The COVID-19 pandemic impact on independent and provider-based rural health clinics' operations and cancer prevention and screening provision in the United States.

INTRODUCTION: The COVID-19 pandemic has disrupted cancer care, but it is unknown how the pandemic has affected care in Medicare-certified rural health clinics (RHCs) where cancer prevention and screening services are critical for their communities. This study examined how the provision of these cancer services changed pre- and peri-pandemic overall and by RHC type (independent and provider-based). METHODS: We administered a cross-sectional survey to a stratified random sample of RHCs to assess clinic characteristics, pandemic stressors, and the provision of cancer prevention and control services among RHCs pre- and peri-pandemic. We used McNemar's test and Wilcoxon signed rank tests to assess differences in the provision of cancer prevention and screening services pre- and peri-pandemic by RHC type. RESULTS: Of the 153 responding RHCs (response rate of 8%), 93 (60.8%) were provider-based and 60 (39.2%) were independent. Both RHC types were similar in their experience of pandemic stressors, though a higher proportion of independent RHCs reported financial concerns and challenges obtaining personal protective equipment. Both types of RHCs provided fewer cancer prevention and screening services peri-pandemic-5.8 to 4.2 for provider-based and 5.3 to 3.5 for independent (P<.05 for both). Across lung, cervical, breast, and colorectal cancer-related services, the proportion of both RHC groups providing services dropped peri-pandemic. DISCUSSION: The pandemic's impact on independent and provider-based RHCs and their patients was considerable. Going forward, greater resources should be targeted to RHCs-particularly independent RHCs-to ensure their ability to initiate and sustain evidence-based prevention and screening services.

Availability of hospital-based cancer services before and after rural hospital closure, 2008-2017.

INTRODUCTION: Rural populations have less access to cancer care services and experience higher cancer mortality rates than their urban counterparts, which may be exacerbated by hospital closures. Our objective was to examine the impact of hospital closures on access to cancer-relevant hospital services across hospital service areas (HSAs). METHODS: We used American Hospital Association survey data from 2008 to 2017 to examine the change in access to cancer-related screening and treatment services across rural HSAs that sustained hospitals over time, experienced any closures, or had all hospitals close. We performed a longitudinal analysis to assess the association between hospital closure occurrence and maintenance or loss of cancer-related service lines accounting for hospital and HSA-level characteristics. Maps were also developed to display changes in the availability of services across HSAs. RESULTS: Of the 2,014 rural HSAs, 3.8% experienced at least 1 hospital closure during the study period, most occurring in the South. Among HSAs that experienced hospital closure, the loss of surgery services lines was most common, while hospital closures did not affect the availability of overall oncology and radiation services. Screening services either were stable (mammography) or increased (endoscopy) in areas with no closures. DISCUSSION: Rural areas persistently experience less access to cancer treatment services, which has been exacerbated by hospital closures. Lack of Medicaid expansion in many Southern states and other policy impacts on hospital financial viability may play a role in this. Future research should explore the impact of closures on cancer treatment receipt and outcomes.

The Problem Of The Color Line: Spatial Access To Hospital Services For Minoritized Racial And Ethnic Groups.

Examining how spatial access to health care varies across geography is key to documenting structural inequalities in the United States. In this article and the accompanying StoryMap, our team identified ZIP Code Tabulation Areas (ZCTAs) with the largest share of minoritized racial and ethnic populations and measured distances to the nearest hospital offering emergency services, trauma care, obstetrics, outpatient surgery, intensive care, and cardiac care. In rural areas, ZCTAs with high Black or American Indian/Alaska Native representation were significantly farther from services than ZCTAs with high White representation. The opposite was true for urban ZCTAs, with high White ZCTAs being farther from most services. These patterns likely result from a combination of housing policies that restrict housing opportunities and federal health policies that are based on service provision rather than community need. The findings also illustrate the difficulty of using a single metric-distance-to investigate access to care on a national scale.

Trends in Cancer Treatment Service Availability Across Critical Access Hospitals and Prospective Payment System Hospitals.

BACKGROUND: Rural residents experience worse cancer prognosis and access to cancer care providers than their urban counterparts. Critical access hospitals (CAHs) represent over half of all rural community hospitals. However, research on cancer services provided within CAHs is limited. OBJECTIVE: The objective of this study was to investigate trends in cancer services availability in urban and rural Prospective Payment System (PPS) hospitals and CAHs. DESIGN: Retrospective, time-series analysis using data from 2008 to 2017 American Hospital Association Annual Surveys. Multivariable logistic regressions were used to examine differential trends in cancer services between urban PPS, rural PPS, and CAHs, overall and among small (<25 beds) hospitals. SUBJECTS: All US acute care and cancer hospitals (4752 in 2008 to 4722 in 2017). MEASURES: Primary outcomes include whether a hospital provided comprehensive oncology services, chemotherapy, and radiation therapy each year. RESULTS: In 2008, CAHs were less likely to provide all cancer services, especially chemotherapy (30.4%) and radiation therapy (2.9%), compared with urban (64.4% and 43.8%, respectively) and rural PPS hospitals (42.0% and 23.3%, respectively). During 2008-2017, compared with similarly sized PPS hospitals, CAHs were more likely to provide oncology services and chemotherapy, but with decreasing trends. Radiation therapy availability between small PPS hospitals and CAHs did not differ. CONCLUSIONS: Compared with all PPS hospitals, CAHs offered fewer cancer treatment services and experienced a decline in service capability over time. These differences in chemotherapy services were mainly driven by hospital size, as small urban and rural PPS hospitals had lower rates of chemotherapy than CAHs. Still, the lower rates of radiotherapy in CAHs highlight disproportionate challenges facing CAHs for some specialty services.

The Intersection of Rural Residence and Minority Race/Ethnicity in Cancer Disparities in the United States.

One in every twenty-five persons in America is a racial/ethnic minority who lives in a rural area. Our objective was to summarize how racism and, subsequently, the social determinants of health disproportionately affect rural racial/ethnic minority populations, provide a review of the cancer disparities experienced by rural racial/ethnic minority groups, and recommend policy, research, and intervention approaches to reduce these disparities. We found that rural Black and American Indian/Alaska Native populations experience greater poverty and lack of access to care, which expose them to greater risk of developing cancer and experiencing poorer cancer outcomes in treatment and ultimately survival. There is a critical need for additional research to understand the disparities experienced by all rural racial/ethnic minority populations. We propose that policies aim to increase access to care and healthcare resources for these communities. Further, that observational and interventional research should more effectively address the intersections of rurality and race/ethnicity through reduced structural and interpersonal biases in cancer care, increased data access, more research on newer cancer screening and treatment modalities, and continued intervention and implementation research to understand how evidence-based practices can most effectively reduce disparities among these populations.

Rural-Urban Mortality Disparities: Variations Across Causes of Death and Race/Ethnicity, 2013-2017.

Objectives. To examine rural-urban disparities in overall mortality and leading causes of death across Hispanic (any race) and non-Hispanic White, Black, American Indian/Alaska Native (AI/AN), and Asian/Pacific Islander populations.Methods. We performed a retrospective analysis of age-adjusted death rates for all-cause mortality and 5 leading causes of death (cardiovascular, cancer, unintentional injuries, chronic lower respiratory disease, and stroke) by rural versus urban county of residence in the United States and race/ethnicity for the period 2013 to 2017.Results. Rural populations, across all racial/ethnic groups, had higher all-cause mortality rates than did their urban counterparts. Comparisons within causes of death documented rural disparities for all conditions except cancer and stroke among Hispanic individuals; Hispanic rural residents had death rates similar to or lower than urban residents. Rural Black populations experienced the highest mortality for cardiovascular disease, cancer, and stroke. Unintentional injury and chronic lower respiratory disease mortality were highest in rural AI/AN and rural non-Hispanic White populations, respectively.Conclusions. Investigating rural-urban disparities without also considering race/ethnicity leaves minority health disparities unexamined and thus unaddressed. Further research is needed to clarify local factors associated with these disparities and to test appropriate interventions.

Toll-like receptor 9 mediates CpG oligonucleotide-induced cellular invasion.

Toll-like receptor 9 (TLR9) belongs to the innate immune system and recognizes microbial and vertebrate DNA. We showed previously that treatment with the TLR9-agonistic ODN M362 (a CpG sequence containing oligonucleotide) induces matrix metalloproteinase-13-mediated invasion in TLR9-expressing human cancer cell lines. Here, we further characterized the role of the TLR9 pathway in this process. We show that CpG oligonucleotides induce invasion in macrophages from wild-type C57/B6 and MyD88 knockout mice and in human MDA-MB-231 breast cancer cells lacking MyD88 expression. This effect was significantly inhibited in macrophages from TLR9 knockout mice and in human MDA-MB-231 breast cancer cells stably expressing TLR9 small interfering RNA or dominant-negative tumor necrosis factor receptor-associated factor 6 (TRAF6). Sequence modifications to the CpG oligonucleotides that targeted the stem loop and other secondary structures were shown to influence the invasion-inducing effect in MDA-MB-231 cells. In contrast, methylation of the cytosine residues of the parent CpG oligonucleotide did not affect the TLR9-mediated invasion compared with the unmethylated parent CpG oligonucleotide. Finally, expression of TLR9 was studied in clinical breast cancer samples and normal breast epithelium with immunohistochemistry. TLR9 staining localized in epithelial cells in both cancer and normal samples. The mean TLR9 staining intensity was significantly increased in the breast cancer cells compared with normal breast epithelial cells. In conclusion, our results suggest that TLR9 expression is increased in breast cancer and CpG oligonucleotide-induced cellular invasion is mediated via TLR9 and TRAF6, independent of MyD88. Further, our findings suggest that the structure and/or stability of DNA may influence the induction of TLR9-mediated invasion in breast cancer.

Inhibition of the mevalonate pathway and activation of p38 MAP kinase are independently regulated by nitrogen-containing bisphosphonates in breast cancer cells.

Bisphosphonates are widely used inhibitors of bone resorption. They also inhibit the growth of various cancer cells in vitro, but the clinical significance of this effect is unclear. The cancer growth inhibitory effects of nitrogen-containing bisphosphonates, (i.e. zoledronate) have been attributed to their ability to inhibit the mevalonate pathway. We have shown that bisphosphonates also induce p38 activation, which signals resistance against the drug-induced growth inhibition through an unknown mechanism. We show here that zoledronate induces a G1/S cell cycle arrest in human MDA-MB-231 breast cancer cells. Furthermore, p38 inhibitor augments bisphosphonate-induced growth inhibition by inducing an additional G2-phase cell cycle arrest. We also show that the nitrogen-containing bisphosphonate-induced effects on p38 phosphorylation occur before accumulation of unprenylated Rap1A or Rac1 activation. Geranylgeranyl pyrophosphate, an end-product of the mevalonate pathway, reversed the accumulation of unprenylated Rap1A but not phosphorylation of p38. Geranylgeranyl pyrophosphate also reversed n-BP induced growth inhibition, but the completeness of this reversal was nitrogen-containing bisphosphonate concentration dependent. Also mevastatin induced the accumulation of unprenylated Rap1A, but it did not induce p38 phosphorylation. In conclusion, our results suggest that in addition to the previously reported effects on apoptosis, nitrogen-containing bisphosphonates also inhibit the growth of MDA-MB-231 breast cancer cells by inducing G1/S cell cycle arrest. The bisphosphonate-induced p38 activation signals for resistance against these drugs, by promoting progression through the G2/M-checkpoint. Of these pathways only growth inhibition is mediated via inhibition of the mevalonate pathway in MDA-MB-231 cells. Combining p38 inhibitors with bisphosphonates may result in increased anti-cancer efficacy.

Toll like receptor-9 agonists stimulate prostate cancer invasion in vitro.

BACKGROUND: Toll-like receptor 9 (TLR9) recognizes microbial DNA. In addition to immune cells, TLR9 expression has been detected in various cancer cells. We showed recently that TLR9 agonistic CpG-oligonucleotides (CpG-ODNs) induce matrix metalloproteinase-13 (MMP-13)-mediated invasion in TLR9-expressing (TLR9(+)) breast cancer cells. We investigated here TLR9 expression and function in human prostate cancer (CaP) cells. METHODS: TLR9 expression was detected with Western blotting and immunohistochemistry. Invasion was studied with Matrigel-assays. MMP-13 was assayed with ELISA. RESULTS: Human CaP cell lines and clinical samples exhibit various levels of TLR9 expression. Treatment of TLR9(+), but not TLR9(-) CaP cells with CpG-ODNs or bacterial DNA increased their invasion, which was inhibited with chloroquine. CpG-ODN-treatment also increased MMP-13 activity and neutralizing anti-MMP-13 antibody prevented CpG-ODN-induced invasion in TLR9(+) CaP cells. Estradiol up-regulated TLR9 expression in LnCaP cells. CONCLUSIONS: TLR9-mediated invasion may represent a novel mechanism through which infections promote prostate cancer.

Differential effects of Ca(2+) on bisphosphonate-induced growth inhibition in breast cancer and mesothelioma cells.

Bisphosphonates are widely clinically used inhibitors of bone resorption. Pre-clinical studies indicate that bisphosphonates also inhibit the growth of various cancer cells in vitro, but their in vivo anti-cancer activity varies greatly, depending on the tumor type. We compared the various cellular effects of bisphosphonates in breast cancer and mesothelioma cells, with differences in growth inhibition responses to bisphosphonate-treatment in vivo. We show that the growth inhibitory effects of nitrogen-containing bisphosphonates are significantly affected by excess Ca(2+) in a cell- and bisphosphonate-specific fashion. Furthermore, excess pyrophosphate-resembling bisphosphonates prevent nitrogen-containing-bisphosphonate-induced accumulation of unprenylated Rap1A, p38 phosphorylation and growth inhibition in human MDA-MB-231 breast cancer and mouse AB-12 mesothelioma cells. For some, but not all tested, pyrophosphate-resembling bisphosphonate: nitrogen-containing bisphosphonate combinations these results may be partially explained by the ability of the excess pyrophosphate-resembling bisphosphonates to chelate Ca(2+). In mice, subcutaneous AB-12 and MDA-MB-231 tumors exhibit positive staining for Ca(2+) minerals, as revealed with Von Kossa stainings. We further show that the AB-12 tumors accumulate significantly more of the bone scanning bisphosphonate, Tc99m-medronate, as compared with MDA-MB-231 tumors. In conclusion, our results suggest that Ca(2+) regulates the growth inhibitory effects of bisphosphonates in a target cell and drug-specific fashion. These findings may be of physiological relevance since many tumor types are calcified. They further suggest that bisphosphonates can accumulate in tumors that are growing at the visceral sites and that differences in tumor accumulation of bisphosphonates may regulate their in vivo sensitivity to these drugs.

Toll-like receptor 9 agonists promote cellular invasion by increasing matrix metalloproteinase activity.

Toll-like receptor 9 (TLR9) recognizes microbial DNA. We show here that TLR9 protein is expressed in human breast cancer cells and clinical breast cancer samples. Stimulation of TLR9-expressing breast cancer cells with the TLR9 agonistic CpG oligonucleotides (1-10 mumol/L) dramatically increased their in vitro invasion in both Matrigel assays and three-dimensional collagen cultures. Similar effects on invasion were seen in TLR9-expressing astrocytoma and glioblastoma cells and in the immortalized human breast epithelial cell line MCF-10A. This effect was not, however, dependent on the CpG content of the TLR9 ligands because the non-CpG oligonucleotides induced invasion of TLR9-expressing cells. CpG or non-CpG oligonucleotide-induced invasion in MDA-MB-231 cells was blunted by chloroquine and they did not induce invasion of TLR9(-) breast cancer cells. Treatment of MDA-MB-231 cells with CpG or non-CpG oligonucleotides induced the formation of approximately 50-kDa gelatinolytic band in zymograms. This band and the increased invasion were abolished by a matrix metalloproteinase (MMP) inhibitor GM6001 but not by a serine proteinase inhibitor aprotinin. Furthermore, CpG oligonucleotide treatment decreased tissue inhibitor of metalloproteinase-3 expression and increased levels of active MMP-13 in TLR9-expressing but not TLR9(-) breast cancer cells without affecting MMP-8. Neutralizing anti-MMP-13 antibodies inhibited the CpG oligonucleotide-induced invasion. These findings suggest that infections may promote cancer progression through a novel TLR9-mediated mechanism. They also propose a new molecular target for cancer therapy, because TLR9 has not been associated with cancer invasiveness previously.

Bisphosphonates inhibit the growth of mesothelioma cells in vitro and in vivo.

PURPOSE: Bisphosphonates (such as risedronate and zoledronate) are widely used inhibitors of bone resorption. Despite their in vitro antiproliferative effects in various cancer cells, bisphosphonates have not exhibited significant antitumor efficacy in animal models of visceral cancer, which may be due to their poor bioavailability. The diagnostic use of radioactive bisphosphonates has revealed the accumulation of bisphosphonates in mesothelioma, which prompted us to test the antitumor efficacy of bisphosphonates in this disease. EXPERIMENTAL DESIGN AND RESULTS: Treatment with either risedronate or zoledronate (2 x 10(-4) to 2 x 10(-6) mol/L) inhibited the growth of AB12 and AC29 mouse mesothelioma cells and induced the accumulation of unprenylated Rap1A in these cells. Both these in vitro effects were reversed by geranygeraniol, an end product of the mevalonate pathway that these bisphosphonates inhibit. Both bisphosphonates also induced the phosphorylation of the p38 mitogen-activated protein kinase in AB12 and AC29 cells. The inhibition of p38 augmented bisphosphonate-induced growth inhibition in these cells. Bisphosphonate-induced p38 phosphorylation was not reversible by geranylgeraniol. Risedronate (15 mg/kg) and zoledronate (0.5 mg/kg) inhibited the growth of s.c. tumors and increased the median survival of mice with i.p. mesothelioma tumors in vivo. DISCUSSION: In conclusion, risedronate and zoledronate inhibit the mevalonate pathway and induce p38 activation in mesothelioma cells in vitro. The effects on the mevalonate pathway dominate because the net result is growth inhibition. Both bisphosphonates also inhibit mesothelioma tumor growth in vivo and prolong the survival of mesothelioma-bearing mice. These results support further study of bisphosphonates in the management of mesothelioma.

Breast cancer cells with inhibition of p38alpha have decreased MMP-9 activity and exhibit decreased bone metastasis in mice.

p38 belongs to a family of mitogen-activated protein kinases, which transfer extracellular signals into intracellular responses. p38 is also frequently detected in clinical breast cancer specimens, but its role as a prognostic factor is not known. Of the various p38 isoforms, p38alpha has been shown to mediate the in vitro invasiveness of breast cancer cells through up-regulation of urokinase plasminogen activator (uPA). We studied the role of p38alpha in breast cancer bone metastases, using dominant negative blockade approach. Human MDA-MB-231 breast cancer clones stably expressing dominant negative p38alpha (p38/AF) exhibited decreased basal MMP-9 activity. TGF-beta1-induced MMP-9 activity was also blunted in these clones, as compared with controls in which TGF-betal up-regulated MMP-9 activity. Consistent with these findings, SB202190, a specific p38 inhibitor, also inhibited TGF-beta1-induced MMP-9 activity in parental cells. The p38/AF clones exhibited also reduced uPA production after growth on vitronectin and decreased cell motility, as compared with controls. VEGF production levels in all the studied clones were similar. The p38/AF clone, which had similar in vitro growth rate as the control pcDNA3 clone, formed significantly less bone metastases in a mouse model, as compared with the control clone. In conclusion, inhibition of the p38alpha pathway results in decreased MMP-9 activity, impaired uPA expression and decreased motility, all of which may contribute to the decreased formation of bone metastasis.