The ‘Bad Luck’ Cancer Analysis, Part II

A new study revisits an analysis made by the same lab in 2015 about the role of random mutations on cancer. The analysis uses computer modeling to estimate how many cancers are the result of replication errors. The authors say their study provides a molecular explanation for the large and apparently unpreventable component of cancer risk that has long puzzled epidemiologists. A study by the same team a few years ago led to lots of debate about cancer prevention, and the role of ‘bad luck’ in cancer. This time, the authors stress that their work “does not diminish the importance of primary prevention but emphasizes that not all cancers can be prevented by avoiding environmental risk factors.”

We asked Otis W. Brawley, M.D., chief medical officer,for his response to the new work.

“This study reaffirms what we have known about cancer for years, namely that many cancers occur not because of anything we did, but because of what we call ‘replication error.’ Replication error can be compared to a genetic game of telephone, where imperfections accumulate until the message is no longer correct. They use a hypothetical example that even people living on another planet where the environment is perfect, there would still be a baseline number of “unavoidable” cancers due to replication errors.

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Otis W. Brawley, M.D.

“The study also reiterates the importance of two other major factors associated with cancer: heredity, and environment. Note that when epidemiologists talk about ‘environment,’ they’re referring not to exposure to toxins alone, but also to things like nutrition, physical activity, passive or direct smoking, sunlight, and other factors people are exposed to in their daily lives.

“The authors acknowledge that there is frequently a mix of these three influences: replication, heredity, and environment and that they can differ for different cancers under different circumstances.

“They calculated the impact of replication error by using a mathematical model to figure out how many times a cell would have to replicate before a random error would cause a cancer to start growing.

“Their initial report several years ago was met with lots of debate. This time, the authors explained the affect with caution and credibility, which should help clarify their conclusions in a way that will find a more receptive audience.

“The findings may lead to additional discussion of the role of ‘bad luck’ in cancer, but in fact the findings confirm something scientists have been talking about for a long time; that someone can do all the right things and still get cancer. This idea applies not only to people whose cancers are the result of replication error, but also to inherited genetic factors.

“While it would be easy to become fatalistic and think there’s nothing to be done about many cancers, in fact the paper reiterates the importance of primary prevention by avoiding environmental risk factors as well as ensuring everyone has access to proven early detection and screening, so we can find those cancers early and intervene in hopes of reducing their impact.”

Posted in Behavior, Communications, Environment, Lifestyle, Prevention, Research | Leave a comment

ACS Study Finds Colorectal Cancer Rates Have Risen Dramatically in Gen X and Millennials

A groundbreaking study by American Cancer Society epidemiologist Rebecca Siegel, MPH finds that people born in the United States in 1990 have double the risk of colon cancer and quadruple the risk of rectal cancer compared to those born around 1950, when colorectal cancer risk was lowest.

polypThe study appears in the Journal of the National Cancer Institute, and  finds colorectal cancer (CRC) incidence rates are rising in young and middle-aged adults, including people in their early 50s, with rectal cancer rates increasing particularly fast. As a result, three in ten rectal cancer diagnoses are now in patients younger than age 55.

Overall, CRC incidence rates have been declining in the United States since the mid-1980s, with steeper drops in the most recent decade driven by screening. Recently though, studies have reported increasing CRC incidence in adults under 50, for whom screening is not recommended for those at average risk. However, these studies did not examine incidence rates by 5-year age group or year of birth, so the scope of the increasing trend had not been fully assessed.

To get a better understanding, investigators led by Ms. Siegel used “age-period-cohort modeling,” a quantitative tool designed to disentangle factors that influence all ages, such as changes in medical practice, from factors that vary by generation, typically due to changes in behavior. They conducted a retrospective study of all patients 20 years and older diagnosed with invasive CRC from 1974 through 2013 in the nine oldest Surveillance, Epidemiology, and End Results (SEER) program registries. There were 490,305 cases included in the analysis.

The study found that after decreasing since 1974, colon cancer incidence rates increased by 1% to 2% per year from the mid-1980s through 2013 in adults ages 20 to 39. In adults 40 to 54, rates increased by 0.5% to 1% per year from the mid-1990s through 2013.

Rectal cancer incidence rates have been increasing even longer and faster than colon cancer, rising about 3% per year from 1974 to 2013 in adults ages 20 to 29 and from 1980 to 2013 in adults ages 30 to 39. In adults ages 40 to 54, rectal cancer rates increased by 2% per year from the 1990s to 2013. In contrast, rectal cancer rates in adults age 55 and older have generally been declining for at least 40 years, well before widespread screening.

Opposing trends in young versus older adults over two decades have closed a previously wide gap in disease risk for people in their early 50s compared to those in their late 50s. Both colon and rectal cancer incidence rates in adults ages 50 to 54 were half those in adults ages 55 to 59 in the early 1990s, but in 2012 to 2013, they were just 12.4% lower for colon and were equal for rectal cancer.

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Rebecca Siegel, MPH

“Trends in young people are a bellwether for the future disease burden,” said Siegel. “Our finding that colorectal cancer risk for millennials has escalated back to the level of those born in the late 1800s is very sobering. Educational campaigns are needed to alert clinicians and the general public about this increase to help reduce delays in diagnosis, which are so prevalent in young people, but also to encourage healthier eating and more active lifestyles to try to reverse this trend.”

In addition, the authors suggest that the age to initiate screening people at average risk may need to be reconsidered. They point out that in 2013, 10,400 new cases of CRC were diagnosed in people in their 40s, with an additional 12,800 cases diagnosed in people in their early 50s. “These numbers are similar to the total number of cervical cancers diagnosed, for which we recommend screening for the 95 million women ages 21 to 65 years,” said Siegel.

That prompts the question: Is ACS going to change its guidelines? For some answers on that, we went to Otis Brawley, M.D., chief medical officer.

“There is increasing evidence, some of it published by ACS investigators, that colorectal cancer is increasing in people younger than age 55 years. This new data will be examined by our independent guidelines development group to review whether a change in our screening recommendations is warranted, particularly since screening can prevent colorectal cancer, averting substantial morbidity and mortality during the most productive years of life.

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Otis W. Brawley, M.D.

“Guidelines from the ACS and others are designed to catch as many cancers as possible while minimizing the adverse effects associated with screening those with low rates of disease. No organization’s guideline is designed to catch every cancer. This often becomes in issue in younger populations, where cancers are more rare, and naturally of great concern.

“Every screening recommendation involves weighing the potential benefits against the harms associated with procedures that come as a result of screening. We need to be sure we’re doing more good than harm.

“The risk of colorectal cancer is increasing for every generation born since the 1950s, something we suspect is due to the complex relationship between obesity, an unhealthy diet, and lack of physical activity.

“No one study is enough to change our guidelines. We continue to track this issue in an effort to make sure our screening recommendations reflect the latest evidence.

“It is important to note that when there is a family history of early onset colorectal cancers, the ACS and others support beginning screening at a younger age.”

You can read more about what we know about colorectal cancer risk on cancer.org.

Article: Colorectal Cancer Incidence Patterns in the United States, 1974-2013; J Natl Cancer Inst (2017) 109(8): DOI: 10.1093/jnci/djw322

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Study Corrects Cancer Data and Finds Cervical Cancer Rates, Disparities Higher than Thought

1024px-squamous_cell_carcinoma_in_the_cervix_pap_stainA new study corrects cervical cancer incidence and mortality rates to account for hysterectomy, and finds both incidence and mortality of cervical cancer has been grossly underestimated, especially in the black population, in which hysterectomy rates are higher. The study, led by Anna L. Beavis, M.D., MPH of Johns Hopkins Medicine finds the prevalence of hysterectomy was greatest in white and black women aged 65 to 69 years, but the peak was significantly higher in black women (58% vs 43% for white women). After correction, the black mortality rate was 10.1 per 100,000 (5.7 per 100,000 without correction), whereas the corrected rate for white women was 4.7 per 100,000 (3.2 per 100,000 without correction). Without correction, the disparity in mortality between the races was underestimated by 44%. The oldest black women had the highest corrected mortality rate at 37.2 deaths per 100,000, a rate that rivals the rates of undeveloped countries.

We asked Otis W. Brawley, M.D. MACP , the American Cancer Society chief medical officer, to respond to the study. 

“This is an important and very well-done study that has real implications in cancer medicine. The United States has very high rates of hysterectomy, so recalculating incidence and mortality after removing those who have had a hysterectomy, and who therefore cannot get cervical cancer, makes sense. After all, statistics are usually provided only for those at risk. For example, testicular cancer rates include only men and not men and women. Even with breast cancer, for which men have very low incidence, we commonly report incidence and mortality in women only.

otis-brawley-potraits-5x7-2016“The message to healthcare providers, insurers, policy makers, and patients is the same: Disparities not only exist in cervical cancer, but at even higher rates than we knew. This study should clearly focus public health efforts about the magnitude of this problem, and help strengthen efforts to overcome it.

“Why do these disparities exist? The reasons are complex, and deeply ingrained in our society. There is good evidence in a number of diseases, even beyond cancer, that even when screening rates are similar, the quality of screening is not. This concept of disparity has been shown true not only in screening, but also in diagnostics and treatment of breast cancer and colon cancer as well as in the treatment of hypertension, diabetes, and cardiovascular disease. It seems quite plausible this is also the case in cervix cancer. We frequently focus on whether screening, diagnostics, and treatment occurred, but we often forget to take into account the quality of these interventions. Even in the case of radiation therapy there is a significant literature on the disparities in completion of treatment.

“Common reasons for the disparities include things like overcrowding and overtaxed doctors and clinics in socioeconomically deprived communities. Patients also have challenges in getting care; simple things such as transportation, especially for radiotherapy where one needs to receive it on a regular basis can be an obstacle. In addition, disparities are often tied up in issues that lead to patients leaving treatment before their therapy is complete.”

 

Posted in Access to Care, Cervical, Disparities, Prevention, Screening | Leave a comment

A Healthful Way to Give to Cancer Patients

As the holidays approach and the year ends, a lot of people are looking for ways to give back, whether it’s gifts to loved ones or donations to their favorite charity (and of course we hope you’ll support the American Cancer Society).

But there’s another way to give; a way to help people with cancer and others stay healthy as winter approaches: By getting your flu shot.

16731-a-nurse-giving-a-middle-aged-man-a-vaccination-shot-pvLast year, most of the people who got flu shots (and only about half of us did) likely did it for a personal reason: to avoid getting flu. But there’s another, altruistic aspect to vaccination that is equally, or perhaps even more important.

Because the vaccine is not perfect, increasing the population of people who get vaccinated is a key part of protection, thanks to something called herd immunity.

People undergoing treatment for cancer as well as others whose immune systems may be compromised may not get as good a response to the vaccine, so it is especially important that those around them –including but not limited to families, loved ones, friends, co-workers, and health professionals– be  vaccinated to reduce the risk of spreading the flu to cancer patients and other vulnerable populations. Also vulnerable are pregnant women, older people, young children, and others with chronic conditions like asthma or diabetes.

You can protect not only yourself but others by getting vaccinated, reducing the chances of flu spreading to these vulnerable populations. It’s a potentially lifesaving gift at a time when many of us are looking for ways to give back.

Visit http://www.cdc.gov/vaccines/adults/find-pay-vaccines.html to find and learn how to pay for a vaccine.

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Melanoma and Alcohol: Another Explanation

A study getting some attention today links alcohol intake with an increased risk of melanoma, an association that had been suggested in previous smaller studies as well as in a combined analysis of 16 studies. party-1173651_960_720How could alcohol raise the risk of melanoma, a cancer strongly linked to ultraviolet (UV) radiation? Well in fact, UV radiation probably shouldn’t be counted out as the possible cause just yet.

Those who’ve studied science are familiar with the saying: “correlation does not imply causation.” That means that just because two factors are associated with each other doesn’t necessarily mean that one causes the other.

tanning-bedSometimes associations between two factors are due to chance (or coincidence); sometimes other factors can be the culprit behind the association between two factors; and sometimes there are other reasons that could lead to a biased association.

That may be the situation with the new study linking melanoma and alcohol. While the investigators of this study did attempt to control for difference in sun exposure, another factor, the use of tanning beds which emit UV radiation and are a known cause of melanoma, may be the culprit. Susan Gapstur, PhD, vice president of epidemiology comments:

“In fact, a recent review (Preventive Medicine Reports 3 (2016) 139–144) pointed out that indoor tanning may explain a recent trend in melanoma. Over the past 15 years, there has been a significant increase in melanomas that appear on the trunk in females, especially in areas where indoor tanning is prevalent.

“Indeed, this new study showed the association between alcohol and melanoma was strongest for the trunk. While those who consumed 20 grams or more of alcohol per day were 2 percent more likely to be diagnosed with melanomas of the head, neck, or extremities, they were 73 percent more likely to be diagnosed with melanomas of the trunk.

“I do wonder if the finding of this study is confounded by tanning bed use. There is evidence, that tanning bed users –particularly young users–are more likely to smoke, drink, and/or use drugs.”

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CDC: Two shots enough for most young patients getting HPV vaccine

gardasil_vaccine_and_boxThe Advisory Committee on Immunization Practices (ACIP) has revised its vaccination schedule for HPV vaccination among younger populations. ACIP says those starting vaccination between ages 9 and 14 can now get just two doses of HPV vaccine rather than three, with the second dose administered 6 to 12 months after the first dose. Three doses remains the recommendation for those 15 and over and for immunocompromised persons. Previously, ACIP recommended all age groups get three doses of the vaccine, with the second dose administered 1 to 2 months after the first, and the third dose administered 6 months after the first dose.

We asked Debbie Saslow, PhD, Senior Director, HPV Related and Women’s Cancers about the change.

The ACIP’s action to revise its recommendation sets in motion the ACS process to review and update its own guideline, which currently closely mirrors the previous ACIP recommendation and emphasizes the need for on-time vaccination, i.e. at age 11-12, when vaccination is most effective.

Read more about HPV vaccines here.

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Report: One in Four Americans over 50 is Inactive

Researchers from the Centers for Disease Control and Prevention (CDC) released new data on the prevalence of physical inactivity among adults age 50 years and older. Inactivity is 63745_151_previewdefined as no activity beyond what one has to do just to get through the day (activities of daily living). When asked “During the past month, other than your regular job, did you participate in any physical activities or exercises such as running, calisthenics, golf, gardening, or walking for exercise?”, 27.5% of the adults surveyed responded ‘no’ – indicating that more than one in four adults 50 and over are inactive.

The prevalence of inactivity varied by region. It was highest in the South (30.1%), followed by the Midwest (28.4%), Northeast (26.6%), and West (23.1%).  The survey also found that inactivity was significantly higher for women, Hispanics and non-Hispanic blacks, and adults with one or more chronic diseases. Inactivity for cancer survivors was reported at just 31.6%.

We asked Colleen Doyle, MS, RD, managing director of nutrition and physical activity at the American Cancer Society for her take on the new data.

“This report is a wake-up call and quite literally a ‘call to action.’ Being physically active reduces the risk of premature death and can help reduce the risk of many chronic diseases, including cancer. Physical activity also helps support improvements in quality of life and healthy aging. While we’ve known that the level of physical inactivity among adults is far too high, this report underscores the fact that inactivity is highest among those who could benefit the most from it.

“Adults with at least one chronic condition were more likely to be sedentary than those without a chronic condition. In the case of cancer, more than 31% of cancer survivors reported getting no physical activity outside of daily life. Studies have shown that exercise can improve cancer survivors’ physical functioning, fatigue, anxiety, depression, self-esteem, and happiness. In addition, studies among survivors of certain cancer types have shown that physically active survivors have a lower risk of recurrence and improved survival compared with those who are inactive.

“For those who do not have a history of cancer, the evidence is clear that being active and reducing sedentary behavior can help reduce the risk of a variety of types of cancer.

The American Cancer Society recommends that everyone, including cancer survivors, strive to be active at for least 150 minutes per week and to avoid inactivity. To encourage and support all individuals in increasing their physical activity level is critically important to our mission to reduce cancer incidence and mortality, as well as to improve the quality of life of cancer survivors.

“It’s important to consider why many Americans are not meeting physical activity guidelines. And there are likely multiple reasons. What is evident, though, is that in many communities, living a physically active lifestyle can be a challenge. The ways in which communities are designed and built can present challenges. When everyday destinations are far from home, walking, bicycling or other forms of active transportation may not be an available or convenient option. Safety concerns, such as lack of access to sidewalks, bike lanes, and traffic control measures, can also be barriers to being active. Lack of access to parks, public pools and green space, which tends to be higher in poor and under-served communities, also contributes to lower rates of physical activity.

“There is much being done but much more that needs to be done to reduce physical inactivity and help people of all ages and health conditions live more physically active lives. All sectors can work together to:

  • Support safe, efficient, and pedestrian-friendly public transit systems and transit-oriented development, and to create and improve walking trails and parks.
  • Open and promote places in communities for individuals to be active such as schools, parks, and malls.
  • Provide evidence-based community programs that help adults, including those with chronic conditions like cancer, start and continue to be active.
  • Work with health professionals to link their patients to community programs and resources for physical activity.

“And as individuals, there is much we can do, too. Commit to be more active yourself, on a daily basis. Encourage and support your family members, friends and co-workers to do the same. Speak up; participate in local planning efforts that support safe and convenient places to be active. Working collectively, we can help create healthier environments to support all of us in living a more physically active life.”

Posted in Access to Care, Disparities, Environment, Lifestyle, Physical Activity, Survivorship | 1 Comment