Predictive value of the flow cytometric PCNA assay (proliferating cell nuclear antigen) in head and neck tumors after accelerated-hyperfractionated radiochemotherapy

Secretory activity and cell cycle alteration of alveolar type II cells in the early and late phase after irradiation

PURPOSE

Type II cells and the surfactant system have been proposed to play a central role in pathogenesis of radiation pneumonitis. We analyzed the secretory function and proliferation parameters of alveolar type II cells in the early (until 24 h) and late phase (1-5 weeks) after irradiation (RT) in vitro and in vivo.

METHODS AND MATERIALS

Type II cells were isolated from rats according to the method of Dobbs. Stimulation of secretion was induced with terbutaline, adenosine triphosphate (ATP), and 12-O-tetradecanoylphorbol-13-acetate (TPA) for a 2-h period. Determination of secretion was performed using (3)H-labeled phosphatidylcholine. For the early-phase analysis, freshly isolated and adherent type II cells were irradiated in vitro with 9-21 Gy (stepwise increase of 3 Gy). Secretion stimulation was initiated 1, 6, 24, and 48 h after RT. For late-phase analysis, type II cells were isolated 1-5 weeks after 18 Gy whole lung or sham RT. Each experiment was repeated at least fivefold. Flow cytometry was used to determine cell cycle distribution and proliferating cell nuclear antigen index.

RESULTS

During the early-phase (in vitro) analysis, we found a normal stimulation of surfactant secretion in irradiated, as well as unirradiated, cells. No change in basal secretion and no dose effect were seen. During the late phase, 1-5 weeks after whole lung RT, we observed enhanced secretory activity for all secretagogues and a small increase in basal secretion in Weeks 3 and 4 (pneumonitis phase) compared with controls. The total number of isolated type II cells, as well as the rate of viable cells, decreased after the second post-RT week. Cell cycle alterations suggesting an irreversible G(2)/M block occurred in the second post-RT week and did not resolve during the observation period. The proliferating cell nuclear antigen index of type II cells from irradiated rats did not differ from that of controls.

CONCLUSION

In contrast to literature data, we observed no direct effect of radiation on secretory activity in the early phase after RT. In our study of isolated type II cells, as well as in intact animals, RT did not result in an impaired surfactant secretion up to 5 weeks after RT. Our in vivo experiments even showed an increased response of phosphatidylcholine secretion to all known secretagogues at Weeks 3 and 4 after whole lung RT, possibly due to inflammatory cytokines. Cell cycle alterations with G(2)/M block and cell loss in the late post-RT period may contribute more to the manifestation of radiation-induced lung damage than functional impairment in type II cells.

Role of multimodal treatment in oropharynx, larynx, and hypopharynx cancer

Due to recent advances in radiation fractionation, radiochemotherapy, and conservative surgical techniques, the concept of multimodal therapy in head and neck cancer is currently changing. The recently published RTOG Phase III trial 9003, with 1,113 patients accrued, showed that hyperfractionation and accelerated fractionation with concomitant boost are more efficacious than standard fractionation for locally-advanced head and neck cancer. Acute, but not late, toxicity was also increased. Three meta-analyses have suggested that the impact of chemotherapy in head and neck cancer is small but is highly associated with the timing of therapy. Concomitant administration of radiation therapy and chemotherapy led to an absolute benefit in 5-year survival of about 10%. This finding has been further supported by recently published randomized prospective trials comparing concomitant radiochemotherapy with radiotherapy alone in advanced head and neck cancer. There is now clear evidence that radiochemotherapy provides a substantial and statistically significant improvement in survival and local-regional control, as compared to radiotherapy alone. Radiochemotherapy should be considered an accepted standard of care in cancers of the oropharynx, particularly for patients with locally-advanced disease who have a good performance status. Two randomized studies conducted by the Department of Veterans' Affairs and the EORTC, with a total of 534 patients accrued, showed that induction chemotherapy followed by radiotherapy of responders yields survival rates equal to those of total laryngectomy with postoperative radiotherapy. After 4 years, one-half to two-thirds of survivors of the chemotherapy arm retained a functional larynx. Larynx preservation using induction chemotherapy can now be regarded as feasible but still investigational. Current phase II studies show excellent larynx preservation rates using a primary concomitant radiochemotherapy with an altered fractionation regimen. More clinical and laboratory research is required to further evaluate the different treatment options of the multimodality concept, and to develop prognostic models that will allow individualization of the therapy.

Prognostic relevance of serum levels of the angiogenic peptide bFGF in advanced carcinoma of the head and neck treated by primary radiochemotherapy

BACKGROUND

The objective of this trial was to analyze the prognostic relevance of the angiogenic peptides basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and matrix metalloproteinase-2 (MMP-2) in the serum of patients with advanced carcinoma of the head and neck treated by primary radiochemotherapy.

METHODS

From 1992 to 1995, 26 patients with advanced head and neck cancer (25 stage IV, 1 stage III UICC) were treated according to the protocol of radiochemotherapy with carboplatin. The pretreatment serum levels VEGF, bFGF, and MMP-2 were measured by ELISA, and data were correlated with tumor characteristics and followed up (median time of follow up, 60 months).

RESULTS

An increase in bFGF serum level above the upper limit of normal controls showed a significant correlation with shorter time the of locoregional control (p =.036). In covariant analysis bFGF serum concentration proved to be independent of other prognostic factors like tumor site, age, total tumor volume, and response to therapy. No prognostic relevance of VEGF and MMP-2 serum levels could be determined.

CONCLUSIONS

The results of this pilot study indicate that the serum concentration of bFGF has prognostic relevance for advanced head and neck cancer.

Oxygenation of Advanced Head and Neck Cancer: Prognostic Marker for the Response to Primary Radiochemotherapy

Recent clinical studies suggest that the degree of tumor oxygenation may be predictive of the response of radiation therapy for cancer. In an exploratory investigation of cervical lymph node metastases in 27 patients with advanced squamous cell carcinoma of the oropharynx and hypopharynx, this relationship was investigated by means of oxygen measurements with an Eppendorf Po2 histograph. The measurements were made before the start of radiation therapy and after the first week of therapy. Clinical response was evaluated 6 weeks after the completion of therapy. Before therapy, marked hypoxia was observed in the lymph node metastases, with a mean Po2 value of 16.1 ± 8.2 mm Hg and a hypoxic fraction (Po2 < 10 mm Hg) of 56.4% ± 20.0%. After the first week of radiation (9 Gy) there was a general reoxygenation (ΔPo2 = 5.0 ± 10.1 mm Hg, P < 0.05; Δhypoxic fraction = −11.3% ± 31.3%, P = 0.11). A relationship between the degree of reoxygenation and tumor response was not observed. Patients without at least partial lymph node response (n = 8) showed poorer pretherapeutic oxygenation (Po2 mean = 11.1 ± 2.9 mm Hg) than those who responded to the therapy (n = 19, PO2 mean = 18.2 ± 8.8 mm Hg). In this investigation of a defined set of patients with advanced carcinoma of the oropharynx and hypopharynx, we found that pretherapeutic oxygenation data are predictive for the therapeutic response to radiation therapy or radiochemotherapy.

Prognostic assessment of sonography and tumor volumetry in advanced cancer of the head and neck by use of doppler ultrasonography

OBJECTIVE

The objective of this trial was to examine the degree of tumor vascularity in lymph node metastases as depicted by computer-assisted color Doppler sonography and the tumor volumes associated with prognosis in carcinomas of the oropharynx and hypopharynx after primary radiochemotherapy.

PATIENTS AND METHODS

In a prospective trial, 25 patients with advanced squamous cell carcinomas of the oropharynx and hypopharynx (stage IV UICC 1997) were treated with radiochemotherapy. The color Doppler findings were quantified with a computer-assisted protocol that quantitatively describes color Doppler images by the relative color pixel density (CPD). As important prognostic cofactor, total tumor volume (TTV) was calculated from CT sections and related to the degree of vascularity.

RESULTS

Low CPD in neck metastases showed a correlation with better overall survival. A high-CPD group and a high-TTV group (median survival 10.1 months) were determined and were compared with all other CPD/TTV combinations (median survival 28.4 months); the difference in survival was significant (P = 0.002).

CONCLUSION

The results indicate that high tumor vascularity in combination with high TTV indicates a particularly bad prognosis in patients treated with primary radiochemotherapy for head and neck cancer.

The prognostic value of proliferating cell nuclear antigen (PCNA) in the advanced cancer of larynx

It was retrospectively examined whether the tumor growth fraction determined by PCNA score in the advanced cancer of larynx could be used as a prognostic factor. There was used immunohistochemical method to evaluate the PCNA score of positive cells in paraffin embedded tissues of laryngeal carcinoma obtained from 90 patients. They were treated by surgery in the Department of Otolaryngology at the Medical University in Cracow, Poland in 1987 and 1988. The follow-up period was not shorter than 5 years. In the examined material there were 59 patients with tumor T3 and 31 with T4. Neck dissection on one or on both sides was performed on patients. The metastases in regional lymph nodes was found in 26 patients. Histologic grading (G1 = 18, G2 = 52 and G3 = 20 patients) and number of mitosis was assessed. The PCNA score was defined by counting positive cells and presented as percentage of a cells. It ranged from 2.1 to 73.0% with the average value of 34.5%. The PCNA score below this level was defined as a low PCNA score (49 patients) and above this level as a high PCNA score (41 patients). There was a correlation between PCNA score and survival of the patients. 35 patients (71.4%) with low PCNA score survived and 15 (36.6%) with high PCNA score (P < 0.05). Similarly the high PCNA score influenced the number of metastases in lymph nodes. They occurred in low and high PCNA score respectively at nine (18.4%) and 17 patients (41.5%) (P < 0.05). There was not found any correlation between PCNA score and tumor differentiation, its size and mitosis number. The PCNA may be a prognostic factor for the patients with advanced cancer of larynx.

Prognostic significance of color Doppler findings in head and neck tumors

We examined whether or not the degree of tumor vascularity in lymph node metastases as depicted by color Doppler is associated with a patient's prognosis. Cervical lymph node metastases in 25 patients with head and neck cancer were examined before combined accelerated radiotherapy and chemotherapy. The findings were quantified using a computer-assisted protocol that quantitatively describes color Doppler images by the relative color pixel density (CPD) and the color hues, which are numerically expressed by the mean color value (MCV). We found that, in the patient group with a CPD below median, the median survival was 958 days and, in the group with a higher CPD, it was 423 days (p = 0.05). The time to detection of distant metastases was 18 months with a low CPD, and 6 months with a high CPD (p = 0.05). However, the time to local or nodal progression was not different between the groups. The MCV was not correlated with prognostic data. These results indicate that, in patients with metastatic head and neck cancer, highly vascularized lymph nodes detected with color Doppler sonography may indicate a shorter survival and earlier occurrence of distant metastases.