AACR, Author Interviews, Brigham & Women's - Harvard, Cancer Research, Nutrition, Prostate Cancer / 10.04.2021
Prostate Cancer: Healthy Lifestyle Can Mitigate Risk of Lethal Disease In Men With Highest Genetic Risk
MedicalResearch.com Interview with:
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Dr. Plym[/caption]
Dr. Anna Plym PhD
Postdoctoral Research Fellow
Brigham and Women's Hospital
Harvard T.H. Chan School of Public Health
MedicalResearch.com: What is the background for this study? What are the main elements of the healthy lifestyle?
Response: Prostate cancer is the most heritable of all cancers, with genetic factors accounting for a large proportion of cases. Although we do not currently know about all the genetic factors contributing, a recent study identified 269 genetic markers for prostate cancer, validated in multiple independent populations (Conti et al., Nature Genetics 2021, Plym et al, JNCI, 2021: https://academic.oup.com/jnci/advance-article-abstract/doi/10.1093/jnci/djab058/6207974). Based on a polygenic risk score derived from these 269 markers, we observed that men with a high polygenic risk score have over a 50% risk of developing prostate cancer within their lifetime. With this excess risk in mind, we were interested in possible ways in which the genetic risk of prostate could be attenuated. An increasing number of studies have suggested that lifestyle factors can affect the risk of lethal prostate cancer – however, these studies have seldom incorporated genetic factors. We know from other diseases that a healthy lifestyle is of benefit for individuals at high genetic risk, and we hypothesized that this would be the case for prostate cancer as well. In this study, we examined a healthy lifestyle score for lethal prostate cancer consisting of six components: healthy weight (BMI < 30), not smoking (never smoked or quit > 10 years ago), vigorous physical exercise (3 or more hours per week), high intake of tomatoes or tomato-based products (7 servings or more per week), high intake of fatty fish (1 or more serving per week) and low intake of processed meat (less than 3 servings/week of beef or pork hot dogs, bacon, salami, bologna, or other processed meat sandwiches) (Kenfield et al, JCO, 2016).
Dr. Plym[/caption]
Dr. Anna Plym PhD
Postdoctoral Research Fellow
Brigham and Women's Hospital
Harvard T.H. Chan School of Public Health
MedicalResearch.com: What is the background for this study? What are the main elements of the healthy lifestyle?
Response: Prostate cancer is the most heritable of all cancers, with genetic factors accounting for a large proportion of cases. Although we do not currently know about all the genetic factors contributing, a recent study identified 269 genetic markers for prostate cancer, validated in multiple independent populations (Conti et al., Nature Genetics 2021, Plym et al, JNCI, 2021: https://academic.oup.com/jnci/advance-article-abstract/doi/10.1093/jnci/djab058/6207974). Based on a polygenic risk score derived from these 269 markers, we observed that men with a high polygenic risk score have over a 50% risk of developing prostate cancer within their lifetime. With this excess risk in mind, we were interested in possible ways in which the genetic risk of prostate could be attenuated. An increasing number of studies have suggested that lifestyle factors can affect the risk of lethal prostate cancer – however, these studies have seldom incorporated genetic factors. We know from other diseases that a healthy lifestyle is of benefit for individuals at high genetic risk, and we hypothesized that this would be the case for prostate cancer as well. In this study, we examined a healthy lifestyle score for lethal prostate cancer consisting of six components: healthy weight (BMI < 30), not smoking (never smoked or quit > 10 years ago), vigorous physical exercise (3 or more hours per week), high intake of tomatoes or tomato-based products (7 servings or more per week), high intake of fatty fish (1 or more serving per week) and low intake of processed meat (less than 3 servings/week of beef or pork hot dogs, bacon, salami, bologna, or other processed meat sandwiches) (Kenfield et al, JCO, 2016).
Dr. Jeffrey Smith[/caption]
Jeffrey R. Smith, MD PhD
Department of Medicine, Division of Genetic Medicine
Vanderbilt-Ingram Cancer Center, and Vanderbilt Genetics Institute
Vanderbilt University Medical Center
Medical Research Service
Tennessee Valley Healthcare System, Veterans Administration
Nashville, TN
MedicalResearch.com: What is the background for this study?
Response: Roughly 20% of men with prostate cancer have a family history of the disease, and 5% meet criteria for hereditary prostate cancer. Although prostate cancer has the greatest heritability of all common cancers (twice that of breast cancer), extensive heterogeneity of its inherited causes has presented a considerable obstacle for traditional pedigree-based genetic investigative approaches. Inherited causes across, as well as within families are diverse.
This study introduced a new familial case-control study design that uses extent of family history as a proxy for genetic burden. It compared a large number of men with prostate cancer, each from a separate family with a strong history of the disease, to screened men with no personal or family history. The study comprehensively deconstructs how the 8q24 chromosomal region impacts risk of hereditary prostate cancer, introducing several new analytical approaches. The locus had been known to alter risk of prostate, breast, colon, ovarian, and numerous additional cancers.
Dr. Taioli[/caption]
Emanuela Taioli, MD, PhD,
Director of the Institute for Translational Epidemiology
Icahn School of Medicine at Mount Sinai
Asociate director for Population Science
Tisch Cancer Institute
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: An excess incidence of prostate cancer has been identified among World Trade Center responders. We wanted to study if this excess was associated with exposure to WTC dust
The results suggest that respiratory exposure to WTC dust can induce inflammatory and immune responses in prostate tissue. Chronic inflammation could facilitate prostate cancer development
Taken together, our results suggest that World Trade Center prostate cancer cases have a distinct gene expression pattern that may be the result of exposure to specific carcinogens during the WTC attacks. WTC dust-exposed rat prostate displayed unique changes in gene expression and immune cell infiltrates after acute dust exposure, suggesting that the effect of exposure may be measured locally in target organs such as prostate. In addition, some of the genes overexpressed in rat normal prostates as a consequence of exposure are also overexpressed in human prostate cancer tissues, suggesting a link between exposure, local immune dysregulation, and prostate cancer development
Dr. Kishan[/caption]
Amar U. Kishan, MD
Assistant Professor
Department of Radiation Oncology
University of California, Los Angeles
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Typical external beam radiation courses range up to 8-9 weeks in length (39-45 treatments). There are data that shorter courses, delivering a higher dose per day, may be just as effective.
Stereotactic body radiotherapy (SBRT) really pushes this concept by condensing the treatment to just four to five treatments, with a high dose per day.
Here, we present the pooled results of the outcomes of 2142 men with low and intermediate risk prostate cancer and a median of 6.9 years of followup.
We demonstrate a very favorable efficacy and safety profile. Specifically, the rates of recurrences were 4.5% and 10.2% for low and intermediate risk disease at 7 years, and rates of late severe toxicity were 2.4% for urinary toxicity and 0.4% for gastrointestinal toxicity.