Introduction: When to Seek Diagnostic Testing

If you notice unusual changes on your skin, it may be time to see a doctor for diagnostic testing. Squamous cell carcinoma, often shortened to SCC, is a type of skin cancer that develops in the flat cells found in the outer layer of your skin, known as the epidermis. While it is usually not life-threatening when caught early, getting the right diagnosis is the first step toward successful treatment.^[1]

People who should consider undergoing diagnostic tests include those who have noticed skin changes that do not heal or go away on their own. This might appear as a thick, scaly area that may bleed or form a sore, or a raised growth that doesn’t disappear over time.^[4] If you have a rough-feeling bump or growth that crusts over like a scab and bleeds, or a wound or sore that won’t heal or keeps coming back after healing, these are strong signals to seek medical attention.^[2]

Certain groups of people are at higher risk and should be especially vigilant about checking their skin and seeking diagnostic evaluation. You may be at increased risk if you have a pale complexion, blue or green eyes, or blonde or red hair. Long-term sun exposure or sun damage to your skin at a young age also raises your risk significantly. People over 65 years of age, those with a weakened immune system, or anyone who has received an organ transplant should pay close attention to skin changes.^[2] Males are about two times more likely to develop squamous cell carcinoma than females, and although people over the age of 50 are most commonly affected, the incidence has been rising in people younger than 50.^[2]

It is also advisable to seek diagnostics if you work outdoors or spend a lot of time in the sun, as these activities increase your exposure to harmful ultraviolet radiation. The earlier you catch squamous cell carcinoma, the more straightforward the treatment and the better the outcome. Even if you are unsure whether a skin change is serious, it is always better to have it checked by a healthcare professional.^[4]

Classic Diagnostic Methods

Diagnosing squamous cell carcinoma begins with a visit to your doctor or a dermatologist. The process typically starts with a physical examination, during which a member of your healthcare team will ask about your health history and carefully examine your skin for signs of squamous cell carcinoma.^[7] This initial assessment helps the doctor determine whether further testing is needed.

The most definitive way to diagnose squamous cell carcinoma is through a skin biopsy. A biopsy is a procedure in which a sample of tissue is removed from the suspicious area of skin and sent to a laboratory for testing. The doctor uses a tool to cut away, shave off, or punch out some or all of the area of skin that looks unusual. The sample is then tested in a lab to see if it contains cancer cells.^[7] While the dermatologist may have a good idea of what a skin abnormality is just by looking at it, the main differences between squamous cell carcinoma and other types of skin cancer, such as basal cell carcinoma, are only clearly visible under a microscope.^[6]

The biopsy procedure is usually straightforward and can be performed in the dermatologist’s office. After the area is numbed with a local anesthetic, the doctor removes the tissue. The removed sample goes to the lab, where specialists examine it closely. If the lab finds cancer cells, the diagnosis is confirmed. If the lab finds cancer cells beyond the margins of the removed tissue, the patient may need to return for more surgery until all margins are cancer-free.^[6]

In cases where squamous cell carcinoma is suspected to have spread beyond the skin, additional diagnostic tests may be necessary. Imaging tests such as computed tomography (CT) scans or magnetic resonance imaging (MRI) can help doctors see whether the cancer has spread to lymph nodes or other parts of the body. A sentinel lymph node biopsy may also be performed if there is concern that the cancer has spread to nearby lymph nodes. This involves identifying and removing the first lymph node to which cancer cells are likely to spread from the primary tumor.^[5]

For most patients, the diagnosis process is not overly complicated. The key is to act quickly when you notice skin changes. Early diagnosis usually requires only a simple skin biopsy, with advanced cases sometimes requiring additional imaging to assess how far the cancer may have spread.^[5]

Diagnostics for Clinical Trial Qualification

Clinical trials are research studies that test new treatments or new ways of using existing treatments. For patients with squamous cell carcinoma, participation in a clinical trial may offer access to cutting-edge therapies that are not yet widely available. However, to qualify for a clinical trial, patients must meet specific criteria, and diagnostic tests play a critical role in determining eligibility.

Standard diagnostic criteria for enrolling patients in clinical trials typically begin with a confirmed diagnosis of squamous cell carcinoma through a skin biopsy. The biopsy not only confirms the presence of cancer but also provides information about the type and characteristics of the cancer cells. This information helps researchers determine whether a patient’s cancer matches the type being studied in the trial.^[7]

In addition to the biopsy, imaging tests such as CT scans, MRI scans, or PET scans may be required to determine the stage of the cancer. Staging describes how far the cancer has spread and is an important factor in clinical trial eligibility. Some trials are designed for patients with early-stage squamous cell carcinoma that has not spread, while others focus on advanced cases where the cancer has metastasized to other parts of the body.^[5]

Blood tests may also be part of the qualification process. These tests can provide information about the patient’s overall health and help ensure that they are strong enough to tolerate the treatments being tested in the trial. For example, blood tests can assess kidney function, liver function, and blood cell counts, all of which are important for determining whether a patient can safely participate in a study.^[5]

Some clinical trials may also require additional specialized tests. For instance, if a trial is testing a treatment that targets a specific genetic mutation or protein, patients may need to undergo genetic testing or immunohistochemistry tests to determine whether their cancer has the specific characteristics that the treatment targets. These tests help researchers match patients with the treatments most likely to benefit them.

Overall, the diagnostic tests used for clinical trial qualification are designed to ensure that the right patients are enrolled in the right studies. This careful matching process helps maximize the chances of success for both the patient and the research study.