Melanoma is the leading cause of death among skin cancer types, so it's understandable that it has become a major focus of the healthcare community. Non-melanoma skin cancers account for over 90 percent of all skin cancers in the United States, and while they are usually more easily managed, they can pose a serious problem if left unchecked.
The distinction between melanoma and non-melanoma skin cancer is important to discuss, as prognosis and management are different for each. Melanoma typically requires targeted therapy or immunotherapy, whereas surgical resection (a procedure to remove part of an organ or gland) and chemotherapy are more common approaches for non-melanoma skin cancer. Newer, targeted therapy approaches have also emerged for non-melanoma skin cancers.
What follows is an overview of the two most common types of non-melanoma skin cancer: basal cell carcinoma and squamous cell carcinoma.
Basal Cell Carcinoma
Basal cell carcinoma originates from cells called keratinocytes. When these cells become cancerous, they may form a localized lesion. The lesion usually appears hard and slightly raised, often with a pearly color and some vascular markings. If a patient presents a lesion of this kind, a biopsy should be performed to confirm the diagnosis.
Basal cell carcinoma is more common in patients who have been exposed to high levels of ultraviolet rays (such as tanning bed use or chronic sun damage), or in those who have compromised immune systems. The disease is fairly common and treatment is usually highly effective. The most common route is surgical excision; if the lesion is small and localized enough, a dermatologist or surgeon will be able to remove it with no further complications.
Cryotherapy and topical treatment are also options, but they are generally reserved for specific situations. For example, if a tumor grows too large for surgery or if it becomes metastatic (when cancer spreads to another part of the body), radiation or a combination of radiation and systemic therapy can be administered.
In the past, chemotherapy regimens, such as carboplatin and paclitaxel, have been offered to patients with unresectable, locally-advanced or metastatic basal cell carcinoma. Recent research has identified a critical pathway in most basal cell carcinoma tumors that can be blocked with targeted therapy. This is called the Hedgehog pathway (no specific relationship to hedgehogs) and the class of drugs are called smoothen (SMO) inhibitors. Vismodigib (Erivedge®) and sonidegib (Odomzo®) are the two FDA approved drugs. Both therapies can be very effective in treating basal carcinoma and have become standard practice.
It should be noted that, even with successful treatment, a case of basal cell carcinoma leaves one at a higher risk for further skin cancers. It is recommended to have regular medical checkups to monitor the condition of your skin.
Squamous Cell Carcinoma
Squamous cell carcinoma, like basal cell carcinoma, originates from keratinocytes, and its risk factors also include ultraviolet ray exposure and a compromised immune system. Lesions from squamous cell carcinoma can appear similar to those of basal cell carcinoma, but often they have a more flesh-colored, scaly and inflamed or irritated appearance. A biopsy is necessary to confirm a diagnosis.
Just as in basal cell carcinoma, surgical excision is the most common treatment option. It's usually cured by surgery alone and other local treatment options can be considered. Squamous cell carcinoma may invade and destroy surrounding tissue or spread to lymph nodes or distant organs if left untreated, so it's important to have any suspicious lesions examined.
In advanced cases, radiation and/or systemic therapy may be offered. Systemic therapy usually involves chemotherapy with regimens such as carboplatin and paclitaxel or capecitabine. However, newer approaches with EGFR targeted therapy and immunotherapy are showing great promise and can be considered.
Final Thought
Basal cell and squamous cell carcinomas are similar in their risk factors, treatment approaches and remission rates. Although they are not as lethal as melanoma, they are very common and are capable of doing significant damage and be deadly if left untreated. For that reason, screening is crucial for every patient, especially those with risk factors like sun exposure, a previous incidence of skin cancer or a compromised immune system.
When seeking treatment for skin cancers, it's often beneficial to hear a second opinion from a multidisciplinary clinic that involves a dermatologist, surgeons and medical oncologists. If you have a large or recurrent tumor that isn't amenable to surgery, there may be effective alternative approaches. Discuss this with your healthcare provider to make sure you are exploring every option available to you.
