Induced Bias Due to Crossover Within Randomized Controlled Trials in Surgical Oncology: A Meta-regression Analysis of Minimally Invasive versus Open Surgery for the Treatment of Gastrointestinal Cancer

Quality of life outcomes comparing primary Transoral Robotic Surgery (TORS) with primary radiotherapy for early-stage oropharyngeal squamous cell carcinoma: A systematic review and meta-analysis

BACKGROUND

Transoral Robotic Surgery (TORS) and radiotherapy are considered oncologically equivalent primary treatment options for early-stage HPV-positive oropharyngeal squamous cell carcinoma (OPSCC). Quality of Life (QoL) and Patient Reported Outcome Measures (PROMs) are therefore imperative in supporting clinical decision-making and optimising patient-centred care. The aim of this article is to evaluate how these primary treatment modalities compare in terms of QoL.

MATERIALS AND METHODS

Systematic review and meta-analysis of studies comparing primary TORS and primary radiotherapy for OPSCC using validated QoL tools. Swallowing and global QoL were the primary endpoints with secondary endpoints including all other QoL domains. An inverse variance random-effects model was employed to calculate the weighted estimate of the treatment effects across trials.

RESULTS

A total of six studies collectively reporting on 555 patients were included (n = 236 TORS and n = 319 radiotherapy). Meta-analysis showed no significant difference for swallowing (mean difference = -0.24, p = 0.89) and global QoL (mean difference = 4.55, p = 0.14). For the remaining QoL domains (neck/shoulder impairment, neurotoxicity, voice, xerostomia, speech, and distress), the scarcity of data did not permit meta-analysis. However, the existing data showed no significant difference for any except for xerostomia where TORS appears favourable in the sole study reporting on this.

CONCLUSIONS

TORS and radiotherapy appear to be comparable primary treatment options for early stage OPSCC when it comes to QoL. However, a substantial proportion of patients in the TORS group received adjuvant (chemo)radiotherapy rendering it difficult to establish the 'true' QoL outcomes following surgery alone. There are also minimal studies reporting QoL outcomes beyond swallowing and global QoL. Further research is therefore needed, including more randomised trials adequately powered to detect differences in QoL outcomes.

Impact of the matching algorithm on the treatment effect estimate: A neutral comparison study

Propensity score matching is increasingly being used in the medical literature. Choice of matching algorithms, reporting quality, and estimands are oftentimes not discussed. We evaluated the impact of propensity score matching algorithms, based on a recent clinical dataset, with three commonly used outcomes. The resulting estimands for different strengths of treatment effects were compared in a neutral comparison study and based on a thoroughly designed simulation study. Different algorithms yielded different levels of balance after matching. Along with full matching and genetic matching with replacement, good balance was achieved with nearest neighbor matching with caliper but thereby more than one fifth of the treated units were discarded. Average marginal treatment effect estimates were least biased with genetic or nearest neighbor matching, both with replacement and full matching. Double adjustment yielded conditional treatment effects that were closer to the true values, throughout. The choice of the matching algorithm had an impact on covariate balance after matching as well as treatment effect estimates. In comparison, genetic matching with replacement yielded better covariate balance than all other matching algorithms. A literature review in the British Medical Journal including its subjournals revealed frequent use of propensity score matching; however, the use of different matching algorithms before treatment effect estimation was only reported in one out of 21 studies. Propensity score matching is a methodology for causal treatment effect estimation from observational data; however, the methodological difficulties and low reporting quality in applied medical research need to be addressed.

GRADE concept 4: rating the certainty of evidence when study interventions or comparators differ from PICO targets

OBJECTIVES

This Grading of Recommendations Assessment, Development and Evaluation (GRADE) concept article offers systematic reviewers, guideline authors, and other users of evidence assistance in addressing randomized trial situations in which interventions or comparators differ from those in the target people, interventions, comparators, and outcomes. To clarify what GRADE considers under indirectness of interventions and comparators, we focus on a particular example: when comparator arm participants receive some or all aspects of the intervention management strategy (treatment switching).

STUDY DESIGN AND SETTING

An interdisciplinary panel of the GRADE working group members developed this concept article through an iterative review of examples in multiple teleconferences, small group sessions, and e-mail correspondence. After presentation at a GRADE working group meeting in November 2022, attendees approved the final concept paper, which we support with examples from systematic reviews and individual trials.

RESULTS

In the presence of safeguards against risk of bias, trials provide unbiased estimates of the effect of an intervention on the people as enrolled, the interventions as implemented, the comparators as implemented, and the outcomes as measured. Within the GRADE framework, differences in the people, interventions, comparators, and outcomes elements between the review or guideline recommendation targets and the trials as implemented constitute issues of indirectness. The intervention or comparator group management strategy as implemented, when it differs from the target comparator, constitutes one potential source of indirectness: Indirectness of interventions and comparators-comparator group receipt of the intervention constitutes a specific subcategory of said indirectness. The proportion of comparator arm participants that received the intervention and the apparent magnitude of effect bear on whether one should rate down, and if one does, to what extent.

CONCLUSION

Treatment switching and other differences between review or guideline recommendation target interventions and comparators vs. interventions and comparators as implemented in otherwise relevant trials are best considered issues of indirectness.

Novel Strategies for Managing Retropharyngeal Lymph Node Metastases in Head and Neck and Thyroid Cancer with Transoral Robotic Surgery (TORS)

Retropharyngeal metastases are encountered in a variety of head and neck malignancies, imposing significant surgical challenges owing to their distinct location and proximity to neurovascular structures. Radiotherapy is the recommended treatment in most cases owing to its oncological efficacy. However, retropharyngeal irradiation affects the superior pharyngeal constrictor muscles and parotid glands, with the potential for long-term dysphagia and xerostomia. A younger oropharyngeal and thyroid cancer patient demographic is trending, fueling interest in treatment de-escalation strategies. Consequently, reducing radiotoxicity and its long-term effects is of special relevance in modern head and neck oncology practice. Through its unique ability to safely extirpate these traditionally difficult-to-access retropharyngeal lymph nodes via a natural orifice, TransOral Robotic Surgery (TORS) can considerably lower the surgical morbidity of retropharyngeal lymph node dissection (RPLND), compared with current existing approaches. This review summarizes the latest developments in the field, exposing current research gaps and discusses specific clinical settings where TORS could enable treatment de-escalation. In early-stage node-negative oropharyngeal cancer, single-modality surgical treatment with TORS RPLND may improve risk stratification of metastasis and recurrence in this region. TORS RPLND is also a potentially viable treatment option in salvage of an isolated retropharyngeal node recurrence or in the primary setting of a thyroid malignancy with a single positive retropharyngeal node. In time, TORS RPLND may provide an alternative de-escalation strategy in these three scenarios. However, with the reported morbidities, further prospective trials with long-term follow-up data are required to prove oncological safety and functional benefits over existing strategies.

Subscapularis-sparing approaches in shoulder arthroplasty: A systematic review

Background

Novel approaches for anatomic and reverse total shoulder arthroplasty (aTSA and rTSA) that spare the subscapularis (SSC) have recently been described. Outcomes for the SSC-sparing approach were evaluated through this systematic review.

Methods

Medline, Embase, PubMed, and CENTRAL were searched.

Results

From 2051 citations, 8 studies were included (aTSA group, n = 241; rTSA group, n = 68). SSC-sparing aTSA and rTSA were associated with significant postoperative improvements in shoulder function and range of motion at 12- to 24-month follow-up.

Conclusion

The SSC-sparing approach may provide a safe alternative for up to two years post-surgery. Evidence for long-term use remains inconclusive.

Shared decision making in surgery: A scoping review of the literature

BACKGROUND

Shared decision making (SDM) has been increasingly implemented to improve health-care outcomes. Despite the mixed efficacy of SDM to provide better patient-guided care, its use in surgery has not been studied. The aim of this study was to systematically review SDM application in surgery.

DESIGN

The search strategy, developed with a medical librarian, included nine databases from inception until June 2019. After a 2-person title and abstract screen, full-text publications were analysed. Data collected included author, year, surgical discipline, location, study duration, type of decision aid, survey methodology and variable outcomes. Quantitative and qualitative cross-sectional studies, as well as RCTs, were included.

RESULTS

A total of 6060 studies were retrieved. A total of 148 were included in the final review. The majority of the studies were in plastic surgery, followed by general surgery and orthopaedics. The use of SDM decreased surgical intervention rate (12 of 22), decisional conflict (25 of 29), and decisional regret (5 of 5), and increased decisional satisfaction (17 of 21), knowledge (33 of 35), SDM preference (13 of 16), and physician trust (4 of 6). Time increase per patient encounter was inconclusive. Cross-sectional studies showed that patients prefer shared treatment and surgical treatment varied less. The results of SDM per type of decision aid vary in terms of their outcome.

CONCLUSION

SDM in surgery decreases decisional conflict, anxiety and surgical intervention rates, while increasing knowledge retained decisional satisfaction, quality and physician trust. Surgical patients also appear to prefer SDM paradigms. SDM appears beneficial in surgery and therefore worth promoting and expanding in use.

Caution is needed in interpreting the results of comparative studies regarding oncological operations by minimally invasive versus laparotomic access

We aim to alert the difference between groups while comparing studies of abdominal oncological operations performed either by minimally invasive or laparotomic approaches and potential conflicts of interest in presenting or interpreting the results. Considering the large volume of scientific articles that are published, there is a need to consider the quality of the scientific production that leads to clinical decision making. In this regards, it is important to take into account the choice of the surgical access route. Randomized, controlled clinical trials are the standard for comparing the effectiveness between these interventions. Although some studies indicate advantages in minimally invasive access, caution is needed when interpreting these findings. There is no detailed observation in each of the comparative study about the real limitations and potential indications for minimally invasive procedures, such as the indications for selected and less advanced cases, in less complex cavities, as well as its elective characteristic. Several abdominal oncological operations via laparotomy would not be plausible to be completely performed through a minimally invasive access. These cases should be carefully selected and excluded from the comparative group. The comparison should be carried out, in a balanced way, with a group that could also have undergone a minimally invasive access, avoiding bias in selecting those cases of minor complexity, placed in the minimally invasive group. It is not a question of criticizing the minimally invasive technologies, but of respecting the surgeon's clinical decision regarding the most convenient method, revalidating the well-performed traditional laparotomy route, which has been unfairly criticized or downplayed by many people.

Prevalence and Impact of Treatment Crossover in Cardiac Surgery Randomized Trials: A Meta-Epidemiologic Study

Background Crossover dilutes treatment effect and reduces statistical power of intention-to-treat analysis. We examined incidence and impact on cardiac surgery randomized controlled trial (RCT) outcomes of crossover from experimental to control interventions, or vice versa. Methods and Results MEDLINE, EMBASE, and Cochrane Library were searched, and RCTs (≥100 patients) comparing ≥2 adult cardiac surgical interventions were included. Crossover from the initial treatment assignment and relative risks (RRs) for each trial's primary end point and mortality at longest available follow-up were extracted. All RRs were calculated as >1 favored control group and <1 favored experimental arm. Primary outcome was the effect estimate for primary end point of each RCT, and secondary outcome was all-cause mortality; both were appraised as RR at the longest follow-up available. Sixty articles reporting on 47 RCTs (25 440 patients) were identified. Median crossover rate from experimental to control group was 7.0% (first quartile, 2.0%; third quartile, 9.7%), whereas from control to experimental group, the rate was 1.3% (first quartile, 0%; third quartile, 3.6%). RRs for primary end point and mortality were higher in RCTs with higher crossover rate from experimental to control group (RR, 1.01 [95% CI, 0.94-1.07] versus RR, 0.80 [95% CI, 0.66-0.97] and RR, 1.02 [95% CI, 0.95-1.11] versus RR, 0.94 [95% CI, 0.82-1.07], respectively). Crossover from control to experimental group did not alter effect estimates for primary end point or mortality (RR, 0.82 [95% CI, 0.63-1.05] versus RR, 0.95 [95% CI, 0.86-1.04] and RR, 0.88 [95% CI, 0.73-1.07] versus RR, 1.02 [95% CI, 0.95-1.09], respectively). Conclusions Crossover from experimental to control group is associated with outcomes of cardiac surgery RCTs. Crossover should be minimized at designing stage and carefully appraised after study completion.

Quality of surgery and surgical reporting for patients with primary gastrointestinal stromal tumours participating in the EORTC STBSG 62024 adjuvant imatinib study

BACKGROUND

EORTC (European Organisation of Research and Treatment of Cancer) 62024 is a phase III randomised trial evaluating adjuvant imatinib in patients with gastrointestinal stromal tumours (GISTs) and no evidence of residual disease after surgery in 908 patients from 11 countries participated. As surgical treatment aspects (tumour rupture and incomplete resection) contribute to the risk of recurrence, the data of primary surgery were reviewed.

METHODS

The surgical record, local pathology report and a surgical questionnaire on details of the operation had to be completed when patients entered the study. Surgeons from 5 countries, covering 8 languages, reviewed the full set of data being available from 793 patients (87.3%).

RESULTS

A known GIST was the reason for surgery in only 58% of the cases, and 12% of the patients were treated as an emergency. The R0-resection rate was 87%. The extent of resection was local excision in 17%, segmental resection in 59%, full-organ resection in 11% and multivisceral resection in 11%, with lymphadenectomy performed in 24% of the patients. Shelling out of the tumour was performed in 9.7%, and the proportion of tumours removed in parts was higher in the endoscopy/laparoscopy group. The incidence of tumour rupture (representing M1) was 9%. The consistency between preoperative and intraoperative findings was 82%. The postoperative complication rate was 7.3%.

CONCLUSION

The standardisation of surgery in this study was inferior. Given the review data, 18% of the patients should not have participated in the trial. Quality of surgery and improperly reported intraoperative details might influence the trial results. A detailed surgical questionnaire filled out by the surgeon is mandatory before entering the patient in an adjuvant trial in GIST.

Minimally Invasive Surgery in Pediatric Surgical Oncology: Practice Evolution at a Contemporary Single-Center Institution and a Guideline Proposal for a Randomized Controlled Study

Background: Despite the lack of randomized or controlled trials for minimally invasive surgery (MIS) in pediatric surgical oncology, the integration of MIS into the surgical practice of pediatric oncology has become increasingly popular. The aim of this study was to evaluate the implementation of MIS in a pediatric tertiary cancer center and compare present use of MIS to that in a previous analysis at our center. Methods: We retrospectively reviewed the medical records of patients with pediatric cancer treated with MIS at a single institution between 2000 and 2014. Results: A total of 252 MIS procedures were performed: 73 laparoscopic (29%) and 179 thoracoscopic (71%). MIS was used for diagnostic purposes in 59% (146 thoracoscopic and 34 laparoscopic) and the therapeutic resection in 24% (39 laparoscopic cases and 33 thoracoscopic cases). Conversion to an open procedure occurred in 18 tumor resections (6%) and in 22 diagnostic biopsies (7%), mostly due to technical challenges in identifying or mobilizing tumors. Complications occurred in seven tumor resections (2%) and included three pneumothoraces, two bleeding complications, one bowel injury, and one wound infection. Complications occurred in 10 diagnostic biopsies (3%), mostly pneumothoraces. No tumor upstaging or trocar site recurrences occurred (follow-up time, 1-15 years). Conclusions: Over the last decade, we demonstrate the evolution of MIS in the management of solid tumors in children. We encourage surgeons and oncologists to join the call to arms to establish prospective trials evaluating MIS in pediatric surgical oncology.

Analyses of repeated failures in cancer therapy for solid tumors: poor tumor-selective drug delivery, low therapeutic efficacy and unsustainable costs

For over six decades reductionist approaches to cancer chemotherapies including recent immunotherapy for solid tumors produced outcome failure-rates of 90% (±5) according to governmental agencies and industry. Despite tremendous public and private funding and initial enthusiasm about missile-therapy for site-specific cancers, molecular targeting drugs for specific enzymes such as kinases or inhibitors of growth factor receptors, the outcomes are very bleak and disappointing. Major scientific reasons for repeated failures of such therapeutic approaches are attributed to reductionist approaches to research and infinite numbers of genetic mutations in chaotic molecular environment of solid tumors that are bases of drug development. Safety and efficacy of candidate drugs tested in test tubes or experimental tumor models of rats or mice are usually evaluated and approved by FDA. Cost-benefit ratios of such ‘targeted’ therapies are also far from ideal as compared with antibiotics half a century ago. Such alarming records of failure of clinical outcomes, the increased publicity for specific vaccines (e.g., HPV or flu) targeting young and old populations, along with increasing rise of cancer incidence and death created huge and unsustainable cost to the public around the globe. This article discusses a closer scientific assessment of current cancer therapeutics and vaccines. We also present future logical approaches to cancer research and therapy and vaccines.