Utility of the ACE Inhibitor Captopril in Mitigating Radiation-associated Pulmonary Toxicity in Lung Cancer: Results From NRG Oncology RTOG 0123

OBJECTIVES

The primary objective of NRG Oncology Radiation Therapy Oncology Group 0123 was to test the ability of the angiotensin-converting enzyme inhibitor captopril to alter the incidence of pulmonary damage after radiation therapy for lung cancer; secondary objectives included analyzing pulmonary cytokine expression, quality of life, and the long-term effects of captopril.

MATERIALS AND METHODS

Eligible patients included stage II-IIIB non-small cell lung cancer, stage I central non-small cell lung cancer, or limited-stage small cell. Patients who met eligibility for randomization at the end of radiotherapy received either captopril or standard care for 1 year. The captopril was to be escalated to 50 mg three times a day. Primary endpoint was incidence of grade 2+ radiation-induced pulmonary toxicity in the first year.

RESULTS

Eighty-one patients were accrued between June 2003 and August 2007. Given the low accrual rate, the study was closed early. No significant safety issues were encountered. Eight patients were ineligible for registration or withdrew consent before randomization and 40 patients were not randomized postradiation. Major reasons for nonrandomization included patients' refusal and physician preference. Of the 33 randomized patients, 20 were analyzable (13 observation, 7 captopril). The incidence of grade 2+ pulmonary toxicity attributable to radiation therapy was 23% (3/13) in the observation arm and 14% (1/7) in the captopril arm.

CONCLUSIONS

Despite significant resources and multiple amendments, NRG Oncology Radiation Therapy Oncology Group 0123 was unable to test the hypothesis that captopril mitigates radiation-induced pulmonary toxicity. It did show the safety of such an approach and the use of newer angiotensin-converting enzyme inhibitors started during radiotherapy may solve the accrual problems.

Validation of a Predictive Model for Survival in Patients With Advanced Cancer: Secondary Analysis of RTOG 9714

Background

The objective of this study was to validate a simple predictive model for survival of patients with advanced cancer.

Methods

Previous studies with training and validation datasets developed a model predicting survival of patients referred for palliative radiotherapy using three readily available factors: primary cancer site, site of metastases and Karnofsky performance score (KPS). This predictive model was used in the current study, where each factor was assigned a value proportional to its prognostic weight and the sum of the weighted scores for each patient was survival prediction score (SPS). Patients were also classified according to their number of risk factors (NRF). Three risk groups were established. The Radiation Therapy and Oncology Group (RTOG) 9714 data was used to provide an additional external validation set comprised of patients treated among multiple institutions with appropriate statistical tests.

Results

The RTOG external validation set comprised of 908 patients treated at 66 different radiation facilities from 1998 to 2002. The SPS method classified all patients into the low-risk group. Based on the NRF, two distinct risk groups with significantly different survival estimates were identified. The ability to predict survival was similar to that of the training and previous validation datasets for both the SPS and NRF methods.

Conclusions

The three variable NRF model is preferred because of its relative simplicity.

Phase II trial of combined high-dose-rate brachytherapy and external beam radiotherapy for adenocarcinoma of the prostate: preliminary results of RTOG 0321

PURPOSE

To estimate the rate of late Grade 3 or greater genitourinary (GU) and gastrointestinal (GI) adverse events (AEs) after treatment with external beam radiotherapy and prostate high-dose-rate (HDR) brachytherapy.

METHODS AND MATERIALS

Each participating institution submitted computed tomography-based HDR brachytherapy dosimetry data electronically for credentialing and for each study patient. Patients with locally confined Stage T1c-T3b prostate cancer were eligible for the present study. All patients were treated with 45 Gy in 25 fractions using external beam radiotherapy and one HDR implant delivering 19 Gy in two fractions. All AEs were graded according to the Common Terminology Criteria for Adverse Events, version 3.0. Late GU/GI AEs were defined as those occurring >9 months from the start of the protocol treatment, in patients with ≥18 months of potential follow-up.

RESULTS

A total of 129 patients from 14 institutions were enrolled in the present study. Of the 129 patients, 125 were eligible, and AE data were available for 112 patients at analysis. The pretreatment characteristics of the patients were as follows: Stage T1c-T2c, 91%; Stage T3a-T3b, 9%; prostate-specific antigen level ≤10 ng/mL, 70%; prostate-specific antigen level >10 but ≤20 ng/mL, 30%; and Gleason score 2-6, 10%; Gleason score 7, 72%; and Gleason score 8-10, 18%. At a median follow-up of 29.6 months, three acute and four late Grade 3 GU/GI AEs were reported. The estimated rate of late Grade 3-5 GU and GI AEs at 18 months was 2.56%.

CONCLUSION

This is the first prospective, multi-institutional trial of computed tomography-based HDR brachytherapy and external beam radiotherapy. The technique and doses used in the present study resulted in acceptable levels of AEs.

Confirmatory factor analysis of brief pain inventory (BPI) functional interference clusters in patients with bone metastases

To determine which of the previously proposed functional interference cluster models is most appropriate in patients with bone metastases and to determine if the cluster structures identified at baseline differed between responders and non-responders following palliative radiotherapy. METHODS: The confirmatory test data set consists of breast and prostate cancer patients treated with palliative radiotherapy between May 2003 to January 2007. Worst pain and functional interference scores were assessed using Brief Pain Inventory at baseline, 4, 8 and 12 weeks post radiation treatment. The baseline cluster structure of the confirmatory dataset was compared to each of the previously proposed baseline cluster models. Maximum likelihood CFA was used to account for possible correlation amongst the factor components. A MIMIC model was used to determine the invariance of the cluster models between responders and non-responders during follow-up. RESULTS: A total of 169 eligible patients were analysed. There were 91 male and 78 female patients with a median age of 68 years. The median KPS was 70. A single 8 Gy and 20 Gy in 5 fractions were used in 97% of all analysed patients. The RTOG model, in which relationships with others and sleep comprised the mood-related interference cluster and walking ability and normal work comprised the physical-interference cluster, provides the best fit for the sample data. The follow-up cluster structure is not similar across the responder groups indicating that cluster structures shift following radiation treatment, as evidenced by pain response. CONCLUSION: Although differing slightly this analysis confirms pretreatment symptom clusters exist for patients with bone metastases from breast or prostate cancer based on the RTOG 9714 data. This could help formulate symptom management interventions at initial diagnosis. Symptom clusters dissolve or change after treatment which may be a function of the treatment or population and requires further study.

Can physicians accurately predict survival time in patients with metastatic cancer? Analysis of RTOG 97-14

PURPOSE

To determine if physician prediction of survival duration (PSD) is accurate for patients with metastatic breast or prostate cancer.

METHODS

Radiation Therapy Oncology Group 9714 (RTOG 9714) was a randomized comparison of radiotherapy schedules for treatment of bone metastases. The treating physician assigned a baseline Karnofsky Performance Score (KPS) and predicted survival duration at study entry. Patients completed the Functional Assessment of Cancer Therapy (FACT). These three were compared to actual survival time.

RESULTS

Eight hundred ninety-eight patients were eligible and analyzable. Actual median survival was 9.3 months. The median PSD was 12 months. PSD, KPS, and FACT were all moderately correlated with actual survival. Patients with higher KPS had a longer survival time (882 patients, Spearman's rho = 0.259, p < 0.0001). The median survival of the 618 expired patients is 6.5 months (PSD was 12 months). The PSD was within 1 month of actual survival in 61 (10%), with 177 (29%) patients surviving more than 1 month longer than predicted and 375 (61%) surviving more than 1 month less than predicted. A univariate analysis of actual overall survival was performed, dividing the PSD into 4 groups. For predicted survivals of 6 months or less, less than 6 to less than 12 months, 12 months, and more than 12 months, median actual survivals were 7.0, 7.2, 9.7. and 13.5 months (p < 0.0001).

CONCLUSIONS

KPS, FACT scores, and PSD all are correlated with actual survival. Physicians on this study were able to predict which patients would have longer survival times, although prediction of survival was optimistic compared to actual survival by an average of 3 months.

Hypophosphatemic vitamin D-resistant rickets, precocious puberty, and the epidermal nevus syndrome

BACKGROUND

The association of multisystem pathologic conditions and epidermal nevi, known as the epidermal nevus syndrome, includes disorders of bone, central nervous system, eye, kidney, vasculature, body symmetry, and skin. Rarely, vitamin D-resistant rickets has been observed in association with this syndrome. Precocious puberty is another rare finding associated with epidermal nevus syndrome, having been observed in 3 patients.

OBSERVATION

A female infant with an extensive epidermal nevus, hypophosphatemia, and precocious puberty is described. Despite medical therapy, the patient's phosphate levels continued to be very low (0.87-0.97 mmol/L), establishing the diagnosis of hypophosphatemic vitamin D-resistant rickets. At 21 months of age, areas of the nevus were excised. Laboratory values obtained shortly after the operation showed a significant, but transient, improvement in the serum phosphate level. After a second excision, maintenance of her serum phosphate level in the range of 1.29 to 1.61 mmol/L was possible.

CONCLUSIONS

There is evidence that epidermal nevi produce a potent phosphaturic factor. We hypothesize that limited excision debulked the nevus sufficiently to allow medical management of the hypophosphatemia. Surgical intervention should be considered for patients affected with vitamin D-resistant rickets with epidermal nevi. The cause of the precocious puberty is unknown. It may be hypothesized that the nevus released a factor that induced puberty.

Blue vitiligo

The progression of vitiligo and postinflammatory hyperpigmentation simultaneously in a patient with AIDS led to the appearance of a blue color on much of the patient's skin. The blue coloration subsequently resolved with follicular repigmentation typical of resolving vitiligo. We believe this is the first reported case of "blue vitiligo."

Three parallel linkage groups of human acidic keratin genes

Two regions of human genomic DNA, each containing several keratin genes, were isolated and partially sequenced. The keratin genes are inactive, having suffered deleterious mutations. Both regions contain at least four keratin genes arranged in a head-to-tail orientation including a pseudogene for keratin K#16. Within each segment there are two keratin genes in close linkage with only 1.5 kb of DNA between them. Sequence comparison of the two regions showed 98.9% identity in both the coding and the intronic segments of the pseudogenes. The pseudogenes show 94% identity to their functional counterparts. Southern hybridization analysis showed that the segments are paralogous, not allelic. The regions are products of two independent, recent duplication events. The first occurred approximately 24 million years ago, after the separation of primates from the rhesus/baboon line. The second is specific for the human lineage, having occurred approximately 3.8 million years ago. Analysis of the genomic DNAs of primates showed the presence of only one of the regions in the DNAs of gibbon and gorilla, while rhesus monkey and baboon were missing both copies. We conclude that the human keratin genes are still actively evolving, with new duplications having occurred as recently as after the separation of human and gorilla ancestors.