Impact of 18 F-Fluciclovine PET/CT Findings on Failure-Free Survival in Biochemical Recurrence of Prostate Cancer Following Salvage Radiation Therapy

PURPOSE

We aimed to evaluate the impact of 18 F-fluciclovine PET/CT imaging on failure-free survival (FFS) post-salvage radiotherapy (SRT) for prostate cancer (PCa) recurrence.

METHODS

Seventy-nine patients were recruited in a phase 2/3 clinical trial to undergo 18 F-fluciclovine PET/CT before SRT for PCa. Four patients with extrapelvic disease were excluded. All patients were followed up at regular intervals up to 48 months. Treatment failure was defined as a serum prostate-specific antigen level of ≥0.2 ng/mL above the nadir after SRT, confirmed with an additional measurement, requiring systemic treatment or clinical progression. Failure-free survival was computed and compared between patients grouped according to 18 F-fluciclovine PET/CT imaging findings.

RESULTS

Eighty percent (60/75) of patients had a positive finding on 18 F-fluciclovine PET/CT, of which 56.7% (34/60) had prostate bed-only uptake, whereas 43.3% (26/60) had pelvic nodal ± bed uptake. Following SRT, disease failure was detected in 36% (27/75) of patients. There was a significant difference in FFS between patients who had a positive versus negative scan (62.3% vs 92.9% [ P < 0.001] at 36 months and 59.4% vs 92.9% [ P < 0.001] at 48 months). Similarly, there was a significant difference in FFS between patients with uptake in pelvic nodes ± bed versus prostate bed only at 36 months (49.8% vs 70.7%; P = 0.003) and at 48 months (49.8% vs 65.6%; P = 0.040). Failure-free survival was also significantly higher in patients with either negative PET/CT or prostate bed-only disease versus those with pelvic nodal ± prostate bed disease at 36 (78% vs 49.8%, P < 0.001) and 48 months (74.4% vs 49.8%, P < 0.001).

CONCLUSIONS

Findings on pre-SRT 18 F-fluciclovine PET/CT imaging, even when acted upon to optimize the treatment decisions and treatment planning, are predictive of post-SRT FFS in men who experience PCa recurrence after radical prostatectomy. A negative 18 F-fluciclovine PET/CT is most predictive of a lower risk of failure, whereas the presence of pelvic nodal recurrence portends a higher risk of SRT failure.

Conditional Survival and Annual Hazard Estimates of Classical Hodgkin Lymphoma

Background

In the present study, we have tried to understand how the level of risk and survival probability changes over time for patients with classical Hodgkin’s lymphoma by employing conditional survival and annual hazard as dynamic estimates of prognosis and survival.

Methods

This retrospective study reviewed the clinical data of patients with newly diagnosed classical Hodgkin’s lymphoma admitted to Peking University Cancer Hospital between January 1, 2008, and December 31, 2017. Conditional survival and annual hazard rate were defined as the survival probability and yearly event rate, respectively, assuming that patients have survived for a defined time.

Results

A total of 384 patients were included (median age, 32 years; range, 6–77 years), of which 218 (56.8%) patients had early-stage disease. The median follow-up time was 41.3 months. The 5-year conditional overall survival (COS) rates remained favorable and showed an increase from 89% at treatment to 94% at year 5, while the 5-year conditional failure-free survival (CFFS) rate increased from 70% at treatment to 96% at year 5. The annual hazard of failure decreased from over 15% at diagnosis to less than 5% after 3 years. Early-stage patients had constantly lower annual estimates for hazard of death (range, 0–3.0%) and failure (range, 0–14.3%). However, the hazard of failure in advanced-stage patients decreased from 24.2% at diagnosis to below 8% after 3 years, whereas the hazard of death was always at relatively low levels. Patients with a high IPS risk score (≥3) had significantly lower COS and CFFS during the first 4 years. Patients who received the BEACOPP regimen had better 5-year COS and 5-year CFFS than those who received the ABVD regimen.

Conclusion

The survival probability increased and hazard of failure decreased over time.

Circulating tumor DNA alterations in patients with metastatic castration-resistant prostate cancer

BACKGROUND

Because cell-free DNA (cfDNA) analysis facilitates the noninvasive genomic profiling of metastatic castration-resistant prostate cancer (mCRPC), the authors evaluated the association between cfDNA alterations and outcomes and evolution with therapy.

METHODS

Patients with mCRPC underwent cfDNA genomic profiling using Guardant360, which examines major cancer-associated genes. Clinical factors, therapy information, failure-free survival, and overall survival (OS) were obtained for select patients. The association between genomic alterations and outcomes was investigated.

RESULTS

Of 514 men with mCRPC, 482 (94%) had ≥1 circulating tumor DNA (ctDNA) alteration. The most common recurrent somatic mutations were in TP53 (36%), androgen receptor (AR) (22%), adenomatous polyposis coli (APC) (10%), neurofibromin 1 (NF1) (9%), epidermal growth factor receptor (EGFR), catenin beta-1 (CTNNB1), and AT-rich interactive domain-containing protein 1A (ARID1A) (6% each); and BRCA1, BRCA2, and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (5% each) The most common genes with increased copy numbers were AR (30%), MYC (20%), and BRAF (18%). Clinical outcomes were available for 163 patients, 46 of whom (28.8%) were untreated for mCRPC. A higher number of ctDNA alterations, AR alterations, and amplifications of MYC and BRAF were associated with worse failure-free survival and/or OS. On multivariable analysis, MYC amplification remained significantly associated with OS. Prior therapy and serial profiling demonstrated the evolution of alterations in AR and other genes.

CONCLUSIONS

ctDNA frequently was detected in this large cohort of "real-world" patients with mCRPC, and the alterations appeared to be similar to previously reported tumor tissue alterations. A higher number of alterations, and AR and MYC alterations, appear to compromise clinical outcomes, suggesting a role for immune checkpoint inhibitors and novel AR and BET inhibitors in selected patients.

RandomizEd phase II trial of Sunitinib four weeks on and two weeks off versus Two weeks on and One week off in metastatic clear-cell type REnal cell carcinoma: RESTORE trial

BACKGROUND

The standard sunitinib schedule, 4 weeks on, followed by 2 weeks off (4/2 schedule), is associated with troublesome toxicities, and maintenance of adequate sunitinib dosing and drug levels, which are essential for achieving an optimal treatment outcome, is challenging. The objective of this study was to investigate the efficacy and safety of an alternative sunitinib dosing schedule of 2 weeks on and 1 week off (2/1 schedule) compared with the standard sunitinib schedule of 4 weeks on and 2 weeks off (4/2 schedule).

PATIENTS AND METHODS

In this multicenter, randomized, open-label, phase II trial, treatment-naïve patients with clear-cell type metastatic renal cell carcinoma (mRCC) were randomly assigned to 4/2 or 2/1 schedules after stratification by Memorial Sloan Kettering Cancer Center risk group and the presence or absence of measurable lesions. The primary end point was the 6-month failure-free survival (FFS) rate, determined by intention-to-treat analysis.

RESULTS

From November 2007 to February 2014, 76 patients were accrued, and 74 were eligible. FFS rates at 6 months were 44% with the 4/2 schedule (N = 36) and 63% with the 2/1 schedule (N = 38). Neutropenia (all grades, 61% versus 37%; grade 3-4, 28% versus 11%) and fatigue (all grades, 83% versus 58%) were more frequently observed with schedule 4/2. There was a strong tendency toward a lower incidence of stomatitis, hand-foot syndrome, and rash with schedule 2/1. Objective response rates (ORRs) were 47% in schedule 2/1 and 36% in schedule 4/2. With a median follow-up of 30.0 months, the median time to progression (TTP) was 12.1 months in schedule 2/1 and 10.1 months in schedule 4/2.

CONCLUSION

Sunitinib administered with a 2/1 schedule is associated with less toxicity and higher FFS at 6 months than a 4/2 schedule, without compromising the efficacy in terms of ORR and TTP (NCT00570882).

Endpoints in phase II trials for advanced non-small cell lung cancer

INTRODUCTION

We investigated the relationships between progression-free survival (PFS), response, confirmed response, and failure-free survival (FFS) with overall survival (OS) to assess their suitability as primary endpoints in phase II trials for advanced non-small cell lung cancer.

METHODS

Individual data of 284 patients from four phase II trials were pooled. Progression status and response were modeled as time dependent variables in a multivariable (adjusted for baseline age, gender, stage, and performance status) Cox proportional hazards model for OS, stratified by trial. Subsequently, Cox proportional hazards models were used to assess the impact of PFS, response, confirmed response, and FFS on subsequent survival, using landmark analysis at 8, 12, 16, 20, and 24 weeks. Model discrimination was evaluated using the concordance index (c-index).

RESULTS

The overall median OS, PFS, and FFS were 9.6, 3.7, and 2.8 months, and the response and confirmed response rates were 21 and 15%, respectively. Both progression status and response as time dependent covariates were significantly associated with OS (p < 0.0001; p = 0.009). PFS and FFS at 12 weeks significantly predicted for subsequent survival with the strongest c-index and hazard ratio combination in landmark analyses (hazard ratio, c-index: PFS: 0.39, 0.67; FFS: 0.37, 0.67). The c-indices for response and confirmed response were low (0.59-0.60), indicating their inability to sufficiently discriminate subsequent patient survival outcomes.

CONCLUSIONS

FFS or PFS at 12 weeks is a stronger predictor of subsequent patient survival compared with tumor response and should be routinely used as endpoints in phase II trials for advanced non-small cell lung cancer.