Macrophages in Skin Cancer: Quantitative and Functional Studies

Comparison of oncostatin M expression in keratoacanthoma and squamous cell carcinoma

Oncostatin M (OSM) is a 28-kDa glycoprotein, produced by stimulated macrophages and T lymphocytes, that inhibits the proliferation and induces differentiation of a number of different cell lines derived from solid tumors. To determine whether keratoacanthoma (KA) is unique or a variant of squamous cell carcinoma (SCC), we compared the immunohistochemical expression of OSM in the tumor cells and peri- and intratumoral macrophages of 21 mature KAs, 7 regressing KAs, and 27 SCCs. An inverse correlation was identified between OSM tumor labeling and the density of OSM-labeled tumor-associated macrophages for KAs (r = -.4; P = .09). OSM tumor expression was significantly more frequent and more intense in KAs than in SCCs (95% versus 63%; P < .01). In contrast, the density of OSM-labeled macrophages was significantly higher in SCCs compared with mature KAs (7/3 high power fields versus 4/3 high power fields; P = .02). These OSM-positive macrophages were predominantly located at the advancing, infiltrative margins of both neoplasms. Regressing KAs demonstrated a decreased level of OSM tumor expression compared with mature KAs (53% versus 95%; P = .001), but there was no difference in density of OSM-labeled macrophages. Both the above differences and the overlapping patterns of OSM expression suggest that KAs are a variant of SCC where OSM, possibly as an autocrine factor, may mediate KA's overwhelming but not absolute tendency to involute.

Biology of cutaneous squamous cell carcinoma

Nonmelanoma skin cancer is the leading cause of cancer in the United States. Cutaneous squamous cell carcinoma is second only to basal cell carcinoma in prevalence and its incidence is increasing. The biology of squamous cell carcinoma is reviewed under the broad areas of etiology, immunobiology, biochemistry, metastatic potential, and therapy, with emphasis on prevention, diagnosis, and management.

Monocyte function in cervical carcinoma: plasma inhibitor of monocyte chemotaxis

Blood monocyte function was tested in 43 untreated patients with carcinoma of the cervix (stages Ib to IIIb) and 50 age-matched controls. Monocyte counts, adhesion to glass, spreading on glass, phagocytosis and killing of Candida albicans, and chemotaxis under agarose were not significantly different between the patient and control groups. In 65% of a further series of 17 patient/control pairs, the plasma of cervical carcinoma patients was shown to contain a cell-directed inhibitor of monocyte chemotaxis. The accumulated evidence indicates that production of such factors by malignant tumors is an important mechanism in counteracting mononuclear phagocyte defense.

The biology of basal cell carcinoma: a review

Features of basal cell carcinoma are reviewed within the broad categories of growth characteristics, histogenesis, ultrastructural features, biochemical properties, site of origin, metastatic potential, and immunobiology. Biologic features that pertain to host-tumor interactions are emphasized. Perhaps a better understanding of these host-tumor relationships will offer more effective methods of treating and preventing these neoplasms in the future.