Characterization of the mononuclear infiltrate in Bowen's disease (squamous cell carcinoma in situ). Evidence for a T cell-mediated anti-tumour immune response

Imiquimod 5% cream monotherapy for cutaneous squamous cell carcinoma in situ (Bowen's disease): A randomized, double-blind, placebo-controlled trial

BACKGROUND

We conducted a double-blind, placebo-controlled, randomized trial to evaluate the preliminary efficacy and safety of imiquimod 5% cream treatment for cutaneous squamous cell carcinoma (SCC) in situ.

METHODS

In all, 31 patients with biopsy-proven cutaneous SCC in situ were randomly assigned to placebo (vehicle) (n = 16) or imiquimod 5% cream (n = 15) daily for 16 weeks. Patients were assessed at week 28 for the primary end point, resolution of cutaneous SCC in situ.

RESULTS

Of the 31 patients enrolled, 3 dropped out. Intention-to-treat analysis revealed 11 of the 15 patients (73%) in the imiquimod group achieved resolution of cutaneous SCC in situ, with no relapse during the 9-month follow-up period; none in the placebo group achieved resolution (P < .001). Imiquimod 5% cream was generally well tolerated and there were no serious adverse events.

LIMITATIONS

Topical imiquimod 5% cream has proven to be an effective treatment for cutaneous SCC in situ. However, studies to define the ideal dosing regimen and cost-effectiveness are required before it can be accepted as a recognized therapy.

CONCLUSIONS

In this controlled trial, patients with cutaneous SCC in situ receiving topical imiquimod 5% cream as monotherapy experienced a high degree of clinical benefit compared with placebo.

Digital syndactylization for the treatment of interdigital squamous cell carcinoma in situ (Bowen disease)

Bowen disease, or squamous cell carcinoma in situ, has been described as a premalignant intraepidermal lesion of the skin. Although more frequently occurring on limbs, interdigital presentation of squamous cell carcinoma in situ in the foot has been rarely reported, likely because of undetected development. Excision has been recommended as the treatment of choice; however, removal of these lesions from intertriginous skin may present few options for skin closure. Interdigital syndactylization may be an acceptable option for the treatment of interdigital manifestations of Bowen disease. The authors present a case of interdigital squamous cell carcinoma in situ successfully treated with excision and digital syndactylization. At the 2-year follow-up, there was no recurrence and no digital deformities.

Imiquimod 5% cream in the treatment of Bowen's disease

BACKGROUND

Large-diameter lesions of Bowen's disease at sites such as the shin may be difficult to treat surgically and may require alternate treatment modalities.

OBJECTIVE

We investigated whether imiquimod 5% cream, a topical immune response modifier that stimulates the production of interferon alfa and other cytokines, is an effective topical treatment for Bowen's disease.

METHODS

This was a phase II, open-label study in 16 patients, treating a single biopsy-proven plaque of Bowen's disease that was 1 cm or larger in diameter, with once-daily self-application of imiquimod 5% cream for 16 weeks. A biopsy was performed on the treated area 6 weeks after the end of treatment, with patient follow-up at 3 and 6 months. Lymphocyte CD4/CD8 ratios were analyzed in pretreatment and posttreatment biopsy specimens by immunophenotyping the lymphocytic infiltrate.

RESULTS

Sixteen patients with Bowen's disease lesions ranging from 1 to 5.4 cm in diameter (0.7-21.6 cm(2) in area) were treated. Fifteen of these lesions were on the legs, and one was on the shoulder. Fourteen of the 15 patients (93% per protocol analysis) had no residual tumor present in their 6-week posttreatment biopsy specimens. One patient died of unrelated intercurrent illness before a biopsy specimen could be obtained. The median CD4/CD8 lymphocyte ratio in pretreatment biopsy specimens was 2:1, and this was reversed to a median of 1:2.2 in the posttreatment specimens. Ten patients completed 16 weeks of treatment, but 6 patients ceased treatment early (between 4 and 8 weeks) because of local skin reactions.

CONCLUSION

Imiquimod 5% cream appears to be an effective treatment for Bowen's disease on the lower limbs. The 93% positive treatment response in biopsy-proven cases (excludes patient who died from an intercurrent illness who did not undergo a posttreatment biopsy) compares favorably with other current treatment modalities. The dosing schedule and length of treatment for Bowen's disease require further evaluation.

Intraperitoneal macrophages and tumor immunity: A review

The macrophage (Mphi) is considered the first line of defense in immune response to foreign invaders. Increasing evidence suggests that Mphi(s) also play an important role against neoplastic cells. Mphi(s) exposed to supraphysiologic concentrations of CO(2) are suppressed. As surgeons apply newer minimally invasive techniques to oncologic therapies, it is important to evaluate the impact of these techniques on host-tumor interactions. We review the current understanding of Mphi biology with specific attention on cytotoxicity in addition to tumor immunity. Although systemic immune function is better preserved after laparoscopy than laparotomy, peritoneal Mphi(s) show reduced function after CO(2) pneumoperitoneum than exposure to air. Mphi(s) have shown cytotoxicity to syngeneic cancer cells and may play an important role in tumor surveillance. The impairment in Mphi function after CO(2) exposure may have an effect on outcome after oncologic surgery. In our understanding, Mphi(s) help destroy neoplastic cells. As CO(2) impairs Mphi activity, laparoscopy may significantly alter the host-tumor interaction.

Immunological relatedness of the protective mechanisms against tuberculosis and cancer

BACKGROUND

Bacille Calmette-Guérin (BCG), an attenuated strain of tuberculous bacillus, is the source of vaccines providing unclear and variable protection against tuberculosis (TB) and cancer. Thermostable macromolecular antigens (TMAs) are major mycobacterial complexes immunodominant in disease. A60 (TMA complex of BCG) protects mice against TB development, via T lymphocyte (TL)-mediated macrophage (Mphi) activation, halting intracellular mycobacterial replication. In most A60-primed mice, cytolytic TLs and Mphi infiltrate cancer tissue, resulting in 80-100% rejection. Adoptive TL transfer is indispensable for Mphi-dependent tumour cell inactivation via oxygen and nitrogen radicals. Neoplasm development induces immune anergy with depletion ofA60-specific TL and activated Mphi. A60 protects mice against TB and cancer by inducing the synthesis of three lymphokines: interleukin 2 (IL-2), interferon gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha). Tumour cells prevent A60-dependent synthesis of these lymphokines in vivo and in vitro.

CONCLUSION

These data provide some clues to immune surveillance and tumour escape mechanisms, as well as to the antituberculous and antineoplastic BCG action.

Characterization of verruciform xanthoma by in situ hybridization and immunohistochemistry

Verruciform xanthoma (VX) is a rare, benign lesion, mainly found in the oral mucosa. Histologically and ultrastructurally, the lesion is characteristic and well defined. However, the etiology of the lesion remains unclear. The purpose of the present study was to elaborate upon the pathogenesis of VX by evaluation of an additional series of oral examples for human papillomaviruses (HPV), using immunohistochemistry and in situ hybridization, and to further characterize the cellular components of VX immunohistochemically. Twelve specimens diagnosed as VX were retrospectively collected. One of the twelve specimens was positive for HPV types 6/11 by in situ hybridization. None of the twelve specimens demonstrated the presence of HPV antigen by immunohistochemistry. By immunohistochemical studies, the predominant cells in the inflammatory infiltrate were T cells. The foam cells were of monocyte/macrophage lineage. S-100-positive (Langerhans) cells were occasionally found in the suprabasal layer of the epithelium. HLA-DR-positive keratinocytes were noted at the intense inflammatory sites. Taken together, these findings suggest that an immune response may play a role, at least in part, in VX pathogenesis.

Effects of krestin (PSK) on tumorigenesis induced by two-stage and complete chemical carcinogenesis

The effects of PSK on tumorigenesis in mouse skin were investigated either when mouse skins were initiated by benzo(a)pyrene and promoted by 12-O-tetradecanoyl-phorbol-13-acetate (Group I, two-stage carcinogenesis) or when both initiated and promoted by benzo(a)pyrene (Group II, complete carcinogenesis). Twelve mice in each group were fed chow with or without 0.4% PSK. This concentration of PSK was determined by calculation to give mice enough PSK to exert antitumorigenic activity without cytotoxicity. By the end of the experimental periods (26 weeks), two carcinoma-burdened mice in Group I without PSK were dead, but no carcinomas at all were identified in the mice fed with PSK, although considerable numbers of papillomas developed in both groups. In Group II, carcinomas started to evolve at the 15th week of the experiment regardless of PSK feeding. The number of carcinomas observed in the mice fed with PSK in Group II was statistically significantly lower than that in the mice fed without PSK. Histologically, mild inflammatory infiltrations were seen around the papillomas, and moderate to dense infiltrations, mainly composed of neutrophils, T lymphocytes, and macrophages, were observed in squamous cell carcinomas. There were apparently no significant differences in the number of the infiltrating cells around carcinomas in PSK (+) and PSK (-) groups in both early and fully developed lesions. However, considerable numbers of cells infiltrating into the nests were observed in the early lesions of elicited carcinomas in the mice fed with PSK, while such cells were rarely seen in carcinoma nests in the group without PSK at that stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical characterization of cellular infiltrates in squamous cell carcinoma and Bowen's disease occurring in one patient

We investigated populations of the infiltrating cells in Bowen's disease (BD) and squamous cell carcinoma (SCC), both of which arose in the same patient, using the Avidin-Biotin-peroxidase complex method with eight monoclonal antibodies. T lymphocytes were most predominant among infiltrating cells; NK cells, B cells, and monocytes were rarely seen in either BD or SCC. Analysis of subsets of the infiltrating T lymphocytes revealed that the number of suppressor/cytotoxic (s/c) T cells was twice that of helper/inducer (h/i) T cells in BD, while the number of s/c T cells was lower than that of h/i T cells in SCC. The immunohistochemical results in the present case differed from those of predominant infiltration of h/i T cells and of s/c T cells in three other reports of BD and SCC. These results suggest that the population of the cellular infiltrates may be modulated by the nature of tumors and by the immuno-competent state of the hosts.

Immunohistochemical characterization of cellular infiltrates in epidermal tumors induced by two-stage and complete chemical carcinogenesis in mouse skin

We investigated the population and pattern of the infiltrated cells in both benign and malignant epidermal tumors which were induced chemically with benzo(a)pyrene (B(a)P) in murine skin. In benign papillomas, which were evolved by a two stage carcinogenesis regimen, a slight to mild inflammatory infiltration around the tumors was observed, and cells infiltrating into the tumor nests were rarely seen. In carcinomas, which were produced by a complete carcinogenesis regimen, a dense inflammatory infiltration was observed around the tumor nests. The infiltrated cells were characterized as T-lymphocytes, macrophages, and neutrophils. Natural killer (NK) cells were found around and in the tumor nests, but their number was small. Both T-lymphocytes and macrophages were found to invade the tumor nests in squamous cell carcinoma whose duration was more than four weeks. This experimental carcinogenesis animal model allows the detailed quantitative and functional analysis of the infiltration of immunocompetent cells into epidermal tumors.