Cancer editon 2017: From the Doctor --- Counter your odds of prostate cancer
By By Samer S. Kasbari, M.D., MS
Published in News on October 8, 2017 3:18 PM
Prostate cancer is the second most common cancer in men worldwide and the first most common in the United States. There are expected to be around 161,000 new prostate cancer diagnoses and approximately 26,7000 prostate cancer deaths in 2017 in the United States alone. Here in the U.S., we have been doing a good job screening and diagnosing prostate cancer at early stages, but we are still far from doing enough. Practicing oncology in eastern North Carolina has given the opportunity to treat many patients with prostate cancer, but I have also realized the lack of adequate education and screening that is desperately needed in our communities.
As a male in America, you have a 16 percent lifetime risk of developing prostate cancer, but the risk of dying because of prostate cancer is much lower at 2.9 percent. Survival from prostate cancer depends on many factors but particularly dependent on the extent of the tumor at the time of diagnosis. For example, 100 percent of all men diagnosed with a localized prostate cancer will be alive after five years from their diagnosis. However, less than a third will be alive in five years if they are diagnosed with metastatic (stage 4) prostate cancer. Thus, a successful screening program that can identify men without any symptoms is expected to significantly reduce prostate cancer complications and death.
Prostate-specific antigen (PSA) testing has revolutionized prostate cancer screening. It was originally used as a tumor marker to detect cancer progression or recurrence, but it has become widely adopted for cancer screening by the early 1990s. Subsequently, there was a huge spike in the incidence of prostate cancer, peaking in 1992. The majority of these newly-diagnosed cases were not clinically symptomatic and led to an increase in prostate surgery (radical prostatectomy) and radiation therapy; both are considered aggressive treatments intended to cure these early state cancers. However, prostate cancer screening has been very controversial, and physicians are constantly updated with new guidelines and recommendations from different medical societies. When it comes to screening, individuals need to discuss the risks and benefits of screening with their physicians. Physicians must take into consideration the age of the patient, his ethnicity, family history of prostate cancer and other medical problems that may affect longevity of the individual patient.
Prostate cancer has many risk factors. The most important are age, ethnicity, genetic predisposition and environmental (including dietary) factors. Age is the strongest factor; age 20-30 years for example will have around 4 percent risk of having prostate cancer compared to up to 73 percent risk in individuals between the age 81-90 years. Ethnicity also plays a major risk. It is not very clear why African Americans have a higher risk than Caucasians or Hispanic men, but it is thought to be related to a combination of dietary and/or genetic factors. In addition to the higher incidence rates among African Americans, the age of onset is earlier than that of other ethnicities. As for dietary risks, high animal fat diet has been shown to increase risk of prostate cancer. A diet low in vegetables may be another risk for prostate cancer. Lycopene (potent anti-oxidant) and tomato-based products are associated with a lower incidence of prostate cancer. Soy intake is postulated to reduce prostate cancer risk. Omega-3 fatty acids and fish oil have been shown in multiple studies to increase the risk of prostate cancer but more definitive studies are still needed to confirm these outcomes.
Lastly, I would like to discuss selenium and vitamin D. Selenium has been widely studied for the last few decades. The relationship between selenium and prostate cancer is complex. The final verdict is with mixed results, but it appears that supplementing with selenium does not reduce the risk of prostate cancer. As for vitamin D, the relationship is also complex on whether there is an increase or decrease in the risk of prostate cancer while taking vitamin D supplements. Vitamin D studies in other cancers have shown a reduced risk of developing cancers when vitamin D level is adequate. Therefore, I have been examining my patients' vitamin D levels and treating according. I personally believe that the future trials will reveal a trend of a protective mechanism from taking vitamin D.
Before I move to treatment modalities for prostate cancer, I would like to briefly discuss cigarette smoking and prostate cancer. Tobacco use is not only known to increase the risk of developing prostate cancer, but it also affects prostate cancer prognosis once a diagnosis is established. Many studies revealed significant increase in the risk of developing aggressive prostate cancer. Smoking at the time of diagnosis also appears to increase the risk of recurrence and prostate cancer mortality. Men with prostate cancer should strongly be encouraged to stop smoking.
So, what do I recommend to decrease your risk of prostate cancer? When it comes to screening, I take into consideration your age and ethnicity. I tend to recommend PSA and digital rectal examination for younger age African Americans males (starting at age 40 instead of 50). Family history is also a crucial part of my decision-making. As for lowering risk of developing prostate cancer, I advocate checking vitamin D level. I encourage an increase in physical activity and exercise regimen. I strongly recommend against any tobacco use. I am a firm believer in a well balanced diet while minimizing processed, "junk" and "fast" foods. I encourage vegetables intake in addition to one to two servings of fruit per day (unless the patient has other dietary restriction to monitor like diabetes). Following up with your primary physician is a must, and staying in tune with your body is a cornerstone for identifying problems at early stages.
Treatment of prostate cancer has evolved tremendously. We have a good problem nowadays since there are many options that were not available just five to seven years ago. For early stage prostate cancer, surgery combined with or without radiation, or radiation alone, continue to be the mainstay of therapy. Hormonal therapy is occasionally used to blunt testosterone levels in early and late stages of prostate cancer. Thanks to clinical trials and research, we now do not rely on only chemotherapy agents to treat advanced prostate cancer. We have newer and effective oral therapeutics and immunotherapy. As we advance into the future of cancer screening and treatment, I can assure you that we are winning the war against, though the journey is still long and tedious!