Assessment and Clinical Significance of Micrometastases in Lymph Nodes of Head and Neck Cancer Patients Detected by E48 (Ly-6D) Quantitative Reverse Transcription-Polymerase Chain Reaction

Abstract

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

Detection of Cervical Lymph Node Micrometastases in Patients with Squamous Cell Carcinoma of the Oral Cavity, Pharynx and Larynx

“…On the other hand, the presence of micrometastases is clinically significant (8,(18)(19)(20). Nieuwenhuis et al found that the survival of patients with cN0 but with one or more micrometastases (detected by molecular analysis) was worse compared to patients without micrometastases (10). Similar results were published by Xu et al (18)(19) and Yamazaki et al (21).…”

Molecular Staging of Cervical Lymph Nodes in Squamous Cell Carcinoma of the Head and Neck

“…Although the speed of the GeneXpert allows for intraoperative analysis of SLNs there may also be additional clinical value if QRT-PCR eventually proves superior to routine pathology, as suggested by Nieuwenhuis et al (33). The detection of occult lymph node disease, and subsequent improved patient staging (28), could have significant consequences for the treatment of SCCHN.…”

“…In head and neck cancer specifically, studies on molecular analysis of cervical lymph node metastasis have used a variety of techniques, including PCR amplification to detect p53 mutations (45), immunohistochemistry staining (with or without serial sectioning) and histopathologic examination (14)(15)(16), and standard RT-PCR-based analysis of tumor maker gene expression (46). More recently, several groups have used quantitative RT-PCR for detection of cervical lymph node metastases (8,47) and Nieuwenhuis et al showed the prognostic value of QRT-PCR in pN0 SCCHN patients (33). This same group also showed the potential for molecular staging of cervical nodes by using tissue obtained via fine-needle aspiration (29).…”

“…Studies in many tumor types including esophageal cancer, colon cancer, breast cancer, melanoma, and SCCHN have showed the ability of an RT-PCR-based assay to detect histologically occult micrometastases (7,9,(26)(27)(28)(29). Many of the earlier RT-PCR studies suffered from poor specificity, but the introduction of real-time quantitative RT-PCR (QRT-PCR) has helped overcome this problem and provides the potential for objective and quantitative analysis of lymph nodes (30)(31)(32)(33). Whereas we are also interested in detection of occult disease by QRT-PCR, we have recently focused on application of this method to rapid, intraoperative analysis of SLNs.…”

Can Early Dissection of Cervical Lymph Nodes Improve Prognosis in Squamous Cell Carcinomas of the Hard Palate

“…Micrometastases are not infrequent with head and neck SCCs [19], and their reported occurrence in the oral cavity is 21.9% [22]. There is no consensus on the relevance of micrometastases to survival, but our recent studies indicate that prognosis is worse when micrometastases are present [23]. …”