Effects of Radiation Doses on Clinical Recurrence in Patients with Biochemically Recurrent Prostate Cancer after Prostatectomy

PURPOSE/OBJECTIVE(S)

Salvage radiotherapy (SRT) to the prostate bed is the only curative treatment for patients with biochemical recurrence (BCR) after radical prostatectomy (RP). Although several systematic reviews indicated that a dose escalation in the range of 60-70 Gy improved biochemical control, the effects of radiation doses on clinical relapse after SRT remain unclear. Our aim was to investigate the relationship between radiation doses and clinical relapse-free survival (cRFS) after SRT.

MATERIALS/METHODS

We identified 295 eligible patients receiving SRT for biochemically recurrent prostate cancer after RP between 2005 and 2018 at 15 institutions. Sixteen patients (5%) received short-term (< 6 months) androgen deprivation therapy (ADT) following RP and/or concurrently with SRT. SRT was delivered to the prostate and seminal vesicle bed using photon beams at a median (range) dose of 66 Gy (61-85) in 1.8-3.0 Gy fractions. The primary outcome was cRFS. Clinical relapse was identified on radiological imaging and/or biopsy and included local recurrence, lymph node metastasis, and distant metastasis. In all analyses, doses were recalculated as an equivalent dose in 2-Gy fractions (EQD2) with α/β = 1.5 Gy. Clinical RFS between the EQD2 ≥ 66 Gy (n = 229) and EQD2 < 66 Gy (n = 66) groups were compared using the Log-rank test, followed by univariate and multivariate Cox regression analyses and a subgroup analysis.

RESULTS

The median follow-up duration was 73 months. Among patients with BCR (n = 119), 79 of 96 (82%) in the EQD2 ≥ 66 Gy group and 21 of 23 (91%) in the EQD2 < 66 Gy group received second salvage ADT (p = 0.36). Among all patients (n = 295), clinical relapse was identified in 22 (7%) patients after SRT. Six-year biochemical relapse-free survival (bRFS), cRFS, cancer-specific survival (CSS), and overall survival (OS) rates were 58%, 93%, 98%, and 94%, respectively. Six-year cRFS rates were 94% (95% confidence interval [CI], 90-97) in the EQD2 ≥ 66 Gy group and 87% (95% CI, 75-93) in the EQD2 < 66 Gy group (p = 0.020). The multivariate analysis revealed that EQD2 < 66 Gy, Gleason score ≥ 8, seminal vesicle involvement, and PSA at BCR ≥ 0.5 ng/ml correlated with clinical relapse (p = 0.0016, 0.014, 0.011, and 0.027, respectively). The subgroup analysis showed the consistent benefit of EQD2 ≥ 66 Gy in patients across most subgroups including PSA at BCR after RP, extracapsular extension, and age at SRT.

CONCLUSION

This large multi-institutional observational study demonstrated that a higher SRT dose (EQD2 ≥ 66 Gy) resulted in superior cRFS. The present result supports the dose recommendations in the 2023 National Comprehensive Cancer Network guidelines (64-72 Gy) even in terms of clinical relapse. Prospective trial is warranted to investigate an upper threshold for optimal SRT dose.

Colonoscopic observation time as a predictor of stigmata of recent hemorrhage identification in colonic diverticular hemorrhage

OBJECTIVES

The strategy of identifying stigmata of recent hemorrhage (SRH) and treating the bleeding source is important for the prevention of rebleeding in colonic diverticular hemorrhage (CDH). However, there are few known reports on SRH identification thus far. This large multicenter study evaluated factors correlated with SRH identification, including observation time during colonoscopy.

METHODS

A total of 392 CDH cases were classified into presumptive CDH (n = 276) or definitive CDH with SRH (n = 116) on the basis of colonoscopy results. Multivariate Cox proportional hazards regression was employed to identify factors correlated with SRH identification. For the endoscopic treatment, endoscopic clips (EC), endoscopic band ligation (EBL) or endoscopic detachable snare ligation (EDSL) was performed.

RESULTS

Longer observation time was significantly correlated with SRH identification in multivariate analysis (OR, 10.3 [95% CI: 3.84-27.9], p<.001). Receiver operating characteristic curve (ROC) analysis of the SRH identification rate by observation time indicated a high area under the curve (AUC) (0.79), and the threshold of the observation time was calculated at 19 min using Youden's index. Moreover, the patients taken endoscopic hemostasis showed significantly lower early rebleeding rate than patients without endoscopic hemostasis (16.4% vs. 31.9%, p=.001), suggesting the importance of identifying SRH and treating the bleeding source for reducing the risk of recurrent bleeding.

CONCLUSIONS

Long-observation time correlated with SRH identification in this study, in which bowel preparation and water-jet scope and cap attachment are commonly used. This is the first known study to highlight the significance of observation time in the SRH identification rates.

A feasibility study comparing gel immersion endoscopic resection and underwater endoscopic mucosal resection for superficial nonampullary duodenal epithelial tumors

BACKGROUND

Although gel immersion endoscopic resection (GIER) is a potential alternative to underwater endoscopic mucosal resection (UEMR) for superficial nonampullary duodenal epithelial tumors (SNADETs), comparisons between the two are currently insufficient.

METHODS

40 consecutive procedures performed in 35 patients were retrospectively reviewed; the primary outcome was procedure time, and the secondary outcomes were en bloc and R0 resection rates, tumor and specimen size, and adverse events.

RESULTS

Lesions were divided into GIER (n = 22) and UEMR groups (n = 18). The median (range) procedure time was significantly shorter in the GIER group than in the UEMR group (2.75 [1-3.5] minutes vs. 3 2 3 4 5 6 7 8 9 10 minutes; P = 0.01). The en bloc resection rate was 100 % in the GIER group, but only 83.3 % in the UEMR group. The R0 resection rate was significantly higher in the GIER group than in the UEMR group (95.5 % vs. 66.7 %; P = 0.03). The median specimen size was larger in the GIER group than in the UEMR group (14 mm vs. 7.5 mm; P < 0.001). The tumor size was not significantly different between the groups and no adverse events were observed.

CONCLUSIONS

GIER is efficacious and safe to treat SNADETs, although additional studies are needed.

The efficacy of prophylactic clip closure of mucosal defects after colorectal endoscopic submucosal dissection on delayed bleeding

OBJECTIVE

Although prophylactic clip closure after endoscopic mucosal resection may prevent delayed bleeding, information regarding colorectal endoscopic submucosal dissection (CR-ESD) is lacking. Therefore, this study evaluated the effect of prophylactic clip closure on delayed bleeding rate after CR-ESD.

MATERIALS AND METHODS

A total of 614 CR-ESD procedures performed in 561 patients were retrospectively reviewed. The primary outcome, which was delayed bleeding rate, was analyzed between the prophylactic clip closure and non-closure groups. Furthermore, the predictors of delayed bleeding were also evaluated.

RESULTS

The patients were divided into the clip closure group (n = 275) and non-closure group (n = 339). Delayed bleeding rate was significantly lower in the closure group than in non-closure group (6 cases [2.2%] vs. 20 cases [5.9%], p = .026). The univariate logistic regression analyses revealed that delayed bleeding was significantly associated with laterally spreading tumor-granular-nodular mixed type (LST-G-Mix; odds ratio [OR], 3.77; 95% confidence interval [CI], 1.70-8.34; p = .001). By contrast, prophylactic clip closure was significantly associated with low delayed bleeding rate (OR, 0.36; 95%CI, 0.14-0.90; p = .029). The multivariate logistic regression analyses revealed LST-G-Mix as a significant independent delayed bleeding predictor (OR, 3.25; 95%CI, 1.45-7.32; p = .004), whereas, prophylactic clip closure was identified as a significant independent preventive factor of delayed bleeding (OR, 0.39; 95%CI, 0.15-1.00; p = .049).

CONCLUSIONS

Prophylactic clip closure after CR-ESD is associated with low delayed bleeding rate. LST-G-Mix promotes delayed bleeding, and performing prophylactic clip closure may be advisable.

Immune Thrombocytopenic Purpura Complicated by Hepatitis C Virus-related Membranoproliferative Glomerulonephritis after Rituximab Therapy

We herein report the case of a 54-year-old Japanese man with hepatitis C virus (HCV)-related membranoproliferative glomerulonephritis (MPGN), which developed at the time of relapse of immune thrombocytopenic purpura (ITP) after rituximab therapy. Antiviral therapy for HCV led to the improvement of both MPGN and ITP. Rituximab therapy may have contributed to the exacerbation of HCV infection and induced the development of HCV-related MPGN and the relapse of ITP. Our case suggested that HCV treatment should be prioritized over rituximab therapy for HCV-positive patients with ITP and that antiviral therapy for HCV may be effective for treating ITP itself.

Learning curve for endoscopic submucosal dissection of early colorectal neoplasms with a monopolar scissor-type knife: use of the cumulative sum method

OBJECTIVE

Although scissor-type knives such as the Stag-Beetle (SB) Knife Jr are expected to result in a safe and easy colorectal endoscopic submucosal dissection (CR-ESD), information regarding the learning curve is lacking. Therefore, this study evaluated the learning curve with using SB Knife Jr.

MATERIALS AND METHODS

We retrospectively reviewed 507 CR-ESD procedures performed in 464 patients using SB Knife Jr. The primary endpoint was a learning curve to achieve a satisfactory complete resection rate. The secondary endpoints were learning curves to achieve a satisfactory en bloc resection rate, curative resection rate, and resection speed.

RESULTS

The complete, en bloc, and curative resection rates were 91.9%, 95.9%, and 84.0%, respectively. Moving average analysis showed that 39 cases were required for a complete resection rate of >80%, 41 for an en bloc resection rate of >90%, and 50 for a curative resection rate of >75%. We divided the procedure into three phases using the cumulative sum method: I, II, and III (cases 1-36, 37-119, and 120-507, respectively). Although we found no significant between-phase differences, the complete resection rate showed an increasing trend in Phase III (83.3 vs. 89.2 vs. 93.3%; p = .099). The en bloc resection rate (91.7 vs. 91.6 vs. 97.2%; p = .047) and resection speed (20.5 vs. 7.2 vs. 6.8 min/cm²; p < .001) were greater in Phase III. Despite the larger specimen size (27.3 vs. 38.2 vs. 40.4 mm; p < .001) and more severe fibrosis (p < .001) in Phase III, the procedure time was shorter (73.8 vs. 57.8 vs. 54.2 min; p = .041). The curative resection rate was not significantly different between phases.

CONCLUSIONS

SB Knife Jr enables safe and easy CR-ESD during the introductory period compared to the conventional tip-type knife and has an acceptable learning curve. Therefore, using this knife will encourage the widespread adoption of CR-ESD in Asian general hospitals and non-Asian countries.

Effects of Early Initiation of Solid Versus Liquid Diet after Endoscopic Submucosal Dissection on Quality of Life and Postoperative Outcomes: A Prospective Pilot Randomized Controlled Trial

BACKGROUND/AIMS

Feeding recommendations after endoscopic submucosal dissection (ESD) for gastric neoplasms are not established and based on clinical experience.

METHODS

This was a prospective pilot randomized controlled trial. Patients undergoing ESD for gastric neoplasms were randomly assigned to solid (n = 50) or liquid diet (n = 50) groups. Beginning the day after hemostasis confirmation until discharge, the solid diet group started on a diet of rice porridge, whereas the liquid diet group started on a liquid diet, with gradual transition to solid food. The primary endpoint was delayed bleeding rate. The secondary endpoints were quality of life (QOL), ulcer-stage, hospital fees, and post-ESD symptoms.

RESULTS

Delayed bleeding occurred in the solid diet group (2%) but not in the liquid diet group. The QOL evaluation using European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-STO22 showed better score in the solid diet group. The patients who felt dietary restriction at discharge was of a larger number in the liquid diet group (p = 0.019). More patients experienced appetite loss (p = 0.038), constipation (p = 0.022), and dietary restriction (p = 0.037) in the liquid diet group during hospitalization. The other endpoints were equivalent between the groups.

CONCLUSION

Early initiation of solid foods after ESD is feasible and associated with higher QOL, potentially rendering conventional liquid diets unnecessary, although additional studies are needed (Trial registration number: UMIN000013297).

Advances in the genome-wide association study of chronic hepatitis B susceptibility in Asian population

Chronic hepatitis B (CHB) is the most common chronic liver disease resulting from viral infection and has become a serious threat to human health. Each year, about 1.2 million people in the world die from diseases caused by chronic infection of hepatitis B virus. The genetic polymorphism is significantly associated with the susceptibility to chronic hepatitis B. Genome-wide association study was recently developed and has become an important tool to detect susceptibility genes of CHB. To date, a number of CHB-associated susceptibility loci and regions have been identified by scientists over the world. To clearly understand the role of susceptibility loci in the occurrence of CHB is important for the early diagnosis and prevention of CHB.

[A case of gastric carcinosarcoma treated with surgical resection and irinotecan and mitomycin C combination therapy]

A 59-year-old man was admitted following episodes of melena. Upper gastrointestinal endoscopy revealed a type 2 carcinoid-like tumor in the cardium of the stomach. Histopathological analysis of a biopsy specimen revealed adenocarcinoma. Although hepatic metastases were detected, total gastrectomy was initially performed for hemorrhage control. The final histopathological diagnosis of the resected primary tumor was gastric carcinosarcoma with an osteosarcoma component. After ineffective first-line combination therapy with S-1 (tegafur, gimeracil, and oteracil) and cisplatin, irinotecan and mitomycin C chemotherapy was introduced. Although the hepatic metastases showed shrinkage after three courses of the chemotherapy, the patient succumbed seven months after surgery. This case report suggests that systemic chemotherapy using irinotecan and mitomycin C may be effective in the treatment of gastric carcinosarcoma with an osteosarcoma component and distant metastases.

Repeated exposure to a tone transiently alters spectral tuning bandwidth of neurons in the central nucleus of inferior colliculus in juvenile rats

Early acoustic experience changes tonal frequency tuning in the inferior colliculus (IC) and the primary auditory cortex. The contributions of IC plasticity to cortical frequency map reorganization are not entirely clear. While most cortical plasticity studies exposed animals to pulsed tones, studies of IC plasticity used either noise or a continuous tone. Here we compared the effects of repeated exposure to single-frequency tone pips on cortical and IC frequency representations in juvenile rats. We found that while tone exposure caused a long-lasting increase in cortical representations of the exposure frequency, changes to IC neurons were limited to a transient narrowing of tuning bandwidth. These results suggest that previously documented cortical frequency map reorganization does not depend on similar changes in the subcortical auditory nuclei.

Mutational state of tumor suppressor genes (DCC, DPC4) and alteration on chromosome 18q21 in human oral cancer

In order to investigate the roles of two candidate tumor suppressor genes, DCC (deleted in colorectal carcinoma) and DPC4 (deleted in pancreatic carcinoma 4) genes in oral squamous cell carcinoma (SCC), we examined 32 primary SCCs by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. Additionally, 32 pairs of normal and tumor DNA from 32 patients with oral SCCs were also analyzed for loss of heterozygosity (LOH) using 10 microsatellite markers on chromosome 18q21 where DCC and DPC4 genes are localized. We detected point mutations of DPC4 gene in two cases by PCR-SSCP analysis and sequencing. One case showed an AGC (Ser) to ACC (Thr) missense mutation at codon 1061 and the other the substitution C for A of the intron between exons 7 and 8. No mutation of DCC gene was observed in our cases. LOH at 18q21 was observed in 14 of the 32 cases (43.8%). The highest frequency (33.3%) of LOH was found at D18S46, and this was significantly correlated with the pathological results. These findings suggest that DCC and DPC4 gene may play minor roles in the genesis of oral SCC, and that another tumor suppressor gene involved in the development of oral SCC may exist in the region of D18S46 of this chromosome.

Quiescence and γH2AX in neuroblastoma are regulated by ouabain/Na,K-ATPase

Background:

Cellular quiescence is a state of reversible proliferation arrest that is induced by anti-mitogenic signals. The endogenous cardiac glycoside ouabain is a specific ligand of the ubiquitous sodium pump, Na,K-ATPase, also known to regulate cell growth through unknown signalling pathways.

Methods:

To investigate the role of ouabain/Na,K-ATPase in uncontrolled neuroblastoma growth we used xenografts, flow cytometry, immunostaining, comet assay, real-time PCR, and electrophysiology after various treatment strategies.

Results:

The ouabain/Na,K-ATPase complex induced quiescence in malignant neuroblastoma. Tumour growth was reduced by >50% when neuroblastoma cells were xenografted into immune-deficient mice that were fed with ouabain. Ouabain-induced S-G2 phase arrest, activated the DNA-damage response (DDR) pathway marker γH2AX, increased the cell cycle regulator p21^Waf1/Cip1 and upregulated the quiescence-specific transcription factor hairy and enhancer of split1 (HES1), causing neuroblastoma cells to ultimately enter G0. Cells re-entered the cell cycle and resumed proliferation, without showing DNA damage, when ouabain was removed.

Conclusion:

These findings demonstrate a novel action of ouabain/Na,K-ATPase as a regulator of quiescence in neuroblastoma, suggesting that ouabain can be used in chemotherapies to suppress tumour growth and/or arrest cells to increase the therapeutic index in combination therapies.

Enhanced frontal function in Parkinson's disease

We investigated the role of dopamine in working memory by examining effects of withdrawing dopaminergic medication in patients with Parkinson's disease. Resistance to distraction during a delayed response task was abnormally enhanced in Parkinson's disease patients OFF medication relative to controls. Conversely, performance on a backward digit span test was impaired in these same Parkinson's disease patients OFF medication. Dopaminergic medication reinstated susceptibility to distraction and backward digit span performance, so that performance of Parkinson's disease patients ON medication did not differ from that of controls. We hypothesize that the enhanced distractor resistance and impaired backward digit span in Parkinson's disease reflects low dopamine levels in the striatum, and perhaps upregulated frontal dopamine levels. Dopaminergic medication may reinstate distractibility by normalizing the balance between striatal and prefrontal dopamine transmission.

Action of neuropeptide Y on nociceptive transmission in substantia gelatinosa of the adult rat spinal dorsal horn

Effects of neuropeptide Y (NPY) on substantia gelatinosa neurons were investigated in adult rat spinal cord slices using blind whole-cell patch-clamp technique. Bath application of NPY (1 microM) induced a membrane hyperpolarization, resulting in a suppression of the dorsal root stimulation-induced action potentials in 24% of the substantia gelatinosa neurons tested. In voltage clamp mode, NPY produced an outward current dose-dependently in about one third of substantia gelatinosa neurons at the holding potential of -60 mV, which was not affected by tetrodotoxin (1 microM). The NPY-induced current was suppressed by perfusion with a Ba2+-containing external solution and a Cs2SO4 or tetraethylammonium-containing pipette solution. In addition, The NPY-induced outward currents reversed its polarity near the equilibrium potential of K+ ions (-93 mV). The response to NPY recorded with guanosine-5'-O-(2-thiodiphosphate)-beta-S (GDP-beta-S) containing pipette solution was abolished 30 min after patch formation, suggesting that the response was mediated by the G-protein-coupled receptors. Application of an NPY-Y1 selective agonist, [Leu(31), Pro(-34)]-NPY (1 microM), for 30 s also induced an outward current with a similar time course and amplitude to that induced by NPY. On the other hand, the NPY response was blocked by a simultaneous application of NPY-Y1 selective antagonist, BIBP 3226 (1 microM). No significant changes were found in amplitude and frequency of miniature excitatory postsynaptic currents and dorsal root evoked excitatory postsynaptic currents by NPY. In addition, NPY did not affect both of the miniature inhibitory postsynaptic currents and evoked inhibitory postsynaptic currents, mediated by either the GABA or glycine receptor. These findings, taken together, suggest that NPY produces an outward current in substantia gelatinosa neurons through G-protein coupled, and NPY-Y1 receptor-mediated activation of K+ channels without affecting presynaptic components. The inhibition of the synaptic transmission from the primary fibers to the substantia gelatinosa neurons is considered to contribute to the antinociceptive effects of NPY.

Re-evaluation of the latent period of bladder cancer in dyestuff-plant workers in Japan

BACKGROUND

The carcinogenesis of benzidine (BZ) and beta-naphthylamine (BNA) for bladder is well known. Although it was thought to be rare to develop occupational bladder cancer more than 20 years after the exposure to these chemicals, there are still new clinical cases even 30 years after exposure. The purpose of this study was to re-evaluate the latent carcinogenic period of BZ and BNA, in order to set the safety period after exposure for the health surveillance system.

METHODS

The subjects were 236 dyestuff-plant workers in Tokyo, who had been exposed to these dyestuffs. The incidence of bladder cancer and its histopathology in this group was surveyed in the period from 1962 to 1996.

RESULTS

Nineteen workers (8.1%) were found to have bladder cancers. The exposure period for these 19 patients was 82.0 +/- 50.2 months. The mean +/- SD latent period from the subjects' initial and final exposure until tumor development was 29.5 +/- 8.2 years and 20.1 +/- 10.6 years, respectively. Significantly, a negative correlation (Pearson) was observed between the exposure period and the latent period from the end of exposure to cancer onset (R = -0.544, P < 0.05). All tumors except one were transitional cell carcinoma. Flow cytometric analysis was performed in 11 patients and all of these patients had DNA aneuploidy.

CONCLUSIONS

The latent periods of bladder cancer caused by BZ and BNA were longer than previously expected. It is necessary to survey the onset of bladder cancer in exposed workers more than 30 years after the initial exposure.