They had all undergone digital mammography, and the women with dense or extremely dense breasts had also undergone ultrasound screening, all with negative results. The women then underwent MRI screening, which identified 11 breast cancers — 7 invasive cancers and 4 ductal carcinoma in situ. The identification of these 11 cancers provided an additional cancer yield of 18.3 per 1000.

My Take: Though not ready for general use, fast MRI is promising. In the screening setting, the investigators achieved a high detection rate. They accomplished this without a high false-positive rate, suggesting that we may have a quality screening test. The negative predictive value (the test says no cancer, when there really is no cancer) was 99.8%. Currently, I believe that 3D (tomosynthesis) mammograms represent the best technology for screening women at average risk. If you have a high risk for breast cancer, ask about risk-reducing methods (including tamoxifen), and whether you should add MIR to your mammogram routine. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

References: http://www.medscape.com/viewarticle/830245; 2014 August 1 issue of the Journal of Clinical Oncology.

PSA for Prostate Cancer Screening? Yes. No. Yes. Maybe.

puzzled man
 
What You Need to Know: Mortality in prostate cancer is lower in areas with frequent use of PSA testing compared with areas with little testing shows a new study. Results from the study show that prostate cancer mortality was 20 percent lower in counties with the highest incidence of prostate cancer, which indicates an early and rapid uptake of PSA testing.
 
The Evidence: The study is based on data from nation-wide, population-based registers in Sweden including the Cancer Register, The Cause of Death Register and the National Prostate Cancer Register (NPCR) of Sweden.

“Our results show that prostate cancer mortality was 20 percent lower in counties with the highest incidence of prostate cancer, indicating an early and rapid uptake of PSA testing, compared with counties with a slow and late increase in PSA testing,” says Pär Stattin, lead investigator of the study. “Since the difference in the number of men diagnosed with prostate cancer is related to how many men undergo PSA testing, we think our data shows that PSA testing and early treatment is related to a modest decrease in risk of prostate cancer death,” says Håkan Jonsson statistician and senior author of the study.

“In contrast to screening in randomized studies our data is based on unorganized, real life PSA testing. We therefore used a statistical method that excludes men that were diagnosed prior to the introduction of PSA testing since these men could not benefit from the effect of PSA testing,” continues Håkan Jonsson.

“The results in our study are very similar to those obtained in a large European randomized clinical study (ERSPC) thus confirming the effect of PSA testing on the risk of prostate cancer death. However, we have to bear in mind that the decrease in mortality is offset by overtreatment and side effects from early treatment. PSA testing sharply increases the risk of overtreatment, i.e. early treatment of cancers that would never have surfaced clinically. We also know that after surgery for prostate cancer most men have decreased erectile function and that a small group of men suffer from urinary incontinence. Our data pinpoints the need for refined methods for PSA testing and improved prostate cancer treatment strategies,” concludes dr Stattin.

My Take: The role of PSA as a screening tool remains unclear. My take is that it leads to overtreatment, but that this is more an issue of how we use the test, rather than the test itself. PSA testing is the best means that we now have available to identify those patients who have prostate cancer.  After a prostate biopsy is done, and if the biopsy identifies cancer, a patient must decide whether to treat the disease or to undergo active surveillance. To make such a decision, the patient needs to be completely informed of their disease status. So have a chat with your health care provider to see if the PSA makes sense for you. Clearly, not everyone benefits from PSA. Still, I think PSA does diminish the risk of death, especially among higher risk populations such as African American men. So don’t ignore PSA testing: Have a dialog with a valued health professional to see if it is appropriate for you. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad:  Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

References:

Umeå universitet. “PSA testing, early treatment decreases risk of prostate cancer death.” ScienceDaily. ScienceDaily, 10 March 2014. www.sciencedaily.com/releases/2014/03/140310090749.htm.

P. Stattin, S. Carlsson, B. Holmstrom, A. Vickers, J. Hugosson, H. Lilja, H. Jonsson. Prostate Cancer Mortality in Areas With High and Low Prostate Cancer Incidence. JNCI Journal of the National Cancer Institute, 2014; DOI: 10.1093/jnci/dju007


What’s Your Risk of Colorectal Cancer?

Please click image to see a colonoscopy.

Investigators at Cleveland Clinic (USA) have developed a new tool called CRC-PRO that allows clinicians to quickly and accurately predict an individual’s risk of colorectal cancer.

How They Developed the CRC-PRO Tool: To develop the Colorectal Cancer Predicted Risk Online tool, Brain Wells, MD, PhD and colleagues analyzed over 180,000 patients from a longitudinal study conducted at the University of Hawaii. Patients were followed for up to 11.5 years to determine the factors associated with the development of colon or rectal cancer.

“Creating a risk calculator that includes multiple risk factors offers clinicians a means to more accurately predict risk than the simple age-based cut-offs currently used in clinical practice,” said Dr. Wells. “Clinicians could decide to screen high-risk patients earlier than age 50, while delaying or foregoing screening in low-risk individuals.”

My Take: The Multiethnic Cohort Study include a diverse population. Previously, most research in this area has been performed predominately among whites. Because cancer risk varies dramatically by race, this tool is especially helpful. I think that risk prediction tools such as this will allow us to customize screening for individuals, in addition to pushing higher risk individuals to improve lifestyle factors linked to colorectal and other cancers. I’m Dr. Michael Hunter. Talk to your doctor about this valuable tool, available at http://www.r-calc.com/ExistingFormulas.aspx?filter=CCQHS

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad:  Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: http://medicalexpress.com/news/2014-01-online-colorectal-cancer.html

Is Lung Cancer Screening For You?

cigarette tobacco smoking lung cancer

The US Preventative Service Task Force recommends annual screening for lung cancer with low-dose CT scans for adults ages 55 to 80 who are at high risk for lung cancer because they have smoked a pack or more per day of cigarettes for at least 30 years and currently smoke or have quit within the past 15 years.

The Task Force issued its long-awaited guideline on lung cancer screening this week. It is estimated that this test could eventually prevent between 8,000 and 22,000 lung cancer deaths per year. About 95% of lung cancers are due to cigarette smoking. In the USA, 37% of Americans are current or former smokers, and 20% still smoke.

What is the US Preventative Service Task Force? The task force is an independent group of experts that makes evidence-based recommendations on preventative services such as screening, preventative medications and counseling services. Their process for developing guidelines involves an extensive review of scientific studies. The task force advises the US Department of Health and Human Services. The Affordable Care Act mandates that health insurance cover screenings that the task force deems useful.

Why Now? The latest recommendation is largely based on the National Cancer Institute’s National Lung Screening Trial. This study began in 2001, and is one of the best-designed cancer screening studies ever conducted. The study issued results fairly recently. Other organizations have issued similar recommendations, including the American College of Chest Surgeons, the American Society of Clinical Oncology, the American Thoracic Society, the American Association for Thoracic Surgery, the National Comprehensive Cancer Network, and the American Cancer Society.

What are the results of the NCI National Lung Screening Trial? The study assessed over 54,000 smokers and showed screening caused a 2-% decline in lung cancer deaths eight to ten years later. This means that 80% of lung cancer deaths still occurred.

Are there potential harms from screening? Yes. More than one in four people screened will have a finding that leads to further testing. Ultimately, 24 out of 25 who get further testing will not have lung cancer. Additional testing may include more imaging, as well as invasive tests such as biopsies or even surgery. In fact, in the National Lung Cancer Screening Trial, about one person died after an invasive procedure triggered by screening for every five to six lives saved because of screening.

My take: Low-dose screening studies reduce the risk of death from lung cancer, albeit with the potential costs detailed above. We also need a screening test for non-smokers and light smokers, as about 1 in 6 who get lung cancer are non-smokers. There is not great benefit to low-dose spiral CT screening for this population. Finally, don’t use screening as an excuse to continue smoking, as there is a greater benefit to quitting in general. I’m Dr. Michael Hunter.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad:  Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: http://www.cnn.com/2014/01/03/health/brawley-lung-cancer/index.html?hpt=hp_bn13