No longer eliciting quite the dread it once did, cancer has become a part of everyday life. We hear about it constantly, know people who have had it, and—most critically—read about the almost daily breakthroughs that have made cancer manageable and, hopefully, will lead to its eradication.
From the air we breathe to the water we drink, certain exposures can pose significant risks. While some toxins lurk and others are far more transparent, become a catalyst for understanding how pollutants and chemicals can affect cancer risk.
environment vs. genetics
We know genetics, environment and lifestyle all can contribute to cancer risk. “The proportion of cancer cases due to environmental causes is higher than that due to genetic causes,” says Dr. Adetunji Toriola of Washington University School of Medicine. “Not everyone who is exposed to similar amounts of a pollutant will develop cancer,” he says. “Genetics and other lifestyle-related factors modify these risks.”
“As far as genetic disposition in cancer development, it only accounts for a very small portion of overall cancer cases, probably no more than 5 to 10 percent,” confirms Dr. H. Shawn Hu, chairman of Mercy Oncology Services. “Although it is critical that physicians look into each patient’s family history and recognize the potential genetic syndromes, I believe the significance of a genetic link to cancer is somewhat overemphasized.”
the long hit list
It is estimated that two of every 10 cancers are due to environmental causes, according to Toriola. More than 100 environmental factors have been classified capable of causing cancer in humans, according to Toriola. Some of the risk factors are well-known, such as radiation exposure from CT scans, asbestos and industrial solvents like benzene, according to Hu. “While some of these factors have a predilection for causing cancer in specific sites, others may affect more than one site,” Toriola says. He singles out arsenic (found in wood preservatives and pesticides), which is associated with an increased risk of skin, lung, bladder and kidney cancers; and cadmium (found in metal coatings and some plastics), which appears to be associated with lung cancer.
air, arsenic, asbestos
Air pollution is associated with an increased risk of lung cancer—the leading cause of cancer death among men and women. It is estimated that more than 170,000 cases worldwide are due to air pollution, according to Toriola. Typically found in industrial settings and older buildings, toxic asbestos fibers are the focus of recent studies that indicate which areas in the country pose the greater risk for asbestos exposure. Geologist Dr. Brenda Buck recently discovered alarming rates of naturally occurring asbestos in the Nevada desert. Buck is collaborating with a leading mesothelioma researcher, Dr. Michele Carbone of the University of Hawaii, to assess the extent of any potential health risks and their implications for people living in the region.
The relationship between epidemiology and environment is further cemented with facts showing that genetic mutations account for only 5 to 10 percent of breast cancers overall, according to the National Cancer Institute. Toriola says that while a mother’s exposure to an environmental factor during pregnancy may increase cancer risk in the child, this depends on other factors. “The cancer consequences depend on the gender and stage in development at the time of exposure, as well as amount and duration of exposure.” The degree to which parental exposure to an environmental factor may increase cancer risk in babies is being examined by The Child Health and Development Studies, which is working with 15,000 women in a one-of-a-kind research program that spans three generations.
[customizing cancer treatment]
Cancer is feared for its indiscriminate nature: it’s an equal-opportunity affliction. But what differentiates us actually could be the key to effective treatment. That, anyway, is the idea behind gene-targeted therapies for cancer patients: customizing treatment is shaping life-saving ways to treat the disease.
focus on the unique
“Individualized therapy is the new watchword,” says Dr. Carl Freter, director of the division of hematology and oncology at Saint Louis University and associate director of SLU Cancer Center. “That’s because we know a lot more about the genetics of cancer.” The idea that treatment for diseases like cancer can and should be tailored to the individual patient has received national support and attention.
In February, the Obama administration outlined its Precision Medicine Initiative, which designates $70 million to the National Cancer Institute to “scale up efforts to identify genomic drivers in cancer and apply that knowledge in the development of more effective approaches to cancer treatment.” The initiative affirms a key shift in expanding the range of possibilities and options for patient treatment.
custom vs. chemo
Gene-targeted therapies are a “broad-based approach that is intellectually different than chemotherapy and informed by vastly increased knowledge of the genetics of cancer and the mechanisms of what makes cancer occur, grow, invade and kill,” says Freter. Targeted therapies focus on specific molecular abnormalities in cells, he adds. While traditional chemotherapy focuses on slowing down the growth of cells, this can be toxic to the patient’s other organ systems.
Freter estimates 50 percent of cancer therapy is now targeted, while the other half is still based on the conventional method of killing rapidly dividing cells. Some physicians use a hybrid approach that combines both traditional chemotherapy and targeted therapies. “All of oncology is moving toward discovering the Achilles’ heel of individual cancers and targeting that,” he adds.
In general, targeted therapy can be a lot easier on patients. The nature of targeted therapy drugs— simpler and smaller—marks a fundamental difference from chemotherapy, says Freter. In contrast to the IV transfusions used often in conventional chemo, targeted therapy drugs frequently are taken orally. If traditional chemotherapy is largely characterized by its fast and aggressive approach to fighting cancer, targeted therapies adopt a slow-and-steady method to halt the growth first before eliminating the cancer. “We have to be more patient, and our traditional measures of response are different. We are still learning and developing better ways to measure clinical responses,” says Freter.
“Whether this is the norm or still experimental depends on what specific cancer you’re talking about,” says Dr. Ron Bose, oncologist at Siteman Cancer Center and Assistant Professor of Medicine and of Cell Biology and Physiology at Washington University. When a drug to inhibit gene alteration in chronic myeloid leukemia went through a clinical trial in 1999, the death rate dropped to 10 percent of what it used to be. More recently, Bose cites a 2004 study that focused on the epidermal growth factor receptor mutation in lung cancer. Patients were given an oral drug and had better outcomes than with standard chemotherapy.
A driving factor for gene-targeted therapies, says Bose, are the significant advances in next-generation DNA sequencing. Within the last five years, enhanced technology has allowed sequencing of millions of base pairs of DNA at a time, compared to just hundreds in the past. “With this increase of speed has come a dramatic fall in the cost of sequencing, with costs comparable to that of an MRI scan,” he says.
As early successes lay the groundwork for further innovations in gene-directed therapy, more recent research in gene amplification and alteration is being conducted on “every conceivable form of cancer,” says SLU’s Freter. “There has been no time in my career like the present in terms of excitement in oncology and development of new drugs that are making major leaps in improving treatments for our patients. They are our individualized focus, and what this is all about.”
The cumulative toll of cancer can leave a patient physically, mentally and emotionally depleted. Even traditional medicine has recognized the benefits of holistic approaches to complement more aggressive medical treatments. Complementary therapies such as yoga, meditation, music and acupressure encourage coping over curing as part of a comprehensive treatment plan for patients.
Traditional oncologists and non-medical practitioners alike are quick to note that holistic approaches can be beneficial when paired with conventional cancer treatment. “We are not here to replace traditional cancer therapy like chemotherapy, radiation or surgery,” says Crystal Weaver, a board-certified music therapist and a certified rehabilitation counselor at SLU Cancer Center.
“I think there is more impact from complementary supportive care, which can include relaxation, therapeutic touch and aromatherapy and can provide a more individual approach,” says Dr. Christos Papageorgiou, oncologist at St. Mary’s Health Center. He also cites the value of these methods because “they do not intervene with conventional therapy and are not pharmaceutically based.”
There is literature to support the benefits of holistic treatment. A 2007 study in the Journal of Clinical Oncology examined aromatherapy massage on cancer patients and noted a clinically important benefit that lasts up to two weeks. A 2011 study in the Journal of Pain and Symptom Management also concluded acupressure was a useful intervention for nausea and pain.
power of positive thinking
“I’m a huge proponent of behavioral intervention as a means to decrease stress,” says Papageorgiou. He refers his patients for integrated therapies such as yoga, meditation and exercise to complement his traditional cancer treatment. Papageorgiou’s patients have reaped the benefits of such therapies, reporting less nausea following acupuncture, and reduced stress, thanks to exercise or yoga.
Achieving a calm state of mind—going to your happy place—can be an effective coping mechanism. “Creating positive thoughts are statistically associated with improved outcomes in patients,” says Papageorgiou. He advocates positive thinking and encourages patients to, in effect, rehabilitate their brain through relaxation and meditation. “Just like any other muscle, you can exercise and educate your brain to have positive thoughts.”
the right notes
Music therapy is another intervention designed to offer patients relief from pain, anxiety, fatigue and other chemotherapy effects. Building on the principles of person-centered therapy, music therapy sessions are specifically customized to the patient’s goals, issues and preferences.
If the patient feels isolated and isn’t getting enough sensory stimulation, a session can feature up-tempo music or invite patient interaction through therapeutic songwriting. Alternately, passive involvement sessions can be optimal for relaxation. Convenience and continuity of care are hallmarks of the music therapy program at SLU Cancer Center, says Weaver. Armed with a guitar and an extensive music background, Weaver and other music therapists can be present at every step of a patient’s treatment, even during long chemo transfusions. And contrary to the belief that classical music is the standard for relaxation, Weaver takes requests from patients who prefer all types of music—country, spiritual, contemporary or pop.
Beyond providing relief from side effects, holistic options can empower patients simply by offering them choices during cancer treatment. From medications, diet, lifestyle changes and courses of treatment, options for cancer patients can be restrictive, says Weaver. Holistic therapies offer a sense of autonomy for patients who may feel like so much in their lives is out of their control. SLU Cancer Center has an open referral process that offers therapeutic services to anyone being treated at the center. “It’s good to offer opportunities, to give patients choice and control,” she says.