Wait-and-see seems justified in case of negative USgFNAC. Strict follow-up with USgFNAC is required. SN identification and aspiration is feasible but did not improve lymph node selection.

The E48 antigen is a successfully explored molecular marker for the diagnosis and therapy of HNSCC. The applicability of E48 as an HNSCC-associated antigen, however, is restricted due to its heterogeneous expression in 30% of tumors; and identification of additional target antigens is therefore desired. E48 belongs to the Ly-6 antigen family, comprising a group of highly homologous, low m.w., GPIanchored surface proteins, of which some show tissue-restricted expression patterns. To identify novel human HNSCC-associated Ly-6 members with squamous cell-associated expression patterns, we performed comprehensive gene-screening consisting of BLAST searches within GenBank databases, followed by expression analysis. Using this approach, the Ly-6K gene could be annotated as a novel member of the human Ly-6 family. Expression of the human Ly-6 genes E48, Ly-6K, PSCA, GML, RIG-E, G6C and Ly-6H was prescreened by qualitative RT-PCR and subsequently analyzed by quantitative RT-PCR in normal keratinocytes, HNSCC cell lines, normal mucosa, HNSCC tumors as well as normal peripheral blood and bone marrow cells. PSCA was highly expressed in normal mucosa, but 100-fold decreased expression was seen in HNSCC. For Ly-6H, GML and G6C, no or very low expression was observed in keratinocytes and HNSCC. Expression of RIG-E was high in normal and malignant squamous cells and in peripheral blood and bone marrow cells, thus limiting its applicability as an HNSCC-associated marker. In contrast, besides the E48 gene, the Ly-6K gene also appeared to be selectively expressed in HNSCC and normal squamous cells. Moreover, expression of Ly-6K was shown in HNSCC cell lines, in which no E48 expression could be detected. These data justify further evaluation of Ly-6K as potential target antigen for the diagnosis and therapy of HNSCC.

SUMMARY:The presence of lymph node metastases is the major determinant for prognosis in head and neck squamous cell carcinoma (HNSCC). It is at present unknown whether the same holds true for the presence of histologically undetectable micrometastases. We analyzed 456 histologically tumor-negative lymph nodes of 23 HNSCC patients without (pN0) and 18 patients with one or two tumor-positive lymph nodes (pNϩ) in their neck dissection specimens at histopathologic examination. To detect the presence of disseminated tumor cells and micrometastases in these lymph nodes, we used real-time quantitative RT-PCR with E48 (Ly-6D) transcripts as a squamous cell-specific molecular marker. The results were compared with histopathologic examination and clinical outcome. E48 transcripts were detected in lymph nodes of 5 (22%) of 23 patients in the pN0 group, and in histologically negative lymph nodes of 10 (56%) of 18 patients in the pNϩ group. In the pN0 group, the presence of E48-positive lymph nodes was significantly associated with a distinctly poor cause-specific survival as compared with those with E48-negative lymph nodes. Our results indicate that E48 real-time quantitative RT-PCR is a suitable method for the detection of micrometastases in lymph nodes of patients with HNSCC. Moreover, detection of micrometastases seems clinically relevant but should be confirmed in a large multicenter trial. (Lab Invest 2003, 83:1233-1240. Head and neck squamous cell carcinoma (HNSCC) accounts for 5% of all newly diagnosed cancers in the Western world (Muir and Weiland, 1995). Dissemination to lymph nodes in the neck is one of the most important prognosticators for HNSCC. Only 7% of patients without lymph node metastases develop distant metastases, whereas this occurs in 50% of patients with more than three tumor-positive lymph nodes (Leemans et al, 1993). Moreover, when tumor is diagnosed in the regional lymph nodes, the neck should be treated. The clinical management is further determined by the number of tumor-containing lymph nodes, the involved level(s) in the neck, and the presence of extranodal spread. Therefore, accurate assessment of the regional lymph nodes for metastases is of crucial importance. However, classical diagnostic modalities, such as radiologic and histopathologic examination are of limited sensitivity to detect small numbers of tumor cells.Recently, molecular techniques have been applied in a number of studies to detect the presence of micrometastases that are missed at routine histologic examination for the early diagnosis of cancer (Brennan et

Our study seems to validate the SN hypothesis for oral and oropharyngeal cancer. The role of SN biopsy in the management of the N0 neck in such patients has yet to be established through prospective trials. SN identification (and thus biopsy) does not seem to be reliable in patients with tumors located in or close to the midline.

Ultrasonography (US)-guided fine-needle aspiration with cytologic examination was combined with lymphoscintigraphy for the identification of sentinel lymph nodes (SLNs) in 12 patients with a squamous cell carcinoma of the oral cavity or oropharynx. Dynamic lymphoscintigraphy and a hand-held gamma probe were used to depict the SLNs to be aspirated. Cytologic examination of the aspirated SLNs revealed neck lymph node status in patients who underwent neck dissection (n = 6). In patients who underwent only transoral excision, one false-negative cytologic result was observed. This combined approach is expected to improve the detection of occult neck lymph node metastases.