Malignant epithelial tumors: Part II. Therapy and prevention

Integrin αE(CD103)β7 in Epithelial Cancer

Interactions of both the innate and the adaptive immune system with tumors are complex and often influence courses and therapeutic treatments in unanticipated ways. Based on the concept that CD8+T cells can mediate important antitumor effects, several therapies now aim to amplify their specific activity. A subpopulation of CD8+ tissue-resident T lymphocytes that express the αE(CD103)β7 integrin has raised particular interest. This receptor presumably contributes to the recruitment and retention of tumor-infiltrating immune cells through interaction with its ligand, E-cadherin. It appears to have regulatory functions and is thought to be a component of some immunological synapses. In TGF-rich environments, the αE(CD103)β7/E-cadherin-interaction enhances the binding strength between tumor cells and infiltrating T lymphocytes. This activity facilitates the release of lytic granule contents and cytokines as well as further immune responses and the killing of target cells. Expression of αE(CD103)β7 in some tumors is associated with a rather favorable prognosis, perhaps with the notable exception of squamous cell carcinoma of the skin. Although epithelial skin tumors are by far the most common tumors of fair-skinned people, there have been very few studies on the distribution of αE(CD103)β7 expressing cells in these neoplasms. Given this background, we describe here that αE(CD103)β7 is scarcely present in basal cell carcinomas, but much more abundant in squamous cell carcinomas with heterogeneous distribution. Notwithstanding a substantial number of studies, the role of αE(CD103)β7 in the tumor context is still far from clear. Here, we summarize the essential current knowledge on αE(CD103)β7 and outline that it is worthwhile to further explore this intriguing receptor with regard to the pathophysiology, therapy, and prognosis of solid tumors.

Cryosurgery, Intralesional Methotrexate and Imiquimod for Keratoacanthoma: Tuning the Combination

Keratoacanthomas (KA) are self-regressing, destructively expanding keratinocyte skin neoplasms typically characterized by sudden onset of explosive growth followed by complete involution. Cryosurgery, intralesional methotrexate and imiquimod have been used alone or in combination of two for the treatment of KA. Presently 3 patients (49, 60, and 65 years old; two females, one suspected with Ferguson-Smith syndrome), with 5 KA (6–24 mm maximal diameter) were treated with the combination of cryosurgery (liquid N₂, open spray, 2 cycles of 15 sec each) and intralesional methotrexate (2.5–30 mg cumulative dose) and subsequent daily application of imiquimod (14–35 days). Starting with 4 cryosurgery/intralesional methotrexate sessions and 5 weeks daily imiquimod, to document feasibility and efficacy we progressively reduced the intensity of the treatment to one cryosurgery/intralesional methotrexate (total dose: 5 mg) session and 14 days of daily imiquimod without compromising efficacy. KA stopped growing promptly with sustained clearance after 6–24 months follow up, implicating a huge potential of therapeutic synergy of the employed modalities in the management of KA. We suggest that, optimized, the present three modalities combination (one session mild cryosurgery/low dose, 5 mg intralesional methotrexate and 2 weeks once daily imiquimod) is a promising treatment for KA that merits evaluation in further studies.