The Importance of Early Cancer Detection: Balancing the Benefits and Harms of Screening Tests

By skipping lengthy and costly check-ups, you can cut down on both time and money. As per the World Health Organization, cancer is the second most frequent cause of death globally, after cardiovascular and circulatory diseases. It claims the lives of one in every six individuals. Breast cancer, lung cancer, and colorectal cancer are the top three types, but fortunately, they can be detected before they reach an irreversible stage.

Debating the Importance of Early Cancer Detection

Many private clinic and laboratory advertisements promise to detect cancer before the appearance of the first symptoms. This promise makes sense because the stage of cancer worsens with time, and treatment is less effective at higher stages. However, the truth is that there is no such predictable pattern.

Oncologists use the concept of cancer stages to classify diseases into standard categories. The first stage is used when the tumor is small and has not yet metastasized, while the fourth stage is used when it has grown beyond the limits of the organ in which it originated.

Oncological diseases, however, can develop in various ways. Some of them are rarely detected in the first stage because they are deep inside the organs, while others heal well despite having metastases. Many others progress so quickly that annual medical examinations cannot diagnose them in time.

Therefore, international oncology discourages asymptomatic patients from undergoing full diagnostics to detect any cancer. Besides being expensive and time-consuming, the research itself is harmful to human health. In fact, many clinics that offer full oncology exams are simply attempting to sell as many tests and diagnostic procedures as possible at once.

Can Screening be Necessary in All Cases?

The balance between potential harm and potential benefit is a fundamental principle in medicine, including for tests such as screening tests. If a person is undergoing testing, the benefits for the patient should outweigh any potential harm.

While timely screening may appear to enable early disease detection and cure, all diagnostic measures carry the potential for harm. For instance, radiation exposure accompanies mammography and computed tomography. If every woman over 18 were to undergo annual mammography to search for asymptomatic cancer, there would be more harm than benefit because breast cancer is rare in young females. Consequently, many completely healthy individuals would receive unnecessary radiation exposure.

Colonoscopy is another screening method that carries a small chance of damaging the colon wall during the procedure. While the statistical risk is low when performed once every 5-10 years, annual or monthly colonoscopies can significantly increase the likelihood of complications, which could lead to life-threatening diagnostic procedure complications.

Aside from direct harm, there is also indirect harm. Sometimes, during an examination, a doctor may discover a neoplasm that will never develop into a large tumor, cause discomfort to the patient, or lead to death. In such cases, the physician cannot be certain of what was discovered and will act based on standard protocol, which may involve additional testing like a biopsy, leading to further complications.

All of these examinations can reduce the patient’s quality of life, either from bruising and pain at the biopsy site or anxiety from anticipation. This does not mean that individuals should avoid screening, but it is crucial to understand that screening is not always beneficial. Therefore, before recommending regular screening for a significant number of people according to a particular procedure, physicians must ensure that screening is effective by assessing studies involving thousands of people.

Which screenings really work

Certain doctors suggest that screening is required for only particular types of cancer, and that healthy individuals should undergo regular screening according to a schedule that may differ depending on their gender and smoking habits. Screening programs and schedules may also differ from country to country, based on national research, incidence statistics, and organizational factors. The recommendations that follow are only applicable to individuals who are not at risk for these cancers.

Screening for Colorectal Cancer

To screen for colon cancer, a colonoscopy and fecal immunochemical test for occult blood can be used, which offers more precise quantitative results. Screening recommendations for colon cancer vary across countries. For instance, in the United States, individuals aged between 45 and 75 are advised to undergo either an annual stool analysis or a colonoscopy every 10 years. In contrast, in Great Britain, individuals aged between 55 and 74 are recommended to have a colonoscopy at 55 years of age and their feces examined every two years starting at 60 years of age.

It’s important to note that blood in the intestines doesn’t always indicate cancer and can be caused by other issues like hemorrhoids. However, if the immunochemical fecal analysis or other tests are positive for blood, it’s important to rule out cancer with a colonoscopy.

During a screening colonoscopy, your doctor can identify and remove polyps in the intestine, which are noncancerous growths that can bleed and potentially turn into cancer over time. While colonoscopy is a necessary procedure for identifying colon cancer, it can be uncomfortable and requires bowel preparation with laxatives. The procedure can be performed under general anesthesia or sedation.

Some countries offer virtual colonoscopy, which uses computed tomography to produce a detailed image of the intestines without using a colonoscope. This screening option is offered every five years in the US, twice as often as regular colonoscopy. However, if any suspicious growths are found on the tomogram, you will need to undergo a traditional colonoscopy for further evaluation.

Screening for lung cancer

LDCT stands for low-dose computed tomography and is a type of screening recommended only for individuals over 55 years of age who currently smoke or quit smoking less than 15 years ago, provided that their smoking index is at least 30 pack-years. The smoking index is calculated based on how many cigarettes a person smokes, equivalent to one pack per day, which is 7300 cigarettes per year. However, pack-years are not calculated based on the actual number of cigarettes smoked over one’s lifetime but instead on a rough estimate. For instance, two years of smoking half a pack a day equals one pack-year. If someone smokes two cigarettes a day, then ten years of smoking equals one pack-year. In the United States, LDCT screening is recommended annually for individuals aged 55 to 74 years old.

One interesting fact to know is that the low-dose computed tomography (LDCT) is a newer type of screening that can capture multiple chest scans from different angles and combine them into a three-dimensional image. This can make any suspicious areas easily visible. Although it has shown promising results in research, it is still in the process of being integrated into various countries’ healthcare systems.

Screening for cervical cancer

A Pap test involves taking a swab from a woman’s cervix and placing it on a glass slide to be stained with a Pap smear. Another option is liquid cytology, where a special brush is used to take a smear and sent for analysis. In certain cases, a high-risk HPV (human papillomavirus) smear may also be necessary to determine the presence of the virus.

In the United States, women should be screened for cervical cancer from 21 to 65 years old. Women under 30 years old should have Pap tests or liquid cytology every 3 years. After 30 years old, it is recommended to have both the Pap test or liquid cytology and the HPV test every 5 years.

In Great Britain, women between the ages of 25 and 64 are screened for cervical cancer. Initially, an HPV test is conducted, and if it is positive, liquid cytology is performed. Up until the age of 50, these tests are taken every 3 years, and then once every 5 years.

It’s important to note that HPV is associated with 99% of cervical cancers, and it is a sexually transmitted disease. There are different types of HPVs, including those that cause warts and those that are high oncogenic risk and are associated with various types of cancer, such as cervical, penile, anal, vulvar, vaginal, and throat cancers. For instance, HPV type 16 causes 50% of cervical cancers, while HPV type 18 causes 20% of cervical cancers.

Timing for the initiation of cervical cancer screening

In most European countries, women over 25 are advised to undergo cervical cancer screening, although Finland and the Netherlands have more well-structured screening programs that begin at the age of 30. In contrast, the United States delays screening until the age of 46, despite the lack of scientific support for this approach.

Determining the appropriate age for cervical cancer screening involves two factors. First, it considers the age when women typically start having sexual intercourse since cervical cancer is primarily caused by the prolonged presence of HPV, which is a sexually transmitted virus. Second, younger women are less likely to develop chronic HPV since their bodies often eliminate the virus on their own. Even if changes are detected during screening, this does not necessarily indicate the presence of cancer. As such, if a woman has not engaged in sexual activity, screening for cervical cancer may not be necessary.

Screening for breast cancer

The Cancer Society recommends mammograms for individuals aged 45 to 54, followed by biennial screenings thereafter. The US Preventive Services Task Force advises biennial mammograms starting at age 50 and continuing until age 74. In the United Kingdom, testing is recommended every three years between ages 50 and 70.

During a mammogram, the breasts are positioned between specialized platforms and briefly compressed to capture images. These images are then analyzed by a doctor using the BI-RADS scale to standardize the results. If the report falls under the first category of BI-RADS, no abnormal findings were detected. A third category of formations is typically non-cancerous, but may require additional exams and observation by a specialist.

What is the recommended frequency for getting a mammogram?

Screening for breast cancer can be controversial for women aged 40 to 49 since their risk of developing the disease is lower than that of older women. Due to the risk of false positive results during this time, many doctors suggest being cautious when prescribing mammography. To ensure a high-quality screening process, it is recommended to take the following steps:

• Prior to having a mammogram, ask your gynecologist or mammologist to examine your breasts for any lumps. If any are found, you may be prescribed a diagnostic mammogram that is analyzed based on additional factors.
• Choose digital mammography, which has a lower radiation dose and produces results that are more easily assessed by a specialist. Unlike regular X-rays, digital mammograms can also be easily transferred to another doctor and are more likely to be given to the patient.
• Schedule your mammogram for the 5th-11th day of your menstrual cycle (counting from the first day of menstruation). Women who have gone through menopause can come at any time. The examination is typically performed by an X-ray technician who should be made aware of any previous mammography results or operations on the mammary gland.
• Take the time to review the radiologist’s interpretation of your mammography results carefully. Without the use of the globally recognized BI-RADS scale, it may be difficult to gauge the expertise of the interpreting doctor. If you have any doubts about the accuracy of the results, it is advisable to seek a second opinion from another clinic. Digital mammography can be particularly useful in this situation, as you can easily transfer the images to another doctor for review. Some radiologists also work remotely, which allows you to choose a specialist from another location and email your mammogram to them after obtaining their approval.

Determining whether you have an increased risk of developing specific types of cancer.

The aforementioned screenings are typically recommended for individuals who are at an average risk of developing cancer, with the exception of lung cancer. However, some individuals may have a higher risk of developing the disease, in which case screenings may begin at an earlier age, be conducted more frequently, or be replaced by alternative tests, such as a breast MRI. Additionally, individuals at an increased risk of cancer may be offered treatment.

Screening may be extended when there is suspicion of a tumor syndrome, which is a condition in which a mutation is passed down through a family and increases the risk of cancer. Tumor syndromes account for around 5-10% of all cancer cases, and mutations in genes such as BRCA1 and BRCA2 are among the most extensively studied as they increase the risk of breast and ovarian cancer. Actress Angelina Jolie underwent a double mastectomy due to her genetic predisposition to breast cancer.

Factors that elevate the risk of developing cancer

Cancer can have multiple causes, which is why various risk factors are considered when designing individual screening programs. Here are some of the most common risk factors:

• Family history: If a person’s immediate family members have had cancer before the age of 50, there may be an inherited genetic predisposition to the disease. However, not all cases of cancer are hereditary, and other risk factors such as bad habits or environmental factors can also contribute to a person’s likelihood of developing cancer.
• Infections: Certain infections like hepatitis B and C, human papillomaviruses, and Helicobacter pylori increase the risk of specific types of cancer, such as liver, cervical, and stomach cancer. People with these infections should be monitored differently than those without them.
• Bad habits: Drinking alcohol and smoking cigarettes are strongly associated with various types of cancer, particularly those of the gastrointestinal tract, head, neck, and lungs. Obesity, especially around the abdominal area, is also a risk factor for several types of cancer.
• UV radiation: Exposure to UV radiation from the sun or tanning beds can cause skin cancer, especially in people with fair skin, a history of childhood sunburn, or a family history of the disease. Using protective measures like sunscreen and wearing protective clothing can help reduce the risk of skin cancer.

Overall, it’s important to consider multiple risk factors when evaluating a person’s cancer risk and developing a screening program tailored to their individual needs.

What are the types of medical tests that are not suitable for cancer screening purposes?

It is not recommended to use cancer screening tests that do not meet the international criteria mentioned earlier in this article. Clinics may provide ultrasound or MRI screening for breast cancer, but it is unnecessary for individuals without a significant risk of the disease. Similarly, fluorography is not useful for screening for lung cancer. Many clinics rely on these ineffective and potentially harmful methods for most of their checkups.

• An MRI, particularly a whole body scan, can result in overdiagnosis, as harmless formations may be detected that will resolve on their own. This can lead to anxiety and unnecessary biopsies.
• Tumor markers, such as CA125, HE4, CEA, NSE, or CA-242, are used by oncologists to monitor the progress of an identified tumor and its response to treatment. However, the presence of a tumor marker in a healthy individual does not necessarily indicate cancer.
• Ultrasound is more precise in diagnosing tumors that have already been identified, but it is not an effective screening method due to its low accuracy, similar to MRI.
• Gene testing at home may promise advice on disease risk, nutrition, and athletics, but the results may not be interpreted accurately by doctors. Mutations in genes such as BRCA1 and BRCA2 are associated with breast cancer, but specialist consultation is essential prior to testing as the results only show likelihood, not the exact outcome.
• Regular self-examination, such as monthly breast or testicular examinations, may cause unnecessary anxiety, but there is little evidence to support any increase in lifespan.

If one’s risk of skin cancer is average, it would be beneficial to conduct a self-diagnosis using the ABCDE method, which is a five-point system for evaluating questionable moles, as well as lumps, sores, or wounds that don’t heal within a month. Moreover, it’s critical to take into account the recommended screening frequency. If, for example, a private clinic offers you a colonoscopy at age 30 and suggests repeating it annually, despite a lack of indications for colorectal cancer, it should be viewed with suspicion.

Be mindful of these symptoms

The purpose of screening is to identify illnesses that may not have noticeable symptoms. However, if any symptoms persist or worsen, it’s advisable to consult a doctor. Although these symptoms may not be indicative of cancer, it’s still important to be watchful. The following list outlines the most common symptoms associated with various types of cancer:

• Unintentional weight loss of more than 4.5 kg while maintaining regular diet and exercise
• A temperature above 38.3 ° C that lasts for more than three weeks
• Severe fatigue that does not improve with rest
• Persistent pain in a part of the body that cannot be explained
• Changes to the skin: darkening, yellowing, redness, itching, or excessive hair growth.

In addition, some tumors may exhibit symptoms that are specific to them. These symptoms are often associated with other conditions, but it’s still advisable to seek the advice of a medical professional. These symptoms include:

• Sudden and persistent changes in bowel movements for several weeks, such as diarrhea, constipation, pain, less frequent urination, or less frequent bowel movements
• Skin, mouth, or genital sores that do not heal for more than a month
• Blood in urine, stools, or vaginal or nipple discharge that occurs occasionally
• Lumps in the chest or other parts of the body that are growing
• Experiencing heartburn, stomach heaviness, belching, nausea, or difficulty swallowing for more than a few weeks
• Wheezing or coughing while breathing that persists for three weeks
• Changes in moles, warts, or freckles, or unusual spots on the skin that do not disappear within a month
• White spots on the tongue or lips.

Most readers are likely to identify at least one symptom, but it’s important to note that the majority of these symptoms are not necessarily indicative of cancer. It’s not advisable to attribute every headache to a brain tumor or to ignore persistent bleeding from the rectum or an itchy birthmark.

The fear of cancer can manifest itself in different ways, with some individuals constantly researching diseases and diagnosing themselves with all types of cancer, while others are too afraid to seek medical attention even when experiencing severe symptoms. Such individuals may choose to turn a blind eye to advice on cancer prevention, and claim that ignorance is bliss. A responsible patient lies somewhere in the middle. When it comes to cancer screening, they remain calm, yet aware that the earlier they seek medical attention with their complaints, the more effective their treatment is likely to be.

Remember

• Do not search for asymptomatic cancer, as it can cause more harm than good.
• Cancer check-ups, full-body MRIs, tumor markers, and complete genetic testing are often unnecessary and may even be hazardous.
• Most individuals should be screened for colorectal cancer, and women should also be screened for breast and cervical cancer. Some smokers and ex-smokers may want to consider testing for lung cancer.
• Changes in moles can be examined, and oncodermatologists should be consulted if there are any significant changes in appearance.
• Consult with your oncologist or medical geneticist to determine if you are at an increased risk for cancer and require additional screening.
• Seek immediate medical attention when experiencing specific symptoms, regardless of your age.