Clinical and Pathologic Studies of Patients Undergoing Treatment With EGFR Inhibitors
Clinical and Pathologic Studies of Patients Undergoing Treatment With EGFR Inhibitors
Cetuximab, erlotinib, and panitumumab are all recently FDA approved epidermal growth factor
 receptor (EGFR) inhibitors that treat a wide variety of tumor types, such as colon, lung, and
 head and neck. Blockade of the EGFR results in inhibition of multiple downstream pathways,
 leading to slowed tumor growth. In addition, these inhibitors may enhance anti-tumor immune
 responses through uncharacterized mechanisms. While producing significant responses in many
 settings, EGFR inhibitors also result in significant skin toxicity (rash) in a high
 percentage of patients. Multiple studies have correlated the presence and severity of rash
 with clinical response. Unfortunately, severe rash can often lead to dose delays, reductions,
 or even discontinuation of EGFR inhibitors, thus limiting their efficacy. The mechanism of
 both the rash and its correlation with tumor response is poorly understood. Skin biopsies
 display a robust leukocyte infiltrate, but a systematic analysis of the type of infiltrating
 leukocytes, activation state, or homing receptor expression has not been performed.
 Chemokines and chemokine receptors control leukocyte trafficking to the skin and other tissue
 sites, and defined receptor profiles for skin-, gut-, and lung-homing leukocytes are well
 established. In this study, the investigators propose to evaluate the homing phenotype of
 leukocytes from peripheral blood and skin biopsies of patients receiving EGFR inhibitors. The
 investigators will use RNA microarrays to evaluate the expression of chemokines and other key
 genes regulated in skin during treatment. The investigators will utilize in vitro methods to
 investigate effects of EGFR inhibitors on imprinting of T cell tissue-specific homing
 receptors. The investigators will examine correlations among the pathologic data, clinical
 findings, and tumor response. If validated, peripheral blood evaluation could potentially be
 used as a predictive indicator for patients receiving EGFR inhibitors. This study may also
 identify novel targets for limiting skin toxicity while receiving EGFR inhibitors, thus
 allowing maximal dosing and clinical response from these agents.
Inclusion Criteria:

 -  Patients are eligible if they have histologically proven adenocarcinoma, are planning
 to or currently undergoing treatment with an anti-EGFR (epidermal growth factor
 receptor) therapy, and are 18 years of age or older.

 Exclusion Criteria:

 -  None