Dr. Diely Pichardo-Johansson: One Third of All Cancer Deaths Can Be Attributed To Smoking
By Diely Pichardo-Johansson, Cancer Care Centers of Brevard // October 20, 2016
Cancer Care Centers of Brevard
BREVARD COUNTY, FLORIDA – The single most important cancer prevention strategy available is tobacco avoidance. According to the American Cancer Society, about one third of all cancer deaths can be attributed to smoking.
Once tobacco is accounted for, the World Cancer Research Fund estimates that 20 percent of new cancers can be directly or indirectly connected to other preventable causes such as obesity, nutritional factors or excessive alcohol intake.
Following are medical interventions for cancer prevention and life-style modification strategies:
Surgery: Surgical approaches to cancer prevention are usually limited to patients with the highest risks. Prophylactic bilateral mastectomies are recommended for the patient affected by a genetic mutation of one of the BRCA genes, or who developed breast cancer at an extremely young age.
In BRCA1 carriers, bilateral salpingo-oophorectomies are recommended by age 40 for ovarian cancer prevention.
Prophylactic colectomy after the age of 18 is advisable in patients with FAP syndrome. Prophylactic hysterectomy should be considered in patients with Lynch syndrome after completing of parity due to increased risk for endometrial carcinoma.
Pharmacological prevention of Breast Cancer: The modified Gail predictive model tries to assess breast cancer risk on a woman based on risk factors such as family history, nuliparity, need for previous biopsies, etc.
If the 5-year risk is estimated to be more than 1.7 percent, and the patient has a life expectancy of at least 10 years, chemoprevention with hormonal therapy is an option. Tamoxifen is the drug with the largest amount of data, the only one with an FDA indication in prevention, and the only option for a premenopausal woman (49 percent risk reduction).
Anastrozole and examestane for 5 years in postmenopausal patients, and are at least as efficient (53-65 percent reduction). Raloxifen (Evista), seems less efficient than tamoxifen in the longterm, but can be considered in a postmenopausal patient with osteoporosis.
Efforts to find a hormonal manipulation strategy to prevent prostate cancer have been discouraging.
Aspirin: Both observational and controlled studies suggest that regular use of aspirin reduces the risk of colon cancer and may also reduce risk of esophageal cancer, gastric, billiary and breast cancer.
That includes randomized controlled data showing a decrease in colon and non-colon malignancies in patients with Lynch syndrome. However, the correct doses are unknown, and studies have used from 81 to 600 mg.
Given aspirin’s other benefits, it makes sense to recommend its use in similar doses to those used for cardiovascular health (81-365 mg).
COX-2 inhibitor Celecoxib was proven to reduce formation of colon adenomatous polyps, but given its cardiovascular risks, is not routinely recommended. The data with regular NSAIDs is more conflicting.
Other: Some vaccinations may help prevent certain cancers in high risk populations such as HPV vaccination for cervical cancer and Hepatitis vaccination for high risk patients. Some screening studies may overlap as cancer prevention, such as colonoscopies, leading to removal of polyps.
Life-style modification: There is a substantial amount of evidence that overweight and obese patients have a higher risk of cancer, especially postmenopausal breast cancer, making maintaining a healthy BMI a “no-brainer” goal.
Prospective studies have failed to show benefit from a low fat diet limited to 20 percent of total calories, consumption of fruits, vegetables and grains in reduction of the risk of invasive breast cancer.
However, the well known benefits of such a diet in overall health merits its promotion. Exercise and limiting alcohol consumption are other examples of safe and advisable modifications.
The limited available controlled and prospective data does not support a cancer protection effect in vitamins and antioxidants – including retinoids, carotenes, selenium and vitamin E – and even suggests that excess may be detrimental.
Even vitamin D, the most recent fad, is being revisited as recent prospective studies show that both low and high levels of it have been associated with increased cancer risk, suggesting a narrow therapeutic index for replacement.
The key is to focus on strategies that have less chance to harm and more to help the overall health. Smoking avoidance is critical and daily aspirin, aiming for a healthy BMI and a healthy diet, can only help the overall health.
ABOUT THE AUTHOR
Dr. Diely Pichardo-Johansson is a board certified physician in hematology, medical oncology and internal medicine. She practices at Cancer Care Centers of Brevard in Melbourne Florida as part of a comprehensive oncology group. She holds a Masters of Science Degree (Summa Cum Laude) from Pontificia Universidad Catolica Madre y Maestra, Santiago in the Dominican Republic. She completed her residency in internal medicine at the Detroit Medical Center at Wayne State University in Detroit, Michigan. Dr. Pichardo completed her fellowship in hematology and medical oncology at the Northwestern University of Chicago, Medical Center.
To reach Dr. Pichardo call 321-952-0898 or log on to CancerCareBrevard.com