Skin Cancer Microenvironment: What We Can Learn from Skin Aging?

Different Pathways of Skin Aging: Objective Instrumental Evaluation

Background/Objectives: Hypertrophic and atrophic skin aging represent two distinct phenotypes: hypertrophic aging is marked by deep wrinkles and a leathery texture, whereas atrophic aging is characterized by overall skin thinning, increased vascularity, and a higher risk of non-melanoma skin cancers. This study aims to elucidate the characteristics and differences between hypertrophic and atrophic facial aging subtypes using two non-invasive imaging devices: VISIA® and dynamic optical coherence tomography (D-OCT). Methods: We retrospectively evaluated patients who had presented to the outpatient dermatological clinic at Policlinico Umberto I hospital in Rome, Italy for a non-invasive facial imaging check-up. We included 40 patients aged 60-75 who were imaged with VISIA® and dynamic optical coherence tomography (D-OCT). Based on the number of UV spots and amount of red found on VISIA®, subjects were grouped into four subgroups (PIGM, RED, CONTROL, PIGM + RED), and trends among them were analyzed. Results: We found a strong correlation between VISIA® red area scores and D-OCT vascular density at 300 µm depth, confirming VISIA®'s effectiveness for assessing facial vascularity. Wrinkle count was highest in areas with UV spots, particularly in the PIGM and PIGM + RED groups. Conversely, low attenuation coefficients and dermal density were observed in regions with low UV spots but high red areas. Intermediate subgroups (CONTROL and PIGM + RED) displayed varying parameters. Conclusions: Non-invasive imaging devices are effective in evaluating facial aging and distinguishing between aging subtypes. This study identified two intermediate aging types in addition to the hypertrophic and atrophic subtypes.

Radiation-induced skin reactions: oxidative damage mechanism and antioxidant protection

According to official statistics, cancer remains the main reason of death and over 50% of patients with cancer receive radiotherapy. However, adverse consequences after radiation exposure like radiation-induced skin reactions (RISR) have negative or even fatal impact on patients' quality of life (QoL). In this review we summarize the mechanisms and managements of RISRs, a process that involve a variety of extracellular and intracellular signals, among which oxidative stress (OS) are now commonly believed to be the initial part of the occurrence of all types of RISRs. As for the management of RISRs, traditional treatments have been widely used but without satisfying outcomes while some promising therapeutic strategies related to OS still need further researches. In the context we discuss how OS leads to the happening of RISRs of different types, hoping it can shed some light on the exploration of new countermeasures.

Immunotherapy in Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most frequent of all cancers, with an increasing incidence. The first line therapy is surgical excision, but topical therapies can be used in low-risk superficial BCCs, while the more advanced, unresectable, or metastatic BCCs benefit from systemic therapies with hedgehog inhibitors and immunotherapy. The purpose of this review is to highlight local and systemic immunotherapies and their efficacy in the management of BCCs. Local therapies can be considered in superficial and low-risk nodular BCCs, with imiquimod frequently used for its antitumor and immunoregulatory properties. Imiquimod alone demonstrated higher histological clearance rates, but patients treated with imiquimod experienced more adverse events than ones treated with other therapies. Imiquimod can be used as an adjuvant before Mohs micrographic surgery and can also be combined with other local therapies, like curettage, electrodesiccation, cryosurgery, and photodynamic therapy, with some treatment methods yielding results comparable with the surgery. Interferons and Interleukin-2 were evaluated in a small number of studies with different results. Systemic immunotherapies with programmed death-ligand 1 (PD-L1) inhibitors showed inconsistent results in patients with advanced BCCs, being effective in some patients that progressed on or were intolerant to hedgehog pathway inhibitors (HHI).

The Keratinocyte in the Picture Cutaneous Melanoma Microenvironment

Melanoma progression is a multistep evolution from a common melanocytic nevus through a radial superficial growth phase, the invasive vertical growth phase finally leading to metastatic dissemination into distant organs. Melanoma aggressiveness largely depends on the propensity to metastasize, which means the capacity to escape from the physiological microenvironment since tissue damage due to primary melanoma lesions is generally modest. Physiologically, epidermal melanocytes are attached to the basement membrane, and their adhesion/migration is under the control of surrounding keratinocytes. Thus, the epidermal compartment represents the first microenvironment responsible for melanoma spread. This complex process involves cell-cell contact and a broad range of secreted bioactive molecules. Invasion, or at the beginning of the microinvasion, implies the breakdown of the dermo-epidermal basement membrane followed by the migration of neoplastic melanocytic cells in the superficial papillary dermis. Correspondingly, several experimental evidences documented the structural and functional rearrangement of the entire tissue surrounding neoplasm that in some way reflects the atypia of tumor cells. Lastly, the microenvironment must support the proliferation and survival of melanocytes outside the normal epidermal-melanin units. This task presumably is mostly delegated to fibroblasts and ultimately to the self-autonomous capacity of melanoma cells. This review will discuss remodeling that occurs in the epidermis during melanoma formation as well as skin changes that occur independently of melanocytic hyperproliferation having possible pro-tumoral features.