Posts Tagged ‘studies’

Questions on Validity of PSA Test as Prostate Cancer Screening Tool?

Prostate Cancer PSA ScreeningViraj Master, MD Prostate cancer is the second leading cause of cancer death among American men.  Nearly 250,000 men will be diagnosed with prostate cancer this year.  More than 32,000 men will die from prostate cancer this year.  In Georgia, 7,360 men will be diagnosed and 1,080 will die.  With statistics like that, we want every advantage possible in our fight with this disease.

Since the early 1990s, the Prostate Specific Antigen (PSA) test has been the primary screening tool used to detect prostate cancer. The PSA is a simple blood test, non-invasive and easy to administer and process.  The US Preventive Services Task Force has recently recommended, however, that the PSA test no longer be offered to men as a screening tool.

This task force is a federally funded independent panel of experts in prevention and evidence-based medicine.  It is comprised of primary care providers such as internists, family practitioners and pediatricians, but not oncologists or urologists.  Their job is to evaluate the benefits of preventive services like screening and make recommendations about which services should be routinely incorporated into primary medical care.

Screening, or early detection, for prostate cancer is a complicated issue.  Unlike the colonoscopy, which provides clear evidence of early detection and has been determined to have saved lives in multiple studies, the PSA test has been contradictory, with some studies showing a benefit, while others did not.  There are many reasons, including the fact that most forms of prostate cancer are relatively slow-growing cancers.  Generally, a man with prostate cancer may live for many years without ever having the cancer discovered.  In fact, many men with prostate cancer will not die from it, but with it.  In addition, high or increasing levels of PSA can indicate an increased risk for prostate cancer, but can also indicate an infection or an enlarged prostate.  So, the USPSTF determined that because of these uncertainties, the risk of over treatment is greater than the benefit, and their recommendation states that PSA tests should no longer be offered as a screening tool.

The biggest issue in prostate cancer that confronts patients, their families and their healthcare providers is to delink screening with treatment.  Not all forms of prostate cancer require active therapeutic interventions, but some do.

While the PSA test is imperfect, it is – at this time – the best tool we have at our disposal for early detection of prostate cancer.  The Winship Cancer Institute of Emory University aligns with the American Urological Association, the American Cancer Society, American College of Physicians and the American College of Preventive Medicine and recommends informed decision-making.  Our recommendation is that men at average risk should receive information, including a PSA test if they want it, at an appropriate middle age, although African American men or men with a family history of prostate cancer should receive information at an earlier age, such as 40, or 45 years.

So, what do we mean when we say “informed decision-making”?  This means that doctors should discuss the potential benefits and harms of PSA screening with their patients and consider their patients’ preferences, overall health, and family history when making decisions regarding screening with a PSA test.

Unfortunately, there is no easy answer.  Each patient comes to us with his own distinctive characteristics, and those characteristics must be taken into consideration when deciding whether to have the PSA test.

About Dr. Viraj Master
Dr. Master specializes in the treatment of adrenal cancer, bladder cancer, kidney cancer, prostate cancer, testicular cancer. He is also an expert in laparoscopic surgery. Dr. Master received his Medical Degree in the University of Chicago in Chicago, Illinois, in 1997. He completed his Internship at University of California, San Francisco in 1999, where he also completed his Fellowship in 2003.

Cancer Patient Rescues Dog and Is Rescued in Return

Carol Witcher & Floyd Henry

Carol Witcher, breast cancer patient & her dog Floyd

Carol Witcher rescued her dog when he was seven months old, but never imagined that he would rescue her in return. Over two years ago, her dog, Floyd Henry displayed some curious behavior that made Carol worry that something may be seriously wrong.

“When he sniffed me, he kind of turned back and really pushed into my right breast, real hard,” Carol recalls. “He started sniffing, sniffing, sniffing.” Carol adds, “He pushed real hard for one shot…Then he looked at me straight in the face, and began to paw my right breast. And I thought, ‘This is not good.’” After four days of continuous sniffing, nudging and pawing from her 8-year-old boxer, Carol made plans to see a doctor at the Winship Cancer Institute of Emory University.

It turned out that Carol did in fact have breast cancer that would require treatment with chemotherapy, surgery and then radiation. According to breast surgical oncologist at Winship, Dr. Sheryl Gabram, “Her type of cancer presented as an indistinct  asymmetry in her breast…I absolutely believe the dog saved Miss Witcher’s life.”

Dr. Gabram and Charlene Bayer PhD, a chemist at Georgia Institute of Technology, are no strangers to this type of phenomena. They have been  investigating  cancer patients’ breath in a pilot study involving 20 volunteers with normal mammograms compared to 20 newly diagnosed breast cancer patients. They have found that cancer causes the body to release certain organic compounds and the patterns of these compounds can be detected with mass spectrometry, a device that separates out compounds for analysis. It is possible that dogs can smell these compounds but people cannot. Ultimately, Drs. Gabram and Bayer hope that this simple breath test could lead to a means to alert physicians in the office that a patient may have an underlying breast cancer. And in Carol Witcher’s case, quite possibly it did.

As Gabram notes, in the study that Miss Witcher was involved in prior to her treatment, “Our model predicted  more than 75 percent of the time correctly which patients did have breast cancer and which ones did not.” This study will be published in early June in the American Surgeon.

ABC News recently covered Carol’s story and discussed previous situations in which the combination of a person’s breath and a dog’s sense of smell led to accurate cancer diagnoses. According to the ABC News story, “In January, a study published in the British journal Gut said that a specially-trained 8-year-old black Labrador retriever named Marine had detected colorectal cancer 91 percent of the time when sniffing patients’ breath, and 97 percent of the time when sniffing stool.” They add that “Dogs have also reportedly sniffed out skin, bladder, lung and ovarian cancers.”
While they might not be able to pinpoint or vocalize what are wrong, canines have demonstrated that they are able to determine that something is wrong.

We will keep you posted on the latest developments in the breath diagnostic work of the team at the Winship Cancer Institute of Emory University, Georgia’s only NCI-designated cancer center, and the Georgia Institute of Technology.  In the meantime, you can learn more about Carol’s story by checking out the ABC News video here.

Why a Pap Smear Might Not Catch All Cervical Cancers

Most women are familiar with the Pap smear, also known as the pap test. Most of us are also aware that the main goal of the Pap smear is to identify cancerous or abnormal cells that may turn into cancer after collecting them from the lining of the cervix. However, based on findings recently published in the International Journal of Cancer, Pap smears may not be the most reliable way to pinpoint cancer types that can often be harder to detect.

According to Kevin Ault, MD, an associate professor of obstetrics and gynecology at Emory’s School of Medicine and Winship Cancer Institute, the Pap smear is not always effective in the diagnosis of adenocarcinoma. Ault came to this conclusion after conducting a post-hoc analysis of Gardasil vaccine trials. Adenocarcinoma is a type of cervical cancer that begins significantly far up the cervical canal, an area that often is not sampled when a Pap smear is conducted.

Andenocarcinoma is the second most common type of cervical cancer, accounting for about 20 percent of all cervical cancer cases. While the overall incidence rate of cervical cancer is on the decline, Ault reports the proportion of andenocarcinoma cervical cancer is rising.

As the 8th most common type of cancer in American women, more than 12,000 new cases of invasive cervical cancer are diagnosed each year. Scientists believe that pre-invasive cervical cancer may develop over a period of months or years after the cervix is infected with the sexually transmitted HPV.

A leading expert and pioneer in the field of human papilloma virus (HPV), Ault suggests women might seek an HPV and Pap test at the same time. Why? A positive HPV test may be an indicator for early stages of adenocarcinoma cervical cancer that can’t be determined via a standard Pap test.

New Blood Test Aids in Early Cancer Detection

Winship at Emory’s Dr. Suresh Ramalingam explains the test and what it means for cancer detection and treatment.

Suresh Ramalingam, MDYou may have heard in news headlines this week about the ability to detect a single cancer cell among billions of healthy cells. This may be possible via a new blood test (under development) that may someday help detect cancer earlier.

For tumors located in organs such as the lung, prostate, colon and breast, access to tumor tissue is only possible with a biopsy. This requires an invasive procedure, which in certain situations involves surgical intervention. It has been known for sometime that tumors shed their cancer cells that can be found in the circulating blood stream. However, the tumor cells are a significant minority in number compared to normal blood cells. Identifying the tumor cells among billions of normal cells has been a major challenge. Currently, it is possible with sophisticated techniques to identify such cells and count them. The number of circulating tumor cells has been linked to survival outcomes in some studies. Now researchers are trying to not only count, but collect these tumor cells and then conduct molecular testing.

Such an advance would have tremendous implications for cancer research and treatment. First of all, it may not be necessary to obtain tumor biopsies if adequate number of cells can be identified in the peripheral blood. It will be possible then, to administer this test during the course of a patient’s treatment to learn how a tumor is changing, because they do change as treatment progresses. It would also be possible to diagnose cancer early as part of screening strategies for patients at risk for developing certain cancers.

So how does this test work and what does it do? The test uses a microchip resembling a lab slide covered in 78,000 tiny posts. Those posts are coated with antibodies that attract and bind to tumor cells like glue. A patient’s blood sample, about a teaspoon full, is forced across the chip. The cancer cells stick, and a stain makes them glow so researchers can capture them for study.

For patients, care-givers and researchers this is very exciting news. However, this technology is just entering the early stages of testing and will have to go through several studies before it can be applied in routine practice. A number of important research questions will still have to be answered regarding the utility of circulating tumor cells, even if the test proves to be successful.

It is important to emphasize that while the new technology is exciting, it is possibly years away from practical application. If you have questions on this new blood test, please leave them in the comments below.

Could Space Travel Cause Lung Cancer in Astronauts?

Researchers are launching a new cancer research initiative – literally. NASA partners with Emory & MCG

NASA has awarded a team of investigators from both the Winship Cancer Institute of Emory University and the Medical College of Georgia $7.6 million over five years to study how a component of space radiation may induce lung cancer.

The award establishes a NASA Specialized Center of Research (NSCOR), consisting of a team of scientists with complementary skills who work closely together to solve a set of research questions. Ya Wang, PhD, professor of radiation oncology at Emory University School of Medicine and Winship Cancer Institute, is director of the NSCOR at Emory.

Interplanetary space travel could expose astronauts to conditions where they are chronically subject to types of radiation not normally encountered on earth. One of these radiation types is high energy charged particles (HZE), which results in complex damage to DNA and a broader stress response by the affected cells and tissues.

There is no epidemiological data for human exposure to HZE particles, although some estimates have been made studying uranium miners and Japanese atomic bomb survivors. Animal experiments show that HZE particle exposure induces more tumors than other forms of radiation such as X-rays or gamma rays.

Because it is a leading form of cancer, lung cancer can be expected to be prominent among increased risks from radiation even though astronauts do not smoke. However, the risk for astronauts remains unclear because the dose of HZE astronauts are expected to receive is very low.

The Emory-MCG researchers will probe whether the broader stress response induced by HZE particles amplifies cancer risk. Investigators will collaborate with physicists at Brookhaven National Laboratory to gather information on HZE’s effects. Individual projects include the study of how cells repair DNA damage induced by HZE particles, how HZE particles generate oxidative stress, and how they trigger regulatory changes in DNA known as methylation.

“The information generated by this project will be critical for estimating risks and establishing countermeasures for cancers associated with long term space travel. In addition, new insights into cancer resulting from all types of radiation exposure, including those found on earth, are likely to emerge from this project,” concludes Dr. Paul Doetsch, PhD, professor of radiation oncology and biochemistry, and associate director of Emory’s NSCOR.