Diverse cutaneous side effects associated with BRAF inhibitor therapy: a clinicopathologic study.

BACKGROUND: Vemurafenib, a novel selective small molecule inhibitor of BRAF, has recently been shown to be effective in the treatment of melanomas harboring the BRAF V600E mutation. Similar to the broad-spectrum RAF inhibitor sorafenib, vemurafenib induces development of squamous cell carcinomas and keratoacanthomas as a side effect of therapy. OBJECTIVE: We sought to detail additional cutaneous adverse effects of vemurafenib and a similar BRAF inhibitor, dabrafenib. METHODS: We evaluated the clinical and histologic feature of skin side effects developing on vemurafenib or dabrafenib therapy in 14 patients. RESULTS: Eight patients developed one or more squamous cell carcinomas, and 11 patients formed benign verrucous keratoses. Eight patients developed single lesions and/or widespread eruptions with histopathologic findings of acantholytic dyskeratosis, consistent with warty dyskeratomas and Darier- or Grover-like rashes, respectively. One patient developed palmoplantar hyperkeratosis, and darkening of existing nevi and new nevi within 2 months of starting vemurafenib. Side effects presented as early as 1 week after beginning therapy, with a mean time of onset of 12.6 weeks in our cohort. LIMITATIONS: This study was limited by the small number of cases, all from a single institution. CONCLUSION: Selective BRAF inhibitor therapy is associated with the development of malignant and benign growths, including keratoacanthoma-like squamous cell carcinomas, warty dyskeratomas, and verrucous keratoses, along with widespread eruptions with histologic features of acantholytic dyskeratosis. Given the potential for malignant lesions to develop on treatment, awareness of potential adverse effects of these agents is necessary, and a low threshold for biopsy of new growths is recommended.

Radiofrequency ablation of primary lung cancer: results from an ablate and resect pilot study.

STUDY OBJECTIVES: The role of radiofrequency ablation (RFA) for primary lung cancer remains poorly defined. The purpose of this "ablate and resect" pilot study was to evaluate the safety of performing RFA in patients with primary non-small cell lung cancer (NSCLC) and to characterize the histologic changes in tumor tissue following such ablation. DESIGN: This prospective study was undertaken at a single institution, and 10 patients were accrued from June 2002 to June 2003. Eligible patients included those with clinical stage I or II disease. RFA of the tumor was performed through a standard thoracotomy followed by conventional lobectomy and lymph node dissection. Extent of cell death was determined histologically. MEASUREMENTS AND RESULTS: Following the exclusion of two patients, the treated portions of eight tumors were examined for tumor cell viability. Gross inspection and routine histologic staining could not reliably identify the "immediately ablated" tissue. However, using a supravital staining technique, the treated areas from seven of the eight tumors (87.5%) demonstrated > 80% nonviability (100% nonviability was noted in the treated areas from three of the eight tumors). No bleeding or thermal complications were noted at the time of RFA, and none of the patients had skin burns at the electrode dispersive pad sites. CONCLUSIONS: RFA of primary NSCLC is feasible and can be performed safely in the setting of an open thoracotomy. Complete tumor cell necrosis, as determined by supravital staining, was noted in the treated areas from three of eight tumors (37.5%). Such complete ablation was observed in the treated areas from smaller tumors (< 2 cm), whereas the treated areas from larger tumors demonstrated incomplete ablation. Additional investigation with histopathologic correlation is needed to fully assess the long-term efficacy of RFA for NSCLC.

The association of cytokeratin-only-positive sentinel lymph nodes and subsequent metastases in breast cancer.

INTRODUCTION: The purpose of this study was to better characterize the clinical significance of cytokeratin immunohistochemistry (IHC)-only-positive lymph node metastases among patients with breast cancer. METHODS: We performed a retrospective review of 334 patients who underwent sentinel lymph node (SLN) biopsy from 1 February 1997 through 31 July 2001. SLN biopsies were evaluated using standard hematoxylin and eosin (H&E) techniques. If H&E was negative, cytokeratin IHC was performed. We then evaluated the incidence of subsequent regional and distant metastatic disease. RESULTS: Cytokeratin IHC was performed on 183 sentinel node biopsies from 180 patients comprising a total of 427 sentinel lymph nodes. The procedures included lumpectomy and SLN biopsy (n = 83), mastectomy with SLN biopsy (n = 7), lumpectomy with SLN biopsy and completion axillary dissection (n = 80), and modified radical mastectomy with SLN biopsy and completion axillary dissection (n = 13). Cytokeratin IHC was negative in 175 axillary specimens and positive in 8 (4.4%) from 8 different patients. In these eight specimens, deeper sections with subsequent H&E staining additionally identified micrometastasis in four patients. Three of these 8 patients (37.5%) developed distant metastatic disease compared with 1 of the 172 patients (0.6%) with negative cytokeratin IHC (P < .001). Additionally, one of the cytokeratin-positive patients developed regional nodal metastasis compared with none of the 172 cytokeratin-negative patients. CONCLUSIONS: Cytokeratin IHC provides a clinically relevant adjunct to H&E staining for evaluating sentinel lymph nodes in breast cancer. These data suggest that patients with cytokeratin-positive sentinel nodes are at increased risk for development of regional and distant metastatic disease.