Early reduction in tumour [18F]fluorothymidine (FLT) uptake in patients with non-small cell lung cancer (NSCLC) treated with radiotherapy alone.

PURPOSE: Changes in tumour 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) uptake during concurrent chemo-radiotherapy in patients with non-small cell lung cancer (NSCLC) have been reported, at variable time points, in two pilot positron emission tomography (PET) studies. The aim of this study was to assess whether FLT changes occur early in response to radiotherapy (RT) without concurrent chemotherapy and whether such changes exceed test-retest variability. METHODS: Sixteen patients with NSCLC, scheduled to have radical RT, underwent FLT PET once/twice at baseline to assess reproducibility and/or after 5-11 RT fractions to evaluate response. Primary and nodal malignant lesions were manually delineated on CT and volume, mean and maximum standardized uptake values (SUV(mean) and SUV(max)) estimated. Analysis included descriptive statistics and parameter fitting to a mixed-effects model accounting for patients having different numbers of evaluable lesions. RESULTS: In all, 35 FLT PET scans from 7 patients with a total of 18 lesions and 12 patients with a total of 30 lesions were evaluated for reproducibility and response, respectively. SUV(mean) reproducibility in primary tumours (SD 8.9%) was better than SUV(max) reproducibility (SD 12.6%). In nodes, SUV(mean) and SUV(max) reproducibilities (SD 18.0 and 17.2%) were comparable but worse than for primary tumours. After 5-11 RT fractions, primary tumour SUV(mean) decreased significantly by 25% (p = 0.0001) in the absence of significant volumetric change, whereas metastatic nodes decreased in volume by 31% (p = 0.020) with a larger SUV(mean) decrease of 40% (p < 0.0001). Similar changes were found for SUV(max). CONCLUSION: Across this group of NSCLC patients, RT induced an early, significant decrease in lesion FLT uptake exceeding test-retest variability. This effect is variable between patients, appears distinct between primary and metastatic nodal lesions, and in primary tumours is lower than previously reported for concurrent chemo-RT at a similar time point. These results confirm the potential for FLT PET to report early on radiation response and to enhance the clinical development of novel drug-radiation combinations by providing an interpretable, early pharmacodynamic end point.

Exercise capacity in idiopathic pulmonary fibrosis: the effect of pulmonary hypertension.

BACKGROUND AND OBJECTIVE: Increased pulmonary arterial pressure (PAP) usually coexists with impaired lung function in IPF. Data on the effect of pulmonary hypertension (PH) on cardiopulmonary responses during exercise in IPF patients is very limited. We sought to investigate the impact of PH on exercise capacity and the correlation between systolic PAP (sPAP) and pulmonary function testing, as well as cardiopulmonary exercise parameters, in patients with IPF and PH. METHODS: Eighty-one consecutive patients with IPF, who were evaluated over a 6-year period, were retrospectively studied. Patients underwent pulmonary function testing, Doppler echocardiography and maximal cardiopulmonary exercise testing. PH was defined as sPAP > 35 mm Hg. RESULTS: PH was diagnosed in 57% of the patients. Categorization of patients according to severity of PH indicated a significant reduction in maximum work rate, peak O(2) uptake, anaerobic threshold and peak O(2) pulse in those with sPAP > 50 mm Hg. In IPF patients with PH, estimated sPAP correlated with peak O(2) uptake, anaerobic threshold, peak O(2) pulse and end-tidal CO(2) at anaerobic threshold, while the strongest correlation was between sPAP and ventilatory equivalent for CO(2) at anaerobic threshold (r = 0.611, P < 0.001). There were no differences in pulmonary function or exercise parameters indicative of lung volume reduction, across the patient categories, and none of these parameters correlated with sPAP. CONCLUSIONS: PH has a negative impact on exercise capacity in IPF patients. In IPF patients with PH, resting sPAP correlated with exercise parameters indicative of gas exchange and circulatory impairment, but not with defective lung mechanics.

The prognostic and predictive value of CA-125 regression during neoadjuvant chemotherapy for advanced ovarian or primary peritoneal carcinoma.

PURPOSE: To assess the significance of CA-125 regression as a prognostic indicator and predictor of optimal cytoreduction at interval debulking surgery (IDS) in women with ovarian or primary peritoneal carcinoma receiving neoadjuvant chemotherapy (NAC). METHODS: 63 women treated between 2004 and 2007 with neoadjuvant platinum-based chemotherapy followed by IDS were studied retrospectively. Pre-operative CA-125 values were used to calculate a regression coefficient (CA-125r) using exponential regression analysis. Outcome endpoints were overall survival (OS), time to CA-125 progression (TTC) by Rustin criteria and time to second-line treatment (TTS). RESULTS: Women with a CA-125 half-life greater than 18 days had a significantly worse OS compared to those with a half-life less than 12 days on univariate testing (HR 3.34, 95% CI 1.25-8.94, p = 0.017). On multivariable analysis, CA-125r was an independent predictor of OS [HR 1.18 (per 0.01 increase in CA-125r), 95% CI 1.01-1.40, p = 0.043]. CA-125r was independently predictive of TTC and TTS (HR 1.17, p ≈ 0.03 for each). CA-125r was also predictive of achieving optimal cytoreduction at IDS (AUC 0.756, p < 0.001). CONCLUSIONS: CA-125 regression rate during pre-operative NAC is of independent prognostic value. CA-125 regression rate strongly predicts for optimal cytoreduction.

Cell Death, Inflammation, Tumor Burden, and Proliferation Blood Biomarkers Predict Lung Cancer Radiotherapy Response and Correlate With Tumor Volume and Proliferation Imaging.

INTRODUCTION: There is an unmet need to develop noninvasive biomarkers to stratify patients in drug-radiotherapy trials. In this pilot study we investigated lung cancer radiotherapy response and toxicity blood biomarkers and correlated findings with tumor volume and proliferation imaging. PATIENTS AND METHODS: Blood samples were collected before and during (day 21) radiotherapy. Twenty-six cell-death, hypoxia, angiogenesis, inflammation, proliferation, invasion, and tumor-burden biomarkers were evaluated. Clinical and laboratory data were collected. Univariate analysis was performed on small-cell and non-small-cell lung cancer (NSCLC) whereas multivariate analysis focused on NSCLC. RESULTS: Blood samples from 78 patients were analyzed. Sixty-one (78.2%) harbored NSCLC, 48 (61.5%) received sequential chemoradiotherapy. Of tested baseline biomarkers, undetectable interleukin (IL)-1b (hazard ratio [HR], 4.02; 95% confidence interval [CI], 2.04-7.93; P < .001) was the only significant survival covariate. Of routinely collected laboratory tests, high baseline neutrophil count was a significant survival covariate (HR, 1.07; 95% CI, 1.02-1.11; P = .017). Baseline IL-1b and neutrophil count were prognostic for survival in a multivariate model. The addition of day-21 cytokeratin-19 antigen modestly improved this model's survival prediction (concordance probability, 0.75-0.78). Chemotherapy (P < .001) and baseline keratinocyte growth factor (P = .019) predicted acute esophagitis, but only chemotherapy remained significant after Bonferroni correction. Baseline angioprotein-1 and hepatocyte growth factor showed a direct correlation with tumor volume whereas changes in vascular cell adhesion molecule 1 showed significant correlations with 18F-fluorothymidine (FLT) positron emission tomography (PET). CONCLUSION: Select biomarkers are prognostic after radiotherapy in this lung cancer series. The correlation between circulating biomarkers and 18F-FLT PET is shown, to our knowledge for the first time, highlighting their potential role as imaging surrogates.

18F-FLT PET imaging of cellular proliferation in pancreatic cancer.

Pancreatic ductal adenocarcinoma is known for its poor prognosis. Since the development of computerized tomography, magnetic resonance and endoscopic ultrasound, novel imaging techniques have struggled to get established in the management of patients diagnosed with pancreatic adenocarcinoma for several reasons. Thus, imaging assessment of pancreatic cancer remains a field with scope for further improvement. In contrast to cross-sectional anatomical imaging methods, molecular imaging modalities such as positron emission tomography (PET) can provide information on tumour function. Particularly, tumour proliferation may be assessed by measurement of intracellular thymidine kinase 1 (TK1) activity level using thymidine analogues radiolabelled with a positron emitter for use with PET. This approach, has been widely explored with [(18)F]-fluoro-3'-deoxy-3'-L-fluorothymidine ((18)F-FLT) PET. This manuscript reviews the rationale and physiology behind (18)F-FLT PET imaging, with special focus on pancreatic cancer and other gastrointestinal malignancies. Potential benefit and challenges of this imaging technique for diagnosis, staging and assessment of treatment response in abdominal malignancies are discussed.

Metastatic castrate-resistant prostate cancer with a late, complete and durable response to docetaxel chemotherapy: a case report.

INTRODUCTION: Although treatment options for men with metastatic castrate-resistant prostate cancer have improved in recent years, the outlook for patients remains poor, with overall survival in the region of 2 years. Response rates with chemotherapy are modest and disease progression is usually observed within months of stopping treatment. CASE PRESENTATION: We present a case of a 72-year-old White man of British origin with metastatic castrate-resistant prostate cancer with bulky lymphadenopathy and a serum prostate-specific antigen of 295 µg/L. He received treatment with docetaxel chemotherapy plus prednisolone, but received just 3 cycles before treatment was stopped due to toxicity and lack of response (prostate-specific antigen was 276 µg/L 4 weeks after the last dose and there was a confirmed stable appearance on computed tomography scan). Unexpectedly, at follow-up 4 months later, the patient was clinically better; his prostate-specific antigen had dramatically improved to 4.1 µg/L and a re-staging computed tomography scan revealed complete resolution of his bulky lymphadenopathy. At the time, he was receiving a luteinising hormone-releasing hormone analogue but no other disease-modulating treatment. He remains well and asymptomatic, with his most recent serum prostate-specific antigen measuring 0.14 µg/L, 18 months after last receiving chemotherapy. CONCLUSION: We report a case of complete and durable regression of metastatic castrate-resistant prostate cancer following palliative chemotherapy which, to the best of our knowledge, has not previously been reported in the literature.

Imaging pharmacodynamics in oncology: the potential significance of "flares".

The clinical use of (18)F-fluorodeoxyglucose (FDG) positron emission tomography in monitoring anticancer treatment is expanding. At the same time a number of radiotracers aiming to image different aspects of tumour biology such as proliferation and apoptosis are being developed. However, the factors determining changes of radiotracer uptake parameters in response to treatment are not well understood. In many cases, cellularity may be the primary determinant of changes of FDG uptake and may confound the interpretation of metabolic changes. Early imaging assessments have in some cases showed transient increases of uptake parameters, commonly termed "flares", which are likely to be unaffected by cellularity and directly reflect pharmacodynamics at a cellular level. In this review a number of settings where molecular imaging "flares" have been described are discussed. Such changes may often be clinically informative and warrant careful study as potential predictive biomarkers.