Nodal CT density and total tumor volume as prognostic factors after radiation therapy of stage III/IV head and neck cancer

Prognostic significance of cervical lymph nodes density evaluated by contrasted computer tomography in head and neck squamous cell carcinoma treated with hyperthermia and radiotherapy

INTRODUCTION

A correlation between node hypodensity assessed by means of computer tomography (CT) and resistance to both chemotherapy and radiation therapy (XRT) in advanced head and neck tumours has been suggested in the literature. The outcome of a retrospective series of 50 patients with head and neck squamous cell carcinoma (SCC) and cervical nodes metastases treated with combined hyperthermia (HT) and definitive XRT was reviewed to investigate if node density confirmed its prognostic value.

MATERIALS AND METHOD

For all patients, a pre-treatment contrasted CT scan performed at the Institution between 1987-1993 was available. The density of the largest node (> 2cm) was compared to that of adjacent nuchal muscles. Nodes with hypodense areas present in more than one third of the total volume were considered necrotic nodes.

RESULTS

The patients were divided in two groups (with and without nodal necrosis), well balanced in terms of potential prognostic factors. No significant difference in overall nodal response rate, local control and survival was found in the two groups of patients.

CONCLUSION

Nodal density assessed by contrasted CT scan in the series did not result in a significant prognostic factor in patients with SCC node metastases treated with HT and XRT. It is suggested that HT could act as a radiosensitizer in the treatment of hypodense (at CT scan) metastatic nodes overcoming the radioresistance of necrotic, presumably hypoxic nodal metastases.

Squamous cell carcinoma of the oropharynx: Ki-67 and p53 can identify patients at high risk for local recurrence after surgery and postoperative radiotherapy

PURPOSE

To assess the prognostic value of biologic (p53, Ki-67) and clinical factors in squamous cell carcinoma of the oropharynx after radical surgery and postoperative radiotherapy (RT).

METHODS AND MATERIALS

Between 1985 and 1995, a total of 102 patients with 104 tumor sites were entered onto the study. Fifty-five primary tumors (53%) involved the tonsils, 26 (25%) the soft palate, and 23 (22%) the base of the tongue. Median age was 53 years (range 36-80 years). The clinical T- and N-categories (UICC 1997) were: T1 (30), T2 (47), T3 (22), T4 (5), N0 (33), N1 (28), N2 (42), and N3 (1). Histologically-clear margins were achieved in all patients by initial surgery. Postoperative RT to the primary and regional lymphatics was given, to a total of 60 Gy in 6 weeks, and single daily fractions of 2 Gy. The expression of the nuclear p53- and Ki-67-labeling index (LI) was investigated by immunostaining using the monoclonal antibodies DO-7 and MIB 1. The nuclear p53-intensity (p53-I) was graded into 4 categories (0/+/++/) by densitometry. Median follow-up was 43 months (range 14-132 months).

RESULTS

Cancer-specific survival, disease-free survival, and locoregional tumor control rates were 74%, 69%, and 75%, respectively, at 5 years. Significant prognostic factors for disease-free survival were: T-category (T1/2: 77% vs. T3/4: 53%, p = 0.02), tumor site (tonsils: 79% vs. soft palate: 70% vs. base of tongue: 45%, p = 0.05), duration of RT (< or = 46 days: 80% vs. > 46 days: 60%, p = 0.04), Ki-67 LI (< or = 20%: 84% vs. > 20%: 49%, p = 0.006) and p53-I (0/+: 56% vs. ++/ : 79%, p = 0.008). A significant prognostic impact on locoregional control was noted for the duration of RT (< or = 46 days: 86% vs. > 46 days: 68%, p = 0.01), tumor site (tonsils: 88% vs. soft palate: 67% vs. base of tongue: 51%, p = 0.02), Ki-67 LI (< or = 20% LI: 87% vs. > 20% LI: 56%, p = 0.018), and the p53-I (0/+: 58% vs. ++/ : 88%, p = 0.0006). On multivariate analysis, the p53 nuclear intensity (p = 0.002) and the Ki-67 index (p = 0.01) remained the only significant factors for locoregional control.

CONCLUSION

Ki-67 labeling index above 20% and a weak p53 nuclear intensity (0/+) are both able to identify patients with squamous cell carcinoma of the oropharynx being at high risk for local recurrence after surgery and postoperative RT. Consequently, in this subgroup an intensification of treatment may be contemplated in prospective trials.

Head and neck cancer: the importance of oxygen

OBJECTIVES

To use recently introduced polarographic technology to characterize the distribution of oxygenation in solid tumors, explore the differences between severe hypoxia and true necrosis, and evaluate the ability to predict treatment outcomes based on tumor oxygenation.

STUDY DESIGN

Prospective, nonrandomized trial of patients with advanced head and neck cancer, conducted at an academic institution.

METHODS

A total of 63 patients underwent polarographic oxygen measurements of their tumors. Experiment 1 was designed to determine whether a gradient of oxygenation exists within tumors by examining several series of measurements in each tumor. Experiment 2 was an analysis of the difference in data variance incurred when comparing oxygen measurements using oxygen electrodes of two different sizes. Experiment 3 compared the proportion of tumor necrosis to the proportion of very low (< or =2.5 mm Hg) polarographic oxygen measurements. Experiment 4 was designed to explore the correlation between oxygenation and treatment outcomes after nonsurgical management.

RESULTS

No gradient of oxygenation was found within cervical lymph node metastases from head and neck squamous cell carcinomas (P > .9). Tumor measurements achieved with larger (17 microm) electrodes displayed smaller variances than those obtained with smaller (12 microm) electrodes, although this difference failed to reach statistical significance (P = .60). There was no correlation between tumor necrosis and the proportion of very low (< or =2.5 mm Hg) oxygen measurements. There was a nonsignificant trend toward poorer locoregional control and overall survival in hypoxic tumors.

CONCLUSIONS

Hypoxia exists within cervical lymph node metastases from head and neck squamous carcinomas, but the hypoxic regions are distributed essentially randomly. As expected, measurements of oxygen achieved with larger electrodes results in lowered variance, but with no change in overall tumor mean oxygen levels. Polarographic oxygen measurements are independent of tumor necrosis. Finally, oxygenation as an independent variable is incapable of predicting prognosis, probably reflecting the multifactorial nature of the biological behavior of head and neck cancers.

Paranasal sinuses and nasopharynx CT and MRI

Neoplastic disease of the nose, paranasal sinuses, the nasopharynx and the parapharyngeal space requires thorough assessment of location and extent in order to plan appropriate treatment. CT allows the deep soft tissue planes to be evaluated and provides a complement to the physical examination. It is especially helpful in regions involving thin bony structures (paranasal sinuses, orbita); here CT performs better than MRI. MRI possesses many advantages over other imaging modalities caused by its excellent tissue contrast. In evaluating regions involving predominantly soft tissue structures (ec nasopharynx and parapharyngeal space) MRI is superior to CT. The possibility to obtain strictly consecutive volume data sets with spiral CT or 3D MRI offer excellent perspectives to visualize the data via 2D or 3D postprocessing. Because head and neck tumors reside in a complex area, having a 3D model of the anatomical features may assist in the delineation of pathology. Data sets may be transferred directly into computer systems and thus be used in computer assisted surgery.

Hypoxic cytotoxic agents: a new approach to cancer chemotherapy

Many of the cells in solid tumors are hypoxic. This makes them resistant to killing by both radiotherapy and most commonly used anticancer drugs. The resistance towards anticancer drugs is because hypoxia induces a non-proliferative state as well as the fact that the hypoxic cells are furthest from the blood vessels in the tumor (and hence the source of drug). However, a new class of drugs - hypoxic cytotoxins can, by killing these hypoxic cells, not only overcome this resistance, but also exploit hypoxia thereby converting it into a therapeutic advantage. The first drug to be tested in the clinic purely for its activity towards hypoxic cells, tirapazamine, is described. Copyright 2000 Harcourt Publishers Ltd.

Prognostic impact of total tumor volume and hemoglobin concentration on the outcome of patients with advanced head and neck cancer after concomitant boost radiochemotherapy

PURPOSE

To identify prognostic clinical and treatment related factors for local control, distant metastasis-free survival, and survival by means of a multivariate analysis in patients with advanced squamous cell carcinoma of the head and neck after concomitant boost radiochemotherapy.

PATIENTS AND METHODS

From 1992 to 1995, 68 patients with squamous cell cancer of the head and neck (93% stage IV disease) were treated with a simultaneous radiochemotherapy with Carboplatin using a concomitant boost technique. The total tumor volume (TTV) was quantitatively determined based on computed tomography scans in 56 patients. A Cox proportional hazards regression analysis was performed for each of the above endpoints and statistical significance of the Cox models was verified using the likelihood ratio test and Bonferroni correction for multiple testing.

RESULTS

The survival and locoregional control rates at three years were 35 and 32%. The multivariate analysis revealed a significant association between the TTV and survival (P = 0.0008) and between the pretreatment serum hemoglobin concentration and locoregional control (P = 0.01) and survival (P = 0.05). The locoregional control was significantly associated with the N-stage (P = 0.007) and there was a good correlation between the N-stage and TTV in this study population.

CONCLUSION

Our data corroborate the prognostic relevance of the tumor volume and hemoglobin concentration. In studies comparing the survival of patients with advanced cancer of the head and neck, the use of the TTV as a covariable may improve the statistical power.

Surfing prognostic factors in head and neck cancer at the millennium

The ability to reliably predict cancer outcome could tailor therapy to the aggressiveness of the tumour to achieve the best results in terms of loco-regional control, overall survival and quality of life. Retrospective and prospective clinical trials involving large series of patients have validated some predictive clinical and pathological factors, whereas the utility of many other prognostic factors has not been established. This has led to some confusion in clinical practice. In order to clarify the significance, role and cost of these prognostic factors we carried out a Medline search of all papers published between 1993 and 1998 concerning the reliability and cost of markers with prognostic significance, in head and neck squamous cell carcinoma, and assessed the results according to a number of criteria relating to reliability and cost. Regarding reliability we classified prognostic factors into: (1) those with a proven significance based on the fact that they were unanimously reported as having an independent statistical correlation with outcome and prognosis; and (2) those for which results were not unanimous, and which significance is still controversial. Cost analysis showed a substantial difference between validated tests which are of low cost and experimental tests which are expensive. Based on these data regarding both the reliability and cost of each prognostic factor, we propose guidelines for their use in clinical practice in the year 2000.

Local-regional control by conventional radiotherapy according to tumor volume in patients with squamous cell carcinoma of the pharyngolarynx

BACKGROUND

To estimate the effect of tumor volume on local-regional control of pharyngolaryngeal cancer by radiotherapy (RT).

METHODS

Definitive RT for 48 patients with squamous cell carcinoma of the lateral wall of the oropharynx, pyriform sinus and supraglottic larynx was reviewed. Tumor volume was estimated from computed tomography and it was expressed as the diameter of a sphere the volume of which is equal to the primary tumor (Td) and sum of the volumes of metastatic adenopathies (Nd). All patients received > or =60 Gy (median 66 Gy) to the gross tumor by conventional fractionation with or without chemotherapy.

RESULTS

A median period of follow-up for survivors was 32.7 months (range, 12.4-68.6). The 2 year local control rate for T1/2 (n = 30) and T3/4 (n = 18) patients was 72 and 65%, respectively (P= 0.966), however, the rates for Td < 4 cm tumors (n = 37) and Td > or = 4 cm tumors (n = 11) were significantly different (80% vs 27%, P < 0.001). The 2 year regional control rates for Nd < 3 cm lesions (n = 29) and Nd > or = 3 cm (n = 19) lesions were 85 and 42%, respectively (P < 0.001). The 2 year ultimate regional control rates for N2/3 disease with Nd < 4 cm (n = 11) and Nd > or = 4 cm (n = 11) were 100 and 42%, respectively (P = 0.004).

CONCLUSIONS

Conventional radiotherapy may allow organ preservation and ultimate local control in patients with Td < 4 cm and Nd < 4 cm disease, but larger volume tumors should be considered candidates for the most intensive chemoradiotherapy.

[Simultaneous radiochemotherapy with carboplatin in patients with inoperable advanced stage III and IV head and neck tumors]

BACKGROUND

The results of treating advanced tumors in the head and neck region with radiotherapy alone are disappointing. Concurrent radiotherapy and chemotherapy may improve this situation. The treatment results of concurrent radiochemotherapy at the University of Rostock were analyzed retrospectively.

PATIENTS AND METHODS

From 1991 to 1996 92 patients with head and neck tumors were treated with concurrent radiochemotherapy (1.8 to 63 Gy; 70 mg/m2 carboplatin day 1 to 5 and 29 to 33) with palliative tumor resection (n = 37) or without surgical treatment (n = 55). Remission rate, overall survival and disease-free survival, local control and acute toxicity were analyzed.

RESULTS

Six weeks after radiochemotherapy 56.5% of patients had a complete remission, 36% a partial remission and 7.5% "no change". With a median follow-up of 42 months (6 to 74 months) overall survival, disease-free survival and local control were 24.3%, 28.9%, 18.0% 5 years after treatment. All these criteria were significantly better in patients with palliative tumor resection compared to no surgical treatment (uni- and multivariate) and in patients with Stage III than in patients with Stage IV carcinomas (univariate), overall survival was significantly better in patients with Stage III (multivariate). A pretherapeutic Hb level below 7.0 mmol/l (11.27 g/dl) reduced the local control significantly (uni- and multivariate). Grade III and IV mucositis was detected in 10%, Grade III leucopenia in 12% of treated patients. Grade IV leucopenia and Grade III thrombopenia were observed in 1 patient each.

CONCLUSION

The toxicity of this treatment is tolerable. However, additional trials must be conducted before considering the palliative tumor resection as standard therapy.