The association of healthcare contact days with physical function and survival in CCTG/AGITG CO.17.

INTRODUCTION: While contact days-days with healthcare contact outside home-are increasingly adopted as a measure of time toxicity and treatment burden, they could also serve as a surrogate of treatment-related harm. We sought to assess the association between contact days and patient-reported outcomes, and the prognostic ability of contact days. METHODS: We conducted a secondary analysis of CO.17 that evaluated cetuximab vs supportive care in patients with advanced colorectal cancer. CO.17 collected EORTC-QLQ-C30 instrument data. We assessed the association between number of contact days in a window and changes in physical function and global health status, and the association between number of contact days in the first 4 weeks with overall survival (OS). RESULTS: There was a negative association between the number of contact days and change in physical function (per each additional contact day at 4 weeks, 1.50 point decrease; and 8 weeks, 1.06 point decrease, p < .0001 for both), but not with global health status. This negative association was seen in patients receiving cetuximab, but not supportive care. More contact days in the first 4 weeks was associated with worse OS for all comers and patients receiving cetuximab (per each additional contact day; all comers, aHR 1.07, 95% CI, 1.05- 1.10; and cetuximab, aHR 1.08, 95%CI 1.05- 1.11, p < .0001 for both). CONCLUSIONS: In this secondary analysis of a clinical trial, more contact days early in the course was associated with declines in physical function and worse survival in all-comers and in participants receiving cancer-directed treatment. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT00079066.

A lack of association between BMI and chemoimmunotherapy efficacy in advanced non-small cell lung cancer: Secondary analysis of the IMpower150 and IMpower130 clinical trials.

BACKGROUND: Multiple studies have indicated that patients with high body mass index (BMI) may have favourable survival outcomes following treatment with an immune checkpoint inhibitor (ICI). However, this evidence is limited by several factors, notably the minimal evidence from randomised controlled trials (RCTs), the use of categorised BMI with inconsistent cut point definitions, and minimal investigation of contemporary combination ICI therapy. Moreover, whether overweight and obese patients gain a larger benefit from contemporary frontline chemoimmunotherapy in non-small cell lung cancer (NSCLC) is unclear. METHODS: This secondary analysis pooled individual patient data from the intention-to-treat population of the IMpower130 and IMpower150 RCTs comparing chemoimmunotherapy versus chemotherapy. Co-primary outcomes were overall survival (OS) and progression-free survival (PFS). The potentially non-linear relationship between BMI and chemoimmunotherapy treatment effect was evaluated using Multivariable Fractional Polynomial Interaction (MFPI). As a sensitivity analysis, chemoimmunotherapy treatment effect (chemoimmunotherapy versus chemotherapy) on survival was also estimated for each BMI subgroup defined by World Health Organisation classification. Exploratory analyses in the respective chemoimmunotherapy and chemotherapy cohort were undertaken to examine the survival outcomes among BMI subgroups. RESULTS: A total of 1282 patients were included. From the MFPI analysis, BMI was not significantly associated with chemoimmunotherapy treatment effect with respect to either OS (p = 0.71) or PFS (p = 0.35). This was supported by the sensitivity analyses that demonstrated no significant treatment effect improvement in OS/PFS among overweight or obese patients compared to normal weight patients (OS: normal BMI HR = 0.74 95% CI 0.59-0.93, overweight HR = 0.78 95% CI 0.61-1.01, obese HR = 0.84 95% CI 0.59-1.20). Exploratory analyses further highlighted that survival outcomes were not significantly different across BMI subgroups in either the chemoimmunotherapy therapy cohort (Median OS: normal BMI 19.9 months, overweight 17.9 months, and obese 19.5 months, p = 0.7) or the chemotherapy cohort (Median OS: normal 14.1 months, overweight 15.9 months, and obese 16.7 months, p = 0.7). CONCLUSION: There was no association between high BMI (overweight or obese individuals) and enhanced chemoimmunotherapy treatment benefit in front-line treatment of advanced non-squamous NSCLC. This contrasts with previous publications that showed a superior treatment benefit in overweight and obese patients treated with immunotherapy given without chemotherapy.

Transverse Colon Primary Tumor Location as a Biomarker in Metastatic Colorectal Cancer: A Pooled Analysis of CCTG/AGITG CO.17 and CO.20 Randomized Clinical Trials.

PURPOSE: Sidedness is prognostic and predictive of anti-EGFR efficacy in metastatic colorectal cancer (mCRC). Transverse colon has been historically excluded from several analyses of sidedness and the optimal division between left- and right-sided colorectal cancer is unclear. We investigated transverse colon primary tumor location as a biomarker in mCRC. EXPERIMENTAL DESIGN: Pooled analysis of CCTG/AGITG CO.17 and CO.20 trials of cetuximab in chemotherapy-refractory mCRC. Outcomes of patients with RAS/BRAF wild-type (WT) mCRC from CO.17 and KRAS WT mCRC from CO.20 were analyzed according to location. RESULTS: A total of 553 patients were analyzed, 32 (5.8%) with cancers from the transverse, 101 (18.3%) from right, and 420 from (75.9%) left colon. Transverse mCRC failed to reach significant benefit from cetuximab versus best supportive care (BSC) for overall survival [OS; median, 5.9 vs. 2.1 months; HR, 0.63; 95% confidence interval (CI), 0.28-1.42; P=0.26] and progression-free survival (PFS; median, 1.8 vs. 1.3 months; HR, 0.57; 95% CI, 0.26-1.28; P=0.16). Analyzing exclusively patients randomized to cetuximab, right-sided and transverse had comparable outcomes for OS (median, 5.6 vs. 5.9 months; HR, 0.82; 95% CI, 0.50-1.34; P=0.43) and PFS (median, 1.9 vs. 1.8 months; HR, 0.78; 95% CI, 0.49-1.26; P=0.31). Patients with left-sided mCRC had superior outcomes with cetuximab compared with transverse for OS (median, 9.7 vs. 5.9 months; HR, 0.42; 95% CI, 0.27-0.67; P=0.0002) and PFS (median, 3.8 vs. 1.8 months; HR, 0,49; 95% CI, 0.31-0.76; P=0.001). Location was not prognostic in patients treated with BSC alone. CONCLUSIONS: Transverse mCRC has comparable prognostic and predictive features with right-sided mCRC.

Plasma Cetuximab Concentrations Correlate With Survival in Patients With Advanced KRAS Wild Type Colorectal Cancer.

BACKGROUND: Cetuximab is a standard of care therapy for patients with RAS wild-type (WT) advanced colorectal cancer. Limited data suggest a wide variation in cetuximab plasma concentrations after standard dosing regimens. We correlated cetuximab plasma concentrations with survival and toxicity. METHODS: The CO. 20 study randomized patients with RAS WT advanced colorectal cancer in a 1:1 ratio to cetuximab 400 mg/m2 intravenously followed by weekly maintenance of 250 mg/m2, plus brivanib 800 mg orally daily or placebo. Blood samples obtained at week 5 precetuximab treatment were analyzed by ELISA. Patients were grouped into tertiles based on plasma cetuximab concentrations. Cetuximab concentration tertiles were correlated with survival outcomes and toxicity. Patient demographic and biochemical parameters were evaluated as co-variables. RESULTS: Week 5 plasma cetuximab concentrations were available for 591 patients (78.8%). The median overall survival (OS) was 11.4 months and 7.8 months for patients in the highest (T3) and lowest tertiles (T1) respectively. On multivariable analysis, plasma cetuximab concentration was associated with OS (HR 0.66, 95% confidence interval [CI]: 0.53-0.83, P < .001, T3 vs. T1), and a trend towards progression-free survival (HR 0.82, 95% CI: 0.66-1.02, P = .07, T3 vs. T1). There was no association between cetuximab concentration and skin toxicity or diarrhea. CONCLUSION: The standard cetuximab dosing regimen may not be optimal for all patients. Further pharmacokinetic studies are needed to optimize cetuximab dosing given the potential improvement in OS.

Advanced statistics identification of participant and treatment predictors associated with severe adverse effects induced by fluoropyrimidine-based chemotherapy.

PURPOSE: Adverse effects following fluoropyrimidine-based chemotherapy regimens are common. However, there are no current accepted diagnostic markers for prediction prior to treatment, and the underlying mechanisms remain unclear. This study aimed to determine genetic and non-genetic predictors of adverse effects. METHODS: Genomic DNA was analyzed for 25 single nucleotide polymorphisms (SNPs). Demographics, comorbidities, cancer and fluoropyrimidine-based chemotherapy regimen types, and adverse effect data were obtained from clinical records for 155 Australian White participants. Associations were determined by bivariate analysis, logistic regression modeling and Bayesian network analysis. RESULTS: Twelve different adverse effects were observed in the participants, the most common severe adverse effect was diarrhea (12.9%). Bivariate analysis revealed associations between all adverse effects except neutropenia, between genetic and non-genetic predictors, and between 8 genetic and 12 non-genetic predictors with more than 1 adverse effect. Logistic regression modeling of adverse effects revealed a greater/sole role for six genetic predictors in overall gastrointestinal toxicity, nausea and/or vomiting, constipation, and neutropenia, and for nine non-genetic predictors in diarrhea, mucositis, neuropathy, generalized pain, hand-foot syndrome, skin toxicity, cardiotoxicity and fatigue. The Bayesian network analysis revealed less directly associated predictors (one genetic and six non-genetic) with adverse effects and confirmed associations between six adverse effects, eight genetic predictors and nine non-genetic predictors. CONCLUSION: This study is the first to link both genetic and non-genetic predictors with adverse effects following fluoropyrimidine-based chemotherapy. Collectively, we report a wealth of information that warrants further investigation to elucidate the clinical significance, especially associations with genetic predictors and adverse effects.

Multi-omic features of oesophageal adenocarcinoma in patients treated with preoperative neoadjuvant therapy.

Oesophageal adenocarcinoma is a poor prognosis cancer and the molecular features underpinning response to treatment remain unclear. We investigate whole genome, transcriptomic and methylation data from 115 oesophageal adenocarcinoma patients mostly from the DOCTOR phase II clinical trial (Australian New Zealand Clinical Trials Registry-ACTRN12609000665235), with exploratory analysis pre-specified in the study protocol of the trial. We report genomic features associated with poorer overall survival, such as the APOBEC mutational and RS3-like rearrangement signatures. We also show that positron emission tomography non-responders have more sub-clonal genomic copy number alterations. Transcriptomic analysis categorises patients into four immune clusters correlated with survival. The immune suppressed cluster is associated with worse survival, enriched with myeloid-derived cells, and an epithelial-mesenchymal transition signature. The immune hot cluster is associated with better survival, enriched with lymphocytes, myeloid-derived cells, and an immune signature including CCL5, CD8A, and NKG7. The immune clusters highlight patients who may respond to immunotherapy and thus may guide future clinical trials.

Survival outcomes for patients with colorectal cancer with synchronous liver only metastasis.

BACKGROUND: Colorectal cancer with synchronous liver-only metastasis is managed with a multimodal approach, however, optimal sequencing of modalities remains unclear. METHODS: A retrospective review of all consecutive rectal or colon cancer cases with synchronous liver-only metastasis was conducted from the South Australian Colorectal Cancer Registry from 2006 to 2021. This study aimed to investigate how order and type of treatment modality affects overall survival. RESULTS: Data of over 5000 cases were analysed (n = 5244), 1420 cases had liver-only metastasis. There were a greater number of colon than rectal primaries (N = 1056 versus 364). Colonic resection was the preferred initial treatment for the colon cohort (60%). In the rectal cohort, 30% had upfront resection followed by 27% that had chemo-radiotherapy as 1st line therapy. For the colon cohort, there was an improved 5-year survival with surgical resection as initial treatment compared to chemotherapy (25% versus 9%, P < 0.001). In the rectal cohort, chemo-radiotherapy as the initial treatment was associated with an improved 5-year survival compared to surgery or chemotherapy (40% versus 26% versus 19%, P = 0.0015). Patients who were able to have liver resection had improved survival, with 50% surviving over 5 years compared to 12 months in the non-resected group (P < 0.001). Primary rectal KRAS wildtype patients who underwent liver resection and received Cetuximab had significantly worse outcomes compared to KRAS wildtype patients who did not (P = 0.0007). CONCLUSIONS: Where surgery is possible, resection of liver metastasis and primary tumour improved overall survival. Further research is required on the use of targeted treatments in patients undergoing liver resection.

Evaluating the Time Toxicity of Cancer Treatment in the CCTG CO.17 Trial.

PURPOSE: The time spent in pursuing treatments for advanced cancer can be substantial. We have previously proposed a pragmatic and patient-centered metric of these time costs-which we term time toxicity-as any day with physical health care system contact. This includes outpatient visits (eg, bloodwork, scans, etc), emergency department visits, and overnight stays in a health care facility. Herein, we sought to assess time toxicity in a completed randomized controlled trial (RCT). METHODS: We conducted a secondary analysis of the Canadian Cancer Trials Group CO.17 RCT that evaluated weekly cetuximab infusions versus supportive care alone in 572 patients with advanced colorectal cancer. Initial results reported a 6-week improvement in median overall survival (OS) with cetuximab (6.1 v 4.6 months). Subsequent analyses reported that benefit was restricted to patients with K-ras wild-type tumors. We calculated patient-level time toxicity by analyzing trial forms. We considered days without health care contact as home days. We compared medians of time measures across arms and stratified results by K-ras status. RESULTS: In the overall population, median time toxic days were higher in the cetuximab arm (28 v 10, P < .001) although median home days were not statistically different between arms (140 v 121, P = .09). In patients with K-ras-mutated tumors, cetuximab was associated with almost numerically equal home days (114 days v 112 days, P = .571) and higher time toxicity (23 days v 11 days, P < .001). In patients with K-ras wild-type tumors, cetuximab was associated with more home days (186 v 132, P < .001). CONCLUSION: This proof-of-concept feasibility study demonstrates that measures of time toxicity can be extracted through secondary analyses of RCTs. In CO.17, despite an overall OS benefit with cetuximab, home days were statistically similar across arms. Such data can supplement traditional survival end points in RCTs. Further work should refine and validate the measure prospectively.[Media: see text].

A Bayesian approach for two-stage multivariate Mendelian randomization with mixed outcomes.

Many research studies have investigated the relationship between baseline factors or exposures, such as patient demographic and disease characteristics, and study outcomes such as toxicities or quality of life, but results from most of these studies may be problematic because of potential confounding effects (eg, the imbalance in baseline factors or exposures). It is important to study whether the baseline factors or exposures have causal effects on the clinical outcomes, so that clinicians can have better understanding of the diseases and develop personalized medicine. Mendelian randomization (MR) provides an efficient way to estimate the causal effects using genetic instrumental variables to handle confounders, but most of the existing studies focus on a single outcome at a time and ignores the correlation structure of multiple outcomes. Given that clinical outcomes like toxicities and quality of life are usually a mixture of different types of variables, and multiple datasets may be available for such outcomes, it may be much more beneficial to analyze them jointly instead of separately. Some well-established methods are available for building multivariate models on mixed outcomes, but they do not incorporate MR mechanism to deal with the confounders. To overcome these challenges, we propose a Bayesian-based two-stage multivariate MR method for mixed outcomes on multiple datasets, called BMRMO. Using simulation studies and clinical applications on the CO.17 and CO.20 studies, we demonstrate better performance of our approach compared to the commonly used univariate two-stage method.

Understanding the Risk of Drug Interactions Between Ritonavir-Containing COVID-19 Therapies and Small-Molecule Kinase Inhibitors in Patients With Cancer.

PURPOSE: The introduction of COVID-19 therapies containing ritonavir has markedly expanded the scope of use for this medicine. As a strong cytochrome P450 3A4 inhibitor, the use of ritonavir is associated with a high drug interaction risk. There are currently no data to inform clinician regarding the likely magnitude and duration of interaction between ritonavir-containing COVID-19 therapies and small-molecule kinase inhibitors (KIs) in patients with cancer. METHODS: Physiologically based pharmacokinetic modeling was used to conduct virtual clinical trials with a parallel group study design in the presence and absence of ritonavir (100 mg twice daily for 5 days). The magnitude and time course of changes in KI exposure when coadministered with ritonavir was evaluated as the primary outcome. RESULTS: Dosing of ritonavir resulted in a > 2-fold increase in steady-state area under the plasma concentration-time curve and maximal concentration for six of the 10 KIs. When the KI was coadministered with ritonavir, dose reductions to between 10% and 75% of the original dose were required to achieve an area under the plasma concentration-time curve within 1.25-fold of the value in the absence of ritonavir. CONCLUSION: To our knowledge, this study provides the first data to assist clinicians' understanding of the drug interaction risk associated with administering ritonavir-containing COVID-19 therapies to patients with cancer who are currently being treated with KIs. These data may support clinicians to make more informed dosing decisions for patients with cancer undergoing treatment with KIs who require treatment with ritonavir-containing COVID-19 antiviral therapies.

Immune and genomic biomarkers of immunotherapy response in cancer of unknown primary.

BACKGROUND: Cancer of unknown primary (CUP) is a heterogeneous group of metastatic cancers where a primary tissue of origin (TOO) is uncertain. Most patients with CUP have limited treatment options and poor survival outcomes. Immune checkpoint inhibitors (ICIs) can be efficacious in some patients with CUP, but the optimal predictive biomarkers are unknown. We therefore assessed immune and genomic biomarkers as well as predicted TOO in patients with CUP, including a subset treated with ICIs. METHODS: Patients with CUP were subject to gene-expression profiling (GEP) and DNA panel sequencing. Immune and stromal-related gene expression was explored by NanoString, including genes associated with immunotherapy response (IR) in other solid malignancies. ICI responsive cancer types were assigned based on Food and Drug Administration-approved indications, and either detection of a latent primary tumor or the TOO was suspected based on genomics informed pathology review. Tumor mutation burden (TMB) and gene mutations were also assessed. RESULTS: A total of 219 patients with CUP were included, 215 assessed for TOO in a previous study, with the majority (163) receiving both RNA and DNA tests. Of GEP profiled cases, 33% (59/175) had a high IR gene-expression score. Of the DNA sequenced cases, 16% (32/203) had high TMB (>10 mutations/Mb), including two with mismatch repair deficiency. Low correlation was observed between TMB and an IR score (R=0.26, p<0.001). Among 110 CUPs with a latent primary or suspected TOO, 47% (52/110) belonged to ICI-responsive cancer types. More than half of the CUPs had at least one feature that may predict ICI response (high IR score, high TMB, ICI-responsive cancer type). Among patients with CUP treated with ICIs, 8/28 (29%) responded (2 complete responses and 6 partial responses). Among non-responders, 9 had stable and 11 had progressive disease. All responders had a high IR score (7/8) and/or high TMB (3/8), while most (5/8) belonged to ICI-responsive cancer types. These features were detected at a lower frequency in non-responders and mostly in patients with stable disease. CONCLUSIONS: A significant fraction of CUP tumors had genomic features previously associated with ICI response. High IR score was the most sensitive predictive feature of ICI response, warranting evaluation in a larger patient series.

A comparison of DNA sequencing and gene expression profiling to assist tissue of origin diagnosis in cancer of unknown primary.

Cancer of unknown primary (CUP) is a syndrome defined by clinical absence of a primary cancer after standardised investigations. Gene expression profiling (GEP) and DNA sequencing have been used to predict primary tissue of origin (TOO) in CUP and find molecularly guided treatments; however, a detailed comparison of the diagnostic yield from these two tests has not been described. Here, we compared the diagnostic utility of RNA and DNA tests in 215 CUP patients (82% received both tests) in a prospective Australian study. Based on retrospective assessment of clinicopathological data, 77% (166/215) of CUPs had insufficient evidence to support TOO diagnosis (clinicopathology unresolved). The remainder had either a latent primary diagnosis (10%) or clinicopathological evidence to support a likely TOO diagnosis (13%) (clinicopathology resolved). We applied a microarray (CUPGuide) or custom NanoString 18-class GEP test to 191 CUPs with an accuracy of 91.5% in known metastatic cancers for high-medium confidence predictions. Classification performance was similar in clinicopathology-resolved CUPs - 80% had high-medium predictions and 94% were concordant with pathology. Notably, only 56% of the clinicopathology-unresolved CUPs had high-medium confidence GEP predictions. Diagnostic DNA features were interrogated in 201 CUP tumours guided by the cancer type specificity of mutations observed across 22 cancer types from the AACR Project GENIE database (77,058 tumours) as well as mutational signatures (e.g. smoking). Among the clinicopathology-unresolved CUPs, mutations and mutational signatures provided additional diagnostic evidence in 31% of cases. GEP classification was useful in only 13% of cases and oncoviral detection in 4%. Among CUPs where genomics informed TOO, lung and biliary cancers were the most frequently identified types, while kidney tumours were another identifiable subset. In conclusion, DNA and RNA profiling supported an unconfirmed TOO diagnosis in one-third of CUPs otherwise unresolved by clinicopathology assessment alone. DNA mutation profiling was the more diagnostically informative assay. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Monitoring quality of care in hepatocellular carcinoma: A modified Delphi consensus.

Although there are several established international guidelines on the management of hepatocellular carcinoma (HCC), there is limited information detailing specific indicators of good quality care. The aim of this study was to develop a core set of quality indicators (QIs) to underpin the management of HCC. We undertook a modified, two-round, Delphi consensus study comprising a working group and experts involved in the management of HCC as well as consumer representatives. QIs were derived from an extensive review of the literature. The role of the participants was to identify the most important and measurable QIs for inclusion in an HCC clinical quality registry. From an initial 94 QIs, 40 were proposed to the participants. Of these, 23 QIs ultimately met the inclusion criteria and were included in the final set. This included (a) nine related to the initial diagnosis and staging, including timing to diagnosis, required baseline clinical and laboratory assessments, prior surveillance for HCC, diagnostic imaging and pathology, tumor staging, and multidisciplinary care; (b) thirteen related to treatment and management, including role of antiviral therapy, timing to treatment, localized ablation and locoregional therapy, surgery, transplantation, systemic therapy, method of response assessment, and supportive care; and (c) one outcome assessment related to surgical mortality. Conclusion: We identified a core set of nationally agreed measurable QIs for the diagnosis, staging, and management of HCC. The adherence to these best practice QIs may lead to system-level improvement in quality of care and, ultimately, improvement in patient outcomes, including survival.

The Management of Unresectable, Advanced Gastrointestinal Stromal Tumours.

Gastrointestinal stromal tumours (GISTs) are the most common gastrointestinal tract mesenchymal tumours. Tyrosine kinase inhibitors (TKIs) have transformed the management of advanced GIST. Imatinib was the first TKI to gain approval as management for patients with advanced GIST, establishing a new standard of care. Since then, as a result of several trials including the GRID and INVICTUS studies, we now have five lines of approved targeted therapy, including imatinib, sunitinib, regorafenib, ripretinib and avapritinib for the treatment of unresectable, advanced GISTs. In this review, the Australasian Gastrointestinal Trials Group (AGITG) provide an overview of the key trials that have changed clinical practice, discuss the molecular drivers of GISTs, the importance of molecular testing and directing therapy according to molecular targets, as well as future strategies in the management of advanced GISTs.

Immunotherapy use in oesophagogastric cancers-a review of the literature.

Cancers of the upper gastrointestinal tract are a leading cause of cancer-related death world-wide and historically have a poor prognosis. The incidence and histology of these cancers have varied temporally and geographically over the last three decades, with an emerging understanding of the differences in the molecular and genetic profiles across different subgroups. Management of oesophagogastric cancers is by a multidisciplinary team with utilisation of surgery, radiotherapy and systemic treatments in combinations where appropriate. Immune checkpoint inhibition (ICI) has drastically changed the treatment landscape of multiple solid malignancies in the last 5 years. In oesophagogastric cancer, clinical trials have only recently shown activity that is often associated with the molecular characteristics of these tumours, in particular PD-L1 scores or microsatellite instability (MSI-H). This review looks to present the pivotal trials in this space, discuss the complexities between trials that may explain the disparate results and assess the benefit ICI offers in the treatment landscape at present.

A longitudinal cohort study of watch and wait in complete clinical responders after chemo-radiotherapy for localised rectal cancer: study protocol.

BACKGROUND: Rectal Cancer is a common malignancy. The current treatment approach for patients with locally advanced rectal cancer involves neoadjuvant chemoradiotherapy followed by surgical resection of the rectum. The resection can lead to complications and long-term consequences. A clinical complete response is observed in some patients after chemoradiotherapy. A number of recent studies have shown that patients can be observed safely after completing chemoradiotherapy (without surgery), provided clinical complete response has been achieved. In this approach, resection is reserved for cases of regrowth. This is called the watch and wait approach. This approach potentially avoids unnecessary surgical resection of the rectum and the resulting complications. In this study, we will prospectively investigate this approach. METHODS: Adult patients with a diagnosis of rectal cancer planned to receive neoadjuvant long course chemoradiotherapy (± subsequent combination chemotherapy) will be consented into the study prior to commencing treatment. After completing the chemoradiotherapy (± subsequent combination chemotherapy), based on the clinical response, subjects will be allocated to one of the following arms: subjects who achieved a clinical complete response will be allocated to the watch and wait arm and others to the standard management arm (which includes resection). The aim of the study is to determine the rate of local failure and other safety and efficacy outcomes in the watch and wait arm. Patient reported outcome measures and the use of biomarkers as part of the clinical monitoring will be studied in both arms of the study. DISCUSSION: This study will prospectively investigate the safety of the watch and wait approach. We will investigate predictive biomarkers (molecular biomarkers and imaging biomarkers) and patient reported outcome measures in the study population and the cost effectiveness of the watch and wait approach. This study will also help evaluate a defined monitoring schedule for patients managed with the watch and wait approach. This protocol covers the first two years of follow up, we are planning a subsequent study which covers year 3-5 follow up for the study population. TRIAL REGISTRATION: Name of the registry: Australia and New Zealand Clinical Trials Registry (ANZCTR). TRIAL REGISTRATION NUMBER: Trial ID: ACTRN12619000207112 Registered 13 February 2019, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=376810.

Efficacy of Atezolizumab in Patients With Advanced NSCLC Receiving Concomitant Antibiotic or Proton Pump Inhibitor Treatment: Pooled Analysis of Five Randomized Control Trials.

INTRODUCTION: Gut dysbiosis may reduce immune checkpoint inhibitor (ICI) efficacy. Antibiotics and proton pump inhibitors (PPIs) are commonly used drugs causing gut dysbiosis. There is limited randomized controlled trial (RCT) evidence on whether antibiotics or PPIs impact ICI benefit versus comparator treatments. METHODS: This study pooled five RCTs (IMpower130, IMpower131, IMpower150, OAK, and POPLAR) evaluating atezolizumab in advanced NSCLC. Atezolizumab efficacy (hazard ratio with 95% confidence intervals) was assessed for subgroups on the basis of antibiotic and PPI use at randomization. The association between antibiotic and PPI use with pretreatment peripheral blood immunophenotype was also explored. RESULTS: Of 4458 participants, 285 received an antibiotic in the 30-day pretreatment and 1225 were using a PPI at treatment initiation. Overall survival efficacy of atezolizumab was similar (p[interaction] = 0.35) for antibiotic users (hazard ratio 95% confidence interval: 0.73 [0.53-0.99]) and antibiotic nonusers (0.82 [0.74-0.91]). Nevertheless, efficacy was reduced (p[interaction] = 0.003) for PPI users (1.00 [0.85-1.17]) compared with PPI nonusers (0.76 [0.69-0.83]). Findings were consistent across RCTs and for progression-free survival. PPI use was associated with 9%, 18%, and 9% lower counts of lymphocytes, CD19+, and CD16+CD56+ immune cells, respectively (p < 0·01). CONCLUSIONS: Reassuringly, atezolizumab efficacy did not differ for antibiotic users. Opposingly, PPI use was consistently associated with decreased atezolizumab efficacy and lower pretreatment counts of lymphocytes, CD19+, and CD16+CD56+ immune cells. Given that approximately 30% of patients with cancer use PPIs, there is an urgent need for evidence on the impacts of PPIs on other ICIs and for the development of guidelines on nonessential PPI use with ICIs.

Gastrointestinal Adenocarcinoma Incidence and Survival Trends in South Australia, 1990-2017.

BACKGROUND & AIMS: Globally, there has been a concerning rise in the incidence of young-onset cancers. The aim of this study was to provide trends in the incidence and survival of gastrointestinal adenocarcinomas (oesophagus, stomach, pancreas, and colorectal) in South Australia over a 27-year period. METHODS: This is a cross-sectional analysis of a prospective longitudinal database including all cases of gastrointestinal adenocarcinomas prospectively reported to the South Australian (State) Cancer Registry from 1990 to 2017. RESULTS: A total of 28,566 patients diagnosed with oesophageal, stomach, pancreatic, or colorectal adenocarcinoma between 1990 and 2017 were included in the study. While the overall incidence for gastrointestinal adenocarcinomas in individuals >50 years has decreased since 2000 (IRR of 0.97 (95% CI 0.94-1.00; p = 0.06)) compared to 1990-1999, the rate amongst individuals aged 18-50 has significantly increased (IRR 1.41 (95% CI 1.27-1.57; p < 0.001)) during the same reference time period. Although noted in both sexes, the rate of increase in incidence was significantly greater in males (11.5 to 19.7/100,000; p < 0.001). The overall survival from adenocarcinomas across all subsites improved in the >50-year cohort in the last decade (HR 0.89 (95% CI 0.86-0.93; p < 0.001)) compared to 1990-1999. In individuals aged 18-50 years, there has only been a significant improvement in survival for colorectal cancer (HR 0.82 (95% CI 0.68-0.99; p < 0.04)), but not the other subsites. A lower overall survival was noted for males in both age cohorts (18-50 years-HR 1.24 (95% CI 1.09-1.13; p < 0.01) and >50 years-HR 1.13 (95% CI 1.10-1.16; p < 0.001), respectively) compared to females. CONCLUSIONS: This study from South Australia demonstrates a significant increase in young-onset gastrointestinal adenocarcinomas over the last 28 years, with a greater increase in the male sex. The only significant improvement in survival in this cohort has been noted in colorectal cancer patients.

Efficacy of first-line atezolizumab combination therapy in patients with non-small cell lung cancer receiving proton pump inhibitors: post hoc analysis of IMpower150.

BACKGROUND: Proton pump inhibitors (PPIs) are commonly used concomitant to cancer treatment and they induce gut microbiota changes. It is increasingly apparent that gut dysbiosis can reduce the effectiveness of immune checkpoint inhibitors (ICI). However, little is known about PPI effects on outcomes with ICIs, particularly in combination, ICI approaches. METHODS: Post hoc, Cox proportional hazard analysis of phase III trial, IMpower150 was conducted to assess the association between PPI use and overall survival (OS) and progression-free survival (PFS) in chemotherapy-naive, metastatic non-squamous non-small cell lung cancer participants randomised atezolizumab plus carboplatin plus paclitaxel (ACP), bevacizumab plus carboplatin plus paclitaxel (BCP), or atezolizumab plus BCP (ABCP). PPI use was defined as any PPI administration between 30 days prior and 30 days after treatment initiation. RESULTS: Of 1202 participants, 441 (37%) received a PPI. PPI use was independently associated with worse OS (n = 748; hazard ratio (HR) [95% confidence interval (CI)] = 1.53 [1.21-1.95], P < 0.001) and PFS (1.34 [1.12-1.61], P = 0.002) in the pooled atezolizumab arms (ACP plus ABCP). This association was not apparent for BCP (n = 368; OS 1.01 [0.73-1.39], P = 0.969; PFS 0.97 [0.76-1.25], P = 0.827). The observed OS treatment effect (HR 95% CI) of the atezolizumab (ACP plus ABCP) arms vs BCP was 1.03 (0.77-1.36) for PPI users compared to 0.68 (0.54-0.86) for non-users (P [interaction] = 0.028). A similar association was noted for ABCP vs BCP (PPI users 0.96 [0.68-1.35]; PPI non-users 0.66 [0.50-0.87]; P [interaction] = 0.095). CONCLUSIONS: PPI use was a negative prognostic marker in patients treated with ACP or ABCP, but not BCP. The analysis suggests that PPIs negatively influence the magnitude of ICI efficacy.