Changes to This Summary (08/23/2011)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

General Information About Merkel Cell Carcinoma ¹

Added Calder et al. as reference 9 ².

Added text ³ to state that national cancer registries from three Scandinavian countries have identified a variety of second cancers diagnosed after Merkel cell carcinoma (MCC) (cited Bzhalava et al. as reference 19).

Added text ⁴ to state that expression of certain viral antigens in MCC cells and the presence of antiviral antibodies have been reported; not all cases of MCC appear to be associated with Merkel cell polyomavirus infection (cited Paik et al. as reference 26).

Added text ⁵ to state that various methods have been used to identify and quantify the presence of MCPyV in MCC tumor specimens, other non-MCC tumors, blood, urine, and other tissues (cited DeCaprio as reference 30 and Laude et al. as reference 31).

Added text ⁶ to state that the significance of the new MCPyV findings remains uncertain; the prognostic significance of viral load, antibody titer levels, and the role of underlying immunosuppression in hosts are under investigation.

Added text ⁷ about the difference in MCPyV prevalence between MCC patients in the United States and Europe versus Australia and the possibility that there may be two independent pathways for the development of MCC (cited Paik et al. as reference 26 and Buck et al. as reference 32).

Added Paulson et al. and Fields et al. as references 52 and 53 ⁸, respectively.

Added text ⁹ to state that standardization of procedures to identify and quantify MCPyV and relevant antibodies is needed to improve understanding of both prognostic and epidemiologic questions (cited Rockville Merkel Cell Carcinoma Group as reference 8).

Cellular Classification of Merkel Cell Carcinoma ¹⁰

Added text ¹¹ to state that the College of American Pathologists has published a protocol for the examination of specimens from patients with MCC of the skin (cited Rao et al. as reference 14).

Treatment Option Overview ¹²

Added text ¹³ about the findings of a retrospective series of 213 patients who underwent surgical treatment of the primary tumor and evaluation of the draining nodes (cited Stokes et al. as reference 13 and level of evidence 3iiiDiii).

Added text ¹⁴ to state that the significance of sentinel lymph node (SLN) positivity remains unclear.

Added text ¹⁵ about a large, retrospective, single-institutional series of 95 patients that identified a SLN in 93 instances and nodal tumor in 42 patients (cited Schwartz et al. as reference 22 and level of evidence 3iiiDiii).

Added text ¹⁵ to state that from 1996 to 2010, another retrospective single-institutional study of 153 patients with localized MCC who underwent SLN biopsy analyzed factors associated with SLN positivity; the best predictors of SLN biopsy positivity were tumor size and lymphovascular invasion (cited Fields et al. as reference 23 and level of evidence 3iiiDiii).

Added text ¹⁶ that asks whether immunihistochemical staining techniques should be used to identify micrometastases in nodes, and whether micrometastatic disease in nodes is clinically relevant in the absence of adequately powered, prospective, randomized clinical trials.

Added text ¹⁷ to state that the primary role of lymph node surgery is for staging and guiding additional treatment.

Cited Foote et al. as reference 35 ¹⁸.

Added text ¹⁹ to state that local and/or regional control of MCC with radiation alone has been reported in small, highly selected, nonrandomized case series of patients with diverse clinical characteristics; typically, these patients have had inoperable primary tumors and/or nodes or were considered medically inappropriate for surgery (cited Veness et al. as reference 29 and Fang et al. as reference 36 and level of evidence 3iiiDiii).