– Cases of cutaneous squamous cell carcinoma (cSCC) are on the rise and are associated with mortality rates similar to melanoma. But even as cSCC draws more attention, two popular staging systems still need refinement, a hematologist-oncologist told dermatologist colleagues.

Both staging systems can be helpful, however, Guilherme Rabinowits, MD, said at Skin Disease Education Foundation’s annual Las Vegas Dermatology Seminar. “The best thing to do is combine both,” he noted, referring to the staging system developed by the Brigham and Women’s Hospital (BWH) and staging systems released in the 7th and 8th editions of the American Joint Committee on Cancer Staging Manual (AJCC 7 and AJCC 8; the latter focuses on head and neck only).

Cutaneous SCC has become a “huge health care burden,” said Dr. Rabinowits of the Miami Cancer Institute/Baptist Health South Florida and Florida International University, Miami. He referred to Medicare data suggesting that cSCC has become as common as basal cell carcinoma (JAMA Dermatol. 2015 Oct;151[10]:1081-6).

While most patients with cSCC have a positive prognosis, he added, the 5-year survival rate among those with the most aggressive disease is only 25%.

As he pointed out, staging systems provide insight into prognosis and treatment, guide appropriate monitoring, and give a common language to clinicians around the world. “When I talk about stage 3, we all understand who we’re talking about,” he said.

Dr. Rabinowits said he formerly worked at BWH so he is especially comfortable with its staging system. It can be appropriate to use both the BWH and AJCC systems at once, he said, noting, however, that studies suggest that the BWH system is superior.

An analysis released in 2014, for example, found that most poor outcomes occurred in patients whose tumors had been rated at lower stages – suggesting less risk – in the AJCC 7 system (J Clin Oncol 2014 Feb 1;32[4]:327-4).

In contrast, the 5% of tumors that were rated at the highest stages in the BWH system – with the highest level of perceived risk – accounted for 70% of nodal metastases and 83% of disease-specific deaths. This group may deserve extra attention in terms of staging and adjuvant treatment in order to improve outcomes, he said.

A study published this year, which compared the BWH and AJCC 8 staging systems, found that they had the same negative predictive value (0.99), while the BWH system showed higher positive predictive value (0.30 vs. 0.17). “Use of BWH tumor classification may minimize the number of patients recommended for radiologic evaluation, close surveillance, and possible adjuvant therapy while still identifying most patients at risk for recurrence, metastasis, and death,” the authors wrote (JAMA Dermatol. 2019 Jul 1;155[7]: 819-25).

As for treatment of localized disease in high-risk patients, Dr. Rabinowits advised turning to a multidisciplinary team for guidance because there are limited prospective randomized data.

Dr. Rabinowits discloses scientific advisory board/consultant relationships (Merck, Regeneron, Sanofi, EMD Serono, Pfizer, and Castle) and shares in Regeneron and Syros Pharmaceuticals. He spoke during a forum on cutaneous malignancies at the meeting.

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