Several specific risk factors have been identified in the recurrence or spreading of cutaneous squamous-cell carcinoma, or skin cancer. These factors, released on July 9, 2008 in The Lancet Oncology, include: a tumor thickness of 6.0 mm or more, desmoplastic growth, location at the ear, and immune suppression.
Squamous-cell carcinomas (SCCs) are some of the most likely cancers to metastasize or spread. To investigate the various parameters that might affect metastasis and local recurrence in skin SCC, Dr Kay Brantsch and Professor Helmut Breuninger, Department of Dermatology, Eberhard Karls University, Tubingen, Germany, and colleagues examined 615 patients between the ages of 27 and 98 years who had had surgery on skin SCC between 1990 and 2001.
The team extracted the tumors and performed a three dimensional histological examination while gathering additional data. These included: tumor thickness, horizontal size, body site, tumor cell shape, desmoplastic or fibrous growth, patient history of multiple SCC, and immunosuppression in the patient. Then, this was compared to the time until metastasis or recurrence in the patient, which was defined as the time frame beginning at diagnosis and ending with the date of diagnosis of metastasis or local recurrence.
In a median follow up of 43 months, 4% (26 patients) experienced metastases and 3% (20 patients) experienced local recurrence. In an examination of their sizes, metastasis occurred in no tumors 2.0 mm or smaller, but did occur in 4% (12 of 318) of tumors between 2.1 mm and 6.0 mm, and 16% (14 of 90) of tumors larger than 6.0 mm.
Several key risk factors were identified for metastasis. First, an increased tumor thickness increased risk by nearly five fold. Additionally, a suppressed immune system increased risk 4.3 times, and an SCC located on the ear nearly doubled the risk. When examining local recurrence, increased tumor thickness indicated a six fold increase in risk, while displaying desmoplasia indicated 16 times the risk. The authors summarized the results as follows: “Only SCC greater than 2·0 mm in thickness are associated with a significant risk of metastasis. Tumours greater than 6·0 mm are associated with a high risk of metastasis and local recurrence. Desmoplastic growth is an independent risk factor for local recurrence.”
The authors further suggest that clinical follow up should be performed every three to four months using ultrasound of the regional lymph nodes. This method has been approved for melanoma patients, and in this case, patients with early lymph-node metastases have a better prognosis than those with advanced nodal disease. They note that further research should be performed to verify the benefits of this action for SCC.
They also argue for modification of the Tumor Node Metastasis (TNM) staging system, which uses parameters such as horizontal tumor size, extradermal skin structure involvement, and degree of cell differentiation to classify different types of tumors. They conclude that these results could help modify these parameters for more effective treatment and follow up: “On the basis of these findings, we believe that a revision of the current TNM staging system is needed for accurate patient staging, patient management in daily practice, and studies on this increasingly important tumour.”
Analysis of risk factors determining prognosis of cutaneous squamous-cell carcinoma: a prospective study
Kay D Brantsch, Christoph Meisner, Birgitt Schonfisch, Birgit Trilling, Jorg Wehner-Caroli, Martin Rocken, Helmut Breuninger
Lancet Oncology, July 9, 2008
DOI:10.1016/S1470- 2045(08)70178-5
Written by Anna Sophia McKenney