April 2026

Basal Cell Carcinoma

Joseph Corsini, Ph.D. and Julie Alessandra, MTE

Basal cells (also called basal keratinocytes) are normal stem cells in the deeper layers of the skin that through a number of developmental stages form keratinocytes and eventually differentiate into the squamous cells which form the outer layer of the skin. Squamous cells have a limited life span so are constantly dying and sloughing off, needing continual replacement to maintain the integrity of the skin. Melanocytes are cells that are distributed in high density throughout the skin, and are also found in other tissues. In the skin, they synthesize melanin and transfer it into to keratinocytes to protect them from the mutagenic effects of UVB light. Cancers can form from all three of the above-mentioned cell types. When basal cells are transformed into cancer cells, they are called basal cell carcinomas. Basal cell tumors develop slowly, are not highly invasive, and do not commonly metastasize. Generally, there is plenty of time to make decisions about treatment. When squamous cells transform into cancer cells, they are termed squamous cell carcinomas. Squamous cell carcinomas are highly invasive and often times readily metastasize to distant locations in the body. Early diagnosis is critical. Melanomas develop from melanocytes, often in the skin but also commonly in other tissues that are populated by melanocytes. 

Basal cell carcinomas are very common but rarely fatal. Because they are almost always curable without chemotherapeutic intervention, they are generally not included in the cancer rate statistics reported by our public agencies and large cancer foundations. While lifetime sun exposure is the most commonly discussed risk factor, it is now clear that genetics of pigmentation, number of burning episodes, intermittent sun exposure, chronic immune suppression, and heavy metal exposure can all contribute significantly to development of the disease (Verkouteren et al 2017). This underscores the importance of pursuing comprehensive wellness strategies that include daily early morning exposure to sunlight, avoiding sunburns, and maintaining a healthy immune system. These cancers occur at a high rate in individuals who do not produce eumelanin (gingers!), most commonly due to recessive inactivating mutations in the melanocortin receptor. Many genetic mutations are present in cancerous basal cells, including disruptions in the hedgehog pathways that cause rapid cell division and inappropriate differentiation. Hedgehog pathway inhibitors are now approved for use in cases of recurrent basal cell carcinoma. There has also been some recent interest and effort directed at treating basal cell carcinomas with checkpoint blockade inhibitors. There are a variety of conventional therapies available, as well as some up-and-coming approaches with less-conventional modalities that are showing promise – all are listed below. The Mohs surgery has been the standard for many decades with up to 99% of patients experiencing no relapse. Some of the other modalities, like cryoablation and radiotherapy can approach 97% with fewer cosmetic issues. The extracts and creams have the highest potential for recurrence, mostly in the 70% range, but also the lowest potential for cosmetic complications. 

Mohs surgery is conducted by removing the basal cell cancer followed by incremental removal of a larger and larger radius until no more cancer cells are visible in the microscope. The incremental microscopic assessment is conducted in the clinic while you are waiting so that you don’t have to return to the clinic over and over again. This technique is estimated to remove all cancer cells 97-99% of the time.

Cryoablation therapy (also called cryosurgery or cryotherapy) utilizes liquid nitrogen, Argon gas, or Nitrous Oxide to freeze the tumor cells. Several freeze-thaw cycles are generally sufficient to lyse and kill the cells. Because the cells break open, this method has the potential of inducing an anti-tumor immune response.  This method has high efficacy, yielding similar recurrence rates to radiotherapy and in some studies it approaches Mohs surgery in low recurrence rates. Scarring is expected to be minimal with this option ( see Tchanque-Fossuo & Eisen 2018; Putinsky et al 2023).

The Antitumor properties of Mistletoe extract (collected from various Viscum species) have been under investigation for many decades. Mistletoe is employed in two primary ways: 1) Intradermally as an immune stimulating agent where it is thought to help activate the natural killer and T cells to overcome immunosuppressive activities of the cancer cell, 2) Direct application or I.V delivery of the mistletoe lectins, which appear to induce tumor cell death through the endoplasmic reticulum death pathways (see Hong & Lyu 2025 for a recent review). Dramatic results showing regression of basal and squamous cell carcinomas through topical application of mistletoe extracts have been published (see Königsberger et al  2024).

Radiotherapy is an accepted viable alternative to surgery. Reported recurrence rates are in the same range as those of surgery (1-3%), and scarring is minimized. Secondary malignancy due to radiation is a remote possibility. For a discussion of this option see Basset-Seguin, N., et al (2020). Electron beam therapy is another approach that yields good cosmetic results (Lee et al 2025). It carries a slight risk of acute skin toxicity and secondary cancers caused by exposure to the electron beams. Image-Guided Superficial Radiotherapy utilizes x-rays to kill tumor cells - practitioners advertise 99% cure rates. The risks of secondary malignancies due to the radiation are unknown. Photodynamic therapy is a non-invasive therapy that uses chemicals which are initially non-toxic but are converted to toxins upon exposure to certain wavelengths of light. These chemicals are applied directly to the cancer lesion followed by illumination with appropriate wavelength of light. Recurrence rates have been reported to be higher than in Mohs or cryoablation, though it is difficult to determine for sure because many of the studies have utilized different time points to measure recurrence (see Tchanque-Fossuo & Eisen 2018). Near Infrared Light Photobiomodulations is the use of near infrared light  alone to treat disease, including cancer. Note that approach is different than near infrared photodynamic therapy. It has been tested extensively in cell culture and animal models (da Silva Ferreira et al 2025), as well as in some clinical trials (Bensadoun et al 2020). While there are a number of anecdotal reports of successful treatment of basal cell carcinoma with near infrared light, we could find no published studies specifically examining use of NIR to treat basal cell carcinoma. Note that there is some evidence that NIR of certain wavelengths can promote proliferation of certain types of cultured tumor cells (Luitel et al 2024), and that different wavelengths may affect different tumor types differently. Although this presents concerns about the use of NIR light to treat cancers, Glass (2023) discusses this general point and is of the opinion that there is no evidence for oncogenic effects of near infrared light in clinical settings.

Curettage combined with electrodessication is another surgical technique used on superficial basal and squamous cell carcinomas. This is an in-office technique in which a scraper (referred to as a curette) is used to remove most of the tumor mass, and then a small high voltage electrode is used to heat and desiccate the remaining tumor cells.  This technique successfully removes the cancer without recurrence in 96% of the cases.

Curaderm is a topical therapy prepared from plant-based alkaloids (active ingredient Solasodine and related alkaloids) and licensed in Australia and in Britain. An older high-quality British study (Punjabi et al 2008) concluded that 78% of the participants had no recurrence after one year - so that is a 22% remission rate after a year, and this is the number often quoted. This recurrence rate for Curaderm is significantly lower than that of the Moh's surgery, cryoablation, and radiotherapy, but seems to be in the same range as recurrence rates with imiquimod and many of the photodynamic therapies, although some photodynamic therapies are in the same recurrence range as cryotherapy and radiotherapy, which are both not quite as good as Moh's. The Collier and Tchanque-Fossuo reviews do a good job of comparing the various treatments and their recurrence rates.

Essential oils have been widely investigated as potential anti-cancer agents, especially in cell culture systems. Most of the studies have not directly compared toxic effects of the oils in normal and tumor cells, so there are still many questions about tumor specificity (Blowman et al 2018).  Because essential oils are easy to apply to the skin, there has been a lot of interest in treating melanomas, squamous cell carcinomas, and basal cell carcinomas. There is one case study describing successful treatment of a basal cell carcinoma with frankincense – the before and after images are dramatic (see Fung et al 2013).

Imiquimod is a chemical that activates Toll-like receptor 7 on antigen presenting cells, inducing release of TNF and other cytokines which in turn stimulates anti-tumor immune responses. Imiquimod was developed for treatment of anal and genital warts, and is now FDA-approved for superficial basal cell carcinoma (see FDA description and Huang et al. 2020 – note that Huang states that Imiquimod is not approved for nodular basal cell carcinomas which are different than superficial BCC’s). Trials with basal cell carcinomas up to that juncture suggest that Imiquimod has a recurrence-free efficacy of around 70%.

Basset-Seguin, N., & Herms, F. (2020). Update on the management of basal cell carcinoma. Acta dermato-venereologica, 100(11), 5750.

Bensadoun, R. J., Epstein, J. B., Nair, R. G., Barasch, A., Raber‐Durlacher, J. E., Migliorati, C., ... & World Association for Laser Therapy (WALT). (2020). Safety and efficacy of photobiomodulation therapy in oncology: a systematic review. Cancer medicine, 9(22), 8279-8300.

Blowman, K., Magalhães, M., Lemos, M. F. L., Cabral, C., & Pires, I. M. (2018). Anticancer properties of essential oils and other natural products. Evidence‐Based Complementary and Alternative Medicine, 2018(1), 3149362.

Collier, N. J., Haylett, A. K., Wong, T. H., Morton, C. A., Ibbotson, S. H., McKenna, K. E., ... & Rhodes, L. E. (2018). Conventional and combination topical photodynamic therapy for basal cell carcinoma: systematic review and meta‐analysis. British Journal of Dermatology, 179(6), 1277-1296.

da Silva Ferreira, A. C., Gomes Farias, T., Cardoso Borges, A. J., Abreu da Silva, M., Barreto Pires, B. R., Mencalha, A. L., & de Souza da Fonseca, A. (2025). Photobiomodulation by infrared radiation on hallmarks of cancer. Lasers in Medical Science, 40(1), 385.

FDA Imiquod (Aldara) https://www.accessdata.fda.gov/drugsatfda_docs/label/2004/20723s016lbl.pdf

Glass, G. E. (2023). Photobiomodulation: a systematic review of the oncologic safety of low-level light therapy for aesthetic skin rejuvenation. Aesthetic Surgery Journal, 43(5), NP357-NP371.

Hong, C. E., & Lyu, S. Y. (2025). Mistletoe in Cancer Cell Biology: Recent Advances. Current Issues in Molecular Biology, 47(8), 672).

Huang, C. M., & Kirchhof, M. G. (2020). Topical imiquimod as a treatment option for nodular basal cell carcinoma: a systematic review. Journal of Cutaneous Medicine and Surgery, 24(5), 495-503.

Königsberger, K., Urech, K., Reif, M., Baumgartner, S., Martin, D., & Tröger, W. (2024). Viscum album lipophilic extract in actinic keratosis, cutaneous squamous cell carcinoma, and basal cell carcinoma: A retrospective case series. Complementary Medicine Research, 31(3), 241-252

Lee, A. D., Lum, N., Thandi, A., Yee, K. A., Seeburruth, D., Park, M., ... & Liu, C. (2025). The clinical outcomes, safety profiles, and treatment patterns of electron beam therapy for basal cell carcinoma. JAAD Reviews, 4, 126-128.

Luitel, B., Duggisani, T., Luitel, A., & LaRocco, J. (2024). Reviewing the efficiency of photobiomodulation therapy in oncological treatment. Frontiers in Oncology, 14, 1447653.

Punjabi, S., Cook, L. J., Kersey, P., Marks, R., & Cerio, R. (2008). Solasodine glycoalkaloids: a novel topical therapy for basal cell carcinoma. A double‐blind, randomized, placebo‐controlled, parallel group, multicenter study. International Journal of Dermatology, 47(1), 78-82.

Pustinsky, I., Dvornikov, A., Kiva, E., Chulkova, S., Egorova, A., Gladilina, I., ... & Kalinin, S. (2023). Cryosurgery for basal cell skin cancer of the head: 15 years of experience. Life, 13(11), 2231.

Tchanque-Fossuo, C. N., & Eisen, D. B. (2018). A systematic review on the use of cryotherapy versus other treatments for basal cell carcinoma. Dermatology Online Journal, 24(11).

Verkouteren, J. A. C., Ramdas, K. H. R., Wakkee, M., & Nijsten, T. (2017). Epidemiology of basal cell carcinoma: scholarly review. British Journal of Dermatology, 177(2), 359-372.

Wang, H., Xu, Y., Shi, J., Gao, X., & Geng, L. (2015). Photodynamic therapy in the treatment of basal cell carcinoma: a systematic review and meta‐analysis. Photodermatology, photoimmunology & photomedicine, 31(1), 44-53.