The Effect of Body Mass Index and Residence in Food Priority Areas on Patterns-of-Care and Cancer Outcomes in Patients With Stage III Non-Small Cell Lung Cancer.

PURPOSE: Patients living in food priority areas (FPAs), where access to healthy meals is challenging, may be at greater risk of nutritional deficits, leading to poorer cancer outcomes. Currently, there are no published data analyzing how FPAs affect patterns-of-care or outcomes for patients with locally advanced non-small cell lung cancer (NSCLC). We aimed to analyze the effect of residing in an FPA on treatments rendered and cancer outcomes in patients with stage III NSCLC treated at a single institution. METHODS AND MATERIALS: This is a retrospective study of 573 patients with locally advanced NSCLC consecutively treated from January 2000 to January 2020. χ2 and Mann-Whitney U tests were performed to determine differences between select variables. Kaplan-Meier analysis and Cox proportional hazard models were used to analyze overall survival (OS) and freedom from recurrence. Cox regression with forward model selection was used for multivariate analysis. RESULTS: Thirty-two percent of patients resided in an FPA (n = 183) and were more likely to self-identify as Black (P < .0001), single (P < .001), <60 years of age (P = .001), and uninsured (P < .0001), with a lower median income (P < .001). Patients in FPAs also had lower mean pre-chemoradiation (CRT) albumin (P = .002), lower pre-CRT body mass index (BMI) (P = .026), and were less likely to receive trimodality therapy (P ≤ .001) compared with patients not living in FPAs. There was no difference in OS or freedom from recurrence between the 2 cohorts. However, in patients with a normal BMI, either pre-CRT (median OS, 18.4 vs 25.0 months; P = .005) or after CRT (15.1 vs 28.1 months, P = .002), residing in an FPA resulted in an OS detriment. CONCLUSIONS: We demonstrated a clear socioeconomic divide in our patient population with stage III NSCLC, where residing in FPAs was associated with less-aggressive therapy and an OS detriment for patients with a normal-weight BMI. We are currently conducting a prospective study characterizing the nutritional needs of patients, particularly those who live in FPAs.

Methods for estimating the site of origin of locoregional recurrence in head and neck squamous cell carcinoma.

PURPOSE: Methods to estimate the likely origin of recurrences after radiation therapy for head and neck squamous cell carcinoma are compared. METHODS AND MATERIALS: A total of 25 patients meeting the following inclusion criteria were randomly selected: curatively intended intensity-modulated radiotherapy planned on a positron emission tomography-computed tomography (PET/CT) scan during the period 2005-2009; squamous cell carcinoma in the oral cavity, pharynx or larynx; complete clinical response followed by locoregional recurrence; and a CT scan at recurrence before any salvage therapy. Exclusion criteria were previous cancer in the area, surgery prior to radiotherapy, or a synchronous cancer. Three methods of estimating focal points of recurrence origin and two volume overlap methods assigning the recurrences to the most central target volumes encompassing at least 50% or 95% of the recurrence volumes were tested. Treatment planning and recurrence scans were rigid and deformable co-registered in order to transfer focal points to the treatment planning scan. Double determinations of all volumes, points, and co-registrations were made. RESULTS: The volume overlap methods assigned the recurrences to significantly more peripheral target volumes than focal methods (p < 0.0001 for all comparisons of 95% overlap vs. focal methods, p < 0.028 for all comparisons of 50% overlap vs. focal methods). Repeated registrations of the same point had higher reproducibility with deformable registration than with rigid registration (median distance 0.31 vs. 0.35 cm, p = 0.015). No significant differences were observed among the focal methods. CONCLUSION: Significant differences between methods were found which may affect strategies to improve radiotherapy based on pattern of failure analyses.

The UK Standardisation of Breast Radiotherapy (START) Trial B of radiotherapy hypofractionation for treatment of early breast cancer: a randomised trial.

BACKGROUND: The international standard radiotherapy schedule for early breast cancer delivers 50 Gy in 25 fractions of 2.0 Gy over 5 weeks, but there is a long history of non-standard regimens delivering a lower total dose using fewer, larger fractions (hypofractionation). We aimed to test the benefits of radiotherapy schedules using fraction sizes larger than 2.0 Gy in terms of local-regional tumour control, normal tissue responses, quality of life, and economic consequences in women prescribed post-operative radiotherapy. METHODS: Between 1999 and 2001, 2215 women with early breast cancer (pT1-3a pN0-1 M0) at 23 centres in the UK were randomly assigned after primary surgery to receive 50 Gy in 25 fractions of 2.0 Gy over 5 weeks or 40 Gy in 15 fractions of 2.67 Gy over 3 weeks. Women were eligible for the trial if they were aged over 18 years, did not have an immediate reconstruction, and were available for follow-up. Randomisation method was computer generated and was not blinded. The protocol-specified principal endpoints were local-regional tumour relapse, defined as reappearance of cancer at irradiated sites, late normal tissue effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN59368779. FINDINGS: 1105 women were assigned to the 50 Gy group and 1110 to the 40 Gy group. After a median follow up of 6.0 years (IQR 5.0-6.2) the rate of local-regional tumour relapse at 5 years was 2.2% (95% CI 1.3-3.1) in the 40 Gy group and 3.3% (95% CI 2.2 to 4.5) in the 50 Gy group, representing an absolute difference of -0.7% (95% CI -1.7% to 0.9%)--ie, the absolute difference in local-regional relapse could be up to 1.7% better and at most 1% worse after 40 Gy than after 50 Gy. Photographic and patient self-assessments indicated lower rates of late adverse effects after 40 Gy than after 50 Gy. INTERPRETATION: A radiation schedule delivering 40 Gy in 15 fractions seems to offer rates of local-regional tumour relapse and late adverse effects at least as favourable as the standard schedule of 50 Gy in 25 fractions.

Carbogen and nicotinamide in locally advanced bladder cancer: early results of a phase-III randomized trial.

PURPOSE: Phase II studies in laryngeal and bladder carcinoma of accelerated radiotherapy with carbogen and nicotinamide (RT+CON) suggested a therapeutic advantage. Therefore, a randomized phase-III trial of RT+CON in locally advanced bladder carcinoma compared to radiotherapy (RT) alone was undertaken. METHODS: One hundred and sixty-five patients with muscle-invasive transitional cell bladder carcinoma were randomized to RT alone and 168 to RT+CON. This paper reports on compliance and toxicity to nicotinamide (NAM) and carbogen and on early radiation-induced adverse bowel and urinary events. RESULTS: Of those receiving RT+CON, 65-69% accepted all doses of NAM. Sixty-four percent of patients presented Grade 1 NAM toxicity (nausea or vomiting), which was severe in 13%. Compliance to carbogen was 85% and none (32 fractions) and 2% (20 fractions) of patients presented severe toxicity. The highest prevalence of severe radiation acute morbidity was seen for urinary frequency (RT: 18% and RT+CON: 15%) and for diarrhea (RT: 3% and RT+CON: 5%). CONCLUSIONS: There is no indication of an increase in radiation-induced morbidity by combining the tumour radiosensitizers carbogen and nicotinamide with radiotherapy. Late morbidity and treatment outcome will ultimately determine if there is a therapeutic benefit.

The UK Standardisation of Breast Radiotherapy (START) Trial A of radiotherapy hypofractionation for treatment of early breast cancer: a randomised trial.

BACKGROUND: The international standard radiotherapy schedule for breast cancer treatment delivers a high total dose in 25 small daily doses (fractions). However, a lower total dose delivered in fewer, larger fractions (hypofractionation) is hypothesised to be at least as safe and effective as the standard treatment. We tested two dose levels of a 13-fraction schedule against the standard regimen with the aim of measuring the sensitivity of normal and malignant tissues to fraction size. METHODS: Between 1998 and 2002, 2236 women with early breast cancer (pT1-3a pN0-1 M0) at 17 centres in the UK were randomly assigned after primary surgery to receive 50 Gy in 25 fractions of 2.0 Gy versus 41.6 Gy or 39 Gy in 13 fractions of 3.2 Gy or 3.0 Gy over 5 weeks. Women were eligible if they were aged over 18 years, did not have an immediate surgical reconstruction, and were available for follow-up. Randomisation method was computer generated and was not blinded. The protocol-specified principal endpoints were local-regional tumour relapse, defined as reappearance of cancer at irradiated sites, late normal tissue effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN59368779. FINDINGS: 749 women were assigned to the 50 Gy group, 750 to the 41.6 Gy group, and 737 to the 39 Gy group. After a median follow up of 5.1 years (IQR 4.4-6.0) the rate of local-regional tumour relapse at 5 years was 3.6% (95% CI 2.2-5.1) after 50 Gy, 3.5% (95% CI 2.1-4.3) after 41.6 Gy, and 5.2% (95% CI 3.5-6.9) after 39 Gy. The estimated absolute differences in 5-year local-regional relapse rates compared with 50 Gy were 0.2% (95% CI -1.3% to 2.6%) after 41.6 Gy and 0.9% (95% CI -0.8% to 3.7%) after 39 Gy. Photographic and patient self-assessments suggested lower rates of late adverse effects after 39 Gy than with 50 Gy, with an HR for late change in breast appearance (photographic) of 0.69 (95% CI 0.52-0.91, p=0.01). From a planned meta-analysis with the pilot trial, the adjusted estimates of alpha/beta value for tumour control was 4.6 Gy (95% CI 1.1-8.1) and for late change in breast appearance (photographic) was 3.4 Gy (95% CI 2.3-4.5). INTERPRETATION: The data are consistent with the hypothesis that breast cancer and the dose-limiting normal tissues respond similarly to change in radiotherapy fraction size. 41.6 Gy in 13 fractions was similar to the control regimen of 50 Gy in 25 fractions in terms of local-regional tumour control and late normal tissue effects, a result consistent with the result of START Trial B. A lower total dose in a smaller number of fractions could offer similar rates of tumour control and normal tissue damage as the international standard fractionation schedule of 50 Gy in 25 fractions.

Pediatric Normal Tissue Effects in the Clinic (PENTEC): An International Collaboration to Analyse Normal Tissue Radiation Dose-Volume Response Relationships for Paediatric Cancer Patients.

With advances in multimodality therapy, childhood cancer cure rates approach 80%. However, both radiotherapy and chemotherapy can cause debilitating or even fatal late adverse events that are critical to understand, mitigate or prevent. QUANTEC (Quantitative Analysis of Normal Tissue Effects in the Clinic) identified radiation dose constraints for normal tissues in adults and pointed out the uncertainties in those constraints. The range of adverse events seen in children is different from that in adults, in part due to the vulnerability/characteristics of radiation damage to developing tissues, and in part due to the typical body sites affected by childhood cancer that lead to collateral irradiation of somewhat different normal tissues and organs compared with adults. Many childhood cancer survivors have a long life expectancy and may develop treatment-induced secondary cancers and severe organ/tissue injury 10, 20 or more years after treatment. Collaborative long-term observational studies and clinical research programmes for survivors of paediatric and adolescent cancer provide adverse event data for follow-up periods exceeding 40 years. Data analysis is challenging due to the interaction between therapeutic and developmental variables, the lack of radiation dose-volume data and the fact that most childhood malignancies are managed with combined modality therapy. PENTEC (Pediatric Normal Tissue Effects in the Clinic) is a volunteer research collaboration of more than 150 physicians, medical physicists, mathematical modellers and epidemiologists organised into 18 organ-specific working groups conducting a critical review and synthesis of quantitative data from existing studies aiming to: (1) establish quantitative, evidence-based dose/volume/risk guidelines to inform radiation treatment planning and, in turn, improve outcomes after radiation therapy for childhood cancers; (2) explore the most relevant risk factors for toxicity, including developmental status; (3) describe specific physics and dosimetric issues relevant to paediatric radiotherapy; and (4) propose dose-volume outcome reporting standards for publications on childhood cancer therapy outcomes. The impact of other critical modifiers of normal tissue radiation damage, including chemotherapy, surgery, stem cell transplantation and underlying genetic predispositions are also considered. The aims of the PENTEC reports are to provide clinicians with an analysis of the best available data to make informed decisions regarding radiation therapy normal organ dose constraints for planning childhood cancer treatment, and to define future research priorities.

Dose escalated, hypofractionated radiotherapy using helical tomotherapy for inoperable non-small cell lung cancer: preliminary results of a risk-stratified phase I dose escalation study.

To improve local control for inoperable non-small cell lung cancer (NSCLC), a phase I dose escalation study for locally advanced and medically inoperable patients was devised to escalate tumor dose while limiting the dose to organs at risk including the esophagus, spinal cord, and residual lung. Helical tomotherapy provided image-guided IMRT, delivered in a 5-week hypofractionated schedule to minimize the effect of accelerated repopulation. Forty-six patients judged not to be surgical candidates with Stage I-IV NSCLC were treated. Concurrent chemotherapy was not allowed. Radiotherapy was delivered via helical tomotherapy and limited to the primary site and clinically proven or suspicious nodal regions without elective nodal irradiation. Patients were placed in 1 of 5 dose bins, all treated for 25 fractions, with dose per fraction ranging from 2.28 to 3.22 Gy. The bin doses of 57 to 80.5 Gy result in 2 Gy/fraction normalized tissue dose (NTD) equivalents of 60 to 100 Gy. In each bin, the starting dose was determined by the relative normalized tissue mean dose modeled to cause < 20% Grade 2 pneumonitis. Dose constraints included spinal cord maximum NTD of 50 Gy, esophageal maximum NTD < 64 Gy to < or = 0.5 cc volume, and esophageal effective volume of 30%. No grade 3 RTOG acute pneumonitis (NCI-CTC v.3) or esophageal toxicities (CTCAE v.3.0 and RTOG) were observed at median follow-up of 8.1 months. Pneumonitis rates were 70% grade 1 and 13% grade 2. Multivariate analysis identified lung NTD(mean) (p=0.012) and administration of adjuvant chemotherapy following radiotherapy (p=0.015) to be independent risk factors for grade 2 pneumonitis. Only seven patients (15%) required narcotic analgesics (RTOG grade 2 toxicity) for esophagitis, with only 2.3% average weight loss during treatment. Best in-field gross response rates were 17% complete response, 43% partial response, 26% stable disease, and 6.5% in-field thoracic progression. The out-of-field thoracic failure rate was 13%, and distal failure rate was 28%. The median survival was 18 months with 2-year overall survival of 46.8% +/- 9.7% for this cohort, 50% of whom were stage IIIB and 30% stage IIIA. Dose escalation can be safely achieved in NSCLC with lower than expected rates of pneumonitis and esophagitis using hypofractionated image-guided IMRT. The maximum tolerated dose has yet to be reached.

Dose- and time-dependent changes in gene expression in human glioma cells after low radiation doses.

We have used DNA microarrays to identify changes in gene expression in cells of the radioresistant human glioma cell lines T98G and U373 after low radiation doses (0.2-2 Gy). Using Bayesian linear models, we have identified a set of genes that respond to low doses of radiation; furthermore, a hypothesis-driven approach to data analysis has allowed us to identify groups of genes with defined non-linear dose responses. Specifically, one of the cell lines we have examined (T98G) shows increased radiosensitivity at low doses (low-dose hyper-radiosensitivity, HRS); thus we have also assessed sets of genes whose dose response mirrors this survival pattern. We have also investigated a time course for induction of genes over the period when the DNA damage response is expected to occur. We have validated these data using quantitative PCR and also compared genes up-regulated in array data to genes present in the polysomal RNA fraction after irradiation. Several of the radioresponsive genes that we describe code for proteins that may have an impact on the outcome of irradiation in these cells, including RAS homologues and kinases involved in checkpoint signaling, so understanding their differential regulation may suggest new ways of altering radioresistance. From a clinical perspective these data may also suggest novel targets that are specifically up-regulated in gliomas during radiotherapy treatments.

Radiotherapy-related lung fibrosis enhanced by tamoxifen.

BACKGROUND: Tamoxifen is an anti-estrogen with proven efficacy and low toxicity in the treatment of breast cancer. However, tamoxifen has been shown to exert a number of nonhormonal as well as hormonal effects. One nonhormonal effect of tamoxifen is the induction of transforming growth factor-beta (TGF-beta) secretion. TGF-beta has been implicated in the pathogenesis of radiation-induced fibrosis. PURPOSE: We investigated the development of lung fibrosis in breast cancer patients who were treated after mastectomy with radiotherapy, with or without simultaneous adjuvant treatment with tamoxifen. METHODS: Data from 196 women were included in the analysis. Eighty-four women were postmenopausal patients who participated in a randomized trial testing tamoxifen as an adjuvant to postmastectomy radiotherapy. The radiotherapy technique employed an 8-MV photon field covering the axillary and the infraclavicular and supraclavicular regions of the affected side of the chest; the chest wall was treated with an abutted electron field. Optical density changes in pretreatment and post-treatment chest x-ray films were used to monitor the development of lung fibrosis; lung reactions were assessed in the photon-irradiated field only. Logistic regression analysis was used to explore relationships between radiation dose and the development of lung fibrosis in patients either receiving or not receiving tamoxifen. All P values are from two-sided tests. RESULTS: Among the 84 women who participated in the randomized trial of radiotherapy plus tamoxifen (n = 38) versus radiotherapy alone (n = 46), there was a significant association between tamoxifen treatment and the incidence of marked lung fibrosis (relative risk = 2.0; 95% confidence interval [CI] = 1.2-3.5; P = .01). When logistic regression analysis was used to evaluate data from all 196 patients, a highly significant relationship was found between the incidence of lung fibrosis and total radiation dose (P = .0005). In the full analysis, an increased risk of marked lung fibrosis was found again for patients who received tamoxifen simultaneously with radiotherapy (with patients receiving radiotherapy alone as the referent, odds ratio = 2.9; 95% CI = 1.3-6.3; P = .007). Patient age and menopausal status did not significantly influence the results. CONCLUSION: Tamoxifen treatment during postmastectomy radiotherapy enhances the risk of radiation-induced lung fibrosis. IMPLICATIONS: In view of pre-existing data, we hypothesize that tamoxifen mediates the enhancement of radiation-induced lung fibrosis through the induction of TGF-beta secretion. If this hypothesis is correct, new strategies might be devised for preventing or reducing radiation-induced fibrosis. Because we studied a relatively small portion of the irradiated lung, we cannot recommend changes in current therapeutic measures; however, we strongly encourage additional studies of lung fibrosis in patients receiving tamoxifen and radiotherapy.

Relative validity of a web-based food frequency questionnaire for patients with type 1 and type 2 diabetes in Denmark.

BACKGROUND: Diet has an important role in the management of diabetes. However, little is known about dietary intake in Danish diabetes patients. A food frequency questionnaire (FFQ) focusing on most relevant nutrients in diabetes including carbohydrates, dietary fibres and simple sugars was developed and validated. OBJECTIVES: To examine the relative validity of nutrients calculated by a web-based food frequency questionnaire for patients with diabetes. DESIGN: The FFQ was validated against a 4-day pre-coded food diary (FD). Intakes of nutrients were calculated. Means of intake were compared and cross-classifications of individuals according to intake were performed. To assess the agreement between the two methods, Pearson and Spearman's correlation coefficients and weighted kappa coefficients were calculated. SUBJECTS: Ninety patients (64 with type 1 diabetes and 26 with type 2 diabetes) accepted to participate in the study. Twenty-six were excluded from the final study population. SETTING: 64 volunteer diabetes patients at the Steno Diabetes Center. RESULTS: Intakes of carbohydrates, simple sugars, dietary fibres and total energy were higher according to the FFQ compared with the FD. However, intakes of nutrients were grossly classified in the same or adjacent quartiles with an average of 82% of the selected nutrients when comparing the two methods. In general, moderate agreement between the two methods was found. CONCLUSION: The FFQ was validated for assessment of a range of nutrients. Comparing the intakes of selected nutrients (carbohydrates, dietary fibres and simple sugars), patients were classified correctly according to low and high intakes. The FFQ is a reliable dietary assessment tool to use in research and evaluation of patient education for patients with diabetes.

Randomized study of initial versus late chest irradiation combined with chemotherapy in limited-stage small-cell lung cancer. Aarhus Lung Cancer Group.

PURPOSE: To evaluate if the timing of chest irradiation with respect to chemotherapy would influence survival and local and distant control in patients with limited-stage small-cell lung cancer (LSCLC). PATIENTS AND METHODS: From 1981 to 1989, 199 consecutive patients with LSCLC were randomly allocated to receive initial chest irradiation (ICI; n = 99) or late chest irradiation (LCI; n = 100) given 18 weeks delayed. Both groups received the same nine cycles of combination chemotherapy: three cycles of cisplatin and etoposide and six cycles of cyclophosphamide, doxorubicin, and vincristine. In the first part of the study, prophylactic cranial irradiation (PCI) was only given to patients randomized to ICI, but after inclusion of 42 patients in the LCI arm, the protocol was changed, so that all patients received PCI independent of the timing of the chest irradiation (CI). A total of 157 patients received PCI with a radiation dose of 25 Gy in 11 fractions. RESULTS: The timing of radiotherapy had no significant effect on the 2-year overall survival rate (20% after ICI v 19% after LCI, P = .4) or the 2-year in-field recurrence rate (72% after ICI v 68% after LCI, P = .2). Median survival durations were 10.5 (ICI) and 12.0 (LCI) months. Similarly, no difference in the 2-year incidence of CNS recurrences was found between the 2 arms in patients who received PCI (19% after ICI v 13% after LCI, P = .24). Bone marrow toxicity was acceptable, as 15% developed World Health Organization (WHO) grade 4 leukocytopenia and 4% grade 4 thrombocytopenia. Grade 4 leukocytopenia was more pronounced in the ICI group. There was no difference in the frequency and severity of other toxicities between the 2 groups. CONCLUSION: Timing of CI did not significantly influence the incidence of in-field recurrences, CNS recurrences, or overall survival.

Value of epidermal growth factor receptor, HER2, p53, and steroid receptors in predicting the efficacy of tamoxifen in high-risk postmenopausal breast cancer patients.

PURPOSE: Few studies have examined the possible importance of biologic prognostic factors in breast cancer connected with differentiation and growth in predicting response to a specific adjuvant treatment. HER2, epidermal growth factor receptor (EGFR), and p53 have all been suggested as possible markers of tamoxifen resistance. The aim of this study was to investigate interactions between adjuvant treatment with tamoxifen and the content of EGFR, HER2, and p53 in steroid receptor-positive patients. PATIENTS AND METHODS: A total of 1,716 high-risk postmenopausal breast cancer patients were randomly assigned to treatment with tamoxifen (868 women) or to observation (848 women) in a prospective trial (Danish Breast Cancer Cooperative Group's 77c protocol). The content of the steroid receptors and expression of p53, EGFR, and HER2 were determined by immunohistochemical analysis of paraffin-embedded tissue. The length of follow-up was 10 years. The end point for this analysis was disease-free survival. RESULTS: Multivariate analysis demonstrated no increased risk of recurrence after treatment with tamoxifen for HER2-, EGFR-, and p53-positive, high-risk, steroid receptor-positive patients. Patients with steroid receptor-positive tumors and positive immunohistochemical staining for HER2, EGFR or p53 benefited from treatment with tamoxifen for 1 year, although the latter variable contained independent prognostic information by itself. CONCLUSION: With the statistical power of the present randomized study, we did not find support for the hypothesis that HER2/EGFR or p53 status predicts benefit from tamoxifen treatment in estrogen receptor-positive patients with early-stage breast cancer. Thus, neither HER2, EGFR, nor p53 overexpression/accumulation should be used as a contraindication for giving tamoxifen.

Selection of active drugs for ovarian cancer based on CA-125 and standard response rates in phase II trials.

PURPOSE: To determine whether precise definitions of response based on serial CA-125 levels can predict the activity of drugs in phase II trials for ovarian cancer as accurately as standard criteria. PATIENTS AND METHODS: Fourteen different drugs for relapsed ovarian cancer were analyzed in 25 treatment groups in 19 clinical trials. Response rates were estimated in 1,457 assessable patients according to standard criteria and in 1,092 assessable patients according to CA-125. For each drug trial, the observed response rates acted as the input data for an evaluation of how the two criteria would perform in a hypothetical Gehan two-stage phase II trial, accepting a target drug efficacy rate of 20% and a rejection error of 5%. RESULTS: CA-125 and clinical response criteria were concordant in 20 of the 25 groups, with less than 5% chance of rejecting the drug in nine groups and greater than 5% in 11 groups. In four groups, the drug had less than 5% chance of being rejected by CA-125 but greater than 5% chance of being rejected by standard criteria. The difference in the classification of drugs by the standard and CA-125 response criteria was not statistically significant (P =.38, McNemar's test). CA-125 response rates were slightly higher than standard response rates by a factor of 1.11. CONCLUSION: Definitions based on a 50% or 75% decrease of CA-125 levels accurately predicted which drugs in phase II trials for relapsed ovarian cancer were active and justified further investigation.

Dose-response relationship of epirubicin in the treatment of postmenopausal patients with metastatic breast cancer: a randomized study of epirubicin at four different dose levels performed by the Danish Breast Cancer Cooperative Group.

PURPOSE: To test for possible correlations between dose of single-drug epirubicin and efficacy/toxicity in postmenopausal women with metastatic breast cancer. The study also included analysis of a correlation between pharmacokinetic and pharmacodynamic parameters. PATIENTS AND METHODS: Two hundred eighty-seven women were randomized to receive either 40, 60, 90, or 135 mg/m2 of epirubicin intravenously (IV) every 3 weeks. Treatment consisted of first-line cytotoxic therapy for metastatic disease. In patients with early progressive disease after either 40 or 60 mg/m2, dose escalation to 135 mg/m2 was performed. A full pharmacokinetic analysis was performed in 78 patients. RESULTS: Among 263 eligible patients, an increase in response rate and time to progression was found with an increase in dose from 40 to 90 mg/m2, while no increase in efficacy was found from 90 to 135 mg/m2. Multivariate analysis, using the Cox proportional hazards model with time to progression as the end point, confirmed that epirubicin dose more than 60 mg/m2 was an independent prognostic covariate. Furthermore, a significant association was established between randomized dose and both hematologic and nonhematologic toxicity. No association between pharmacokinetic parameters and efficacy parameters was demonstrated. On the other hand, a significant correlation between pharmacokinetic parameters and both hematologic and nonhematologic toxicity was found. CONCLUSION: An increase in dose of epirubicin from 40 to 90 mg/m2 is accompanied by increased efficacy. Further increases in dose do not yield increased efficacy. A positive correlation between epirubicin dose and toxicity, as well as a correlation between pharmacokinetic parameters and toxicity, was also established.

Is there a radiobiologic basis for improving the treatment of advanced stage cervical cancer?

The success of radiotherapy in eradicating the primary tumor in patients with locally advanced cervical cancer is limited by normal tissue tolerance. Systematic recording of morbidity and treatment parameters is therefore very important for radiobiologic treatment optimization and clinical decision making. There is substantial evidence that fractionation schedules employing large doses per fraction lead to a loss of therapeutic ratio. A similar argument could be used for high-dose-rate (HDR) brachytherapy that should also be administered in small dose fractions. However, HDR brachytherapy might convey some advantage to physical dose distribution that should be weighed against the radiobiologic advantages of low-dose-rate (LDR) continuous irradiation. Increasing overall treatment time reduces local control probability, whereas a shorter overall treatment time by accelerated fractionation may improve the therapeutic ratio, at least in fast-growing tumors. Hypoxia and reduced oxygen delivery are associated with poor radiation response. Anemia should be compensated, if necessary. The role of hypoxic modification needs to be further explored. In the future, the therapeutic ratio may also be improved by the use of chemical and biologic response modifiers. Tumors are heterogeneous with respect to intrinsic radiosensitivity, proliferation parameters, and extent of hypoxia. Until a detailed prognostic profile can be obtained for each patient, optimal curative radiotherapy must aim for a sufficient dose, short overall treatment time, hypoxic modification, and LDR or low dose per fraction.

Proliferative response of mouse spermatogonial stem cells after irradiation: a quantitative model analysis of experimental data.

The testes of CDF1 mice were irradiated with single doses of X-rays ranging from 2-16 Gy. The number of haploid cells in the testis at different times after irradiation (42-350 days) was determined by one-parameter flow cytometry both for irradiated animals and for age-matched controls. Based on literature data on the kinetics of the spermatogenesis in mice, a mathematical model of the (hierarchical) germ tissue was developed. Using this model, the processes of radiation-induced cell loss and subsequent recovery were simulated and free parameters of the model were estimated by fitting the model prediction to the experimental data. One of the aims of the study was to investigate the kinetic behaviour of spermatogonial stem cells and the corresponding control mechanisms. In order to fit the data, the model has to include the following features: (i) A preferential self-repopulation of spermatogonial stem cells following tissue injury. The model-estimated probability of a self-renewing division rises from 50% (the steady-state value) to 95% if the stem-cell population is reduced to 10% of its normal size. (ii) A relatively low, almost constant turnover rate of the stem-cell compartment. It is suggested by the analysis that less than 10% of the spermatogonial stem cells present in the testis divide per day, regardless of the degree of cellular depletion. (iii) A mechanism responsible for incomplete recovery. The observed incomplete recovery of spermatogenesis after single doses exceeding 10 Gy can be described quantitatively assuming that the stem cells are organized into discrete proliferative structures, the number of cells per structure being about 60.

The predictive value of quantitative computed tomography for vertebral body compressive strength and ash density.

Whole lumbar vertebral sections (L2 and L3) were obtained from 30 elderly individuals aged 43-95 years, mean 81 years (13 females, 17 males). None of the subjects had had malignant diseases. Quantitative computed tomography (QCT) was performed on an EMI 7070 scanner. One 8 mm slice parallel to the end-plates was obtained from the center of each vertebral body. The trabecular bone mass in each slice was outlined interactively by means of a tracer-ball. A CT-histogram was recorded inside this area, and average CT-values were expressed in Hounsfield Units (HU). The whole vertebral body (L2) was compressed in a materials testing machine. From the central part of L3, vertical cylindrical pure trabecular bone specimens were obtained. The biomechanical competence of these specimens was also assessed by means of a materials testing machine. Finally, all bone specimens were incinerated for determination of apparent ash-density. Highly significant positive correlations were found between average CT-values and (a) stress values of the trabecular bone (r = 0.81, p less than 0.001) and (b) ash-density of the pure trabecular bone (r = 0.81, p less than 0.001). Furthermore, a significant positive correlation was found between CT-values and (a) total vertebral body load (r = 0.72, p less than 0.001), (b) total vertebral body stress (load/cross-sectional area) (r = 0.55, p less than 0.001) and (c) ash-density of the whole vertebral body (r = 0.76, p less than 0.001). It is concluded that quantitative computed tomography gives valid predictions of both vertebral trabecular bone mass and mechanical competence.(ABSTRACT TRUNCATED AT 250 WORDS)

Altered fractionation and combined radio-chemotherapy approaches: pioneering new opportunities in head and neck oncology.

Squamous cell carcinoma of the head and neck (HNSCC) are increasingly treated by multimodality approaches combining surgery, radiotherapy and chemotherapy. Randomised controlled trials have demonstrated major improvements in loco-regional tumour control from altered fractionation radiotherapy, accelerated fractionation and hyperfractionation, as compared with conventional fractionation. This experience is summarised, and the limit as to how far these modifications can be taken is discussed. It is emphasised that radiation fractionation will need to be optimised separately in multimodality strategies. Combined chemotherapy and radiotherapy has also been shown in phase III trials to produce an improved survival and an improved disease control. Chemotherapy may be given as neoadjuvant, concurrent or adjuvant treatment and the biological rationales for each of these, and the data supporting them, are reviewed. Although, large meta-analyses have shown concurrent chemoradiation to be the most effective, there is still a strong rationale for trying to develop neoadjuvant and adjuvant schedules. New, more active drugs may be important in this context. As therapy is becoming more intense, a careful recording and reporting of treatment-related morbidity is a crucial element in estimating the therapeutic gain from competing therapeutic management strategies. Development of non-cytostatic drugs and individualization of therapy using molecular prognostic markers are exciting areas of research with a great potential for improving therapy in the next decade and these are briefly discussed. Finally, a number of avenues for further research are identified.

Clinical correlations between late normal tissue endpoints after radiotherapy: implications for predictive assays of radiosensitivity.

The discovery that certain genetic syndromes are associated with a high cellular radiosensitivity has stirred interest in the concept that radiosensitivity of persons in general should have a genetic component. This has motivated research into assays for prediction of cellular normal tissue radiosensitivity. If such an intrinsic factor were a major factor in the development of late normal tissue injury, this should be detectable as a correlation between the probability of developing injury in different tissues. This hypothesis is tested in a series of 229 patients treated with postmastectomy radiotherapy and evaluated with respect to a number of late endpoints 16 to 71 months after the end of treatment. In each patient, the presence of marked subcutaneous fibrosis and telangiectasia were evaluated in two different treatment areas: in a photon field underneath a 5-mm wax bolus and in an abutted electron field used for treating the chest wall. The use of two different doses per fraction and the fact that a single anterior photon field was used with the dose prescribed at the level of the mid-axilla, led to a substantial variation in total dose and dose per fraction in these patients. A non-tissue-specific patient-to-patient difference in radiosensitivity would cause higher than expected reactions in one treatment area to be correlated with higher than expected reactions in the other area. For each of the two endpoints, telangiectasia or subcutaneous fibrosis, patients experiencing stronger than expected reactions in one treatment area tended to do so in the other area as well. Thus, a strong host factor appears to exist for a specific endpoint. It is an open question whether this is explained by individual variability in intrinsic radiosensitivity, progression rate of injury or other. Contrary to this, no significant correlation was seen when pairing the two late end-points, fibrosis and telangiectasia. Thus, patients showing stronger than expected fibrosis developed on average marked telangiectasia with a probability well predicted from their total dose and dose per fraction. These findings suggest that an assay for clinical expression of late injury would have to be specific for that type of injury.

An evolutionary-game model of tumour-cell interactions: possible relevance to gene therapy.

Evolutionary games have been applied as simple mathematical models of populations where interactions between individuals control the dynamics. Recently, it has been proposed to use this type of model to describe the evolution of tumour cell populations with interactions between cells. We extent the analysis to allow for synergistic effects between cells. A mathematical model of a tumour cell population is presented in which population-level synergy is assumed to originate through the interaction of triplets of cells. A threshold of two cooperating cells is assumed to be required to produce a proliferative advantage. The mathematical behaviour of this model is explored. Even this simple synergism (minor clustering effect) is sufficient to generate qualitatively different cell-population dynamics from the models published previously. The most notable feature of the model is the existence of an unstable internal equilibrium separating two stable equilibria. Thus, cells of a malignant phenotype can exist in a stable polymorphism, but may be driven to extinction by relatively modest perturbations of their relative frequency. The proposed model has some features that may be of interest to biological interpretations of gene therapy. Two prototypical strategies for gene therapy are suggested, both of them leading to extinction of the malignant phenotype: one approach would be to reduce the relative proportion of the cooperating malignant cell type below a certain critical value. Another approach would be to increase the critical threshold value without reducing the relative frequency of cells of the malignant phenotype.