“Joe Weatherly, DO, and Andrew Buelt, DO, are family medicine residents in St. Petersburg, Fla. Together, they co-produce the podcast Questioning Medicine, where they deconstruct issues confronting today’s clinicians. In this guest blog, Weatherly gives his take on breast cancer screening…
“In 2014, there will be an estimated 1,665,540 cancer diagnoses, and approximately 585,720 deaths from cancer or complications from the treatment of cancer. Estimates are that 3% to 35% of cancer patients avoid premature death by screening alone.
“This sounds wonderful. Those individuals and their stories are the poster children for preventive medicine. The cost and collateral impact on their lives is well worth it to those who prolong life and obtain ‘remission.’
“Only 17 percent of top-ranked consumer health websites advise against screening for prostate cancer, a recommendation made more than two years ago by the U.S. Preventive Services Task Force (USPSTF), according to a study presented at the 2014 Clinical Congress of the American College of Surgeons.
“In an Internet search for the phrase ‘prostate cancer screening’ on three main U.S. search engines, study researchers found that most sites appearing on the first results page recommended a patient-individualized approach to screening.
“Prostate cancer is the most common cancer in men besides skin cancer, affecting one in seven American men over their lifetime according to the American Cancer Society.1 Screening, which is routine testing in the absence of symptoms, can detect prostate cancer early. Screening tests for this cancer are the prostate-specific antigen (PSA) blood test, a digital rectal exam, or both.
” ‘The recommendation not to screen men for prostate cancer is controversial,’ said lead author Philip Zhao, MD, a urologist at The Arthur Smith Institute for Urology at North Shore–Long Island Jewish Health System, New Hyde Park, N.Y. He performed the research while a resident physician at Rutgers–Robert Wood Johnson Medical School, New Brunswick, N.J, under the guidance of Robert E. Weiss, MD, professor of urology.
” ‘Our study results suggest that two-thirds of the online community disagree with the USPSTF recommendation against prostate cancer screening,’ Dr. Zhao said.”
“A new Canadian guideline recommends that the prostate-specific antigen (PSA) test should not be used to screen for prostate cancer based on evidence that shows an increased risk of harm and uncertain benefits. The guideline is published in CMAJ (Canadian Medical Association Journal)
” ‘Some people believe men should be screened for prostate cancer with the PSA test but the evidence indicates otherwise,’ states Dr. Neil Bell, member of the Canadian Task Force on Preventive Health Care and chair of the prostate cancer guideline working group. ‘These recommendations balance the possible benefits of PSA screening with the potential harms of false positives, overdiagnosis and treatment of prostate cancer.’
“For men with prostate cancer diagnosed through PSA screening, between 11.3% and 19.8% will receive a false-positive diagnosis, and 40% to 56% will be affected by overdiagnosis leading to invasive treatment. Treatment such as surgery can cause postoperative complications, such as infection (in 11% to 21% of men), urinary incontinence (in up to 17.8%), erectile dysfunction (23.4%) and other complications.”
“Cancer Research UK scientists have discovered that lung cancers can lie dormant for over 20 years before suddenly turning into an aggressive form of the disease, according to a study published in Science today.
“The team studied lung cancers from seven patients – including smokers, ex-smokers and never smokers. They found that after the first genetic mistakes that cause the cancer, it can exist undetected for many years until new, additional, faults trigger rapid growth of the disease.
“During this expansion there is a surge of different genetic faults appearing in separate areas of the tumour. Each distinct section evolves down different paths – meaning that every part of the tumour is genetically unique.
“This research – jointly funded by Cancer Research UK and the Rosetrees Trust – highlights the need for better ways to detect the disease earlier. Two-thirds of patients are diagnosed with advanced forms of the disease when treatments are less likely to be successful.
“By revealing that lung cancers can lie dormant for many years the researchers hope this study will help improve early detection of the disease.”
“As prostate cancer awareness month just ended, prostate cancer screening seemed a fitting subject for this week’s blog.
“Those who know the evidence might think this argument pits European practices against our own domestic actions. Almost like a Ryder Cup for prostate screening. However, I recently saw that almost 50% of patients admit to undergoing lubed finger insertions and blood tests, which we know to be fairly inaccurate, in the last 12 months.
“In a Research Letter in JAMA Internal Medicine by Sammon et al., the fact that so many physicians are still screening for prostate cancer makes my evidence-based medicine soul cringe. In a 2012 survey, the authors found that among 114,544 respondents, 37% had undergone screening. Higher socioeconomic status nearly doubled a man’s odds of being screened (odds ratio 1.91, 95% CI 2.69-3.34).
“Low-dose computed tomography (LDCT) is a low-cost and cost-effective strategy for screening Medicare beneficiaries for lung cancer, according to a study published in the August issue of American Health & Drug Benefits.
“Bruce S. Pyenson, from Milliman Inc. in New York City, and colleagues estimated the cost and cost-effectiveness (cost per life-year saved) of LDCT lung cancer screening in the Medicare population at high risk for lung cancer. Medicare & Medicaid Services (CMS) beneficiary files (2012) were used to establish Medicare costs, enrollment, and demographics. CMS and U.S. Census Bureau projections were used for forecasts to 2014.
“The researchers found that approximately 4.9 million high-risk Medicare beneficiaries would meet criteria for lung cancer screening in 2014. Without screening, Medicare patients newly diagnosed with lung cancer have an average life expectancy of approximately three years. The average annual cost of LDCT lung cancer screening is estimated to be $241 per Medicare person screened. For Medicare beneficiaries aged 55 to 80 years with a history of ≥30 pack-years of smoking and who had smoked within 15 years, assuming a 50 percent screening rate, LDCT screening for lung cancer is low cost, at approximately $1 per member per month. This screening demonstrates highly cost-effectiveness, at <$19,000 per life-year saved.
” ‘If all eligible Medicare beneficiaries had been screened and treated consistently from age 55 years, approximately 358,134 additional individuals with current or past lung cancer would be alive in 2014,’ the authors write. ‘LDCT screening is a low-cost and cost-effective strategy that fits well within the standard Medicare benefit, including its claims payment and quality monitoring.’ “
The gist: This article discusses the results of a clinical trial—a research study with volunteer patients. The goal of the trial was to test whether the drug crizotinib (Xalkori) works for certain people with advanced non-small cell lung cancer (NSCLC). All of the patients who participated in the trial had a tumor mutation known as a ROS1 rearrangement, which can be detected using molecular testing. When treated with Xalkori, these patients experienced promising results. The researchers say the results highlight the importance of molecular testing for ROS1 rearrangement in people with advanced NSCLC.
“Objective responses occurred in 72% of patients with mutation-specific non-small cell lung cancer (NSCLC) treated with crizotinib (Xalkori), final results from a small clinical trial showed.
“Median response duration approached 1½ years, and median progression-free survival (PFS) had reached 19.2 months with follow-up ongoing.
“All 50 patients enrolled in the study had chromosomal rearrangements in ROS1, which several lines of evidence suggested would be susceptible to ALK inhibitors such as crizotinib, Alice T. Shaw, MD, PhD, of Massachusetts General Hospital in Boston, reported here at the European Society of Medical Oncology.
” ‘ROS1 rearrangement defines a second molecular subgroup of NSCLC for which crizotinib is highly active,’ Shaw and colleagues concluded in an article published simultaneously in the New England Journal of Medicine. ‘In the majority of patients, crizotinib induced durable clinical responses and was associated with grade 2 or lower toxic effects.
” ‘These results highlight the importance of screening for this genetic alteration in patients with advanced NSCLC.’ “
The gist: Cancer can be detected using a technique called photoacoustic imaging. This technique gives a doctors clear pictures of the inside of the body so they can detect tumors. However, use of this technique has been limited because improving it would require potentially toxic ‘photosensitizer’ molecules to increase the resolution of the pictures. Now, researchers have found a low-toxicity photosensitizer that could safely enhance photoacoustic imaging for cancer detection.
“Concerns over toxicity have constrained the clinical application of photoacoustic imaging—a new experimental technique used to detect tumors lurking among healthy cells. A*STAR researchers from the Singapore Bioimaging Consortium and an international team have now discovered how to improve both the safety and the tumor-locating efficacy of photoacoustic imaging using ‘photosensitizer’ contrast agents.
“Unlike typical optical measurements, photoacoustic imaging can probe deep into tissue by using ultrasonic waves generated by laser light pulses. This hybrid method produces strikingly clear pictures of complex biosystems, such as vascular tumor networks in organs and tissues. However, clinical applications of photoacoustic imaging have been limited by safety concerns surrounding ‘contrast agents’—light-absorbing molecules injected into cells to enhance imaging resolution.
“Photosensitizers are molecules that play key roles in a cancer treatment known as photodynamic therapy. These nontoxic substances, which are normally based on conjugated aromatic ring systems, specifically bind to malignant cells while leaving healthy tissue untouched. Exposing a photosensitizer to laser light causes it to produce excited-state oxygen molecules, which react with diseased cells to kill them. The photosensitizer is then rapidly eliminated from the target tissue.”
“Screen-detected lung cancer prevalence, as well false-positive results, were higher among Medicare-eligible participants compared with younger participants, according to results of a secondary analysis of the National Lung Screening Trial.
“Initial results of the National Lung Screening Trial (NLST) demonstrated a 20% reduction in the risk for lung cancer with annual low-dose CT compared with chest radiography in high-risk adults aged 55 to 74 years. The findings served, in part, as the basis for the US Preventive Services Task Force’s recommendation — issued in December 2013 — that high-risk individuals aged 55 to 80 undergo annual lung cancer screening with low-dose CT.
“However, experts have debated whether the annual screens should be covered for Medicare beneficiaries, who comprised approximately 25% of the trial’s population (age 55 to 64 years, n=19,612; age 65 to 74 years, n=7,110). In April, the Medicare Evidence Development & Coverage Advisory Committee expressed low to intermediate confidence that the benefits of annual screening outweighed the potential risks in the Medicare population.”