In head and neck squamous cell carcinomas (HNSCC), metastasis to cervical lymph nodes is a major determinant of patient outcome. To detect metastases, we used the MET oncogene as marker, which encodes the receptor for hepa-tocyte growth factor/scatter factor, mediating epithelial cell motility and invasiveness. The MET gene is expressed in epithelia and over-expressed in carcinomas of specific histo-types, but not in lymphatic tissue. A total of 151 lymph nodes from 20 squamous cell carcinomas were studied with both in-depth histology and end-point and real-time quantitative RT-PCR. MET-encoded sequences were found in 61 of 151 nodes (40%), of which 24 (16%) were found metastatic by in-depth histopathology. Parallel routine histopathologic analysis of 654 lymph nodes from the same cases identified 36 metastases (5%). Real-time quantitative RT-PCR was used to measure MET gene-specific mRNA in normal tissues, primary tumors and lymphatic metastases and showed a 2-8-fold increased expression in tumor cells which metastasize. RT-PCR for 3 cytokeratins expressed in HNSCC (K4, K10 and K13) proved to be less sensitive in detecting occult lym-phatic metastases. Western blot analysis demonstrated the presence of the full-size MET receptor in primary tumors and lymph node metastases; immunohistochemistry showed receptor localization in tumor cells. Altogether, these data demonstrate that the MET gene product is a valuable marker with which to detect occult tumor cells in lymph nodes, thanks to its high expression in metastatic cells. After RT-PCR analysis we were able to attribute a more advanced stage to 10 out of 20 HNSCC cases, including 5 cases classified as tumor-free after routine histopathology. Squamous cell carcinoma is the most frequent epithelial tumor occurring in the head and neck. These tumors can arise throughout the lining of the upper aero-digestive tract and tend to metastasize to regional lymph nodes, rather than to spread hematogenously. It is widely accepted that the presence of lymph node metastases is the most important prognostic factor in head and neck squamous cell carcinoma (HNSCC). Thus, the assessment of cervical nodes is an important step in both pre-operative and post-operative management of HNSCC patients and neck dissection is considered both a staging and a curative procedure (for a review, see Snow and Bartelink, 1995). Detection of metastases is routinely performed by histopathological analysis and the frequency of early metastatic relapse indicates that a number of disseminated tumor cells are undetectable by current methods. It is therefore mandatory to find both a method and a marker to detect and to diagnose microscopic and occult metastases. Recently, polymerase chain reaction (PCR)-based techniques have been applied in an attempt to facilitate detection of micrometastases in lymph nodes and, as a marker, the expression of either tissue-specific and/or tumor-specific molecules has been proposed. Oncogene abnormalities may be considered rational cancer markers, as either mutation or...

The c-MET oncogene encodes the receptor for hepatocyte growth factor/scatter factor (HGF/SF), which is known to stimulate the invasive growth of epithelial cells cultured in vitro. The Met/HGF receptor is a heterodimeric transmembrane tyrosine kinase, which is a prototype for a new family of growth factor receptors. The c-MET oncogene is expressed in several types of epithelial tissue including keratinocytes and is over-expressed in a number of human carcinomas. Studies on various carcinoma cell lines have shown that over-expression and structural alteration of the receptor result in its activation and confer tumorigenesis. We have studied Met/HGF receptor expression in tissue specimens from 34 patients with head and neck squamous cell carcinomas (HNSCC) and in 17 regional lymph node metastases. Western blot analysis was employed, using monoclonal antibodies directed against either the intracellular or extracellular domain of the receptor. Each sample was compared to its normal counterpart. The receptor did not show any major structural alterations in HNSCC tissues, but its expression was increased from 2- to 50-fold in about 70% of tumors. Immunohistochemistry then showed that the same antibodies stained only a few cells in the basal layer of normal squamous epithelium but intensely marked tumor cells. In the lymph node metastases of Met-positive tumors, receptor expression was maintained and sometimes increased with respect to primary tumors. Immunohistochemical analysis of the metastatic lymph nodes showed that cells were negative in the normal lymphatic tissue and strongly stained in tumor cells. Over-expression of the Met/HGF receptor was found at all tumor stages but was more significant in those associated with enlarged or multiple (N2-N3) lymph node metastases. These data show that expression of the Met/HGF receptor may be involved in the progression of HNSCC towards a metastatic phenotype and may be a useful marker of head and neck tumor cell spread to regional lymph nodes.

Summary The efficacy of ten daily injections of 500 or 500,000 U of recombinant interleukin 2 (IL-2) day-' given 1.5 cm from the insertion of the sternocleidomastoid muscle on the mastoid was evaluated in 31 patients with recurrent head and neck squamous cell carcinoma. No toxic effects were noted. One complete response (CR) and three partial responses (PRs) were observed in the 16 patients who received 500 U of IL-2, whereas the higher dose was not effective. The CR was recorded in one of the seven patients with a oropharyngeal recurrence. Partial responses were obtained in 1/5 patients with hypopharyngeal recurrences, in 1/5 patients with oral cavity recurrences and 1/7 patients with laryngeal recurrences. The duration of the responses was 3-5 months and additional courses of ten injections of IL-2 had no further effect.

No abstract

Twenty patients with recurrent, inoperable head and neck squamous cell carcinoma received perilymphatic injections of natural interleukin-2 (nIL-2) for 10 days. Ten patients received 200 units (U) of nIL-2; five 1,000 U; and five 5,000 U. Irrespective of the location of the recurrence, the injections were always performed 1.5 cm below the insertion of the sternocleidomastoid muscle on the mastoid. When the ipsilateral lymphatic chain was still present, they were performed on the same side as the tumor site, whereas when it had been stripped as a result of previous surgery, they were contralateral. Patients who had undergone bilateral neck dissection were injected on the tumor side. Whenever possible, the treatment was repeated after 45-day intervals. In 13 patients (65%) with bilateral or contralateral lymph nodes, complete or partial disappearance of the lesion was observed. Despite these marked responses, the tumor always relapsed, and subsequent IL-2 courses were poorly effective. There were no systemic disturbances during or after treatment, but only moderate local swelling and pain.

The phenotypical and functional aspects of tonsillar (TMNC) and peripheral blood mononuclear cells (PBMNC) obtained from 40 patients who had undergone adeno-tonsillectomy for different tonsillar diseases were investigated. TMNC and PBMC were separately tested at the time of surgery; then a further investigation on the peripheral blood lymphocytes was performed three months after surgery. The most interesting findings are presented and discussed with particular attention to their clinical implications.

IL2Rs, in the presence of IL2, mediate activation and proliferation of human normal lymphocytes and modulate functional changes of some human leukocytic malignancies. IL2Rs have been demonstrated also on human neoplastic and fetal non-hematologic cells in vitro, although their functional role has not been described. We describe the presence of high affinity IL2Rs on squamous cell carcinoma of the head and neck (SCCHN) lines in vitro. Expression of 200 binding sites for IL2 with an affinity of 17 x 10(-12) was demonstrated by radiobinding experiments. When cytocentrifuged SCCHN cells were studied by immunoperoxidase staining, strong positive staining was repeatedly obtained using a monoclonal antibody to the p70 subunit of the IL2Rs. Experiments in vitro and in vivo, in a nude mouse model, showed a functional role for these receptors. In fact, low doses (8-500 U/ml) of IL2 were able to inhibit growth of 11 of the 16 SCCHN lines tested. Our observations may have broad implications for the immunotherapy of cancer in general, showing the complementary immunomodulatory and direct effects of IL2.

Clinical, immunological, immunophenotypical, pathological and molecular biological studies were performed on tumor infiltrating lymphocytes (TIL) and lymph node lymphocytes (LN-ly) of 8 patients with squamous cell carcinoma of the oral cavity and oropharynx treated with 10 daily locoregional injections of low doses of IL-2 before surgery. No complications were seen during or after surgery. In 3 cases the LN-ly showed a moderate LAK activity, higher in the LN-ly omolateral to the tumor and near the IL-2 injection site; in 2 of these 3 patients a good LAK activity was induced after 6-day culture with IL-2. The LN-ly derived from nodes next to the tumor showed a decreased NK activity and proliferative ability both in basal conditions and after in vitro lymphokine challenging. LN-ly of 2 IL-2 treated patients showed high levels of mRNA encoding for IL-2-R, while it was absent in 2 untreated cases. Immunophenotypical studies on TIL showed statistically improved levels of CD25+ and LAK1+ cells in treated cases. Clusters of CD11c+ (macrophages) cells were seen close to the neoplastic sheets.