More than an ounce of prevention
Studies build knowledge
Contralateral prophylactic mastectomy not always best option
Breast cancer patients requesting removal of a healthy breast, along with the diseased one, is fast becoming the “norm” in clinics around the country.
From a patient’s perspective, the hope is that undergoing a contralateral prophylactic mastectomy (CPM) will hopefully reduce the risk of developing cancer in the healthy breast at a later date and improve chances of survival.
The problem with this rationale, according to Abenaa Brewster, M.D., associate professor in MD Anderson’s Department of Clinical Cancer Prevention, is that there is no significant data on whether removing the healthy breast affects survival at all.
“In fact, women with nonhereditary breast cancer have a very low risk of breast cancer developing in the healthy breast,” Brewster says.
In a recent study published in the journal Cancer, Brewster and a team of researchers observed the data of more than 3,800 female mastectomy-treated breast cancer patients. Their intent was to determine if there was an association between CPM, breast cancer disease-free (DFS) and overall survival.
By matching patients in the CPM and non-CPM groups using propensity scores — a technique that estimates the effect of CPM by accounting for such indicators as age, disease stage and treatment — researchers could reduce bias. The study also compared patients based on whether they had hormone receptor-negative breast cancer or hormone receptor-positive breast cancer.
They discovered improved DFS was more predominant among hormone receptor-negative patients who did not receive the drugs tamoxifen and arimidex, as compared to hormone receptor-positive patients. The study also identified that balancing these indicators was important because women who underwent CPM were more likely to be younger than age 50, Caucasian and have stage I or II breast cancer.
“Our findings indicate that small subgroups of patients may benefit from CPM, but we need to study these groups more closely,” Brewster says. She also stresses that the results indicate important implications for a more personalized approach to determining which breast cancer patients at average risk should be targeted for removal of a healthy breast.
Lagging in the race to survive
Despite being diagnosed in earlier stages and at younger ages, African-American patients are more likely to die from renal cell carcinoma (RCC), an invasive form of kidney cancer, than Caucasians.
The findings published online in Cancer, a journal of the American Cancer Society, analyzed data from a 15-year period that included nearly 40,000 patients — 4,359 black and 34,991 white — diagnosed with RCC. The study was led by Wong-Ho Chow, Ph.D., professor in MD Anderson’s Department of Epidemiology, and conducted at the National Cancer Institute.
Chow and her collaborators found that 72.6% of Caucasian patients survived at least five years after their diagnosis as compared to 68% of African-Americans. Also compelling is that 10.5% of white patients did not undergo surgery to remove the tumor as compared to 14.5% of black patients. It is important to note that survival rates were much lower for both groups who did not have surgery to remove their tumors.
Depression in bladder cancer patients, contralateral prophylactic mastectomy and survival rates of African-American versus Caucasian kidney cancer patients represent just three areas of study in the wide spectrum of research under way in MD Anderson’s Division of Cancer Prevention and Population Sciences.
Carried out by epidemiologists, behavioral scientists, cancer prevention experts and those researching health disparities, these studies focus on prevention and early detection of cancer.
The goal: To gain a deeper understanding of risk factors and discover interventions that can prevent disease.
Depression, telomere length may affect bladder cancer survival
“A sad soul can kill you quicker, far quicker, than a germ,” John Steinbeck wrote. Bladder cancer patients, who often suffer from depression, understand the deeper meaning of this quote.
For patients, a disease like bladder cancer can be a battle, often burdened with overwhelming depression. Given that managing stress can be difficult even under ordinary circumstances, feelings of fear and depression in cancer patients are understandable.
However, a number of studies have shown that people’s mental attitudes can impact physical health. To determine the effects of depression on bladder cancer patients’ disease progression and survival, Xifeng Wu, M.D., Ph.D., professor and chair of the Department of Epidemiology, was principal investigator on a related study conducted at MD Anderson.
Findings revealed that depression and certain age-related biomarkers could affect a bladder cancer patient’s likelihood of survival. The results may improve the prediction of bladder cancer outcomes. They also highlight the critical importance of enhanced stress management, the regular screening of cancer patients for depression and the need to provide appropriate interventions.
“People are not treating the depression directly, but are mainly focused on coping with cancer,” says Meng Chen, Ph.D., instructor in MD Anderson’s Department of Epidemiology. “Not taking depression into consideration leads to additional stress that decreases survival.”
The research also identified the shortened length of telomeres (specialized structures that protect the end of chromosomes from deterioration) as an age-associated biomarker in bladder cancer. As part of the aging process, telomeres get shorter, which makes the cells stop dividing and eventually die.
The study confirms that a combination of factors — longer telomeres and low levels of depressive symptoms — greatly increase survival for bladder cancer patients.
By Joey Tran