Relationship between delay in radiotherapy and biochemical control in prostate cancer

Impact of delays in radiotherapy of head and neck cancer on outcome

BACKGROUND

In head and neck cancer (HNC), the relationship between a delay in starting radiotherapy (RT) and the outcome is unclear. The aim of the present study was to determine the impact of the amount of time before treatment intervention (TTI) and the growth kinetics of individual tumors on treatment outcomes and survival.

METHODS

Two hundred sixty-two HNC patients with 273 primary tumors, treated with definitive (chemo) RT, were retrospectively analyzed. The TTI was defined as the time interval between the date of histopathologic diagnosis and the first day of the RT course. Volumetric data on 57 tumors were obtained from diagnostic and RT planning computer tomography (CT) scans in order to calculate the tumor growth kinetic parameters.

RESULTS

No significant association between locoregional control or cause-specific hazards and TTI was found. The log hazard for locoregional recurrence linearly increased during the first 40 days of waiting for RT, although this was not significant. The median tumor volume relative increase rate and tumor volume doubling time was 3.2%/day and 19 days, respectively, and neither had any impact on locoregional control or cause-specific hazards.

CONCLUSION

The association between a delay in starting RT and the outcome is complex and does not harm all patients waiting for RT. Further research into imaging-derived kinetic data on individual tumors is warranted in order to identify patients at an increased risk of adverse outcomes due to a delay in starting RT.

Curative Radiation Therapy at Time of Progression Under Active Surveillance Compared With Up-front Radical Radiation Therapy for Prostate Cancer

PURPOSE

To describe and compare outcomes in men with initially presumed indolent prostate cancer receiving definitive radiation therapy after active surveillance (AS) versus those in a risk-matched cohort undergoing up-front radiation therapy.

METHODS AND MATERIALS

Men prospectively enrolled in an AS program between 1992 and 2014 and subsequently undergoing curative radiation therapy (ie, image guided radiation therapy [IGRT] or low-dose-rate brachytherapy [LDR-BT]) were identified. Biochemical relapse-free rate (bRFR), metastasis-free rate (mFR), and overall survival (OS) were compared against a cohort of men treated up front, matched by age, clinical prognostic indices (risk group, prostate-specific antigen, cT category, Gleason score, percentage of involved biopsy cores), and radiation therapy modality.

RESULTS

Of 1070 patients in the AS registry, 200 underwent definitive radiation therapy (143 IGRT and 57 LDR-BT) after a median of 32.9 (interquartile range [IQR] 20.6-59.8) months on surveillance. Main reasons for treatment were grade and volume upgrading (57.5% and 26%, respectively). Median follow-up after radiation therapy was 4.9 (IQR 3.1-7.5) years. At 5 years the bRFR, mFR, and OS were, respectively, 97%, 99%, and 98.5%. No patient died of prostate cancer. Adequate risk-matching was confirmed in an independent cohort comprising 359 patients receiving up-front IGRT (71%) or LDR-BT (29%) and followed for a median of 9 (IQR 3.1-7.5) years. There was no difference in the disease-specific outcomes (bRFR, mFR) between the 2 cohorts (Gray's P value of .257 and .934, respectively). In multivariate analyses, timing of radical radiation therapy (deferred vs up-front) was not correlated to biochemical relapse or metastases occurrence.

CONCLUSIONS

Curative-intent radiation therapy (ie, dose-escalated IGRT or LDR-BT) after a period of AS renders excellent oncologic outcomes at 5 years. Deferring radical therapy after a period of AS does not seem to result in inferior oncologic outcomes compared with patients with similar risk characteristics undergoing up-front treatment.

Evaluating the effect of time from prostate cancer diagnosis to radical prostatectomy on cancer control: Can surgery be postponed safely?

OBJECTIVE

To test the prognostic role of treatment delay in patients affected by prostate cancer (PCa).

MATERIALS AND METHODS

The study included 2,653 patients treated with radical prostatectomy (RP) at a single institution between 2006 and 2011. The evaluated outcomes were biochemical recurrence (BCR) and clinical recurrence (CR). Multivariable Cox regression analysis was used to test the association between time from diagnosis to RP and oncological outcomes. Nonparametric curve fitting methods were used to graphically explore the relationship between time from diagnosis to RP and oncological outcomes. Sensitivity analyses were repeated in the subgroups of low-, intermediate-, and high-risk patients.

RESULTS

At median follow-up of 56 months (interquartile range: 26, 92), 283 patients experienced BCR, and 84 patients developed CR. Median time from PCa diagnosis to surgery was 2.8 months (interquartile range: 1.6, 4.7). At multivariable Cox regression analysis, time from biopsy to RP was significantly associated with an increased risk of BCR (hazard ratio = 1.02, P = 0.0005) and CR (hazard ratio = 1.03, P = 0.0002). Using Nonparametric curve fitting methods, a significant increased risk of BCR and CR after approximately 18 months was observed. However, when sensitivity analyses were repeated according to risk groups, this effect was maintained in high-risk patients only, and such time interval was reduced to 12 months.

CONCLUSIONS

Despite the overall trend on higher rate of cancer relapse after RP, the effect of treatment delay from biopsy to RP was significantly evident in high-risk patients only. Even in high-risk patients surgical treatment can be postponed safely, but not beyond the 12-month landmark.

Effects of Time to Treatment on Biochemical and Clinical Outcomes for Patients With Prostate Cancer Treated With Definitive Radiation

INTRODUCTION

The purpose of this study was to evaluate if time to treatment (TTT) has an effect on outcomes for patients with localized prostate cancer treated with definitive external beam radiation therapy (EBRT).

PATIENTS AND METHODS

We included 4064 patients (1549 low-risk, 1612 intermediate-risk, and 903 high-risk) treated with EBRT. For each National Comprehensive Cancer Network (NCCN) risk group, TTT (defined as the time between initial positive prostate biopsy and start of RT) was analyzed in 4 intervals: < 3, 3-6, 6-9, and 9-24 months. We recorded the use of androgen deprivation therapy among patients with intermediate-risk and high-risk disease.

RESULTS

The median TTT was 3.3 months (range, 0.6-23.5 months), and it was similar for each risk group (range, 3.3-3.4 months). The median follow up was 64 months. There were no significant differences in biochemical failure, distant metastasis, or overall survival for patients with TTT < 3, 3-6, 6-9, or 9-24 months for each risk group. There were also no significant differences in the outcomes at 5 years when patients with TTT > 3.3 months were compared with those with TTT ≤ 3.3 months for each risk group. For high-risk men, 328 of 450 (72.9%) with TTT > 3.3 months were on androgen deprivation therapy (ADT) versus 299 of 453 (66%) with TTT ≤ 3.3 months. Among men with high-risk cancer treated without ADT, there remained no significant difference in outcomes between TTT > 3.3 months and TTT ≤ 3.3 months.

CONCLUSION

TTT was not associated with significant differences in outcomes among each risk group of men with localized prostate cancer treated with EBRT. Among the high-risk patients, there were no observed detriments in outcomes with TTT > 3.3 months regardless of androgen deprivation therapy use.

Effect of Patient Demographic Characteristics and Radiation Timing on PSA Reduction in Patients Treated With Definitive Radiation Therapy for Prostate Cancer

INTRODUCTION

The purpose of this study was to assess how demographic characteristics and temporal factors including time to treatment (TTT) and elapsed time of treatment (ETT) affect prostate-specific antigen (PSA) levels during and after radiation treatment for low- and intermediate-risk prostate cancer.

PATIENTS AND METHODS

A retrospective review of 1584 patients was conducted on patients diagnosed with prostate cancer between 2005 and 2013, from which 147 patients were found to have completed definitive external beam radiation therapy (EBRT) monotherapy. Demographic data, TTT (days between diagnosis and EBRT start date), ETT (days between EBRT start and stop date), and Gleason score were collected on these patients and analysis of variance was performed to analyze the relationship of these factors with PSA changes. PSA changes were calculated during treatment as the difference between pre- and posttreatment PSA levels and after treatment as 3-year and overall PSA velocities.

RESULTS

Patients who spoke Haitian Creole (P = .039) and those with a longer ETT (P = .029) had significantly greater PSA decline during treatment, primarily as a result of higher pretreatment PSA levels. Patients with Gleason score 4+3 disease had significantly greater 3-year (P = .033) and overall (P = .019) PSA velocities. Race and/or ethnicity, insurance type, marital status, and age were not associated with any PSA variable.

CONCLUSION

Disparities in prostate cancer are not reflected in PSA dynamics during or after radiation treatment, but are evident in PSA level at presentation. Timeliness of treatment was not found to affect true PSA change due to EBRT in low- and intermediate-risk prostate cancer patients.

Active surveillance for clinically localized prostate cancer--a systematic review

Active surveillance (AS) has been introduced as an observational strategy to delay or avoid curative treatment without compromising long-term cancer-specific survival. The 10 studies included in this review, published between 2008 and 2013, generally agreed upon patients selection for the AS strategy and how they should be managed within the program. However, uncertainties persists concerning optimal patient selection and reliable progression criteria, as well as the long-term safety of AS.

Racial and ethnic differences in time to treatment for patients with localized prostate cancer

OBJECTIVE

To investigate the racial/ethnic differences in the time to treatment among patients with prostate cancer.

MATERIALS AND METHODS

All 3448 men diagnosed with localized prostate cancer at Kaiser Permanente Southern California from 2006 to 2007 were identified. The patients were passively followed up through their electronic health records until definitive treatment, defined as the first treatment given with curative intent within 1 year of diagnosis. Cox proportional hazard models, with PROC SURVEYPHREG procedures, were used to account for the variability in time to the different treatments within multiple medical centers.

RESULTS

The overall median time to treatment was 102 days, with modest differences for whites (100 days), blacks (104 days), and Hispanics (99 days). In the adjusted model, black men had a significantly longer time to surgery (adjusted hazard ratio 0.74, 95% confidence interval 0.56-0.91) compared with white men. Hispanic men (adjusted hazard ratio 1.44, 95% confidence interval 1.07-1.74) experienced significantly shorter times to radiotherapy compared with white men. No difference was found in the time to radiotherapy or brachytherapy for black men relative to white men.

CONCLUSION

These data suggest that minimal racial/ethnic differences exist in the time to treatment after the diagnosis of prostate cancer in this equal-access setting. This is encouraging, but does not mean that all men were satisfied with their treatment choice.

Timing of curative treatment for prostate cancer: a systematic review

CONTEXT

Delaying definitive therapy unfavourably affects outcomes in many malignancies. Diagnostic, psychological, and logistical reasons but also active surveillance (AS) strategies can lead to treatment delay, an increase in the interval between the diagnosis and treatment of prostate cancer (PCa).

OBJECTIVE

To review and summarise the current literature on the impact of treatment delay on PCa oncologic outcomes.

EVIDENCE ACQUISITION

A comprehensive search of PubMed and Embase databases until 30 September 2012 was performed. Studies comparing pathologic, biochemical recurrence (BCR), and mortality outcomes between patients receiving direct and delayed curative treatment were included. Studies presenting single-arm results following AS were excluded.

EVIDENCE SYNTHESIS

Seventeen studies were included: 13 on radical prostatectomy, 3 on radiation therapy, and 1 combined both. A total of 34 517 PCa patients receiving radical local therapy between 1981 and 2009 were described. Some studies included low-risk PCa only; others included a wider spectrum of disease. Four studies found a significant effect of treatment delay on outcomes in multivariate analysis. Two included low-risk patients only, but it was unknown whether AS was applied or repeat biopsy triggered active therapy during AS. The two other studies found a negative effect on BCR rates of 2.5-9 mo delay in higher risk patients (respectively defined as any with T ≥ 2b, prostate-specific antigen >10, Gleason score >6, >34-50% positive cores; or D'Amico intermediate risk-group). All studies were retrospective and nonrandomised. Reasons for delay were not always clear, and time-to-event analyses may be subject to bias.

CONCLUSIONS

Treatment delay of several months or even years does not appear to affect outcomes of men with low-risk PCa. Limited data suggest treatment delay may have an impact on men with non-low-risk PCa. Most AS protocols suggest a confirmatory biopsy to avoid delaying treatment in those who harbour higher risk disease that was initially misclassified.

Effect of patient-related delay in diagnosis on the extent of disease and prognosis in nasopharyngeal carcinoma

BACKGROUND

The reasons causing the patient-related delay in diagnosis (PRDD) and the effects of PRDD on the extent of disease and prognosis in the nasopharyngeal carcinoma (NPC) remain uncertain. The aim of this study was to investigate the status of PRDD and evaluate the relationship between PRDD and prognostic factors of NPC.

METHODS

The data of 216 patients with NPC, from 2002 to 2006, were analyzed retrospectively with respect to patient age, gender, smoking status, education experience, living area, and symptoms. PRDD was recorded as the time from initial symptoms to the first visit to a medical doctor. The extent of disease was determined by TNM staging according to the International Union Against Cancer classification in 1997.

RESULTS

PRDD of the analyzed cases ranged from half a month to 24 months, with a mean delay in diagnosis of 5.6 months. Senior residents and low education population tended to have longer PRDD (p < 0.05). There was a significant correlation between PRDD and the degree of invasion, clinical stage of NPC (p < 0.05).

CONCLUSION

Senior residents and low education population tend to have longer PRDD. Delay in diagnosis correlates with the degree of invasion and stage of NPC.

Staging saturation biopsy in patients with prostate cancer on active surveillance protocol

OBJECTIVES

One option for the management of low-grade, low-stage prostate cancer is to delay or forego treatment unless evidence of an increased risk of disease progression exists. Accurate assessment of the disease extent and aggressiveness is necessary to determine the candidates for active surveillance (AS). Office-based saturation prostate biopsy (SB) provides more accurate staging than traditional biopsy; therefore, we studied its role in patients on an AS protocol.

METHODS

Our database identified 52 men with prostate cancer treated with AS from July 2000 to May 2007. The records were reviewed to determine the role of SB in determining the need for definitive therapy.

RESULTS

The patients had a median age of 69 years (range 51 to 83) and median prostate-specific antigen (PSA) level of 5.1 ng/mL (range 0.5 to 47). Patients underwent subsequent staging 20-core SB a median of 9 months (range 1 to 20 months) after diagnosis. The disease of 20 patients (38%) was upstaged as defined by an increase in Gleason score or increased disease volume, leading to a recommendation for active treatment. Patients with disease upstaging had had significantly fewer cores taken at the initial diagnostic biopsy (11% with 20 cores or more compared with 55% with fewer than 20 cores, P = 0.002).

CONCLUSIONS

SB might lead to a more accurate assessment of the extent and grade of disease in men with prostate cancer on an AS protocol than traditional biopsy. In our series, more than one half of patients who pursue an AS protocol delayed or avoided local therapy. No patient developed clinical metastasis, but long-term surveillance is required.