BUB1 regulates non-homologous end joining pathway to mediate radioresistance in triple-negative breast cancer.

Background: Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer subtype often treated with radiotherapy (RT). Due to its intrinsic heterogeneity and lack of effective targets, it is crucial to identify novel molecular targets that would increase RT efficacy. Here we demonstrate the role of BUB1 (cell cycle Ser/Thr kinase) in TNBC radioresistance and offer a novel strategy to improve TNBC treatment. Methods: Gene expression analysis was performed to look at genes upregulated in TNBC patient samples compared to other subtypes. Cell proliferation and clonogenic survivals assays determined the IC 50 of BUB1 inhibitor (BAY1816032) and radiation enhancement ratio (rER) with pharmacologic and genomic BUB1 inhibition. Mammary fat pad xenografts experiments were performed in CB17/SCID. The mechanism through which BUB1 inhibitor sensitizes TNBC cells to radiotherapy was delineated by γ-H2AX foci assays, BLRR, Immunoblotting, qPCR, CHX chase, and cell fractionation assays. Results: BUB1 is overexpressed in BC and its expression is considerably elevated in TNBC with poor survival outcomes. Pharmacological or genomic ablation of BUB1 sensitized multiple TNBC cell lines to cell killing by radiation, although breast epithelial cells showed no radiosensitization with BUB1 inhibition. Kinase function of BUB1 is mainly accountable for this radiosensitization phenotype. BUB1 ablation also led to radiosensitization in TNBC tumor xenografts with significantly increased tumor growth delay and overall survival. Mechanistically, BUB1 ablation inhibited the repair of radiation-induced DNA double strand breaks (DSBs). BUB1 ablation stabilized phospho-DNAPKcs (S2056) following RT such that half-lives could not be estimated. In contrast, RT alone caused BUB1 stabilization, but pre-treatment with BUB1 inhibitor prevented stabilization (t 1/2 , ∼8 h). Nuclear and chromatin-enriched fractionations illustrated an increase in recruitment of phospho- and total-DNAPK, and KAP1 to chromatin indicating that BUB1 is indispensable in the activation and recruitment of non-homologous end joining (NHEJ) proteins to DSBs. Additionally, BUB1 staining of TNBC tissue microarrays demonstrated significant correlation of BUB1 protein expression with tumor grade. Conclusions: BUB1 ablation sensitizes TNBC cell lines and xenografts to RT and BUB1 mediated radiosensitization may occur through NHEJ. Together, these results highlight BUB1 as a novel molecular target for radiosensitization in women with TNBC.

PIKfyve controls dendritic cell function and tumor immunity.

The modern armamentarium for cancer treatment includes immunotherapy and targeted therapy, such as protein kinase inhibitors. However, the mechanisms that allow cancer-targeting drugs to effectively mobilize dendritic cells (DCs) and affect immunotherapy are poorly understood. Here, we report that among shared gene targets of clinically relevant protein kinase inhibitors, high PIKFYVE expression was least predictive of complete response in patients who received immune checkpoint blockade (ICB). In immune cells, high PIKFYVE expression in DCs was associated with worse response to ICB. Genetic and pharmacological studies demonstrated that PIKfyve ablation enhanced DC function via selectively altering the alternate/non-canonical NF-κB pathway. Both loss of Pikfyve in DCs and treatment with apilimod, a potent and specific PIKfyve inhibitor, restrained tumor growth, enhanced DC-dependent T cell immunity, and potentiated ICB efficacy in tumor-bearing mouse models. Furthermore, the combination of a vaccine adjuvant and apilimod reduced tumor progression in vivo. Thus, PIKfyve negatively controls DCs, and PIKfyve inhibition has promise for cancer immunotherapy and vaccine treatment strategies.

Potentiating the radiation-induced type I interferon antitumoral immune response by ATM inhibition in pancreatic cancer.

Radiotherapy induces a type I interferon-mediated (T1IFN-mediated) antitumoral immune response that we hypothesized could be potentiated by a first-in-class ataxia telangiectasia mutated (ATM) inhibitor, leading to enhanced innate immune signaling, T1IFN expression, and sensitization to immunotherapy in pancreatic cancer. We evaluated the effects of AZD1390 or a structurally related compound, AZD0156, on innate immune signaling and found that both inhibitors enhanced radiation-induced T1IFN expression via the POLIII/RIG-I/MAVS pathway. In immunocompetent syngeneic mouse models of pancreatic cancer, ATM inhibitor enhanced radiation-induced antitumoral immune responses and sensitized tumors to anti-PD-L1, producing immunogenic memory and durable tumor control. Therapeutic responses were associated with increased intratumoral CD8+ T cell frequency and effector function. Tumor control was dependent on CD8+ T cells, as therapeutic efficacy was blunted in CD8+ T cell-depleted mice. Adaptive immune responses to combination therapy provided systemic control of contralateral tumors outside of the radiation field. Taken together, we show that a clinical candidate ATM inhibitor enhances radiation-induced T1IFN, leading to both innate and subsequent adaptive antitumoral immune responses and sensitization of otherwise resistant pancreatic cancer to immunotherapy.

Class II HLA-DRB4 is a predictive biomarker for survival following immunotherapy in metastatic non-small cell lung cancer.

Immune checkpoint inhibitors (ICI) are important treatment options for metastatic non-small cell lung cancer (mNSCLC). However, not all patients benefit from ICIs and can experience immune-related adverse events (irAEs). Limited understanding exists for germline determinants of ICI efficacy and toxicity, but Human Leukocyte Antigen (HLA) genes have emerged as a potential predictive biomarker. We performed HLA typing on 85 patients with mNSCLC, on ICI therapy and analyzed the impact of HLA Class II genotype on progression free survival (PFS), overall survival (OS), and irAEs. Most patients received pembrolizumab (83.5%). HLA-DRB4 genotype was seen in 34/85 (40%) and its presence correlated with improved OS in both univariate (p = 0.022; 26.3 months vs 10.2 months) and multivariate analysis (p = 0.011, HR 0.49, 95% CI [0.29, 0.85]). PFS did not reach significance (univariate, p = 0.12, 8.2 months vs 5.1 months). Eleven patients developed endocrine irAEs. HLA-DRB4 was the predominant genotype among these patients (9/11, 81.8%). Cumulative incidence of endocrine irAEs was higher in patients with HLA-DRB4 (p = 0.0139). Our study is the first to suggest that patients with metastatic NSCLC patients on ICI therapy with HLA-DRB4 genotype experience improved survival outcomes. Patients with HLA-DRB4 had the longest median OS (26.3 months). Additionally, we found a correlation between HLA-DRB4 and the occurrence of endocrine irAEs.

Pneumonitis After Chemoradiotherapy and Adjuvant Durvalumab in Stage III Non-Small Cell Lung Cancer.

PURPOSE: Adjuvant durvalumab after definitive chemoradiotherapy (CRT) for unresectable stage III non-small cell lung cancer (NSCLC) is well-tolerated in clinical trials. However, pneumonitis rates outside of clinical trials remain poorly defined with CRT followed by durvalumab. We aimed to describe the influence of durvalumab on pneumonitis rates among a large cohort of patients with stage III NSCLC. METHODS AND MATERIALS: We studied patients with stage III NSCLC in the national Veterans Health Administration from 2015 to 2021 who received concurrent CRT alone or with adjuvant durvalumab. We defined pneumonitis as worsening respiratory symptoms with radiographic changes within 2 years of CRT and graded events according to National Cancer Institute Common Terminology Criteria for Adverse Events version 4.03. We used Cox regression to analyze risk factors for pneumonitis and the effect of postbaseline pneumonitis on overall survival. RESULTS: Among 1994 patients (989 CRT alone, 1005 CRT followed by adjuvant durvalumab), the 2-year incidence of grade 2 or higher pneumonitis was 13.9% for CRT alone versus 22.1% for CRT plus durvalumab (unadjusted P < .001). On multivariable analysis, durvalumab was associated with higher risk of grade 2 pneumonitis (hazard ratio, 1.45; 95% CI, 1.09-1.93; P = .012) but not grade 3 to 5 pneumonitis (P = .2). Grade 3 pneumonitis conferred worse overall survival (hazard ratio, 2.51; 95% CI, 2.06-3.05; P < .001) but grade 2 pneumonitis did not (P = .4). CONCLUSIONS: Adjuvant durvalumab use was associated with increased risk of low-grade but not higher-grade pneumonitis. Reassuringly, low-grade pneumonitis did not increase mortality risk. We observed increased rates of high-grade pneumonitis relative to clinical trials; the reasons for this require further study.

Targeting the lipid kinase PIKfyve upregulates surface expression of MHC class I to augment cancer immunotherapy.

Despite the remarkable clinical success of immunotherapies in a subset of cancer patients, many fail to respond to treatment and exhibit resistance. Here, we found that genetic or pharmacologic inhibition of the lipid kinase PIKfyve, a regulator of autophagic flux and lysosomal biogenesis, upregulated surface expression of major histocompatibility complex class I (MHC-I) in cancer cells via impairing autophagic flux, resulting in enhanced cancer cell killing mediated by CD8+ T cells. Genetic depletion or pharmacologic inhibition of PIKfyve elevated tumor-specific MHC-I surface expression, increased intratumoral functional CD8+ T cells, and slowed tumor progression in multiple syngeneic mouse models. Importantly, enhanced antitumor responses by Pikfyve-depletion were CD8+ T cell- and MHC-I-dependent, as CD8+ T cell depletion or B2m knockout rescued tumor growth. Furthermore, PIKfyve inhibition improved response to immune checkpoint blockade (ICB), adoptive cell therapy, and a therapeutic vaccine. High expression of PIKFYVE was also predictive of poor response to ICB and prognostic of poor survival in ICB-treated cohorts. Collectively, our findings show that targeting PIKfyve enhances immunotherapies by elevating surface expression of MHC-I in cancer cells, and PIKfyve inhibitors have potential as agents to increase immunotherapy response in cancer patients.

Evaluation of the Prognostic Role of Liver Metastases on Patient Outcomes: Systematic Review and Meta-analysis.

ABSTRACT: The liver is a common site of metastasis for many primary malignancies, but the quantitative impact on survival is unknown. We performed a systematic review and meta-analysis of 83 studies (604,853 patients) assessing the overall hazard associated with liver metastases by primary tumor type and treatment regimen. The pooled overall survival hazard ratio (HR) for all included studies was 1.77 (95% confidence interval [CI], 1.62-1.93). Patients with breast cancer primaries fared the worst (HR, 2.37; 95% CI, 1.64-3.44), as did patients treated with immunotherapies (HR, 1.86; 95% CI, 1.42-2.42). Liver metastases negatively impact survival, necessitating new approaches to disease management.

Impact of immune tolerance mechanisms on the efficacy of immunotherapy in primary and secondary liver cancers.

The liver is a functionally unique organ with an immunosuppressive microenvironment. The liver is the sixth most common site of primary cancer in humans and is a frequent site of metastasis from other solid tumors. The development of effective therapies for primary and metastatic liver cancer has been challenging due to the complex metabolic and immune microenvironment of the liver. The liver tumor microenvironment (TME) in primary and secondary (metastatic) liver cancers is heterogenous and consists of unique immune and stromal cell populations. Crosstalk between these cell populations and tumor cells creates an immunosuppressive microenvironment within the liver which potentiates cancer progression. Immune checkpoint inhibitors (ICIs) are now clinically approved for the management of primary and secondary liver cancer and can partially overcome liver immune tolerance, but their efficacy is limited. In this review, we describe the liver microenvironment and the use of immunotherapy in primary and secondary liver cancer. We discuss emerging combination strategies utilizing locoregional and systemic therapy approaches which may enhance efficacy of immunotherapy in primary and secondary liver cancer. A deeper understanding of the immunosuppressive microenvironment of the liver will inform novel therapies and therapeutic combinations in order to improve outcomes of patients with primary and secondary liver cancer.

Adopting Weight-Based Dosing With Pharmacy-Level Stewardship Strategies Could Reduce Cancer Drug Spending By Millions.

Immune checkpoint inhibitors, a class of drugs used in approximately forty unique cancer indications, are a sizable component of the economic burden of cancer care in the US. Instead of personalized weight-based dosing, immune checkpoint inhibitors are most commonly administered at "one-size-fits-all" flat doses that are higher than necessary for the vast majority of patients. We hypothesized that personalized weight-based dosing along with common stewardship efforts at the pharmacy level, such as dose rounding and vial sharing, would lead to reductions in immune checkpoint inhibitor use and lower spending. Using data from the Veterans Health Administration (VHA) and Medicare drug prices, we estimated reductions in immune checkpoint inhibitor use and spending that would be associated with pharmacy-level stewardship strategies, in a case-control simulation study of individual patient-level immune checkpoint inhibitor administration events. We identified baseline annual VHA spending for these drugs of approximately $537 million. Combining weight-based dosing, dose rounding, and pharmacy-level vial sharing would generate expected annual VHA health system savings of $74 million (13.7 percent). We conclude that adoption of pharmacologically justified immune checkpoint inhibitor stewardship measures would generate sizable reductions in spending for these drugs. Combining these operational innovations with value-based drug price negotiation enabled by recent policy changes may improve the long-term financial viability of cancer care in the US.

Intersection of immune and oncometabolic pathways drives cancer hyperprogression during immunotherapy.

Immune checkpoint blockade (ICB) can produce durable responses against cancer. We and others have found that a subset of patients experiences paradoxical rapid cancer progression during immunotherapy. It is poorly understood how tumors can accelerate their progression during ICB. In some preclinical models, ICB causes hyperprogressive disease (HPD). While immune exclusion drives resistance to ICB, counterintuitively, patients with HPD and complete response (CR) following ICB manifest comparable levels of tumor-infiltrating CD8+ T cells and interferon γ (IFNγ) gene signature. Interestingly, patients with HPD but not CR exhibit elevated tumoral fibroblast growth factor 2 (FGF2) and ß-catenin signaling. In animal models, T cell-derived IFNγ promotes tumor FGF2 signaling, thereby suppressing PKM2 activity and decreasing NAD+, resulting in reduction of SIRT1-mediated ß-catenin deacetylation and enhanced ß-catenin acetylation, consequently reprograming tumor stemness. Targeting the IFNγ-PKM2-ß-catenin axis prevents HPD in preclinical models. Thus, the crosstalk of core immunogenic, metabolic, and oncogenic pathways via the IFNγ-PKM2-ß-catenin cascade underlies ICB-associated HPD.

Public reporting of black participation in anti-hypertensive drug clinical trials.

BACKGROUND: Non-Hispanic Black people in the United States have the highest prevalence of essential hypertension. Unfortunately, clinical trials often underrepresent Black patients. We aim to understand whether trial sponsorship type is associated with representation of Black participants in anti-hypertensive drug clinical trials. Then, we contextualize our findings amongst current efforts to improve diversity in clinical research populations. METHODS: We searched ClinicalTrials.gov in May 2022 for antihypertensive drug trials. Of n = 408 trials in our initial search, n = 97 (23.77%) met inclusion criteria and were stratified by sponsorship type (industry vs non-industry). Standardized tests of difference were employed to compare characteristics of these trials, and linear regression was used to model change over time. RESULTS: Of 97 trials reporting results from 2010 to 2020, there were minimal differences in the percent of Black patients enrolled in anti-hypertensive clinical trials by sponsorship type. Both industry and non-industry sponsored studies had high rates of non-reporting, with slightly more non-reporting for industry (73.2%) vs non-industry (66.67%) studies. Industry funded studies reported results to ClinicalTrials.gov within 23.3 ± 15.0 months from completing studies, while non-industry funded trials reported within 18.9 ± 10.8 months. CONCLUSIONS: Despite Black Americans carrying the highest burden of disease for essential hypertension, they are underrepresented in anti-hypertension clinical trials and their overall participation has decreased between 2010 and 2020. In addition, there is major underreporting of trial participant race. We implore researchers and funders to establish clear, meaningful targets for anti-hypertensive drug trial diversity, and improve transparency in reporting of study characteristics.

High-content CRISPR screening in tumor immunology.

CRISPR screening is a powerful tool that links specific genetic alterations to corresponding phenotypes, thus allowing for high-throughput identification of novel gene functions. Pooled CRISPR screens have enabled discovery of innate and adaptive immune response regulators in the setting of viral infection and cancer. Emerging methods couple pooled CRISPR screens with parallel high-content readouts at the transcriptomic, epigenetic, proteomic, and optical levels. These approaches are illuminating cancer immune evasion mechanisms as well as nominating novel targets that augment T cell activation, increase T cell infiltration into tumors, and promote enhanced T cell cytotoxicity. This review details recent methodological advances in high-content CRISPR screens and highlights the impact this technology is having on tumor immunology.

Fat Fuels the Fire in Cervical Cancer.

Cervical cancer is the second most common cause of cancer mortality among young women and disproportionately impacts underserved patient populations. An obesity paradox has been observed in cervical cancer wherein patients with higher body mass indices benefit more from standard-of-care chemoradiation. However, the molecular pathways through which obesity modulates treatment response are poorly defined. In exciting work in this issue of Cancer Research, Muhammad and colleagues have shown that monounsaturated and diunsaturated free fatty acids released by adipocytes activate ß-oxidation within tumor cells, which potentiates radiotherapy. This work extends our understanding of the metabolic vulnerabilities of cervical cancer. See related article by Muhammad et al., p. 4515.

Prognostic Hematologic Biomarkers Following Immune Checkpoint Inhibition in Metastatic Uveal Melanoma.

Background: There is no standardized treatment for metastatic uveal melanoma (MUM) but immune checkpoint inhibitors (ICI) are increasingly used. While ICI has transformed the survival of metastatic cutaneous melanoma, MUM patients do not equally benefit. Factors known to affect ICI response include the hematologic markers, lactate dehydrogenase (LDH) and neutrophil:lymphocyte ratio (NLR). We evaluated the prognostic value of LDH and NLR at the start of ICI and on treatment in MUM. Methods: MUM patients were treated between August 2006 and May 2022 with combination ipilimumab/nivolumab or ipilimumab/nivolumab/pembrolizumab single-agent therapy. Univariable (UVA) and multivariable (MVA) analyses were used to assess the prognostic value of predefined baseline factors on progression-free (PFS) and overall survival (OS). Results: In forty-six patients with MUM treated with ICI, elevated baseline and on-treatment LDH was prognostic for OS (start of ICI, HR (95% CI): 3.6 (1.9−7.0), p < 0.01; on-treatment, HR (95% CI): 3.7 (1.6−8.8), p < 0.01) and PFS (start of ICI, (HR (95% CI): 2.8 (1.5−5.4), p < 0.0001); on-treatment LDH (HR (95% CI): 2.2 (1.1−4.3), p < 0.01). On-treatment NLR was prognostic for PFS (HR (95% CI): 1.9 (1.0−3.9), p < 0.01). On-treatment LDH remained an important contributor to survival on MVA (OS: HR (95% CI): 1.001 (1.00−1.002), p < 0.05); PFS: HR (95% CI): 1.001 (1.00−1.002), p < 0.01). Conclusions: This study demonstrates that LDH and NLR could be useful in the prognostication of MUM patients treated with ICI. Additional studies are needed to confirm the importance of these and other prognostic biomarkers.

Updates in combined approaches of radiotherapy and immune checkpoint inhibitors for the treatment of breast cancer.

Breast cancer is the most prevalent non-skin cancer diagnosed in females and developing novel therapeutic strategies to improve patient outcomes is crucial. The immune system plays an integral role in the body's response to breast cancer and modulating this immune response through immunotherapy is a promising therapeutic option. Although immune checkpoint inhibitors were recently approved for the treatment of breast cancer patients, not all patients respond to immune checkpoint inhibitors as a monotherapy, highlighting the need to better understand the biology underlying patient response. Additionally, as radiotherapy is a critical component of breast cancer treatment, understanding the interplay of radiation and immune checkpoint inhibitors will be vital as recent studies suggest that combined therapies may induce synergistic effects in preclinical models of breast cancer. This review will discuss the mechanisms supporting combined approaches with radiotherapy and immune checkpoint inhibitors for the treatment of breast cancer. Moreover, this review will analyze the current clinical trials examining combined approaches of radiotherapy, immunotherapy, chemotherapy, and targeted therapy. Finally, this review will evaluate data regarding treatment tolerance and potential biomarkers for these emerging therapies aimed at improving breast cancer outcomes.

Association of Prostate-Specific Antigen Screening Rates With Subsequent Metastatic Prostate Cancer Incidence at US Veterans Health Administration Facilities.

Importance: There is controversy about the benefit of prostate-specific antigen (PSA) screening. Prostate-specific antigen screening rates have decreased since 2008 in the US, and the incidence of metastatic prostate cancer has increased. However, there is no direct epidemiologic evidence of a correlation between population PSA screening rates and subsequent metastatic prostate cancer rates. Objective: To assess whether facility-level variation in PSA screening rates is associated with subsequent facility-level metastatic prostate cancer incidence. Design, Setting, and Participants: This retrospective cohort used data for all men aged 40 years or older with an encounter at 128 facilities in the US Veterans Health Administration (VHA) from January 1, 2005, to December 31, 2019. Exposures: Yearly facility-level PSA screening rates, defined as the proportion of men aged 40 years or older with a PSA test in each year, and long-term nonscreening rates, defined as the proportion of men aged 40 years or older without a PSA test in the prior 3 years, from January 1, 2005, to December 31, 2014. Main Outcomes and Measures: The main outcomes were facility-level yearly counts of incident metastatic prostate cancer diagnoses and age-adjusted yearly metastatic prostate cancer incidence rates (per 100 000 men) 5 years after each PSA screening exposure year. Results: The cohort included 4 678 412 men in 2005 and 5 371 701 men in 2019. Prostate-specific antigen screening rates decreased from 47.2% in 2005 to 37.0% in 2019, and metastatic prostate cancer incidence increased from 5.2 per 100 000 men in 2005 to 7.9 per 100 000 men in 2019. Higher facility-level PSA screening rates were associated with lower metastatic prostate cancer incidence 5 years later (incidence rate ratio [IRR], 0.91 per 10% increase in PSA screening rate; 95% CI, 0.87-0.96; P < .001). Higher long-term nonscreening rates were associated with higher metastatic prostate cancer incidence 5 years later (IRR, 1.11 per 10% increase in long-term nonscreening rate; 95% CI, 1.03-1.19; P = .01). Conclusions and Relevance: From 2005 to 2019, PSA screening rates decreased in the national VHA system. Facilities with higher PSA screening rates had lower subsequent rates of metastatic prostate cancer. These data may be used to inform shared decision-making about the potential benefits of PSA screening among men who wish to reduce their risk of metastatic prostate cancer.

Early Response Assessment in Advanced Stage Melanoma Treated with Combination Ipilimumab/Nivolumab.

Background: Standard combination ipilimumab/nivolumab (I/N) is given as 4 induction doses for advanced stage melanoma followed by nivolumab single-agent maintenance therapy. While many patients receive less than 4 doses due to immune-related toxicities, it is unclear if fewer doses of I/N may still provide long term clinical benefit. Our aim is to determine if response assessment after 1 or 2 doses of I/N can predict long-term survival and assess if fewer doses of I/N can lead to similar survival outcomes. Methods: We performed a retrospective analysis on a cohort of patients with advanced melanoma who w0ere treated with standard I/N. Cox regression of progression-free survival (PFS) and overall survival (OS) models were performed to assess the relationship between response after 1 or 2 doses of I/N and risk of progression and/or death. Clinical benefit response (CBR) was assessed, defined as SD (stable disease) + PR (partial response) + CR (complete response) by imaging. Among patients who achieved a CBR after 1 or 2 doses of I/N, a multivariable Cox regression of survival was used to compare 1 or 2 vs 3 or 4 doses of I/N adjusted by known prognostic variables in advanced melanoma. Results: 199 patients were evaluated. Patients with CBR after 1 dose of I/N had improved PFS (HR: 0.16, 95% CI 0.08-0.33; p<0.001) and OS (HR: 0.12, 0.05-0.32; p<0.001) compared to progressive disease (PD). Patients with CBR (vs PD) after 2 doses of I/N also had improved PFS (HR: 0.09, 0.05-0.16; p<0.001) and OS (HR: 0.07, 0.03-0.14; p<0.001). There was no survival risk difference comparing 1 or 2 vs 3 or 4 doses of I/N for PFS (HR: 0.95, 0.37-2.48; p=0.921) and OS (HR: 1.04, 0.22-4.78; p=0.965). Conclusions: Early interval imaging with response during induction with I/N may be predictive of long-term survival in advanced stage melanoma. CBR after 1 or 2 doses of I/N is associated with favorable survival outcomes, even in the setting of fewer I/N doses received. Further studies are warranted to evaluate if electively administering fewer combination I/N doses despite tolerance in select patients may balance the benefits of therapy while decreasing toxicities.

De-escalating adjuvant durvalumab treatment duration in stage III non-small cell lung cancer.

BACKGROUND: One year of adjuvant durvalumab following concurrent chemoradiotherapy significantly improves progression-free survival (PFS) and overall survival (OS) for patients with stage III non-small cell lung cancer (NSCLC). However, the optimal length of adjuvant therapy has not been determined. METHODS: We identified patients with stage III NSCLC treated with definitive chemoradiation and adjuvant durvalumab from November 2017 to April 2021 from the United States Veterans Affairs system. Predictors of early durvalumab discontinuation were evaluated with Cox proportional hazards regression. The effect of differing durations of durvalumab treatment (up to 6, 9, and 12 months) on PFS and OS were compared with a marginal structural model and time-dependent Cox modelling. RESULTS: We included 1006 patients with stage III non-small cell lung cancer who received concurrent chemoradiotherapy and at least one dose of adjuvant durvalumab. The median duration of durvalumab treatment was 7 months (interquartile range 2.8-11.5) and 31% completed the intended durvalumab course. The most common reasons for early discontinuation were tumour progression (22%), immune-related adverse events (15%), and non-immune-related toxicity (6.0%), Marginal structural models suggested similar PFS for 9 months versus 12 months of durvalumab treatment and inferior PFS for 6 months versus 12 months. CONCLUSIONS: A substantial proportion of patients undergoing adjuvant durvalumab discontinue therapy early due to toxicity, and shorter durvalumab treatment durations may provide similar disease control to 12 months of therapy. Prospective randomised controlled studies are needed to characterise the optimal durvalumab treatment duration in locally advanced NSCLC patients.

Harnessing the DNA Repair Pathway in Breast Cancer: Germline Mutations/Polymorphisms in Breast Radiation.

Molecular profiling facilitates opportunities for personalization of breast cancer management. Increasing availability of germline and somatic sequencing provides insight into predictors of treatment efficacy and treatment tolerance of patients with breast cancer. The presence of pathologic mutations can guide patient selection for breast conserving surgery vs mastectomy. However, our understanding of the interplay between genetic variants and radiotherapy responses and side effects remains incomplete. Here we review the available data on germline mutations and polymorphisms in breast cancer. We also outline their association with treatment tolerance, locoregional outcomes, and ongoing efforts to transform these insights into more effective treatment strategies in combination with radiotherapy.

Prognostic and Predictive Role of PD-L1 Expression in Stage III Non-small Cell Lung Cancer Treated With Definitive Chemoradiation and Adjuvant Durvalumab.

PURPOSE: It is unclear whether programmed death ligand 1 (PD-L1) expression is prognostic or predictive of immunotherapy benefit among patients with stage III non-small cell lung cancer (NSCLC) treated with definitive chemoradiation and adjuvant durvalumab. METHODS AND MATERIALS: We determined pretreatment tumor PD-L1 expression for 312 patients with stage III NSCLC treated with definitive chemoradiation and at least 1 dose of adjuvant durvalumab between November 2017 and April 2021 across the national Veterans Health Administration. Progression-free survival (PFS) and overall survival (OS) in PD-L1 expression subgroups (<1%, 1%-49%, and 50%-100%) were compared with 994 patients with stage III NSCLC treated without adjuvant durvalumab from 2015 to 2016. RESULTS: PD-L1 expression was <1%, 1% to 49%, and 50% to 100% in 109 (34.9%), 96 (30.7%), and 107 (34.3%) patients, respectively. Increasing PD-L1 expression was associated with longer PFS (adjusted hazard ratio [aHR], 0.84 per 25% absolute increase in expression; 95% confidence interval [CI], 0.75-0.94; P = .003) and OS (aHR, 0.86 per 25% absolute increase in expression; 95% CI, 0.74-0.99; P = .036). Compared with the no-durvalumab group, PFS was longer for PD-L1 50% to 100% (aHR, 0.44; 95% CI, 0.32-0.60; P < .001) and PD-L1 1% to 49% (aHR, 0.64; 95% CI, 0.47-0.86; P = .003) but not PD-L1 <1% (aHR, 0.84; 95% CI, 0.64-1.10; P = .19). Similar results were found for OS, with no significant difference between the no-durvalumab group and PD-L1 <1% (aHR, 0.81; 95% CI, 0.58-1.13; P = .22). CONCLUSIONS: Increasing tumor PD-L1 expression is prognostic for PFS and OS among patients with stage III NSCLC treated with adjuvant durvalumab, and patients with PD-L1 expression <1% may have limited benefit from adjuvant durvalumab.