Case Presentation: Pembrolizumab for Non-Melanoma Skin Cancer Case Presentation

Cynthia is a 65-year-old woman with a history of tobacco use, hypertension, and multiple non-melanoma skin cancers (NMSC). She presented with multiple new cutaneous lesions suspicious for additional NMSCs, including 2 lesions of the scalp vertex, which were successfully excised and reconstructed. The larger of the 2 lesions was a pT30 invasive cutaneous squamous cell cancer (cSCC). A biopsy of multiple additional lesions demonstrated basal cell carcinomas (BCC) of the nose tip, medial canthus of the left eye, and the left forearm, as well as an invasive cSCC of the upper lip. Multiple other actinic keratoses were also identified. 

The patient was started on nicotinamide 500 mg, twice daily for prevention of further NMSCs. The patient was referred for multidisciplinary evaluation to address the additional BCCs and cSCCs.  

Dermatologic surgery advised that surgery could likely achieve a high cure rate for the additional NMSCs. However, given the anatomic locations of the eye and upper lip, more extensive reconstructive surgery would have been required. Surgical reconstruction also posed a risk to subsequent function of the lip and eyelid. The patient’s ongoing tobacco use would also increase the risk for poor outcomes with advanced reconstructive surgery.

Radiational oncology also evaluated the patient and recommended palliative radiation for treatment of the forearm, nose tip, and medial canthus of the eye BCCs. However, radiation for the cSCC of the upper lip would also pose a significant risk for morbidity. Cynthia underwent radiotherapy treatment for the BCCs and tolerated treatment without adverse effects. She was then referred to medical oncology to discuss immunotherapy for the residual invasive cSCC.

After a discussion with Cynthia and her family regarding the trade-offs in risk of pembrolizumab immunotherapy vs surgery or radiation, the decision was made to proceed with systemic pembrolizumab for the treatment of the locally-advanced cSCC.

After recovering from radiotherapy with improvement noted in all radiated lesions, Cynthia began pembrolizumab 200mg, every 3 weeks, based on data from the results of the KEYNOTE-629 study.¹ In this clinical trial, 50% of patients with locally advanced cSCC saw a long-term reduction in the size of their tumors with 17% of patients having complete regression of their cSCC.

Cynthia tolerated pembrolizumab without notable adverse effects. Her upper lip cSCC had reduced in size by about half after 2 months of the treatment. No further growth in her other treated areas were found. An additional skin lesion over her posterior leg that had not been biopsied also regressed during treatment.

Cynthia continues on pembrolizumab 400mg, every 6 weeks (per the label from the US Food and Drug Administration). She receives regular dermatologic exams to assess response to treatment, as well as for skin surveillance for new NMSCs and previously treated NMSCs. She also continues oral nicotinamide 500mg, twice daily, which in a randomized controlled study, was shown to be safe and to prevent onset of new NMSCs.²

Cynthia has experienced regression of all initial NMSCs and has tolerated her treatments without significant adverse effects.

References:

1. Hughes BGM, Munoz-Couselo E, Mortier L, et al. Pembrolizumab for locally advanced and recurrent/metastatic cutaneous squamous cell carcinoma (KEYNOTE-629 study): an open-label, nonrandomized, multicenter, phase II trial. Ann Oncol. 2021;32(10):1276-1285. doi:10.1016/j.annonc.2021.07.008
2. Chen AC, Martin AJ, Choy B. A phase 3 randomized trial of nicotinamide for skin-cancer chemoprevention. N Engl J Med. 2015;373(17):1618-26. doi:10.1056/NEJMoa1506197