Treatment of invasive squamous cell carcinoma with 5 percent imiquimod cream
- Author(s): Konstantopoulou, M
- Lord, MG
- Macfarlane, AW
- et al.
Treatment of invasive squamous cell carcinoma with 5-percent imiquimod creamDepartments of Dermatology and Pathology, Ysbyty Gwynedd Hospital, Bangor, LL57 2PW, UK. Maria.Konstantopopoulou@nww-tr.wales.nhs.uk
M Konstantopoulou, MG Lord, AW Macfarlane
Dermatology Online Journal 12 (3): 10
Skin cancer is a major problem in the elderly. Squamous cell carcinoma (SCC), the second most common skin cancer, typically occurs in this age group. Despite a number of modalities readily available for treatment (depending on the tumor site, and depth of invasion) there remains the problem of individuals with multiple lesions who may be unsuitable for existing treatments for SCC, particularly surgery. Consequently, the search for novel treatments continues. To our knowledge, there are only 6 published reports of invasive SCC treated with 5-percent imiquimod cream.
Skin cancer is a major problem in the elderly. Squamous cell carcinoma (SCC), the second most common skin cancer, typically occurs in this age group. Despite a number of modalities readily available for treatment (depending on the tumor site, depth of invasion) there remains the problem of individuals with multiple lesions who may be unsuitable for existing treatments for SCC, particularly surgery. Consequently, the search for novel treatments continues. To our knowledge, there are only 6 published reports of invasive SCC treated with 5-percent imiquimod cream [1, 2, 3, 4, 5, 6].
An 89-year-old woman presented with three lesions on her lower limbs. She had previous treatments for multiple basal cell carcinomas, actinic keratoses, Bowen disease, and invasive SCCs at various sites. The new lesions were on the left foot (one) and right lower leg (two) (Figs. 1a and 1c), and all showed changes of poorly differentiated SCC histologically (Figs. 2a and 2c). She declined surgical excision; radiotherapy was felt to be a poor option.
|Figure 1a||Figure 1b|
|Figure 1. (a) Dorsum, left foot before treatment and (b) after treatment.|
|Figure 1c||Figure 1d|
|Figure 1. (c) Outer aspect, right lower leg before treatment and (d) after treatment.|
She was treated with 5-percent imiquimod cream, initially to just the lesion on the dorsum of the foot, for 8-12 hours at night for three nights each week (3×/week). Treatment was well tolerated by week 2, so the frequency was increased to 5×/week and all three lesions treated. Gradually, two lesions diminished in size. Treatment was continued until there was no clinical evidence of residual tumor at these sites (19 weeks) (Figs. 1b and 1d); repeat biopsies showed only a focus of dysplastic cells with no invasion (dorsum, left foot), and epidermal hyperplasia with no significant cytological atypia (outer aspect, right lower leg) (Figs. 2b and 2d). Neither now showed evidence of invasive SCC. After 16 months there was no recurrence of either lesion. The third lesion (right lower leg, not illustrated) did not respond to topical imiquimod and was later surgically excised.
Imiquimod is a topically applied imidazoquiline immunomodulator that enhances both innate and cell-mediated immunity [1, 2]. It may be effective in a wide range of infectious and neoplastic dermatologic conditions [2, 5]. It acts as an immune modulator via binding to toll-like receptor 7 present on dendritic cells, macrophages, and monocytes [4, 6], leading to the release of proinflammatory mediators, including interferon-α, interleukins 1, 6, 8, 12, and tumor necrosis factor-α among others [3, 4]. Imiquimod directly activates natural killers cells, effects proliferation of B cells, and enhances migration and antigen presentation by Langherhans cells [1, 4]. Direct antineoplastic activity via induction of apoptosis in tumor cells has been proposed [2, 4]. Local complications of topical imiquimod treatment are frequent; significant inflammation is inevitable [1, 5].
There are relatively few reports detailing the successful use topical imiquimod for treating invasive SCC and, as in our case, not all tumors seem to respond. Nevertheless, given the success in our case for two poorly differentiated invasive SCCs, we feel that it has a place in treatment. It may be of use in patients unsuitable for more invasive procedures or for selected early lesions. Careful clinical and histological followup is indicated.
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