Late Urinary Toxicity and QoL with Curative Radiotherapy for High-Risk Prostate Cancer: Dose-Effect Relations in the POP-RT Randomized Phase III Trial

PURPOSE/OBJECTIVE(S)

Whole pelvic radiotherapy (WPRT) showed better biochemical failure-free survival and metastasis-free survival than prostate-only radiotherapy (PORT) in the phase III randomized POP-RT trial for high and very high-risk prostate cancer, albeit with higher RTOG grade 2 late urinary toxicity. We report updated long term, symptom-wise comparison and dose-effect relations from this trial.

MATERIALS/METHODS

Late urinary toxicity, and cumulative severity of each symptom over the follow-up period was graded using CTCAE v5.0. Grade 2+ toxicities were compared between the trial arms by chi square test. Bladder dosimetry in 5-Gy increments (V5, V10, V15...V65 Gy, V68 Gy) from the trial database of approved radiotherapy plans, was compared for each urinary symptom and overall late gr2+ toxicity by student t-test. Observed differences in dosimetric parameters were tested using multivariable logistic regression analysis, including age at diagnosis, known diabetes, tumor stage, trial arm, and prior transurethral resection of prostate (TURP). Urinary QOL scores were compared between arms using generalised linear mixed model.

RESULTS

Combined late symptom-wise toxicity and dose-volume data were available for analysis for 193/224 patients. At a median follow-up of 75 months, cumulative CTCAE gr2+ late urinary toxicity remained higher with WPRT than PORT, though not statistically significant (36.5% vs 26.8%, p = 0.15). Grade 3 toxicity was low and similar in both arms. Symptom-wise cumulative rates showed no significant difference between arms (Table 1). Dosimetric comparison showed significantly higher bladder V5-V15 in patients with gr2+ toxicity over those with

CONCLUSION

Compared to prostate-only radiotherapy, whole pelvic radiotherapy resulted similar Grade 3 urinary toxicity of about 5% with about 10% higher cumulative grade 2+ urinary toxicity over long term follow up. This difference was not reflected in patient-reported QOL. WPRT particularly increased urgency and hematuria. Larger bladder volume being irradiated with 5Gy to 15Gy dose range could contribute to increase in urinary symptoms.

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Affiliation(s)

G Maheshwari Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
P Maitre Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
J Sarkar Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
V Raveendran Department of Medical Physics, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
R Phurailatpam Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
P Singh Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
V Murthy Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India

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Outcomes in Locally Advanced Non-Metastatic Prostate Cancer Presenting with Low PSA at Diagnosis

PURPOSE/OBJECTIVE(S)

Men with low serum prostate-specific antigen (PSA) and high Gleason grade group (GGG) are thought to have poor outcomes compared to high PSA secretors. However, there is limited outcome data to support this. We report clinical outcomes from a single-institutional cohort of men presenting with locally advanced prostate cancer but low serum PSA.

MATERIALS/METHODS

Data from electronic database of a UK tertiary cancer center was acquired for men with histological diagnosis of prostate adenocarcinoma, GGG 4 or 5, stage ≥cT3a, and PSA <10ug/L at diagnosis. Men with metastatic disease, or prior androgen deprivation therapy (ADT) were excluded. Biochemical progression was defined as per Phoenix criteria (PSA > nadir+2) for primary radiotherapy, or PSA >0.2 ug/L after primary prostatectomy (and post-operative radiotherapy, if received). Overall survival (OS, from date of diagnosis to death), metastasis-free survival (MFS, from diagnosis to first recorded metastasis or death), and biochemical progression free survival (bPFS, from diagnosis to biochemical progression or death) were estimated by Kaplan Meier method, and multivariable analysis performed using Cox proportional hazards method.

RESULTS

Medical records of 7,200 men presenting with non-metastatic prostate cancer from 2013 to 2021 were screened, of which 270 men satisfying the eligibility criteria were included for this study. Initial analysis of 123 men shows median PSA at presentation 7.1 ug/L (IQR 5.6-8.5), and median age 70 years (IQR 65-75). Histology was GGG 4 in 47.6% and 5 in 52.4%. Tumor stage was cT3a in 56.6%, cT3b in 36.9%, and T4 in 6.6%. Pelvic nodes were involved in 5% patients. Majority (83.7%) were treated with radical radiotherapy (external beam alone 64.2%, brachytherapy boost 19.5%), with 24 months ADT; 11.4% underwent radical prostatectomy, and 4.9% received ADT alone. Three men (2.4%) received docetaxel, and one received abiraterone. At a median follow up of 66 months (IQR 27-77), 36 (29.3%) patients had biochemical failure. Total 23 (18.6%) patients had metastases at recurrence, which were visceral in 4%, bone-only in 10%, and nodal-only in 4%. Total 38 (30.6%) patients had died, 23% with prostate cancer and 11% due to other causes. Five-year bPFS was 65.9%, MFS 69.0%, and OS was 77.4%. GGG 5 (versus 4) was associated with significantly worse 5-year bPFS (59.4% vs 73.9%, HR 1.8, 95% CI 1.0-3.2, p = 0.05) and MFS (59.2% vs 81.6%, HR 2.2, 1.2-4.2, p = 0.02). On multivariable analysis including age and PSA at diagnosis, only GGG 5 was associated with worse bPFS (HR 1.8, 1.0-3.3, p = 0.05) and MFS (HR 2.42, 1.25-4.67, p = 0.009).

CONCLUSION

Men with low secreting but high Gleason grade group prostate cancer are a relatively rare group with poor clinical outcomes despite being non-metastatic. Ongoing work (expected completion June 2023) will analyze remaining cases, and compare outcomes within an expanded multicentric cohort with matched controls having elevated PSA at presentation.

Prospective Comparative Study of Quality of Life in Bladder Cancer Patients Undergoing Cystectomy or Bladder Preservation

PURPOSE/OBJECTIVE(S)

Health-related Quality of life (HRQOL) may be decisive when different treatments yield comparable survival outcomes. We compared QOL in patients undergoing radical cystectomy with ileal conduit (RCIC) or bladder preservation (BP) with (chemo)radiotherapy for bladder cancer.

MATERIALS/METHODS

Patients with histological diagnosis of bladder cancer, stage T1-T4, N0-N1, M0 with a minimum follow-up of 6 months from the last treatment intervention (RCIC or BP) and alive without disease at the time of QOL assessment were eligible for inclusion. After ethics committee approval, two HRQOL instruments were translated, validated and administered: Bladder cancer index (BCI) for bladder cancer-specific HRQOL, which includes 36 items under three domains - bladder, bowel and sexual function and the EORTC QLQ C30 which includes 30 items under three domains - functional, symptom and global health. The mean QOL scores across various domains and specific questions were compared between the two treatment groups using the independent t-test.

RESULTS

Of the 104 patients enrolled, 56 had RCIC, and 48 received BP, and included 95 (91.3%) males. The median time from treatment completion to QOL assessment was 22 months (IQR 10-56). The median age for the entire cohort was 62 years (IQR 55-68), 65.5 years (IQR 55-71) in BP and 59.5 years (IQR 55-66) in RCIC. Overall, mean BCI urinary scores and bowel scores were high in both groups, with no significant difference in function or bother subdomains between the two groups (Table 1). Overall, BCI sexual scores were low in both the groups but significantly better after BP (BPmean 56.9, RCICmean 41.5, p = 0.01). Mean scores for sexual function BPmean 38.4 and RCIC mean 25 p (0.07) and sexual bother BPmean 81 RCICmean 62 (p 0.02) subdomains. There was no significant difference in EORTC QOL outcomes in functional (BPmean 91.4, RCICmean 88.7 p 0.23), symptom (BPmean 89.8, RCICmean 89, p = 0.68) and global health scale (BPmean 76.8, RCICmean 78.5, p = 0.69) in both groups. On question-wise assessment, the ability to perform an exercise (BPmean 94.2, RCICmean 85, p = 0.06) and urinary leakage at night time (BPmean 91.7, RCICmean 77.6, p = 0.01) were better in the BP group, while scores for blood in the urine (BPmean 89.1, RCICmean 97, p = 0.05) were better in the RCIC group compared to BP.

CONCLUSION

Overall, QOL was good in both groups in the urinary and bowel domains while it was low in the sexual domain. However, bladder preservation performed significantly better in the sexual domain than RCIC.

Study Protocol of the Bladder Adjuvant RadioTherapy (BART) Trial: A Randomised Phase III Trial of Adjuvant Radiotherapy Following Cystectomy in Bladder Cancer

AIMS

To assess the efficacy and safety of adjuvant radiotherapy in patients with high-risk muscle-invasive bladder cancer (MIBC) following radical cystectomy (RC) and chemotherapy.

MATERIALS AND METHODS

The BART (Bladder Adjuvant RadioTherapy) trial is an ongoing multicentric, randomised, phase III trial comparing the efficacy and safety of adjuvant radiotherapy versus observation in patients with high-risk MIBC. The key eligibility criteria include ≥pT3, node-positive (pN+), positive margins and/or nodal yield <10, or, neoadjuvant chemotherapy for cT3/T4/N+ disease. In total, 153 patients will be accrued and randomised, in a 1:1 ratio, to either observation (standard arm) or adjuvant radiotherapy (test arm) following surgery and chemotherapy. Stratification parameters include nodal status (N+ versus N0) and chemotherapy (neoadjuvant chemotherapy versus adjuvant chemotherapy versus no chemotherapy). For patients in the test arm, adjuvant radiotherapy to cystectomy bed and pelvic nodes is planned with intensity-modulated radiotherapy to a dose of 50.4 Gy in 28 fractions using daily image guidance. All patients will follow-up with 3-monthly clinical review and urine cytology for 2 years and subsequently 6 monthly until 5 years, with contrast-enhanced computed tomography abdomen pelvis 6 monthly for 2 years and annually until 5 years. Physician-scored toxicity using Common Terminology Criteria for Adverse Events version 5.0 and patient-reported quality of life using the Functional Assessment of Cancer Therapy - Colorectal questionnaire is recorded pre-treatment and at follow-up.

ENDPOINTS AND STATISTICS

The primary endpoint is 2-year locoregional recurrence-free survival. The sample size calculation was based on the estimated improvement in 2-year locoregional recurrence-free survival from 70% in the standard arm to 85% in the test arm (hazard ratio 0.45) using 80% statistical power and a two-sided alpha error of 0.05. Secondary endpoints include disease-free survival, overall survival, acute and late toxicity, patterns of failure and quality of life.

CONCLUSION

The BART trial aims to evaluate whether contemporary radiotherapy after standard-of-care surgery and chemotherapy reduces pelvic recurrences safely and also potentially affects survival in high-risk MIBC.

Multi-Institutional Clinical Outcomes of Biopsy Gleason Grade Group 5 Prostate Cancers Treated With Contemporary High-Dose Radiation and Long-Term Androgen Deprivation Therapy

AIMS

This multicentric retrospective study reports long-term clinical outcomes of non-metastatic grade group 5 prostate cancers treated with external beam radiotherapy (EBRT) alone with long-term androgen deprivation therapy (ADT).

MATERIALS AND METHODS

Patients treated across 19 institutions were studied. The key endpoints that were evaluated were 5-year biochemical recurrence-free survival (bRFS), metastases-free survival (MFS), overall survival, together with EBRT-related acute and late toxicities. The impact of various prognostic factors on the studied endpoints was analysed using univariate and multivariate analyses.

RESULTS

Among the 462 patients, 88% (405) had Gleason 9 disease and 31% (142) had primary Gleason pattern 5. A prostate-specific membrane antigen positron emission tomography-computed tomography scan was used for staging in 33% (153), 80% (371) were staged as T3/T4 and 30% (142) with pelvic nodal disease. The median ADT duration was 24 months; 66% received hypofractionated EBRT and 71.4% (330) received pelvic nodal irradiation. With a median follow-up of 56 months, the 5-year bRFS, MFS and overall survival were 73.1%, 77.4% and 90.5%, respectively. Primary Gleason pattern 5 was associated with worse bRFS, MFS and overall survival with hazard ratios of 0.51 (95% confidence interval 0.35 to 0.73, P < 0.001), 0.64 (95% confidence interval 0.43 to 0.96, P = 0.031) and 0.52 (95% confidence interval 0.28 to 0.97, P = 0.040), respectively, whereas pelvic nodal disease was associated with worse bRFS (hazard ratio 0.67, 95% confidence interval 0.46 to 0.98, P = 0.039) and MFS (hazard ratio 0.56, 95% confidence interval 0.37 to 0.85, P = 0.006). The acute and late radiation-related toxicities were low overall and pelvic nodal irradiation was associated with higher toxicities.

CONCLUSION

Contemporary EBRT and long-term ADT led to excellent 5-year clinical outcomes and low rates of toxicity in this cohort of non-metastatic grade group 5 prostate cancers. Primary Gleason pattern 5 and pelvic node disease portends inferior clinical outcomes.

High-dose salvage re-irradiation for recurrent/progressive adult diffuse glioma: healing or hurting?

PURPOSE

To report survival outcomes and identify prognostic factors of salvage re-irradiation (re-RT) in recurrent/progressive glioma.

METHODS

Medical records of patients treated with high-dose re-RT as part of multi-modality salvage therapy for recurrence/progression of adult diffuse glioma from 2010 to 2019 were analyzed retrospectively.

RESULTS

A total of 111 patients developing recurrent/progressive high-grade glioma after adequate upfront treatment at initial diagnosis were included. The first course of radiotherapy (RT) had been delivered to a median dose of 59.4 Gy with an inter-quartile range (IQR) of 54-60 Gy. Median time to recurrence/progression was 4.3 years (IQR = 2.3-7.4 years) while the median time to re-RT was 4.8 years (IQR = 3.6-7.9 years). Re-RT was delivered with intensity-modulated radiation therapy (IMRT) using 1.8 Gy/fraction to a median dose of 54 Gy (IQR = 50.4-55.8 Gy) for a cumulative median equivalent dose in 2-Gy fractions (EQD2) of 104.3 Gy (IQR = 102.6-109.4 Gy). At a median follow-up of 14 months after re-RT, the 1-year Kaplan-Meier estimates of post-re-RT progression-free survival (PFS) and overall survival (OS) were 42.8 and 61.8%, respectively. Univariate analysis identified histological grade at recurrence/progression; histological subtype; disease-free interval (DFI) and time interval between both courses of RT; performance status at re-RT; dose at re-RT and cumulative EQD2; isocitrate dehydrogenase (IDH) mutation; and O⁶-methyl-guanine DNA methyl transferase (MGMT) gene promoter methylation as significant prognostic factors. Preserved performance status, longer DFI, prolonged time interval between both courses of RT, and presence of IDH mutation were associated with significantly improved PFS on multi-variate analysis. However, only performance status retained independent prognostic significance for OS on multi-variate analysis. Post-treatment changes were seen in 33 (30%) patients on follow-up imaging, with higher cumulative dose (EQD2 ≥ 104.3 Gy) being associated with increased risk of post-re-RT pseudo-progression.

CONCLUSION

This clinical audit reports encouraging survival outcomes and identifies key prognostic factors associated with high-dose salvage re-RT in recurrent/progressive glioma.

Structural and Energetic Effects of O2'-Ribose Methylation of Protonated Purine Nucleosides

The chemical difference between DNA and RNA nucleosides is their 2'-hydrogen versus 2'-hydroxyl substituents. Modification of the ribosyl moiety at the 2'-position and 2'-O-methylation in particular, is common among natural post-transcriptional modifications of RNA. 2'-Modification may alter the electronic properties and hydrogen-bonding characteristics of the nucleoside and thus may lead to enhanced stabilization or malfunction. The structures and relative glycosidic bond stabilities of the protonated forms of the 2'-O-methylated purine nucleosides, 2'-O-methyladenosine (Adom) and 2'-O-methylguanosine (Guom), were examined using two complementary tandem mass spectrometry approaches, infrared multiple photon dissociation action spectroscopy and energy-resolved collision-induced dissociation. Theoretical calculations were also performed to predict the structures and relative stabilities of stable low-energy conformations of the protonated forms of the 2'-O-methylated purine nucleosides and their infrared spectra in the gas phase. Low-energy conformations highly parallel to those found for the protonated forms of the canonical DNA and RNA purine nucleosides are also found for the protonated 2'-O-methylated purine nucleosides. Importantly, the preferred site of protonation, nucleobase orientation, and sugar puckering are preserved among the DNA, RNA, and 2'-O-methylated variants of the protonated purine nucleosides. The 2'-substituent does however influence hydrogen-bond stabilization as the 2'-O-methyl and 2'-hydroxyl substituents enable a hydrogen-bonding interaction between the 2'- and 3'-substituents, whereas a 2'-hydrogen atom does not. Further, 2'-O-methylation reduces the number of stable low-energy hydrogen-bonded conformations possible and importantly inverts the preferred polarity of this interaction versus that of the RNA analogues. Trends in the CID_50% values extracted from survival yield analyses of the 2'-O-methylated and canonical DNA and RNA forms of the protonated purine nucleosides are employed to elucidate their relative glycosidic bond stabilities. The glycosidic bond stability of Adom is found to exceed that of its DNA and RNA analogues. The glycosidic bond stability of Guom is also found to exceed that of its DNA analogue; however, this modification weakens this bond relative to its RNA counterpart. The glycosidic bond stability of the protonated purine nucleosides appears to be correlated with the hydrogen-bond stabilization of the sugar moiety.

Drugs Effect on Platelet Survival Time: Comparison of Two Pyrimido-Pyrimidine Derivatives in Patients with Aortic or Mitral Replacement

A prospective randomized trial of the effects of 2 antiplatelet aggregating drugs, dipyridamole (375 mg/d), a related substance RA 233 (1500 mg/d) and placebo, concomitantly with oral anticoagulants, was carried out in patients with prior valvular replacement. The study was aimed to determine effect on platelet survival time (PST) of these 2 agents. The trial sample consisted of 40 males and 15 females aged 40–70 years (average 53 years). 32 received Björk-Shiley valve in aortic position; 23 underwent mitral valve replacement: 3 with Cooley-Cutter, 11 with Lillehei- Kaster 500 and 9 with Starr-Edwards 6120 prostheses; 28 patients had aortic stenosis, 21 aortic insufficiency. All the PST measured after 3 months of treatment were within normal ranges and not different between placebo, dipyridamole or RA 233 treated subjects: averages in days were, respectively, 7.49, 7.11 and 6.88. The present study did not support the claim that modem valve prosthesis could lead to a shortened PST.

Gas phase infrared spectroscopy of selectively prepared ions

The first example of direct structural characterization of polyaromatic ions by coupling a Fourier transform ion cyclotron resonance mass spectrometer with an infrared free-electron laser is presented. Measurement of the IR spectra of selectively prepared ionic reactive intermediates is allowed by the association of the high peak power and wide tunability of the laser with the flexibility of the spectrometer, where several mass selection and ion reaction steps can be combined, as demonstrated in the case of iron cation complexes of hydrocarbons. The present experimental setup opens the way to understanding chemical reaction paths.

Infrared spectra of gas-phase V(+)-(benzene) and V(+)-(benzene)(2) complexes

The organometallic ions V+-(benzene) and V+-(benzene)2 are produced by laser vaporization in a pulsed nozzle source. They are trapped and mass selected in an ion-trap/time-of-flight mass spectrometer, and their infrared spectra are measured with resonance-enhanced multiphoton photodissociation (IR-REMPD) spectroscopy with a tunable free-electron laser. Vibrational bands in the 600-1800 cm-1 region are characteristic of the benzene molecular moiety perturbed by the metal cation bonding. Experimental data are compared to the IR spectra derived from density functional calculations. Vibrational patterns in V+-(C6H6) indicate that the metal is bound in an eta6 pi-bonding configuration, while V+-(C6H6)2 is a sandwich. Trapped-ion IR-REMPD is a general method to access the vibrational spectroscopy of organometallic ions and their clusters.

Intravenous phenytoin loading in patients after neurosurgery and in status epilepticus. A population pharmacokinetic study

In 49 patients treated with intravenous phenytoin after a neurosurgical procedure or because of repetitive frequent seizures, the serum concentration was measured before and 2 hours after an intravenous bolus injection. Based on these data the apparent volume of distribution and intra- and interpatient variability were determined in this representative patient population, using the statistical package NONMEM. From 5 characteristics tested (age, sex, bodyweight, serum albumin, renal function) only bodyweight was found to significantly influence the apparent volume of distribution of phenytoin. The population average was estimated as 1.0 +/- 0.04 L/kg (estimate +/- SE) and interindividual variability, expressed as coefficient of variation, was 23 +/- 6%. By means of Monte Carlo simulations an optimal dosing scheme for phenytoin loading has been calculated. Based on these results, a dose of 15 mg/kg divided into 3 intravenous injections administered 2 hours apart at a maximum rate of 50 mg/min is recommended. This loading regimen should result in therapeutic concentrations (10 to 20 mg/L) in 90% of patients within 6 hours.

Drugs effect on platelet survival time: comparison of two pyrimido-pyrimidine derivatives in patients with aortic or mitral replacement

A prospective randomized trial of the effects of 2 antiplatelet aggregating drugs, dipyridamole (375 mg/d), a related substance RA 233 (1500 mg/d) and placebo, concomitantly with oral anticoagulants, was carried out in patients with prior valvular replacement. The study was aimed to determine effect on platelet survival time (PST) of these 2 agents. The trial sample consisted of 40 males and 15 females aged 40-70 years (average 53 years). 32 received Björk-Shiley valve in aortic position, 23 underwent mitral valve replacement: 3 with Cooley-Cutter, 11 with Lillehei-Kaster 500 and 9 with Starr-Edwards 6120 prostheses; 28 patients had aortic stenosis, 21 aortic insufficiency. All the PST measured after 3 months of treatment were within normal ranges and not different between placebo, dipyridamole or RA 233 treated subjects: averages in days were, respectively, 7.49, 7.11 and 6.88. The present study did not support the claim that modern valve prosthesis could lead to a shortened PST.