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Current Oncology (Toronto, Ont.) Oct 2023Prostate cancer ranks as the second most common malignancy in males. Prostate cancer progressing on androgen deprivation therapy (ADT) is castration-resistant prostate... (Meta-Analysis)
Meta-Analysis Review
Prostate cancer ranks as the second most common malignancy in males. Prostate cancer progressing on androgen deprivation therapy (ADT) is castration-resistant prostate cancer (CRPC). Poly-ADP ribose polymerase (PARP) inhibitors (PARPis) have been at the forefront of the treatment of CRPC. We aim to better characterize the progression-free survival (PFS) and overall survival (OS) in metastatic CRPC patients treated with PARPis. A systemic review search was conducted using National Clinical Trial (NCT), PubMed, Embase, Scopus, and Central Cochrane Registry. The improvement in overall survival was statistically significant, favoring PARPis (hazard ratio (HR) 0.855; 95% confidence interval (CI) 0.752-0.974; = 0.018). The improvement in progression-free survival was also statistically significant, with results favoring PARPis (HR 0.626; 95%CI 0.566-0.692; = 0.000). In a subgroup analysis, similar results were observed where the efficacy of PARPis was evaluated in a subgroup of patients without homologous recombination repair (HRR) gene mutation, which showed improvement in PFS favoring PARPis (HR 0.747; 95%CI 0.0.637-0.877; = 0.000). Our meta-analysis of seven RCTs showed that PARPis significantly increased PFS and OS when used with or without antihormonal agents like abiraterone or enzalutamide.
Topics: Humans; Male; Androgen Antagonists; Poly(ADP-ribose) Polymerase Inhibitors; Progression-Free Survival; Prostatic Neoplasms, Castration-Resistant; Randomized Controlled Trials as Topic
PubMed: 37887569
DOI: 10.3390/curroncol30100669 -
Journal of Bacteriology Oct 2023Ribonucleotides frequently contaminate DNA and, if not removed, cause genomic instability. Consequently, all organisms are equipped with RNase H enzymes to remove...
Ribonucleotides frequently contaminate DNA and, if not removed, cause genomic instability. Consequently, all organisms are equipped with RNase H enzymes to remove RNA-DNA hybrids (RDHs). lacking RNase HI () and RNase HII () enzymes, the ∆ ∆ double mutant, accumulates RDHs in its DNA. These RDHs can convert into RNA-containing DNA lesions (R-lesions) of unclear nature that compromise genomic stability. The ∆ double mutant has severe phenotypes, like growth inhibition, replication stress, sensitivity to ultraviolet radiation, SOS induction, increased chromosomal fragmentation, and defects in nucleoid organization. In this study, we found that RNase HI deficiency also alters wild-type levels of DNA supercoiling. Despite these severe chromosomal complications, ∆ double mutant survives, suggesting that dedicated pathways operate to avoid or repair R-lesions. To identify these pathways, we systematically searched for mutants synthetic lethal (colethal) with the defect using an unbiased color screen and a candidate gene approach. We identified both novel and previously reported -colethal and -coinhibited mutants, characterized them, and sorted them into avoidance or repair pathways. These mutants operate in various parts of nucleic acid metabolism, including replication fork progression, R-loop prevention and removal, nucleoid organization, tRNA modification, recombinational repair, and chromosome-dimer resolution, demonstrating the pleiotropic nature of RNase H deficiency. IMPORTANCE Ribonucleotides (rNs) are structurally very similar to deoxyribonucleotides. Consequently, rN contamination of DNA is common and pervasive across all domains of life. Failure to remove rNs from DNA has severe consequences, and all organisms are equipped with RNase H enzymes to remove RNA-DNA hybrids. RNase H deficiency leads to complications in bacteria, yeast, and mouse, and diseases like progressive external ophthalmoplegia (mitochondrial defects in RNASEH1) and Aicardi-Goutières syndrome (defects in RNASEH2) in humans. mutant, deficient in RNases H, has severe chromosomal complications. Despite substantial problems, nearly half of the mutant population survives. We have identified novel and previously confirmed pathways in various parts of nucleic acid metabolism that ensure survival with RNase H deficiency.
Topics: Humans; Animals; Mice; Escherichia coli; Ultraviolet Rays; DNA; Genomic Instability; Ribonuclease H; RNA; Ribonucleotides
PubMed: 37819120
DOI: 10.1128/jb.00280-23 -
Pharmacological Research Oct 2023The addition of PARP inhibitors to chemotherapy has been assessed in > 80 clinical trials across multiple malignancies, on the premise that PARP inhibitors will...
PURPOSE
The addition of PARP inhibitors to chemotherapy has been assessed in > 80 clinical trials across multiple malignancies, on the premise that PARP inhibitors will increase chemotherapy effectiveness regardless of whether cancers have underlying disruption of DNA repair pathways. Consequently, the majority of combination therapy trials have been performed on patients without biomarker selection, despite the use of homologous recombination deficiency to dictate use of PARP inhibitors in the maintenance setting. An unresolved question is whether biomarkers are needed to identify patients who respond to combination PARP inhibitors and chemotherapy.
METHODS
A systematic literature review identified studies using PARP inhibitors in combination with chemotherapy versus chemotherapy alone, where the study included a biomarker of DNA repair function (BRCA1, BRCA2, homologous recombination deficiency test, ATM, ERCC1, SLFN11). Hazard ratios (HR) were pooled in a meta-analysis using generic inverse-variance, and fixed or random effects modelling. Subgroup analyses were conducted on biomarker selection and type of malignancy.
RESULTS
Nine studies comprising 2547 patients met the inclusion criteria. Progression-free survival (PFS) was significantly better in patients with a DNA repair biomarker (HR: 0.57, 95% CI: 0.48-0.68, p < 0.00001), but there was no benefit in patients who lacked a biomarker (HR: 0.94, 95% CI: 0.82-1.08, p = 0.38). Subgroup analysis showed that BRCA status and SLFN11 biomarkers could predict benefit, and biomarker-driven benefit occurred in ovarian, breast and small cell lung cancers. The addition of PARP inhibitors to chemotherapy was associated with increased grade 3/4 side effects, and particularly neutropenia.
CONCLUSIONS
Combination therapy only improves PFS in patients with identifiable DNA repair biomarkers. This indicates that PARP inhibitors do not sensitise patients to chemotherapy treatment, except where their cancer has a homologous recombination defect, or an alternative biomarker of altered DNA repair. While effective in patients with DNA repair biomarkers, there is a risk of high-grade haematological side-effects with the use of combination therapy. Thus, the benefit in PFS from combination therapy must be weighed against potential adverse effects, as individual arms of treatment can also confer benefit.
PubMed: 37717683
DOI: 10.1016/j.phrs.2023.106927 -
Ontario Health Technology Assessment... 2023Ovarian cancer affects the cells of the ovaries, and epithelial cancer is the most common type of malignant ovarian cancer. The homologous recombination repair pathway...
Homologous Recombination Deficiency Testing to Inform Patient Decisions About Niraparib Maintenance Therapy for High-Grade Serous or Endometrioid Epithelial Ovarian Cancer: A Health Technology Assessment.
BACKGROUND
Ovarian cancer affects the cells of the ovaries, and epithelial cancer is the most common type of malignant ovarian cancer. The homologous recombination repair pathway enables error-free repair of DNA double-strand breaks. Damage of key genes associated with this pathway leads to homologous recombination deficiency (HRD), which results in unrepaired DNA and can lead to cancer. Tumours with HRD are believed to be sensitive to treatment with poly-adenosine diphosphate (ADP)-ribose polymerase (PARP) inhibitors, such as niraparib. We conducted a health technology assessment to evaluate the clinical utility and cost-effectiveness of HRD testing to inform patient decisions about the use of niraparib maintenance therapy for patients with high-grade serous or endometrioid epithelial ovarian cancer. We also evaluated the efficacy and safety of niraparib maintenance therapy in patients with HRD or homologous recombination proficiency (HRP), the cost-effectiveness of HRD testing, the budget impact of publicly funding HRD testing, and patient preferences and values.
METHODS
We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Cochrane risk-of-bias tool for randomized trials version 2, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-utility analysis with a 5-year time horizon from a public payer perspective. We also analyzed the budget impact of publicly funding HRD testing in people with ovarian cancer in Ontario. We performed a literature search for quantitative evidence of patient and provider preferences with respect to HRD testing and maintenance therapy with PARP inhibitors. To contextualize the potential value of HRD testing, we spoke with people with ovarian cancer.
RESULTS
The clinical evidence review included two studies in high-grade epithelial ovarian cancer (one in patients with newly diagnosed advanced cases and one in patients with recurrent cancer). The studies evaluated niraparib maintenance therapy compared with no maintenance therapy and used HRD testing to group patients according to HRD status. Compared to placebo, niraparib maintenance therapy improved progression-free survival in patients with newly diagnosed and recurrent ovarian cancer, and in tumours with HRD or HRP (GRADE: High), but the studies did not compare the results between the HRD and HRP groups. The frequency of adverse events was higher in the niraparib group. We identified no studies that evaluated the clinical utility of HRD testing.We conducted a primary economic evaluation to evaluate the cost-effectiveness of HRD testing for people with newly diagnosed ovarian cancer in an Ontario setting. Our analysis used a 5-year time horizon. HRD testing (for all eligible people or only for people with wild type) resulted in a lower proportion of patients receiving niraparib maintenance therapy, leading to lower costs and fewer quality-adjusted life-years (QALYs). The average total cost per patient was $131,375 for no HRD testing, $126,867 for HRD testing only in people with wild type, and $127,746 for HRD testing in all eligible people. The average total QALYs per patient were 2.087 for no HRD testing, 1.971 for HRD testing only in people with wild type, and 1.971 for HRD testing in all eligible people. Our budget impact analysis suggested that assuming a high uptake rate, publicly funding HRD testing for people with newly diagnosed ovarian cancer would lead to a total saving of $9.00 million (if HRD testing were funded for all) to $12.67 million (if HRD testing were funded for people with wild type) over the next 5 years. Publicly funding HRD testing for people with recurrent cancer would lead to a total saving of $16.31 million (if HRD testing were funded for all) to $21.67 million (if HRD testing were funded for people with wild type) over the next 5 years.We identified no studies that evaluated quantitative preferences for HRD testing. Based on two studies that evaluated patients and oncologists' preferences for maintenance therapy with a PARP inhibitor in the recurrent setting, a decrease in moderate to severe adverse events was more important for patients than an improvement in progression-free survival; however, improvement in progression-free survival was more important for oncologists. Both patients and oncologists accepted some trade-offs between efficacy and safety. The people with ovarian cancer we spoke with demonstrated a shared value for access to information, prevention of cancer recurrence, and overall survival with minimal adverse effects. This was consistent with findings from another survey in patients with ovarian cancer and at least one episode of recurrence, which suggest that patients prioritize treatment benefit over some treatment adverse events in the context of niraparib maintenance therapy. Interviewees also emphasized the importance of the patient-doctor partnership, access to local health care services, and patient education.
CONCLUSIONS
In patients with newly diagnosed (advanced) or recurrent high-grade serous or endometrioid ovarian cancer, niraparib maintenance therapy improved progression-free survival compared with no maintenance therapy in tumours with HRD or HRP (GRADE: High). Because we identified no studies on the clinical utility of HRD testing, we cannot comment on how it would affect patient decisions and clinical outcomes.Over a 5-year time horizon, HRD testing for people with wild type could save $4,509 per person and lead to a loss of 0.116 QALY. The findings of our economic analyses are dependent on assumptions about the use of niraparib following HRD testing. We estimate that publicly funding HRD testing would lead to a total saving of $9 million to $12.67 million for newly diagnosed cancer, and a total saving of $16.31 million to $21.67 million for recurrent cancer over 5 years, assuming the use of niraparib maintenance therapy would be reduced following HRD testing.Patients prioritized decreasing the risk of moderate to severe adverse events of maintenance therapy with PARP inhibitors over improving progression-free survival, and oncologists prioritized improving progression-free survival over decreasing the risk of moderate to severe adverse events. However, both patients and oncologists were open to accepting certain trade-offs between treatment efficacy and toxicity. The people we interviewed, who had lived experience with ovarian cancer and genetic testing, valued the potential clinical benefits of HRD testing for themselves and their family members. They emphasized patient education as an important consideration for public funding in Ontario.
Topics: Humans; Female; Carcinoma, Ovarian Epithelial; Technology Assessment, Biomedical; Poly(ADP-ribose) Polymerase Inhibitors; Carcinoma, Endometrioid; Ovarian Neoplasms
PubMed: 37637244
DOI: No ID Found -
International Journal of Molecular... Aug 2023PARPi, in combination with ionizing radiation, has demonstrated the ability to enhance cellular radiosensitivity in different tumors. The rationale is that the exposure...
PARPi, in combination with ionizing radiation, has demonstrated the ability to enhance cellular radiosensitivity in different tumors. The rationale is that the exposure to radiation leads to both physical and biochemical damage to DNA, prompting cells to initiate three primary mechanisms for DNA repair. Two double-stranded DNA breaks (DSB) repair pathways: (1) non-homologous end-joining (NHEJ) and (2) homologous recombination (HR); and (3) a single-stranded DNA break (SSB) repair pathway (base excision repair, BER). In this scenario, PARPi can serve as radiosensitizers by leveraging the BER pathway. This mechanism heightens the likelihood of replication forks collapsing, consequently leading to the formation of persistent DSBs. Together, the combination of PARPi and radiotherapy is a potent oncological strategy. This combination has proven its efficacy in different tumors. However, in prostate cancer, there are only preclinical studies to support it and, recently, an ongoing clinical trial. The objective of this paper is to perform a review of the current evidence regarding the use of PARPi and radiotherapy (RT) in PCa and to give future insight on this topic.
Topics: Humans; Male; DNA Repair; Medical Oncology; Poly(ADP-ribose) Polymerase Inhibitors; Prostatic Neoplasms; Radiation Oncology
PubMed: 37629155
DOI: 10.3390/ijms241612978 -
BJU International Dec 2023To compare radiographic progression-free survival (rPFS), overall survival (OS), and treatment-emergent adverse events (TEAEs) among patients with metastatic... (Meta-Analysis)
Meta-Analysis Review
Poly(adenosine diphosphate-ribose) polymerase inhibitor combinations in first-line metastatic castrate-resistant prostate cancer setting: a systematic review and meta-analysis.
OBJECTIVES
To compare radiographic progression-free survival (rPFS), overall survival (OS), and treatment-emergent adverse events (TEAEs) among patients with metastatic castrate-resistant prostate cancer (mCRPC) receiving a combination of first-line poly(adenosine diphosphate-ribose) polymerase inhibitors (PARPi) plus androgen receptor axis-targeted agents (ARAT) vs placebo/ARAT.
MATERIALS AND METHODS
We conducted a systematic review/meta-analysis of all published Phase III randomised controlled trials using EMBASE, MEDLINE, and Cochrane (inception until 6 June 2023). Published full-text manuscripts and conference abstracts were inclusion eligible. Study selection/data extraction were independently performed by two authors. The Cochrane Risk-of-Bias 2 Tool was used, and certainty of evidence assessed using the Grading of Recommendations, Assessment, Development, and Evaluations framework. Pooled hazard ratios (HRs) and relative risks, with corresponding confidence intervals (CIs), were generated using random-effects models.
RESULTS
Three trials were identified: PROpel, MAGNITUDE, and TALAPRO-2. Compared to placebo/ARAT, the PARPi/ARAT combination was associated with a 35% rPFS improvement in the overall cohort (HR 0.65, 95% CI 0.56-0.76), with 68%, 45%, and 26% improvements in the BReast CAncer gene 1/gene 2 (BRCA1/2)-mutated (BRCA1/2m; P < 0.001), homologous recombination repair-mutated (HRRm; P < 0.001), and non-HRRm cohorts (P = 0.003), respectively. OS data maturity ranged from 31% to 48%, with overall cohort OS data unavailable from MAGNITUDE. The PROpel/TALAPRO-2 pooled analysis demonstrated a 16% OS improvement in the overall cohort (HR 0.84, 95 CI 0.72-0.98; P = 0.02). OS in the HRRm (HR 0.76, 95% CI 0.61-0.95) and the BRCA1/2m cohorts (HR 0.53, 95% CI 0.18-1.56) were improved, with a higher effect magnitude compared to the overall cohort. This combination was associated with a 45% relative risk increase in Grade ≥3 TEAEs, including 6.22-fold for Grade ≥3 anaemia (31.9% vs 4.9%).
CONCLUSIONS
The addition of PARPi to ARAT in the first-line mCRPC setting is associated with rPFS benefits across subgroups, with the greatest magnitude of benefit in BRCA1/2m patients. OS benefits remain inconsistent irrespective of HRRm status, with significant increases in Grade ≥3 TEAEs, particularly anaemia. Currently, we suggest this combined approach be selectively offered to HRRm patients, preferentially BRCA1/2m.
Topics: Male; Humans; BRCA1 Protein; Ribose; Prostatic Neoplasms, Castration-Resistant; BRCA2 Protein; Anemia; Adenosine Diphosphate
PubMed: 37461140
DOI: 10.1111/bju.16130 -
The Surgeon : Journal of the Royal... Aug 2023To compare the efficacy of recombinant human bone morphogenetic proteins (rhBMPs) and autologous bone graft (ABG) on the healing of long bone non-union. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To compare the efficacy of recombinant human bone morphogenetic proteins (rhBMPs) and autologous bone graft (ABG) on the healing of long bone non-union.
METHODS
A systematic literature search was conducted on PubMed, Web of Science, Cochrane Library, and CNKI up to December 2021. Two authors independently screened the studies, extracted data, and assessed the quality of the trials. A Meta-analysis was performed using state software (version 12.0).
RESULTS
A total of 14 studies were included in this meta-analysis. Overall, there was no significant difference between the rhBMPs group and the ABG group in terms of healing rate (RR = 1.04, 95% CI = 0.96-1.12, p = 0.365) and healing time (SMD = -0.31, 95% CI = -0.76-0.14, p = 0.175). Subgroup analysis showed rhBMPs lead to higher healing rates (RR = 1.35, 95% CI = 1.17-1.56, p < 0.001), and shorter healing time (SMD = -0.65, 95% CI = -1.08 to -0.22, p = 0.003) in the subgroup of moderate-quality studies. Sensitivity analysis proved that our conclusions were relatively robust. No significant publication bias was recognized in all studies (Begg's test, p = 0.193; Egger's test, p = 0.307).
CONCLUSIONS
RhBMPs or combined with allografts bone, inorganic bone was a valid alternative to ABG for the treatment of long bone non-union.
Topics: Humans; Bone Transplantation; Wound Healing; Bone Morphogenetic Proteins
PubMed: 36682906
DOI: 10.1016/j.surge.2022.11.004 -
Cartilage Mar 2023To evaluate the efficacy of fibroblast growth factor-18 (FGF-18) augmentation for improving articular cartilage healing following surgical repair in preclinical ()...
OBJECTIVE
To evaluate the efficacy of fibroblast growth factor-18 (FGF-18) augmentation for improving articular cartilage healing following surgical repair in preclinical () animal models.
DESIGN
A systematic review was performed evaluating the efficacy of FGF-18 augmentation with cartilage surgery compared with cartilage surgery without FGF-18 augmentation in living animal models. Eligible intervention groups were FGF-18 treatment in conjunction with orthopedic procedures, including microfracture, osteochondral auto/allograft transplantation, and cellular-based repair. Outcome variables were: International Cartilage Repair Society (ICRS) score, modified O'Driscoll histology score, tissue infill score, qualitative histology, and adverse events. Descriptive statistics were recorded and summarized for each included study.
RESULTS
In total, 493 studies were identified and 4 studies were included in the final analysis. All studies were randomized controlled trials evaluating use of recombinant human FGF-18 (rhFGF-18). Animal models included ovine ( = 3) and equine ( = 1), with rhFGF-18 use following microfracture ( = 3) or osteochondral defect repair ( = 1). The rhFGF-18 was delivered via intra-articular injection ( = 2), collagen membrane scaffold ( = 1), or both ( = 1). All studies reported significant, positive improvements in cartilage defect repair with rhFGF-18 compared with controls based on ICRS score ( = 4), modified O'Driscoll score ( = 4), tissue infill ( = 3), and expression of collagen type II ( = 4) ( < 0.05). No adverse events were reported with the intra-articular administration of this growth factor, indicating short-term safety and efficacy of rhFGF-18 .
CONCLUSION
This systematic review provides evidence that rhFGF-18 significantly improves cartilage healing at 6 months postoperatively following microfracture or osteochondral defect repair in preclinical randomized controlled trials.
Topics: Animals; Humans; Sheep; Horses; Fractures, Stress; Cartilage, Articular; Fibroblast Growth Factors; Collagen
PubMed: 36541606
DOI: 10.1177/19476035221142010 -
Prostate Cancer and Prostatic Diseases Dec 2023The goal of precision medicine in prostate cancer (PCa) is to individualize the treatment according to the patient's germline mutation status. PCa has a very high rate... (Review)
Review
BACKGROUND
The goal of precision medicine in prostate cancer (PCa) is to individualize the treatment according to the patient's germline mutation status. PCa has a very high rate of genetic predisposition compared with other cancers in men, with an estimated rate of cancers ascribable to hereditary factors of 5-15%.
METHODS
A systematic search (PubMed, Web of Science, and ClinicalTrials.gov) of English literature from 2000 to 2022, using the keywords "prostate cancer", "germline mutations", "family history", and "inheritance" was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.
RESULTS
The search identified 980 publications. Of these, 200 papers were removed before screening (duplicates, non-English literature, and publication year before 2000) and 245 records were excluded after title/abstract screening. Finally, 50 articles were included in the final analysis. We analyze the latest evidence on the genetic basis of PCa predisposition and clinical implications for more personalized screening protocols and therapeutic management of this high-prevalent cancer.
DISCUSSION
Emerging data show that germline mutations in homologous recombination genes (BRCA1/2, ATM, CHECK2), in mismatch repair genes (MLH1, MLH2, MSH6), and other additional genes are associated with the development and aggressiveness of PCa. Germline testing and genetic counseling have increasingly important implications in cancer screening and therapeutic decisions making for patients affected by PCa. Patients with localized PCa and some gene mutations are more likely to develop aggressive cancer, so active treatment may be preferable to active surveillance for these patients. Moreover, in patients with metastatic PCa, these gene alterations may be useful biomarkers for predicting response to specific therapy such as PARP inhibitors, recently approved for the treatment of metastatic castration-resistant PCa. The evidence supports recent guidelines and recommendations considering germline genetic testing for patients with a positive family history of PCa or men with high risk or metastatic disease.
Topics: Male; Humans; Prostatic Neoplasms; Germ-Line Mutation; BRCA1 Protein; Precision Medicine; BRCA2 Protein
PubMed: 36434163
DOI: 10.1038/s41391-022-00609-3 -
Journal of Stomatology, Oral and... Apr 2023To identify clinical decisions on surgical as well as non-surgical modalities for the treatment of CLP patients based on randomized controlled trials (RCTs).
AIM
To identify clinical decisions on surgical as well as non-surgical modalities for the treatment of CLP patients based on randomized controlled trials (RCTs).
MATERIALS AND METHODS
PubMed, Ebscohost, and Cochrane Library were searched and 20 articles based on RCTs conducted on cleft patient management were identified.
RESULTS
The topics explored were infant orthopedics, lip and palate repair, alveolar bone grafting, and management of cleft maxillary hypoplasia. Nasoalveolar molding (NAM) was found to have great benefits when carried out within one month of birth. Fisher and Mohler's lip repair technique and use of recombinant human bone morphogenetic protein-2 (rh-BMP2) for alveolar bone grafting showed promising results. rh-BMP2 for alveolar bone grafting appears to be a promising alternative to autografts.
CONCLUSION
Early commencement of NAM in neonatal life is of great benefit to cleft patients. There is a need for more multicentre collaborations, mainly to identify the ideal surgical technique to reduce the variability in treatment and to ensure that the patient receives appropriate evidence-based treatment.
Topics: Infant, Newborn; Humans; Cleft Lip; Cleft Palate; Preoperative Care
PubMed: 36410660
DOI: 10.1016/j.jormas.2022.11.014