Functional organ preservation in locally advanced laryngeal squamous cell carcinoma: is there a role for induction chemotherapy?

Concurrent chemoradiation (CRT) is currently the most effective strategy for organ preservation in locally advanced laryngeal squamous cell carcinoma (SCC) unsuitable for function-preserving surgery. The larynx preservation approach of induction chemotherapy followed by radiotherapy in responders is based on the hypothesis that tumours that show a satisfactory response to induction chemotherapy are more likely to respond to radiation-based treatment. This enables the use of chemotherapy response to identify patients who are more likely to achieve long-term disease control with organ-preserving therapies. An induction chemotherapy response allows prognostication, outcome prediction and treatment selection in patients with locally advanced laryngeal SCC. Excellent survival outcomes have been achieved with induction chemotherapy followed by CRT as definitive therapy in responders. The addition of docetaxel to cisplatin and 5-fluorouracil induction chemotherapy has also resulted in higher larynx preservation rates. Future organ preservation studies should assess whether induction chemotherapy with docetaxel, cisplatin and 5-fluorouracil followed by CRT in responders improves survival compared with an unselected approach of primary CRT in all eligible patients with T2 or T3 laryngeal SCC. The primary end point of such studies should be laryngo-oesophageal dysfunction-free survival, which focuses on the treatment goals of survival, disease control and laryngeal-oesophageal function after therapy. In addition, the inclusion of patients with N2 or N3 disease will help to determine whether the addition of docetaxel, cisplatin and 5-fluorouracil to CRT reduces the incidence of distant relapse in advanced laryngeal SCC. Other areas of interest include the use of concurrent cetuximab in place of platinum-based chemotherapy with radiotherapy in larynx preservation and the search for better predictive markers of successful larynx preservation than induction chemotherapy response.

Target volume definition for intensity-modulated radiotherapy after induction chemotherapy and patterns of treatment failure after sequential chemoradiotherapy in locoregionally advanced oropharyngeal squamous cell carcinoma.

AIMS: To validate our approach to target volume definition for intensity-modulated radiotherapy (IMRT) after induction chemotherapy and to analyse the pattern of treatment failure in patients with locoregionally advanced oropharyngeal squamous cell carcinoma (SCC) after sequential chemoradiotherapy (SCRT). MATERIALS AND METHODS: We studied all patients with locoregionally advanced oropharyngeal SCC treated with SCRT, definitive IMRT and no prior surgery between December 2004 and February 2010. SCRT consisted of three cycles of induction chemotherapy followed by IMRT with concurrent weekly chemotherapy. Our approach to IMRT tumour volume definition after induction chemotherapy was similar to recommendations from published clinical practice guidelines. Volumetric expansion was used to create the high-dose clinical target volume with a margin of 10 mm. The high-dose planning target volume (PTV) was treated to 65 Gy, whereas the prophylactic-dose PTV received 54 Gy over 30 fractions using the simultaneous integrated boost technique. The location and extent of each treatment failure was recorded, reconstructed on the planning computed tomography images and analysed using the dose distribution of the IMRT plan. RESULTS: Fifty-two patients were included. The median follow-up was 32.2 months (range 5.0-67.1 months). There were seven local failures, no regional recurrences and one with distant disease. None of the patients required post-treatment neck dissection. All local failures were in-field and occurred within the high-dose PTV. There were no marginal recurrences. Actuarial recurrence-free, disease-specific and overall survival rates at 3 years were 83.9, 85.9 and 79.7%, respectively. CONCLUSIONS: The absence of marginal recurrences validated the approach to IMRT target volume definition after induction chemotherapy proposed by clinical practice guidelines and practised at our institution. It suggested a lack of benefit with the use of larger geometric margins and additional anatomical expansion for the high-dose clinical target volume. SCRT resulted in excellent regional and distant disease control in patients with locoregionally advanced oropharyngeal SCC.

Feasibility and tolerance of sequential chemoradiotherapy in squamous cell carcinoma of the head and neck.

This paper evaluates the feasibility and tolerance of sequential chemoradiotherapy in patients with squamous cell carcinoma of the head and neck and ascertains whether the use of induction chemotherapy compromises delivery of subsequent radiotherapy with or without concurrent chemotherapy. We also compared sequential chemoradiotherapy treatment adherence between the elderly and younger patients with squamous cell carcinoma of the head and neck. One hundred and ninety-four patients with head and neck squamous cell carcinoma who received induction chemotherapy with cisplatin and 5-fluorouracil were included in this study. Treatment-related death rate from induction chemotherapy was 1.5%. One hundred and ninety-one patients (98.5%) proceeded to radical radiotherapy, with 90.1% also receiving planned concomitant chemotherapy. One hundred and seventy-eight patients (93.2%) completed radiotherapy with no prolongation of the treatment duration. There were no statistical differences in sequential chemoradiotherapy treatment adherence and tolerance between the elderly and younger patients apart from the proportion who required hospitalisation during radiotherapy. Induction chemotherapy in head and neck squamous cell carcinoma does not compromise delivery of definitive radiotherapy with or without concurrent chemotherapy. Elderly patients with head and neck squamous cell carcinoma are able to tolerate aggressive treatments such as sequential chemoradiotherapy. Treatment 'deintensification' based solely on chronological age is not recommended.

Interobserver variation in parotid gland delineation: a study of its impact on intensity-modulated radiotherapy solutions with a systematic review of the literature.

OBJECTIVES: This study evaluates the interobserver variation in parotid gland delineation and its impact on intensity-modulated radiotherapy (IMRT) solutions. METHODS: The CT volumetric data sets of 10 patients with oropharyngeal squamous cell carcinoma who had been treated with parotid-sparing IMRT were used. Four radiation oncologists and three radiologists delineated the parotid gland that had been spared using IMRT. The dose-volume histogram (DVH) for each study contour was calculated using the IMRT plan actually delivered for that patient. This was compared with the original DVH obtained when the plan was used clinically. RESULTS: 70 study contours were analysed. The mean parotid dose achieved during the actual treatment was within 10% of 24 Gy for all cases. Using the study contours, the mean parotid dose obtained was within 10% of 24 Gy for only 53% of volumes by radiation oncologists and 55% of volumes by radiologists. The parotid DVHs of 46% of the study contours were sufficiently different from those used clinically, such that a different IMRT plan would have been produced. CONCLUSION: Interobserver variation in parotid gland delineation is significant. Further studies are required to determine ways of improving the interobserver consistency in parotid gland definition.

Neck dissection can be avoided after sequential chemoradiotherapy and negative post-treatment positron emission tomography-computed tomography in N2 head and neck squamous cell carcinoma.

AIMS: This study assessed neck control in patients with N2 head and neck squamous cell carcinoma (HNSCC) treated with sequential chemoradiotherapy (SCRT) and the incidence of neck recurrence when neck dissection was withheld in those with negative post-treatment fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET). MATERIALS AND METHODS: Thirty-four consecutive patients with N2 HNSCC who were treated with radical intent using SCRT were included. Twenty-seven patients received concomitant platinum-based chemotherapy with their radiotherapy. Nineteen patients were treated with intensity-modulated radiotherapy. PET-computed tomography (PET-CT) was obtained 3 months after the completion of radical radiotherapy. Neck dissection was carried out only in those with increased FDG uptake in the neck. RESULTS: The median follow-up was 39.1 months. One patient had increased FDG uptake in the neck post-treatment, which was false positive for malignancy. The remaining 33 patients were observed without neck dissection. No regional recurrence occurred. The negative predictive value (NPV) of post-treatment PET-CT was 100%. CONCLUSIONS: Good disease control in the neck can be achieved in patients with N2 HNSCC with SCRT. Post-treatment PET-CT has a high NPV. Neck dissection can be avoided if post-treatment PET-CT is negative.

General practitioner assessment of stage and performance status in lung cancer patients at a population level: implications for prognosis and radiotherapy needs analyses.

BACKGROUND: Stage, weight loss, and performance status (PS) are important prognostic factors and eligibility factors for curative intent therapy for lung cancer patients. Details of stage, weight loss, and PS are often not collected until referral to a cancer specialist, and since not all patients are referred to cancer specialists these important variables are not well defined at a population level. PATIENTS AND METHODS: Data on stage, weight loss, PS and referral pattern were requested from general practitioners (GPs) on all lung cancer patients diagnosed between May and June of 2002 in the province of British Columbia, Canada. Outcomes were analyzed in relation to survival and referral to a cancer centre. RESULTS: 395 patients were identified, and GP questionnaires were returned on 85% of the cases. Patients referred to a cancer centre shortly after diagnosis differed from those who were not referred. Patients who were not referred to a cancer centre consisted of two groups-patients with localized disease and good PS who tended to have a better survival than those who were referred, and patients with advanced disease and poor performance status who tended to have a worse survival than those who were referred. GP assessed stage and PS are prognostic factors for survival. CONCLUSIONS: GP assessed stage and PS are prognostic factors for survival in lung cancer patients. The case mix of patients who are not referred to a cancer centre shortly after their diagnosis differs from those that are referred.

Modulation of antagonist binding to histamine H1-receptors by sodium ions and by 2-amino-2-hydroxymethyl-propan-1,3-diol HCl.

1. NaCl (100 mM) reduced the potency of (+)-N-methyl-4-methyldiphenhydramine ((+)-QMDP) as an inhibitor of the binding of [3H]-mepyramine to histamine H1-receptors on guinea-pig cerebellar membranes to a greater extent than that of mepyramine, consistent with the greater inhibitory effect of Na+ on the binding of [3H]-QMDP than on the binding of [3H]-mepyramine. 2. The concentration of 2-amino-2-hydroxymethyl-propan-1,3-diol HCl (Tris, HCl) buffer, pH 7.5, present had little effect on the temelastine-insensitive binding of [3H]-mepyramine, but caused a concentration-dependent inhibition of the binding of [3H]-mepyramine sensitive to 1 microM temelastine (H1-receptor binding), with an approximate IC50 of 75 mM, assuming that complete inhibition would have been achieved. 3. Inhibition of [3H]-mepyramine binding by Na+ was more marked in 10 mM than in 50 mM Tris HCl and was not evident in 200 mM Tris HCl. 4. The Kd for the temelastine-sensitive binding of [3H]-mepyramine measured in 10 mM Tris HCl, 0.24 +/- 0.01 nM, was increased by 2.2 +/- 0.2 fold by 100 mM NaCl, without any significant change in the maximum binding (Bmax). The Bmax for [3H]-mepyramine was similarly unchanged in 50 mM Tris HCl, but the Kd was increased 2.5 +/- 0.2 fold. 5. The Kd for the temelastine-sensitive binding of [3H]-mepyramine was also increased in 50 mM,compared with 10 mM, N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulphonic acid] KOH (HEPES.KOH)buffer (Kd 0.25 +/- 0.02 nm in 10 mM HEPES), but the evidence for an interaction between HEPES and Na+ was less clear.6. The effect of 100 mM NaCl on the inhibition of [3H]-mepyramine binding in 10 mM Tris HCl was examined for a range of antagonists. The decrease in potency caused by Na+ was greatest for triprolidine, (+)-chlorpheniramine and benzilylcholine (9.6-10.3 fold increase in K1 values) but the binding of mepyramine and promethazine was much less affected (1.8 and 1.9 fold increase in Kd respectively). The Kd for temelastine was not significantly changed. In contrast to the general decrease in antagonist affinity in the presence of Na+, the for MDL 16,455A (4-[1-hydroxy-4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]butyl]-alpha,alpha-dimethylbenzene acetic acid) was increased, but only by 1.5 fold.7. It is concluded that Na+ can act as an allosteric effector of the binding of antagonists at the histamine HI-receptor. Tris HCl also appears to have an allosteric action at the H1-receptor.