What are the symptoms or signs of early cancers?
Unfortunately these early cancers are mostly without symptoms. Typically by the time a cancer is large enough to be palpable or cause pain – difficulty swallowing, breathing problems or bleeding – treatment becomes more complicated and the chance of cure decreases.
What is cancer screening?
Cancer screening is looking for cancer or conditions that may lead to cancer before a person has any symptoms. Screening tests sometimes involve a physical examination, examination of the blood, urine or stool as well as imaging procedures (taking pictures of areas of the body). Some screening tests have risks, but typically the benefits of these tests tend to outweigh these risks.
Who should be screened for cancer?
Screening is usually recommended for people with risk factors for certain cancers. Cancer risk factors could include age, use of tobacco products, exposure to radiation, certain chemicals, infectious agents such as bacteria and viruses as well as a family history of certain cancers and genetic abnormalities.
Suggestions for early detection and screening
First, talk to your doctor. Ask about your cancer risks and recommended screening tests based on your risk factors.
Breast cancer screening options include annual mammograms beginning at age 40 as well as clinical breast exams every 3 years from ages 20 to 39 and annually thereafter.
For colon cancer, options include colonoscopy beginning at age 50. Other screening tools include flexible sigmoidoscopy, virtual colonoscopy, double contrast barium enema (DCBE) and stool occult blood and stool DNA testing.
Cervical cancer screening includes annual pap smears beginning 3 years after onset of sexual intercourse or age 21.
Prostate cancer screening includes a PSA (prostate specific antigen) blood test beginning at age 40 to 50 depending on risk factors.
For ovarian cancer, periodic screening with a CA 125 blood test and transvaginal ultrasound may be useful in people with a familial ovarian cancer genetic syndrome who have not had their ovaries removed.
Unfortunately not all cancers have effective screening tests or recommendations. Lung cancer is still the leading cause of cancer related death. Lung cancer screening with imaging studies (CT scans) may allow early detection of lung cancers however the impact on overall mortality remains unclear but is actively being studied.
An annual full body skin exam by trained clinicians is useful in people at high risk for skin cancers.
What about cancer prevention?
Many cancers are preventable. Several lifestyle changes in addition to routine screening as noted above can significantly reduce your risk of developing certain cancers. These include avoiding tobacco, excessive sun exposure, weight reduction, limit alcohol intake and protection from sexually transmitted diseases. A healthy diet rich in fruits, vegetables, whole grains and low in saturated fats is also helpful.
The bottom line is that early detection remains the most valuable tool in the fight against cancer. As an oncologist, every time a new cancer is diagnosed I always ask myself "Did we find this as early as we could? Were screening opportunities missed? Was this preventable?" Sometimes people put off screening because of fears about what could potentially be found. It is important to understand that such delays could mean the difference between a curable and an incurable cancer. Finding cancers early makes a real difference. In the end, early detection is cost effective and saves lives.
written by Daniel Ekaha, M.D.
Hematologist and Medical Oncologist
York Cancer Center