Definition & Overview
Cancer screening is a test performed to confirm and diagnose cancer, especially in its early stages. It is also a preventive measure for people who are considered to be high risk.
Cancer is often a life-threatening disease caused by the mutation of the body’s cells. Usually, these are either immature or abnormal cells that refuse to die and spread and travel through the bloodstream, leading to metastasis (the spread of cancer to other nearby organs). Cancer cells can destroy other healthy cells and produce complications that may ultimately lead to death.
These cells may develop and spread very slowly, spanning years, or quickly that the patient’s health deteriorates in a matter of days or months. Therefore, prompt and regular cancer screening can help save lives as long as the disease is detected early.
Although not all types of cancer—there are already around a hundred of them—have a standard screening test, the most common ones such as lung, oral, breast, colon, cervical, ovarian, and prostate, do.
On the other hand, not all cancer screening exams are mandatory, but men and women can use the guidelines issued by health providers and the American Cancer Society when deciding which test/s to undergo.
Some of the tests include:
- Colonoscopy (colon or GI-related cancer)
- Fecal occult blood test (colon or rectal cancer)
- Mammography (breast cancer)
- Pap test (cervical cancer)
- HPV testing (cervical cancer)
- Breast MRI (breast cancer)
- CA-125 test (ovarian cancer)
- PSA test (prostate cancer)
- Skin exam
- Transvaginal ultrasound (uterine or ovarian cancer)
Who Should Take It and Expected Results
You should seriously consider undergoing cancer screening tests if you fall under any of the following categories:
Patients who are showing symptoms – the symptoms can vary depending on the type of cancer, but usually those whose conditions have worsened despite the medications may be later asked to undergo a cancer screening test.
Patients who are high risk – A high-risk patient is someone who had cancer before, has immediate family members or relatives diagnosed with cancer, or has been tested to carry certain genetic risks factors such as BRCA1 and BRCA2 genes that can increase the risk of breast cancer by up to 80%. Take note, however, that heredity plays only about 5% of the cancer diagnosis. More often than not, cancer is caused by other factors such as exposure to possible carcinogens (substances that can cause cancer), obesity, and the presence of other diseases such as Barrett’s esophagus.
Individuals who are at least 40 years old – General population (people who are not high risk or are otherwise healthy) are recommended to undergo cancer screening tests when they reach 40 years old as a preventative measure. The type of test to be conducted will be based on the patient's lifestyle and risk factors.
It may take at least a week before results come out. Depending on the outcome, the patient may be considered cancer free or referred to an oncologist for medical help.
How Does It Work?
There are many ways to perform a cancer screening test. The first is through a physical examination where the doctor observes the patient’s area of concern and checks for any possible signs of cancer such as lumps in the breast, white patches on the tongue, or bleeding in the rectum.
The doctor may also ask about the patient’s medical and family history to assess the risk of cancer based on heredity or prevalence of a chronic illness (e.g., obese people may develop pancreatic or liver cancer).
The most common way of conducting the tests is through laboratory exams, including a biopsy. Scraped cells, tissues, fecal matter, or fluids such as blood and urine are collected by the doctor and sent to a laboratory, which then examines the samples for the presence of any abnormal cells.
For those who are high risk, genetic testing may also be requested. This may include a Myriad Genetic Testing profile, which can identify if the blood samples carry certain genetic markers that can confirm the presence of cancer.
Imaging procedures are also carried out. These include mammography (for the breast), and X-ray (for lung cancer). Meanwhile, endoscopy, colonoscopy, ultrasounds, MRI, and PET scan are also considered standard cancer screening procedures. However, they are not deemed as priority tests unless there’s no other option or the doctor highly suspects cancer and wants to determine if it has already spread to other organs.
Risks and Complications
One of the reasons why screening test guidelines exist is to minimize the risks and complications, which may include the following:
Wrong results – Results can be false positive or false negative, both of which can significantly affect the decision of the patient later on. False positives, for example, can lead to over-treatment wherein the patient is forced to go through treatments that are not necessary in the first place. False negatives, on the other hand, may mean missing out on an immediate treatment that can save the patient's life.
Bleeding –This is common in tests that are minimally invasive, such as endoscopy or colonoscopy. In these types of exams, a probe or a scope is inserted into the body. The light attached to it illuminates the internal body part while the camera delivers a live feed into a computer monitor. Sometimes these can hurt the organs, causing mild to serious internal bleeding.
Human error –A new study has revealed that some lab technicians in charge of determining the presence of cancer cells in samples do have a difficulty in correctly assessing them.
Fortunately, new novel tests such as breathing exam for lung cancer are already being tested, so risks and complications may eventually be reduced. In the end, the benefits still outweigh the risks.