Impact of metastases on nodal immunoreactivity in head and neck cancer

Does unnecessary elective neck treatment affect the prognosis of N0 laryngeal cancer patients?

OBJECTIVE

Among detractors of elective neck (N0) treatments, most suggest that lymphadenectomy removes a barrier to the spread of disease with deleterious immunologic consequences. To test this hypothesis we performed a retrospective comparison of the survival results of N0 laryngeal cancer patients who received unnecessary elective neck treatments (N0-) and those of N0 patients subjected to close and regular follow-up.

MATERIAL AND METHODS

A retrospective chart review of 749 N0 laryngeal cancer patients treated at the Institute of Otolaryngology-Head and Neck Surgery, University of Florence between January 1980 and January 1993 was performed. Of these, 245 (33%) received elective neck dissection (ED), while the remaining 504 (67%) N0 patients were subjected to close and regular follow-up (wait-and-see policy; WS).

RESULTS

Of the 245 ED patients, 43 (17.5%) showed an occult neck disease, while of the 504 WS subjects, 83 (17%) developed neck metastases during follow-up. Moreover, 15 ED patients subsequently experienced a contralateral occult failure despite a unilateral negative neck specimen (N0-). Thus, ultimately 187 ED (164 of whom were treated unilaterally and 23 bilaterally) and 421 WS patients were used for survival analysis. No differences in terms of postoperative complications, local or distant failure or disease-free or overall actuarial survival were found between the two groups analyzed.

CONCLUSIONS

These data indicate that unilateral or bilateral removal of cervical lymphatics in the absence of histologically proven lymph node metastases does not negatively affect the prognosis of N0 laryngeal cancer patients who were overtreated to the neck.

Immunological approach in the evaluation of regional lymph nodes of patients with squamous cell carcinoma of the head and neck

In cancer, regional lymph node (LN) cells are one of the first components of the immune system to have contact with tumor cells or their products. Therefore, the phenotype and functional properties of hematopoietic cells present within the tumor-draining LN are important to understanding their role in the control of malignant cells. Based on the locoregional metastatic behavior of squamous cell carcinoma of the head and neck (SCCH&N) region, we analyzed tumor-draining lymph nodes from SCCH&N patients to obtain insights into regional tumor immunity. Using a three-color fluorescent labeling technique, surface antigen expression was visualized in mononuclear cells of lymph nodes that were obtained from head and neck cancer patients and compared to mononuclear cells of normal lymph nodes. Cell cycle analyses were performed using propidium iodide. Proliferation after phytohemagglutinin stimulation was measured by a sodium tetrazolium-based assay. LN histology was correlated with flow cytometric findings. Regional lymph nodes of head and neck cancer patients undergo morphologic and functional changes. Flow cytometry revealed a decrease in CD8(+) T cells and in some lymph nodes the presence of second or third populations of larger cells with distinct size and granularity that expressed both T (gammadelta/alphabeta) and different natural killer cell markers. Moreover, cell cycle analyses and proliferation assays showed a diminished response to mitogenic stimuli. These changes were found in both metastatic and hyperplastic lymph nodes from head and neck cancer patients; however, no alterations were found in control lymph nodes or peripheral blood mononuclear cells from noncancer patients. The immune alterations detected in lymphocytes present within the draining lymph nodes of head and neck cancer patients may improve our understanding of how tumor cells escape host immunosurveillance. However, this dysfunction in local draining lymph nodes may not be detected systemically.

Interleukin-2 mediated regulation of mitogen-activated T cell reactivity from different lymphoid sources in patients with squamous cell carcinoma of the oral cavity

Peripheral blood lymphocytes (PBL) from patients with oral cancer (treated and untreated), oral leukoplakia and healthy donors; lymphocytes from metastatic and non-metastatic lymph nodes (met LNL and non-met LNL); and tumor infiltrating lymphocytes (TIL) were tested for proliferative response to mitogen PHA (phytohemagglutinin) and its augmentation by recombinant Interleukin-2 (rIL-2), for expression of Tac antigen (CD25) and for production of IL-2. Depressed PHA responses were found in PBL of treated and untreated patients, and in TIL. Addition of IL-2 could bring about 16% to 31% augmentation in lymphocyte response to PHA from all the three sources. PBL from 50% of healthy donors, 45% of patients with leukoplakia, 25% untreated oral cancer patients and 35% treated oral cancer patients showed IL-2 mediated augmentation of PHA response. While, 40% non-met LNL samples, 70% met LNL samples and only 23% TIL samples showed increased mitogen induced proliferation by IL-2. The augmented levels of PHA response of PBL from treated and untreated patients, and of TIL, were still below those of normal PBL. PBL from patients with leukoplakia, treated oral cancer patients and TIL showed depressed CD25 antigen expression. Depressed IL-2 production was observed only in PBL of leukoplakia patients. Thus the IL-2 mediated events of T cell activation from different lymphoid sources in patients with oral cancer did not correlate with their proliferative responses.