A phase 2 trial of salvage radiation and concurrent weekly docetaxel after a rising prostate-specific antigen level after radical prostatectomy

Purpose/Objective(s)

We sought to assess the utility of docetaxel administered concurrently with salvage radiation therapy (SRT) following postprostatectomy biochemical failure (BF).

Methods and materials

Men with postprostatectomy BF were accrued on a single-arm phase 2 clinical trial. SRT doses ranged from 64.8 to 70.2 Gy and were delivered in 1.8-Gy fractions to the prostate bed alone as the clinical target volume with a +1-cm uniform planning target volume expansion. The primary endpoint was progression-free survival at 4 years compared with the Stephenson nomogram estimate. Kaplan-Meier methods were used to assess late toxicity, BF, and distant metastases. An unplanned matched-pair analysis was performed with 19 patients treated with SRT alone.

Results

Nineteen men were accrued and treated. Median follow-up was 4.8 years. Median pre-RT prostate-specific antigen level was 0.7 ng/mL (interquartile range, 0.4-1.3 ng/mL). All 8 cycles of docetaxel were completed in 17 (89%) patients. Acute grade 1-4 toxicities were observed in 79%, 50%, 58%, and 11%, respectively. A total of 68% of acute grade 1 toxicities were related to fatigue, urinary, or bowel symptoms. For grade 2 toxicities, 76% were related to neutropenia, fatigue, or urinary symptoms. Acute grade 3 and 4 toxicities were most commonly neutropenia (84% and 100%, respectively). All late toxicities were grade 1 to 2 with 89% related to bowel or urinary function. Predicted 4-year progression-free survival was 39% and observed was 42% (90% confidence interval [CI], 24-60). Matched-pair analysis demonstrated no significant improvement in BF (P = .96, hazard ratio, 0.98; 90% CI, 0.4-2.3) or distant metastases (P = .09; hazard ratio, 0.3; 90% CI, 0.07-1.2), and no difference between late bowel (P = .60) or urinary toxicity (P = .41).

Conclusions

Docetaxel can safely be administered concurrently with SRT without significantly impacting posttreatment toxicity. Neutropenia was the most significant acute toxicity. Given the small sample size, no clear clinical benefit was observed. Larger studies are needed to determine the efficacy of concurrent docetaxel in this setting.

Randomized phase II trial of urethral sparing intensity modulated radiation therapy in low-risk prostate cancer: implications for focal therapy

Background

Low-risk prostate cancer (PCa) patients have excellent outcomes, with treatment modality often selected by perceived effects on quality of life. Acute urinary symptoms are common during external beam radiotherapy (EBRT), while chronic symptoms have been linked to urethral dose. Since most low-risk PCa occurs in the peripheral zone (PZ), we hypothesized that EBRT using urethral sparing intensity modulated radiation therapy (US-IMRT) could improve urinary health-related quality of life (HRQOL) while maintaining high rates of PCa control.

Methods

Patients with National Comprehensive Cancer Network (NCCN) defined low-risk PCa with no visible lesion within 5 mm of the prostatic urethra on MRI were randomized to US-IMRT or standard (S-) IMRT. Prescription dose was 75.6 Gy in 41 fractions to the PZ + 3–5 mm for US-IMRT and to the prostate + 3 mm for S-IMRT. For US-IMRT, mean proximal and distal urethral doses were limited to 65 Gy and 74 Gy, respectively. HRQOL was assessed using the Expanded Prostate Cancer Index (EPIC) Quality of Life questionnaire. The primary endpoint was change in urinary HRQOL at 3 months.

Results

From June 2004 to November 2006, 16 patients were randomized, after which a futility analysis concluded that continued accrual was unlikely to demonstrate a difference in the primary endpoint. Mean change in EPIC urinary HRQOL at 3 months was −0.5 ± 11.2 in the US-IMRT arm and +3.9 ± 15.3 in the S-IMRT arm (p = 0.52). Median PSA nadir was higher in the US-IMRT arm (1.46 vs. 0.78, p = 0.05). At 4.7 years median follow-up, three US-IMRT and no S-IMRT patients experienced PSA failure (p = 0.06; HR 8.8, 95% CI 0.9–86). Two out of 3 patients with PSA failure had biopsy-proven local failure, both located contralateral to the original site of disease.

Conclusions

Compared with S-IMRT, US-IMRT failed to improve urinary HRQOL and resulted in higher PSA nadir and inferior biochemical control. The high rate of PSA failure and contralateral local failures in US-IMRT patients, despite careful selection of MRI-screened low-risk patients, serve as a cautionary tale for focal PCa treatments.

Adjuvant therapy for soft tissue sarcoma

Wide surgical excision is the backbone of therapy for localized soft tissue sarcoma and often produces excellent results. Patients with a marginal resection of disease and high-grade or large tumors are at an increased risk of recurrence. Radiation therapy (external beam or brachytherapy) has been shown to reduce the risk of local recurrence of disease and should be offered to patients with large (>5 cm) or high-grade sarcomas, especially if a wide resection cannot be performed. Use of preoperative versus postoperative radiation therapy should be planned, in consultation with a radiation oncologist and a surgical oncologist, before resection of the sarcoma if possible. Chemotherapy using an anthracycline- and ifosfamide-based regimen may improve disease-free and overall survival rates. Chemotherapy appears to be most beneficial for patients with very large (> or = 10 cm), high-grade sarcomas of the extremity who are at a high risk of experiencing distant recurrence of disease. The effect of adjuvant chemotherapy on overall survival remains controversial. Research is greatly needed to identify the patients who are most likely to benefit from conventional chemotherapy, improve the treatment of retroperitoneal sarcomas, and identify novel agents that may impact the natural history of high-risk soft tissue sarcoma.

Inhibition of mTOR radiosensitizes soft tissue sarcoma and tumor vasculature

PURPOSE

The PI3K/Akt/mTOR prosurvival pathway is frequently up-regulated in soft tissue sarcoma. Mammalian target of rapamycin (mTOR) inhibitors, such as rapamycin, have recently shown clinical benefit in soft tissue sarcoma, and mTOR inhibition has also been associated with radiosensitization of carcinoma and endothelial cells. This study tested the hypothesis that rapamycin radiosensitizes soft tissue sarcoma and endothelial cells in vitro and in vivo through the inhibition of mTOR.

EXPERIMENTAL DESIGN

Colony formation assays were done to determine the radiosensitizing properties of rapamycin on three human soft tissue sarcoma cell lines (SK-LMS-1, SW-872, and HT-1080) and human dermal microvascular endothelial cells (HDMEC). The functional effects of rapamycin and radiation on the endothelial compartment were evaluated with microvascular sprouting assays. The in vivo radiosensitizing activity of rapamycin was assessed with s.c. SK-LMS-1 nude mice xenografts treated with concurrent daily rapamycin, radiation, or both for three weeks.

RESULTS

In vitro radiosensitization was shown in all three soft tissue sarcoma cell lines with minimally cytotoxic doses of rapamycin. SK-LMS-1 xenografts displayed significant tumor growth delay with rapamycin and radiation compared with either treatment alone. Radiation resulted in transient increased mTOR function, whereas rapamycin abolished this signaling in irradiated and unirradiated samples. In HDMEC, rapamycin and radiation reduced microvessel sprouting, but did not alter colony formation.

CONCLUSIONS

Minimally cytotoxic concentrations of rapamycin inhibited the mTOR cascade in culture and in vivo while radiosensitizing soft tissue sarcoma, and produced synergistic effects with radiation on HDMEC microvessel formation. By targeting both tumor and endothelial compartments, rapamycin produced potent radiosensitization of soft tissue sarcoma xenografts. Clinical trials combining rapamycin and radiotherapy in soft tissue sarcoma are warranted.

Potential surrogate endpoints for prostate cancer survival: analysis of a phase III randomized trial

BACKGROUND

The identification of surrogate endpoints for prostate cancer-specific survival may shorten the length of clinical trials for prostate cancer. We evaluated distant metastasis and general clinical treatment failure as potential surrogates for prostate cancer-specific survival by use of data from the Radiation Therapy and Oncology Group 92-02 randomized trial.

METHODS

Patients (n = 1554 randomly assigned and 1521 evaluable for this analysis) with locally advanced prostate cancer had been treated with 4 months of neoadjuvant and concurrent androgen deprivation therapy with external beam radiation therapy and then randomly assigned to no additional therapy (control arm) or 24 additional months of androgen deprivation therapy (experimental arm). Data from landmark analyses at 3 and 5 years for general clinical treatment failure (defined as documented local disease progression, regional or distant metastasis, initiation of androgen deprivation therapy, or a prostate-specific antigen level of 25 ng/mL or higher after radiation therapy) and/or distant metastasis were tested as surrogate endpoints for prostate cancer-specific survival at 10 years by use of Prentice's four criteria. All statistical tests were two-sided.

RESULTS

At 3 years, 1364 patients were alive and contributed data for analysis. Both distant metastasis and general clinical treatment failure at 3 years were consistent with all four of Prentice's criteria for being surrogate endpoints for prostate cancer-specific survival at 10 years. At 5 years, 1178 patients were alive and contributed data for analysis. Although prostate cancer-specific survival was not statistically significantly different between treatment arms at 5 years (P = .08), both endpoints were consistent with Prentice's remaining criteria.

CONCLUSIONS

Distant metastasis and general clinical treatment failure at 3 years may be candidate surrogate endpoints for prostate cancer-specific survival at 10 years. These endpoints, however, must be validated in other datasets.

Loss of Raf kinase inhibitory protein induces radioresistance in prostate cancer

PURPOSE

External beam radiotherapy (RT) is often used in an attempt to cure localized prostate cancer (PCa), but it is only palliative against disseminated disease. Raf kinase inhibitory protein (RKIP) is a metastasis suppressor whose expression is reduced in approximately 50% of localized PCa tissues and is absent in metastases. Chemotherapeutic agents have been shown to induce tumor apoptosis through induction of RKIP expression. Our goal was to test whether RT similarly induces apoptosis through induction of RKIP expression.

METHODS AND MATERIALS

The C4-2B PCa cell line was engineered to overexpress or underexpress RKIP. The engineered cells were tested for apoptosis in cell culture and tumor regression in mice after RT.

RESULTS

RT induced both RKIP expression and apoptosis of PCa cells. Overexpression of RKIP sensitized PCa cells to radiation-induced apoptosis. In contrast, short-hairpin targeting of RKIP, so that RT could not induce RKIP expression, protected cells from radiation-induced apoptosis. In a murine model, knockdown of RKIP in PCa cells diminished radiation-induced apoptosis. Molecular concept mapping of genes altered on manipulation of RKIP expression revealed an inverse correlation with the concept of genes altered by RT.

CONCLUSION

The data presented in this report indicate that the loss of RKIP, as seen in primary PCa tumors and metastases, confers protection against radiation-induced apoptosis. Therefore, it is conceivable that the loss of RKIP confers a growth advantage on PCa cells at distant sites, because the loss of RKIP would decrease apoptosis, favoring proliferation.

No effect of statins on biochemical outcomes after radiotherapy for localized prostate cancer

OBJECTIVES

To examine the effect of concurrent statin use during definitive radiotherapy (RT) on the biochemical outcomes for localized prostate cancer.

METHODS

A total of 968 patients treated with RT had information about medication use available. Of these, 23% had been taking using statins during RT. Progression-free survival (PFS) was determined by a biochemical failure definition of prostate-specific antigen nadir plus 2 ng/mL, clinical failure, start of androgen deprivation therapy, or death.

RESULTS

The mean patient age was 68 years. The median radiation dose was 76 Gy. Of the patients, 29% underwent androgen deprivation therapy. The 5-year overall survival rate was 83%. The median PFS time was 7.8 years versus 6.4 years, and the 5-year PFS rate was 70% versus 59% in favor of the statin users (P = 0.03). The analysis by risk group demonstrated no significant statin effect in any of the three risk strata. Stratification by hydrophilic versus hydrophobic statin agents revealed similar results. Multivariate analysis revealed that T stage (P <0.0001), pretreatment prostate-specific antigen level (P <0.0001), and Gleason score (P = 0.0026) were significant predictors of PFS; however, statin use (P = 0.48), androgen deprivation therapy (P = 0.95), pelvic RT (P = 0.96), radiation dose (P = 0.13), age (P = 0.19), and year of treatment (P = 0.07) were not.

CONCLUSIONS

Statin use did not affect PFS after adjusting for differences in treatment year and multiple prognostic factors. However, T stage, baseline prostate-specific antigen level, and Gleason score were critical determinants of prostate-specific antigen failure. These results did not differ when hydrophilic pravastatin was excluded.

Long-Term Outcomes After Radiotherapy for Retroperitoneal and Deep Truncal Sarcoma

PURPOSE

To determine the long-term outcomes after multimodality treatment of retroperitoneal, pelvic, and deep truncal sarcomas and to identify the factors associated with local control (LC), distant metastasis (DM), and overall survival (OS).

METHODS AND MATERIALS

A total of 85 patients with retroperitoneal, pelvic, and deep truncal sarcomas were treated with radiotherapy (RT) between 1987 and 2005. A retrospective analysis of LC, DM, and OS was conducted using log-rank and Cox regression statistical methods.

RESULTS

The 2- and 5-year LC, DM, and OS rates were 66% and 51%, 38% and 58%, and 70% and 34%, respectively. Negative surgical margins and a higher radiation dose were associated with greater LC rates on both univariate and multivariate analyses, and female gender was significantly associated with greater LC on multivariate analysis only. None of the analyzed risk factors was significantly associated with DM, although patients with high-grade tumors showed a trend toward an increased risk of DM. Gross residual disease after resection and high tumor grade were associated with worse OS rates on univariate and multivariate analyses, and male gender was significantly associated with worse OS on multivariate analysis only. A time-dependent analysis of LC in relation to DM demonstrated that patients with local failure had a hazard ratio of 19.7 for DM compared with patients without local failure (p < 0.0001). Of the 85 patients, 5 and 8, respectively, had clinically significant acute and late toxicity.

CONCLUSION

The results of this study emphasize the importance of LC in patients with retroperitoneal sarcoma. Radiation dose escalation or radiosensitization strategies to enhance LC are warranted.

Percent positive biopsy cores as a prognostic factor for prostate cancer treated with external beam radiation

OBJECTIVES

To examine the prognostic value of percent positive cores (PPC) in prostate cancer patients treated with external beam radiotherapy (RT).

METHODS

An institutional review board-approved, retrospective analysis was conducted on 814 patients treated with RT with or without hormonal therapy between 1984 and 2002. Percent positive cores (number of positive cores divided by total number of cores) was calculable for 591 patients with a median follow-up of 65 months. Univariate and multivariable analyses were performed using Kaplan-Meier and Cox proportional hazard methods relating PPC to other risk factors, biochemical/clinical disease-free survival (PSA-DFS), prostate cancer-specific survival (DSS), and overall survival (OS).

RESULTS

Percent positive cores was associated with stage, Gleason score (GS), pretreatment serum prostate-specific antigen (PSA) level, and use of adjunctive androgen suppression therapy. The 5-year PSA-DFS, DSS, and OS rates were 80%, 99%, and 91%, respectively, for patients with PPC less than 50%, compared with 56%, 94%, and 87% for patients with PPC 50% or greater (P <0.0001, <0.004, and <0.04, respectively). Multivariable analysis revealed that PPC, stage, GS, PSA, and androgen suppression therapy were all significantly associated with PSA-DFS, whereas only GS was associated with DSS and OS. For high, intermediate, and low-risk patients, 5-year PSA-DFS was 62% versus 39%, 80% versus 59%, and 90% versus 82% for PPC less than 50% versus PPC 50% or greater, respectively.

CONCLUSIONS

Percent positive cores predicts outcome of prostate cancer patients treated with RT, independently of other known prognostic factors. Percent positive cores may have particular use for further risk stratification within established clinical risk categories.

Cochlear implantation with ipsilateral petroclival chondrosarcoma

OBJECTIVE

To highlight a case of cochlear implantation in the setting of ipsilateral petrous apex chondrosarcoma.

BACKGROUND

A patient with bilateral progressive hearing loss was incidentally found to have a destructive right petrous apex lesion on computed tomography before cochlear implantation. The patient had no associated symptoms and a magnetic resonance imaging scan was obtained, narrowing the differential diagnosis. A middle cranial fossa approach was performed for synchronous biopsy of the lesion and cochlear implantation.

RESULTS

Frozen sections revealed a low-grade chondroid lesion, and a Med-El Combi 40+ cochlear implant with a split electrode array was inserted via the middle fossa. Final pathologic examination revealed a Grade I chondrosarcoma. The patient suffered no complications postoperatively and was followed-up over 5 years with serial computed tomographic scans and clinical examinations. No additional treatment was administered. Eighteen months postoperatively, the patient experienced episodic vertigo. There were no new findings on computed tomography, and the vertigo improved with a low-salt diet. Otherwise, the patient had excellent hearing results, and the lesion has not progressed under observation.

CONCLUSION

The implications of observing low-grade chondrosarcomas in well-selected patients and the unique aspect of cochlear implantation on the affected side are discussed.

Full-dose gemcitabine and concurrent radiotherapy for unresectable pancreatic cancer

PURPOSE

Full-dose gemcitabine and concurrent radiotherapy is a promising treatment approach in unresectable pancreatic cancer. This study was conducted to assess the pattern of failure and toxicity associated with the use of conformal treatment volumes, omitting prophylactic lymph node irradiation.

METHODS AND MATERIALS

Seventy-four patients with locally advanced pancreatic cancer were treated between 1997 and 2005 with full-dose (1000 mg/m(2), Days 1, 8, and 15) gemcitabine and concurrent radiotherapy (36 Gy [median] in 15 daily fractions). The planning target volume (PTV) was limited to the gross tumor volume (GTV) plus 1-cm margin. Patient computed tomography (CT) scans were systematically reviewed to determine the pattern of failure. Kaplan-Meier and Cox-regression models were used to analyze freedom from local progression (FFLP), distant failure, overall survival (OS), and toxicity.

RESULTS

With a median follow-up of 10.6 months (20.6 months in living patients), the 1-year and 2-year FFLP rates were 64% and 38%, respectively. Four patients (5%) failed in the peripancreatic lymph nodes (3 in-field and 1 marginal failure). Median OS was 11.2 months. Analyzed as a time-dependent covariate, local failure was a significant predictor of OS (p = 0.0074). Sixteen patients (22%) had significant gastrointestinal (GI) toxicity (> or = Grade 3). PTV correlated with significant GI toxicity (p = 0.007).

CONCLUSIONS

Freedom from local progression in unresectable pancreatic cancer is suboptimal. In conjunction with full-dose gemcitabine, the use of conformal fields encompassing only the GTV helps reduce toxicity and does not result in marginal failures. Our findings provide rationale for intensification of local therapy in conjunction with more effective systemic therapy.

Targeted and systemic radiotherapy in the treatment of bone metastasis

Cancer metastasis to the bone develops commonly in patients with a variety of malignancies, and is a major cause of morbidity and diminished quality of life in a significant proportion of cancer patients. The effective treatment of bone metastasis requires cooperation between medical, surgical and radiation oncologists. Radiotherapy, either in the form of targeted external beam radiation therapy, or systemic administration of radionuclides, plays a central role in treatment of symptomatic bone metastases. The appropriate external beam treatment techniques, dose and fractionation regimens for the treatment of symptomatic, localized bone metastasis have been established in prospective clinical trials. Large-field, hemi-body irradiation has been utilized for treatment of symptoms related to more widely disseminated bone metastases, but has been associated with substantial toxicity. Strontium-89 and Samarium-153 are widely available systemically administered radionuclides that are useful for the treatment of widely disseminated disease, and have largely supplanted the use of hemi-body irradiation. Combined with appropriate medical and surgical interventions, as well as the appropriate use of analgesics, radiotherapy is a well-tolerated and highly effective treatment for the palliation of symptomatic bone metastases.

Multiple Interacting Oncogenes on the 8p11-p12 Amplicon in Human Breast Cancer

The 8p11-p12 genomic region is amplified in 15% of breast cancers and harbors several candidate oncogenes. However, functional evidence for a transforming role for these genes is lacking. We identified 21 genes from this region as potential oncogenes based on statistical association between copy number and expression. We further showed that three of these genes (LSM1, BAG4, and C8orf4) induce transformed phenotypes when overexpressed in MCF-10A cells, and overexpression of these genes in combination influences the growth factor independence phenotype and the ability of the cells to grow under anchorage-independent conditions. Thus, LSM1, BAG4, and C8orf4 are breast cancer oncogenes that can work in combination to influence the transformed phenotype in human mammary epithelial cells.

Nadir prostate-specific antigen within 12 months after radiotherapy predicts biochemical and distant failure

OBJECTIVES

To determine whether nadir prostate-specific antigen (PSA) levels within 12 months (nadir PSA12) after completion of radiotherapy (RT) can be used as an early marker of recurrence risk.

METHODS

A total of 4839 patients were treated with RT and without hormonal therapy from 1986 to 1995 for Stage T1-T2 prostate cancer at nine institutions. Of these 4839 patients, 4833, with a median follow-up of 6.3 years, met the criteria for analysis. The study endpoints included freedom from PSA failure, initiation of androgen deprivation, or documented local or distant failure (PSA-DFS); freedom from clinically apparent distant metastasis (DMFS); and overall survival (OS).

RESULTS

Patients with a nadir PSA12 of 2.0 ng/mL or less had an 8-year PSA-DFS, DMFS, and OS rate of 55%, 95%, and 73%, respectively, compared with 40%, 88%, and 69%, respectively, for patients with a nadir PSA12 of more than 2.0 ng/mL. Multivariate analysis confirmed that a nadir PSA12 of greater than 2 ng/mL was an independent predictor of PSA-DFS, DMFS, and OS. Classification and regression tree analysis identified the nadir PSA12 levels after RT associated with PSA-DFS, DMFS, and OS. Nadir PSA12, combined with the pretreatment PSA level, identified patients at particularly high risk of distant metastasis.

CONCLUSIONS

The results of this large, multi-institutional study have demonstrated that nadir PSA12 is predictive of clinical outcomes for patients with localized prostate cancer after RT. A high pretreatment PSA level and high nadir PSA12 will identify patients at particularly high risk who might benefit from early adjuvant therapy.

E-Cadherin Protein Expression Predicts Prostate Cancer Salvage Radiotherapy Outcomes

PURPOSE

Radiotherapy for biochemical prostate cancer recurrence after prostatectomy achieves durable salvage rates of only 40% to 50%. Improved methods of identifying patients unlikely to benefit from salvage radiotherapy are needed. Altered expression of the adhesion molecule E-cadherin may be associated with the invasive and metastatic phenotype. We examined the relationship between E-cadherin expression and outcomes after salvage radiotherapy.

MATERIALS AND METHODS

E-cadherin expression was examined by immunohistochemistical analysis of a tissue microarray of prostatectomy tissues from patients who underwent salvage radiotherapy. The relation between E-cadherin staining, other risk factors and biochemical failure after salvage radiotherapy was analyzed using Kaplan-Meier and Cox regression methods.

RESULTS

Of 37 analyzable cases 25 showed aberrant E-cadherin expression, while the remainder had normal expression. At a median clinical followup of 40 months univariate analysis demonstrated that E-cadherin staining was not associated with Gleason score, extracapsular extension, surgical margin status, pre-prostatectomy or pre-radiotherapy prostate specific antigen, complete biochemical response after radiotherapy or adjunctive hormonal therapy but it was associated with seminal vesicle invasion. Two-year failure-free survival was 55% in patients with aberrant E-cadherin expression compared with 92% in patients with normal E-cadherin expression (p = 0.02). Multivariate analysis confirmed that aberrant E-cadherin expression was associated with salvage radiotherapy failure (p = 0.03).

CONCLUSIONS

Aberrant E-cadherin staining is associated with increased biochemical failure rates after salvage radiotherapy. Patients with biochemical failure after prostatectomy and aberrant E-cadherin expression are likely to have subclinical disseminated disease. Early systemic therapy may be warranted in these patients.

Clonality of sarcomatous and carcinomatous elements in sarcomatoid carcinoma of the prostate

Sarcomatoid carcinomas of the prostate are rare malignancies composed of carcinomatous and sarcomatous elements. Their etiology is uncertain and may represent a single malignant process or a mixture of two distinct malignancies. We report a clinical case of a patient who presented with locally advanced disease and was treated with hormonal and cytotoxic chemotherapy, but ultimately developed distant metastasis and died of the disease. A loss-of-heterozygosity analysis of the primary and metastatic tissues provided compelling evidence that the carcinomatous and sarcomatous elements are clonally related, supporting the hypothesis that a single malignant process underlies the etiology of sarcomatoid carcinoma of the prostate.

Primary versus radiation-associated craniofacial osteosarcoma

BACKGROUND

Craniofacial osteosarcoma differs from long bone osteosarcoma in that patients are older, tumors are often low grade, and prognosis is more favorable. Although most are sporadic, some tumors occur in association with prior radiation therapy. The purpose of the current study was to compare clinicopathologic and prognostic features of primary and radiation-associated osteosarcoma.

METHODS

The study group consisted of 15 primary and 6 radiation-associated osteosarcomas. Clinical and follow-up data were obtained in every case. Tissue microarrays were immunohistochemically stained for p53, pRB, Ki-67 (MIB-1), and ezrin. DNA was sequenced for TP53 mutations.

RESULTS

All radiation-associated osteosarcomas were high grade and half were fibroblastic. In contrast, 47% of primary craniofacial osteosarcomas were high grade and only 1 was fibroblastic. All radiation-associated osteosarcomas recurred, half the patients died of disease, 2 were alive with unresectable tumors, whereas only 1 was alive without disease. In contrast, 80% of patients with primary tumors were alive without disease, 33% had local recurrences, and 13% died of disease. Radiation-associated tumors overexpressed p53 more often (33% vs. 13%), more often had TP53 mutations (33% vs. 8%), had higher proliferative activity (67% vs. 0% showing >50% MIB-1 staining), and expressed ezrin more frequently (83% vs. 40%) than primary tumors. Compared with a control group of 24 high- and 7 low-grade primary extremity osteosarcomas, radiation-associated tumors marked as the high-grade tumors.

CONCLUSIONS

Craniofacial radiation-associated osteosarcomas are high-grade tumors that behave more aggressively than most primary craniofacial osteosarcomas. In addition, they demonstrate higher expression rates of adverse prognostic indicators, further highlighting the distinction.

PSA nadir predicts biochemical and distant failures after external beam radiotherapy for prostate cancer: a multi-institutional analysis

PURPOSE

To determine the significance of prostate-specific antigen (PSA) nadir (nPSA) and the time to nPSA (T(nPSA)) in predicting biochemical or clinical disease-free survival (PSA-DFS) and distant metastasis-free survival (DMFS) in patients treated with definitive external beam radiotherapy (RT) for clinical Stage T1b-T2 prostate cancer.

METHODS AND MATERIALS

Nine participating institutions submitted data on 4839 patients treated between 1986 and 1995 for Stage T1b-T2cN0-NxM0 prostate cancer. All patients were treated definitively with RT alone to doses > or =60 Gy, without neoadjuvant or planned adjuvant androgen suppression. A total of 4833 patients with a median follow-up of 6.3 years met the criteria for analysis. Two endpoints were considered: (1) PSA-DFS, defined as freedom from PSA failure (American Society for Therapeutic Radiology and Oncology definition), initiation of androgen suppression after completion of RT, or documented local or distant failure; and (2) DMFS, defined as freedom from clinically apparent distant failure. In patients with failure, nPSA was defined as the lowest PSA measurement before any failure. In patients without failure, nPSA was the lowest PSA measurement during the entire follow-up period. T(nPSA) was calculated from the completion of RT to the nPSA date.

RESULTS

A greater nPSA level and shorter T(nPSA) were associated with decreased PSA-DFS and DMFS in all patients and in all risk categories (low [Stage T1b, T1c, or T2a, Gleason score < or =6, and PSA level < or =10 ng/mL], intermediate [Stage T1b, T1c, or T2a, Gleason score < or =6, and PSA level >10 but < or =20 ng/mL, or Stage T2b or T2c, Gleason score < or =6, and PSA level < or =20 ng/mL, or Gleason score 7 and PSA level < or =20 ng/mL], and high [Gleason score 8-10 or PSA level >20 ng/mL]), regardless of RT dose. The 8-year PSA-DFS and DMFS rate for patients with nPSA <0.5 ng/mL was 75% and 97%; nPSA > or =0.5 but <1.0 ng/mL, 52% and 96%; nPSA > or =1.0 but <2.0 ng/mL, 40% and 91%; and nPSA > or =2.0 ng/mL, 17% and 73%, respectively. The 8-year PSA-DFS and DMFS rate for patients with T(nPSA) <6 months was 27% and 66%; T(nPSA) > or =6 but <12 months, 31% and 85%; T(nPSA) > or =12 but <24 months, 42% and 94%; and T(nPSA) > or =24 months, 75% and 99%, respectively. A shorter T(nPSA) was associated with decreased PSA-DFS and DMFS, regardless of the nPSA. Both nPSA and T(nPSA) were significant predictors of PSA-DFS and DMFS in multivariate models incorporating clinical stage, Gleason score, initial PSA level, and RT dose. The significance of nPSA and T(nPSA) was supported by landmark analysis, as well as by analysis of nPSA and T(nPSA) as time-dependent covariates. A dose > or =70 Gy was associated with a lower nPSA level and longer T(nPSA) in all risk categories, and a greater dose was significantly associated with greater PSA-DFS and DMFS in multivariate analysis. Regression analysis confirmed that higher clinical stage, Gleason score, and initial PSA were associated with a greater nPSA level.

CONCLUSION

The results of this large, multi-institutional analysis of 4833 patients have provided important evidence that nPSA and T(nPSA) after definitive external beam RT are not only predictive of a predominantly PSA endpoint (PSA-DFS), but are also predictive of distant metastasis in all clinical risk categories. Greater RT doses were associated with lower nPSA, longer T(nPSA), and improved PSA-DFS and DMFS.

Genomic and Expression Analysis of the 8p11–12 Amplicon in Human Breast Cancer Cell Lines

Gene amplification is an important mechanism of oncogene activation in breast and other cancers. Characterization of amplified regions of the genome in breast cancer has led to the identification of important oncogenes including erbB-2/HER-2, C-MYC, and fibroblast growth factor receptor (FGFR) 2. Chromosome 8p11-p12 is amplified in 10-15% of human breast cancers. The putative oncogene FGFR1 localizes to this region; however, we show evidence that FGFR inhibition fails to slow growth of three breast cancer cell lines with 8p11-p12 amplification. We present a detailed analysis of this amplicon in three human breast cancer cell lines using comparative genomic hybridization, traditional Southern and Northern analysis, and chromosome 8 cDNA microarray expression profiling. This study has identified new candidate oncogenes within the 8p11-p12 region, supporting the hypothesis that genes other than FGFR1 may contribute to oncogenesis in breast cancers with proximal 8p amplification.

Family history of prostate cancer and relapse after definitive external beam radiation therapy

PURPOSE

The influence of family history on outcome after definitive therapy for prostate cancer has been disputed. One series reported increased relapse rates in men with a positive family history of prostate cancer treated with radical prostatectomy or radiation therapy, whereas others have reported no difference in outcome. We examined our series of patients treated with definitive external beam radiation therapy to determine if a positive family history for prostate cancer is associated with better or worse outcome.

METHODS AND MATERIALS

Family history information was available for 538 patients treated with radiation therapy for prostate cancer between 1983 and 2001. Prostate cancer in one or more first-degree relatives (father, brother, or son) was considered a positive family history. The endpoint of interest was time to prostate-specific antigen failure or initiation of hormonal therapy after radiation therapy.

RESULTS

Ninety-seven of 538 patients (18%) had a positive family history. There were no significant differences between the positive and negative family history groups. Family history had no effect on relapse-free survival rates in the entire cohort (p = 0.94) or in any subgroup. African American patients with a positive family history had significantly worse 5-year relapse-free survival rates, although there were few patients in this subgroup. Neither family history nor race was a statistically significant predictor of relapse in multivariate analysis; however, combined African American race and positive family history was associated with worse relapse-free survival rates.

CONCLUSIONS

In this large study of patients receiving definitive radiation therapy for localized prostate cancer, no relationship was found between positive first-degree family history of prostate cancer and relapse. The influence of family history on clinical outcome may be more understandable once the gene or genes responsible for hereditary prostate cancer are identified.

Linkage analysis of 153 prostate cancer families over a 30-cM region containing the putative susceptibility locus HPCX

Several genetic epidemiological studies have provided data to support the hypothesis that there are genes on the X chromosome that may contribute to prostate cancer susceptibility. A recent linkage study of 360 prostate cancer families described evidence for a prostate cancer predisposition gene, termed HPCX, which maps to Xq27-28. To confirm the potential contribution of this locus to prostate cancer susceptibility in an independent dataset, we studied 153 unrelated families who are participants in the University of Michigan Prostate Cancer Genetics Project. Families selected for this analysis have at least two living family members with prostate cancer that are related in a way that they could potentially share a common ancestral copy of an X chromosome. DNA samples were genotyped using a panel of seven polymorphic markers spanning 30 cM and containing the HPCX candidate region. The resulting data were analyzed using both nonparametric and parametric linkage methods. Analysis of all 153 families using multipoint non-parametric linkage (NPL) methods resulted in positive NPL Z-scores across the entire candidate interval (NPL Z-scores of 0.23-1.06, with corresponding one-sided Ps of 0.41 and 0.15, respectively). The 11 African-American families had negative NPL Z-scores across the same 30-cM interval. Analysis of the 140 Caucasian families produced a maximal NPL Z-score of 1.20, with a corresponding one-sided P of 0.12 at marker DXS1113. The subset of families with no evidence of male-to-male disease transmission and with early-onset prostate cancer (average age at diagnosis within a family < or = 65 years) contributed disproportionately to the evidence for linkage for the entire dataset in the HPCX candidate region (near marker DXS1113). In conclusion, this study of 153 families, each with two or more living members with prostate cancer, provides some additional support for the existence of a prostate cancer susceptibility gene at Xq27-28.

Cloning and tissue expression of the mouse ortholog of AIM1, a betagamma-crystallin superfamily member

We report the isolation of the murine ortholog of AIM1, a human gene whose expression is associated with the reversal of tumorigenicity in an experimental model of melanoma. Mouse and human AIM1 are more than 90% identical in amino acid sequence in the betagamma-crystallin repeats and the C-terminal domain, and more than 75% identical in the extended N-terminal domain. Consistent with the isolated cDNA representing the authentic AIM1 ortholog, linkage analysis localized mouse Aim1 to proximal mouse Chromosome (Chr) 10 in a conserved linkage group with genes localized to human Chr band 6q21. Searches of EST databases identified a second AIM1-like gene in both mouse and human, suggesting the existence of a gene family. Northern analysis demonstrates Aim1 is expressed most abundantly in adult skin, lung, heart, liver, and kidney and is temporally regulated during embryogenesis. Aim1 is expressed highly in the shaft region of the hair follicles and the presumptive ectoderm, but not at detectable levels in melanocytes or melanocyte precursor cells.

Cloning a novel member of the human interferon-inducible gene family associated with control of tumorigenicity in a model of human melanoma

Chromosome 6-mediated suppression of tumorigenicity in malignant melanoma cell lines provides a model system to identify genes associated with the reversion of the tumorigenic phenotype. Using subtractive cDNA selection, we recently identified a series of novel genes which are differentially expressed in association with chromosome 6-mediated suppression. We now report the molecular characterization of a novel gene termed AIM2 for (Absent In Melanoma), which represents a 1485 bp cDNA. An open reading frame of 1032 base pairs, corresponding to 344 amino acid residues, is predicted. The predicted protein shares a conserved sequence domain of approximately 200 amino acids with known interferon-inducible genes of both human and mouse. We demonstrate that the AIM2 gene encodes a transcript of approximately 2 kb which is expressed in spleen, small intestine, and peripheral blood leukocytes. In addition, we have localized AIM2 to the long arm of human chromosome 1 (band q22) in a highly conserved region which also contains the known interferon-inducible genes IFI16 and MNDA. We have also demonstrated that, like IFI16 and MNDA, AIM2 is induced in HL60 cells by interferon gamma. Our findings support the existence of a family of genes in this region similar to the well-characterized mouse Ifi200 gene family.

AIM1, a novel non-lens member of the betagamma-crystallin superfamily, is associated with the control of tumorigenicity in human malignant melanoma

AIM1 is a novel gene whose expression is associated with the experimental reversal of tumorigenicity of human malignant melanoma. The predicted protein product of the major 4.1-kb transcript shows striking similarity to the betagamma-crystallin superfamily. All known members of this superfamily contain two or four characteristic motifs arranged as one or two symmetrical domains. AIM1, in contrast, contains 12 betagamma motifs, suggesting a 6-domain structure resembling a trimer of beta- or gamma-crystallin subunits. The structure of the AIM1 gene shows remarkable similarity to beta-crystallin genes, with homologous introns delineating equivalent protein structural units. AIM1 is the first mammalian member of the betagamma superfamily with a primarily non-lens role. Other parts of the predicted AIM1 protein sequence have weak similarity with filament or actin-binding proteins. AIM1 is a good candidate for the putative suppressor of malignant melanoma on chromosome 6, possibly exerting its effects through interactions with the cytoskeleton.

Isolation of chromosome-specific ESTs by microdissection-mediated cDNA capture

Despite dramatic advances in the identification of human expressed sequence tags (ESTs), techniques that facilitate isolation of chromosome or chromosome band-specific ESTs would be of considerable value. This report demonstrates the feasibility of identifying chromosome-specific ESTs following microdissection of a single-copy chromosome region. For this study, a reduced complexity cDNA library was linkered and hybridized to normal human metaphase chromosomes. After stringency washes, the entire long arm of chromosome 6 (6q) was microdissected. Following PCR amplification using linker-specific primers, captured cDNAs were subcloned and 187 individual clones picked at random. These 187 clones were then sorted by filter cross-hybridization into 34 unique groups. Of these 34 groups, 19 (56%) mapped to chromosome 6 by Southern blot. We identified three previously known genes, human cytovillin (ezrin) mapped previously to 6q25-26, human cardiac gap junction protein (connexin 43) mapped previously to 6q21-23.2 and prolyloligopeptidase, which had not been mapped previously. BLASTN identified three clone groups with homology to known ESTs and 12 representing novel cDNA sequences. Six of the groups were sublocalized to specific band regions of 6q using a chromosome 6 hybrid mapping panel, five representative clones were tested on Northern analysis to verify their expression, and finally, nine clones were mapped against the Gene bridge 4 reduction hybrid panel to confirm their genetic map location on 6q. These results demonstrate that microdissection of single-copy sequences has sufficient specificity for isolation of chromosome-specific cDNAs.

Reversion of monochromosome-mediated suppression of tumorigenicity in malignant melanoma by retroviral transduction

We have developed a general strategy to reverse monochromosome suppression of the malignant phenotypes by retroviral transduction. Our approach involved the introduction of a retroviral expression vector-carried cDNA library into a chromosome 6-suppressed melanoma subline UACC-903(+6) [J. M. Trent et al., Science (Washington DC), 247: 568-571, 1990]. The cDNA library was constructed from polyadenylated RNA isolated from the suppressed UACC-903(+6) cells, packaged into high-titer amphotropic retrovirus particles, and transduced into UACC-903(+6) cells. Revertant his(R) transductants were selected by isolating colony-forming cells in soft agar. A total of 121 large (> 150 microm) colonies was picked from soft agar culture with 18 of 121 (15%) established as permanent sublines. The revertant sublines demonstrated 7-58% cloning efficiency upon plating in agar, in contrast to <0.05% for the UACC-903(+6) subline. All 18 revertant sublines, termed SRS1-SRS18 (for "selection of revertants for suppression"), displayed a reduced population-doubling time, with 9 of 18 showing focus formation in monolayer similar to the parental (nonsuppressed) cell line. Preliminary evidence for reversion of the suppressed phenotype by injection of cells into athymic nude mice has been completed for one revertant subline. Southern analysis has demonstrated integration of the retroviral vector sequence in all 18 sublines. This approach should facilitate the identification of genes involved in the tumorigenic phenotype of malignant melanoma, and is readily adaptable to other model systems.

Isolation and characterization of genes associated with chromosome-6 mediated tumor suppression in human malignant melanoma

Melanocytic transformation is thought to occur by the sequential accumulation of genetic alterations. Evidence implicating human chromosomes as a site for a gene(s) involved in melanoma suppression comes from studies of LOH [loss of heterozygosity], cytogenetics and biologic reversion of tumorigenicity following the introduction of a normal chromosome 6 by microcell-mediated chromosome transfer (Trent et al., 1990). Using a tumorigenic melanoma cell line (UACC 903) and a chromosome-6 suppressed melanoma subline [UACC 903 (+6)], we have isolated a series of genes uniquely expressed in the suppressed subline. A modified PCR-based cDNA subtraction technique was used to generate subtracted cDNA sublibraries for both the parental and (+6) suppressed cells. A total of 32 randomly selected clones from the suppressed sublibrary were isolated and examined, with 24 detecting a transcript by Northern analysis. Of these 24 clones, 21 (88%) demonstrated elevated expressed by Northern analysis in the suppressed subline relative to the tumorigenic parental cell line. In 6/21 differentially expressed clones (29%), expression was exclusive to the suppressed subline. Partial sequence analysis and database searching of these clones indicated that 5/6 were novel with one representing a previously characterized gene. Chromosomal localization of the five novel clones was performed following PCR amplification of a human/rodent somatic cell hybrid mapping panel or fluorescent in situ hybridization. One cDNA (termed AIM1) was localized to a band-region of chromosome 6 frequently deleted in melanomas (6q21). This novel approach should facilitate the identification of genes whose expression is causally related to the suppressed phenotype.

Rapid detection, cloning and molecular cytogenetic characterisation of sequences from an MRP-encoding amplicon by chromosome microdissection

Chromosome microdissection was utilised for the analysis of cytogenetic markers of gene amplification [homogeneously staining regions (hsrs) and double minutes (dmins)] in two doxorubicin-resistant cell lines, fibrosarcoma HT1080/DR4 and small-cell lung cancer H69AR. Microdissection products from the hsr(7)(p12p15) of HT1080/DR4 were amplified and used for fluorescent in situ hybridisation (micro-FISH) analysis of drug-sensitive HT1080, resistant HT1080/DR4 and normal lymphocytes. The results demonstrated that the hsr contains a domain of DNA amplification of complex origin including sequences derived from 16p11.2-16p13.1, 2q11.2, 7q32-7q34 and 10q22. The amplification was confirmed by converting the micro-dissected probe into a microclone library for probing HT1080 and HT1080/DR4 Southerns. A micro-FISH probe from normal band region 16p11-16p13 further demonstrated amplification of 16p sequences in both HT1080/DR4 and H69AR. During the course of this analysis, Cole et al. (1992) (Science, 258, 1650-1653) published the amplification of the MRP gene in H69AR cells, which maps to chromosome 16p13.1. Our results corroborate the finding of MRP amplification in these doxorubicin-resistant cell lines, but, importantly, they provide information on the composition of the complex amplicon contributions from four different chromosomes. This study demonstrates the potential utility of chromosome microdissection for the rapid recovery of sequences from amplified regions in drug-resistant cells.

Use of catheter-tip velocity--pressure transducer to evaluate left ventricular function in man: effects of intravenous propranolol

A catheter-tip velocity transducer with two high-fidelity pressure manometers was used to evaluate the left ventricular (LV) hemodynamic effects of intravenous propranolol (10 mg). Nine patients without clinical evidence of heart failure were studied. Pulsatile ascending aortic blood flow velocity and pressure and LV pressure were measured continuously during drug administration. Beat-to-beat changes in stroke volume index, stroke work index, LV end-diastolic pressure, maximum blood flow velocity and acceleration, and maximum LV dP/dt were determined. Propranolol produced a decrease in maximum blood flow velocity (from 58 +/- 4.7 to 42 +/- 5.1 cm/sec, p less than 0.002), and acceleration (from 1181 +/- 130 to 847 +/- 117 cm/sec2, p less than 0.002, max dP/dt (from 1361 +/- 70 to 1146 +/- 63 mm Hg/sec, p less than 0.002), stroke volume index (from 47 +/- 3.0 to 38 +/- 3.2 ml/m2, p less than 0.002) and total stroke work index (from 702 +/- 33 to 603 +/- 44 mJ/m2 p less than 0.04), with little change in mean aortic pressure, peak systolic pressure and LV end-diastolic pressure. Depression in myocardial function was detectable within 1 minute after initiation of propranolol and persisted when negative chronotropic effects were eliminated by atrial pacing. The multisensor catheter technique allows rapid and safe detection of changes in cardiovascular function during propranolol administration in conscious man.