Meta-Analysis of 5-Fraction Preoperative Radiotherapy for Soft Tissue Sarcoma

OBJECTIVES

Studies investigating preoperative 5-fraction radiation therapy (RT) for soft tissue sarcoma (STS) are limited. We performed a meta-analysis to determine the efficacy and safety of this treatment paradigm.

METHODS

This study-level meta-analysis was conducted using Bayesian methods. Statistical estimation for risk of outcome rates was conducted by posterior mean and 95% highest posterior density (HPD) intervals. Studies with 2-year local control (LC) and description of major wound complications (MWC) per the CAN-NCIC-SR2 study were included and served as the primary endpoints. Secondary endpoints included rates of acute and late toxicity. A total of 10 studies were identified and 7 met the inclusion criteria. Subgroup analyses were performed for ≥30 Gy vs <30 Gy.

RESULTS

A total of 209 patients from 7 studies were included. Five studies used ≥30 Gy (n=144), and 2 studies <30 Gy (n=64). Median follow-up was 29 months (range: 21 to 57 mo). Primary tumor location was lower extremity in 68% and upper extremity in 22%. Most tumors were intermediate or high grade (95%, 160/169), and 50% (79/158) were >10 cm. The two-year LC for the entire cohort was 96.9%, and the rate of MWC was 30.6%. There was a trend toward improved LC with ≥ 30 Gy (95% HPD: 0.95 to 0.99 vs 0.84 to 0.99). There was no difference in MWC (95% HPD: 0.18 to 0.42 vs 0.17 to 0.55) or late toxicity between the groups.

CONCLUSION

Preoperative 5-fraction RT for STS demonstrates excellent 2-year LC with MWC and toxicity similar to standard fractionation preoperative RT. Multi-institutional trials with a universal RT protocol are warranted.

The dilemma of radiation necrosis from diagnosis to treatment in the management of brain metastases

Radiation therapy with stereotactic radiosurgery (SRS) or whole brain radiation therapy is a mainstay of treatment for patients with brain metastases. The use of SRS in the management of brain metastases is becoming increasingly common and provides excellent local control. Cerebral radiation necrosis (RN) is a late complication of radiation treatment that can be seen months to years following treatment and is often indistinguishable from tumor progression on conventional imaging. In this review article, we explore risk factors associated with the development of radiation necrosis, advanced imaging modalities used to aid in diagnosis, and potential treatment strategies to manage side effects.

Clinical Outcomes for Patients with Brain Metastases from Upper Gastrointestinal Cancer Treated with Stereotactic Radiosurgery

PURPOSE/OBJECTIVE(S)

Prior studies have reported outcomes for brain metastases from gastrointestinal (GI) primary cancers treated with stereotactic radiosurgery (SRS); however, most include a majority of colorectal cancer. Few studies specifically evaluate SRS treatment response for brain metastases from upper GI cancers. We report our institutional outcomes for patients with upper GI cancers who were treated with SRS for brain metastases.

MATERIALS/METHODS

Patients with an upper GI cancer who underwent SRS for brain metastases between 1991 and 2021 were retrospectively reviewed from a single institution IRB-approved database. The primary endpoint was local failure (LF) and secondary endpoint was overall survival (OS). LF was estimated using the Cumulative Incidence Function with death as a competing risk. Survival analysis was performed with the Kaplan-Meier Method. Predictors of cumulative incidence of LF were assessed using competing risk regression.

RESULTS

Forty-nine patients with 107 brain metastases were analyzed. Forty-two (86%) patients were male. The median follow-up time was 6.7 months (range: 0.4-61.7 months) and median OS was 7.5 months (range: 0.9-61.7 months). The median Karnofsky Performance Score (KPS) was 80 (range: 40-100). The primary disease site was esophagus in 87 (81%) lesions, pancreas in 10 (9.3%) lesions, stomach in 5 (4.7%) lesions, liver in 2 (1.9%) lesions, gallbladder in 2 (1.9%) lesions, and small intestine in 1 (0.9%) lesion. The median metastasis size was 1.4 cm (range: 0.3-6.7 cm). The median prescription dose and fraction number were 24 Gy (range: 14-30 Gy) and 1 fraction (range: 1-2 fractions), respectively. The cumulative incidence of LF at 6 and 12 months was 5.6% (95% CI: 2.3-11%) and 12% (95% CI: 6.9-20%), respectively. Overall survival at 6 and 12 months was 59% (95% CI: 50-69%) and 35% (95% CI: 27-46%), respectively. On univariate analysis, female gender (HR = 0.19, 95% CI: 0.06-0.61, p = 0.005), Black race (HR = 0.09, 95% CI: 0.03-0.23, p = <0.001), and larger tumors (HR = 1.35, 95% CI: 1.03-1.78, p = 0.03) were significantly associated with local failure.

CONCLUSION

SRS for brain metastases from upper GI cancers is an appropriate treatment option and provides excellent local control. Unlike prior studies that have reported lower local control rates for all GI cancers with brain metastases treated with SRS, our data show that local failure rates in brain metastases from upper GI cancers specifically are more consistent with previously published data from other disease sites. Further studies evaluating SRS treatment response for brain metastases from GI cancers should separate upper GI and lower GI cancers.

Development of an RPA for Prediction of Radiation Necrosis Following Single Fraction Gamma Knife Radiosurgery for Brain Metastases

PURPOSE/OBJECTIVE(S)

Radiation necrosis (RN) is a potential complication following treatment of brain metastases with stereotactic radiosurgery (SRS). Several risk factors for RN have been reported, but to our knowledge there are no recursive partitioning analysis (RPA) models to identify patients at highest risk for RN. We therefore sought to develop a predictive tool to identify patients at highest risk for the development of RN following single fraction SRS.

MATERIALS/METHODS

Patients who underwent single fraction SRS for brain metastases from 2017-2021 were identified from a single institutional IRB-approved database. Patients with concern for RN were discussed in a multi-disciplinary setting and a diagnosis of RN was made based on pathologic or radiographic findings. Cox proportional hazards regression was done to identify factors associated with RN. RPA was performed to categorize patients into distinct risk groups for RN. Variables with p<0.1 on univariate analysis from the Cox regression analysis were included in the RPA. Patients with staged SRS, incomplete treatment records, or < 3 months radiographic follow-up were excluded from the analysis.

RESULTS

The study population comprised 1,011 lesions from 283 patients with a median follow-up of 9.7 months. The majority of lesions had non-small cell lung cancer (NSCLC) (49%) as the primary site followed by breast (12%) and melanoma (11%). The median prescription dose was 24 Gy (range: 12-24 Gy). RN was diagnosed in 12.2% of lesions, of which 28% (35/123) were symptomatic RN. The median time to RN was 4.9 months. Variables identified for inclusion in the RPA included primary tumor site, use of targeted therapy, tumor location, pre-SRS hemorrhage, post-SRS hemorrhage, prior SRS to other lesions, number of SRS targets, maximum dose, maximum lesion diameter, 70% isodose line, heterogeneity index, conformality index, and gradient index. RPA identified four distinct groups. Group 1 was defined as maximum lesion diameter (MLD) <0.8 cm with primary tumor site other than breast, colorectal (CRC) or NSCLC (n = 174); group 2 was MLD <0.8 cm with breast, CRC, or NSCLC (n = 372). Group 3 was defined as MLD ≥ 0.8 cm without post-SRS hemorrhage (n = 336) and group 4 was MLD ≥0.8 cm with post-SRS hemorrhage (n = 129). Two-year RN free survival for all lesions was 82%, 100% for group 1, 89% for group 2, 76% for group 3, and 58% for group 4.

CONCLUSION

We created the first RPA predictive model for RN following single fraction SRS and identified a subgroup of patients at highest risk. This RPA can help guide clinicians when educating patients on RN risk for brain metastases.

Dosimetric Analysis of Major Wound Complications Following Preoperative Ultra-Hypofractionated Radiation Therapy for Soft Tissue Sarcoma

PURPOSE/OBJECTIVE(S)

Preoperative radiation therapy (RT) for soft tissue sarcomas (STS), delivered with conventional fractionation, has been shown to reduce long-term toxicity at the expense of increased postoperative major wound complications (MWC). Ultra-hypofractionated RT has emerged as a potential alternative preoperative modality with early but comparable outcomes to conventional regimens. However, limited data are available evaluating dosimetric, patient, and treatment specific factors associated with development of MWC in this setting.

MATERIALS/METHODS

This IRB approved review included STS patients treated with preoperative 5 fraction daily RT followed by surgical resection within 7 days. Patients were evaluated for MWCs in association with patient and tumor characteristics, dosimetric parameters, and treatment techniques. MWCs were defined as a return to operating room, readmission for wound care or IV antibiotics, and persistent deep packing for >120 days. Prescription isodose line, PTV mean dose and the PTV volume exposed to 105% and 110% of prescribed dose were recorded. Dose to tissue likely to be involved in wound healing was assessed by creating a 1 cm thick superficial skin strip within 2 cm of the PTV which was then evaluated for volume, mean dose, V15, V21, V27, and V30. Secondary endpoints were locoregional control (LRC), metastasis free survival (MFS), and overall survival (OS).

RESULTS

A total of 31 patients with a median age of 66 years (range 28-87) and a median follow up of 21 months (IQR 8-43) were included. All patients received 30 Gy in 5 fractions using IMRT/VMAT. There were 11 upper limb (36%) and 20 lower limb (65%) tumors included. Median time to resection following RT was 1 day (IQR 0-3). Median tumor size was 8 cm (IQR 5-13). MWC occurred in 13 patients (42%) with 10 patients (32%) requiring additional surgery. Dehiscence and infection requiring IV antibiotics occurred in 12 (39%) and 6 patients (19%), respectively. RT plans were predominately prescribed to the PTV mean (87%) with a median prescription isodose of 97% (IQR 96-97) and PTV mean dose of 3110 cGy (IQR 3089-3142). Median PTV volume, mean dose, and volume of PTV receiving 105% and 110% of the prescribed dose were higher in the MWC cohort although none reached significance. Similarly, for the 1 cm skin strip the median volume, mean dose, V30, V27, V21, and V15 were all higher in the MWC cohort without significant difference. Among patient, treatment, and tumor factors: tumor size, location, grade, margin status, type of wound closure, and prior non-oncologic resection were not associated with MWC. LRC, MFS, and OS at 3-years were 96%, 67%, and 76%, respectively.

CONCLUSION

Although not reaching significance, increased plan homogeneity and reduced dose/volume relationships in proximity to the skin trended to reduced MWC in this limited cohort. Multi-institutional collaboration may be warranted to better identify factors associated with MWC in patients treated with preoperative ultra-hypofractionated RT.

Multi-Institutional Validation of the Recursive Partitioning Analysis for Overall Survival in Patients Undergoing Spine Radiosurgery for Spine Metastasis

PURPOSE/OBJECTIVE(S)

The recently published spine radiosurgery (sSRS) recursive partitioning analysis (RPA) for overall survival (OS) separated patients into 3 distinct prognostic groups. We sought to externally validate this RPA using 3 separate multi-institutional datasets.

MATERIALS/METHODS

A total of 444 patients were utilized to develop the recently published sSRS RPA predictive of OS in patients with spine metastases. The RPA identified three distinct prognostic classes. RPA Class 1 was defined as KPS >70 and controlled systemic disease (n = 142); RPA Class 2 was defined as KPS>70 with uncontrolled systemic disease or KPS ≤70, age ≥54 and absence of visceral metastases (n = 207); RPA Class 3 was defined as KPS ≤70 and age <54 years or KPS≤70, age ≥54 years and presence of visceral metastases (n = 95). We utilized data from 3 large tertiary care centers to independently validate this RPA. Data from each institution was utilized independently to validate the RPA to minimize confounding based on institutional differences in patient selection. A total of 1,184 patients (221 patients from institution A, 749 institution B, and 214 from institution C) were in the validation cohort and were divided based on their RPA Class. Kaplan-Meier method was used to estimate OS and log-rank test was used to compare OS between RPA classes.

RESULTS

In each of the validation cohorts, the median OS was 19.9 months (institution A), 11.0 months (institution B), and 24.4 months (institution C). The patient distribution into RPA classification based on Institution A/B/C was, Class 1 (19.4%, 15.1%, 50.5%), Class 2 (74.7%, 57.7%%, 37.9%), and Class 3 (5.9%, 27.2%%, 11.2%), respectively. The median OS for patients in the validation cohort at Institution A/B/C based on RPA class was Class 1 (54 months, 27.1 months, 50.0 months), Class 2 (15.9 months, 13.0 months, 15.1 months) and Class 3 (6.9 months, 3.5 months, 6.1 months), respectively. Patients in RPA Class 1 had a significantly better OS compared to those in Class 2 of the each of the three external institution validation cohorts (p<0.01). Similarly, patients in RPA Class 2 had a significantly better OS compared to those in Class 3 (p<0.01).

CONCLUSION

The external datasets from three large institutions independently validated the spine SRS RPA successfully for OS in patients undergoing sSRS for spinal metastases. This is the first RPA for OS to have been externally validated using multiple large datasets. Based on this validation, upfront spine SRS is strongly supported for patients in RPA Class 1 and Class 2 and is also cost effective with median OS >11 months for these patients. Patients in RPA Class 3 would benefit most from upfront conventional radiotherapy given their poor expected survival. Given successful external validation, this RPA helps guide physicians to identify those patients with spinal metastases who most benefit from sSRS.

Meta-Analysis of Five Fraction Preoperative Radiotherapy for Soft Tissue Sarcoma

PURPOSE/OBJECTIVE(S)

There is increasing interest in shorter courses of radiation therapy (RT) in the management of soft tissue sarcoma (STS). Studies investigating preoperative ultra-hypofractionated 5-fraction RT for STS are few and often limited to single institution experiences with less than 50 patients. We therefore performed a meta-analysis to determine the efficacy and safety of preoperative 5-fraction RT for STS based on currently published literature, with an analysis evaluating effects of dose delivered.

MATERIALS/METHODS

This study level meta-analysis was conducted using Bayesian methods. Statistical estimation for risk of outcome rates were conducted by posterior mean and 95% highest posterior density (HPD) intervals. Studies with two-year local control (LC) and description of major wound complications (MWC) per the CAN-NCIC-SR2 study were included in this meta-analysis, and these served as the primary endpoints. Secondary endpoints included rates of acute and late toxicity. A total of ten studies were identified; seven met inclusion criteria (Kalbasi 2020, Kubicek 2021, Leite 2021, Spalek 2021, Gobo Silva 2021, Bedi 2022, Mayo 2022). Three studies (Kosela-Paterczyk 2014, Kosela-Paterczyk 2021, Potkrajcic 2021) did not include adequate information to accurately determine 2-year LC or MWC. Subgroup analyses were performed for ≥30 Gy vs <30 Gy as the EQD2 of 30 Gy in 5 fractions for an α/β of 3-4 is 50-54 Gy, equivalent to standard preoperative RT fractionation.

RESULTS

A total of 208 patients were included from seven studies. Five studies used ≥30 Gy (n = 144) and 2 studies <30 Gy (n = 64). The median follow-up was 29 months (range: 21-57). Primary tumor location was lower extremity in 68%, upper extremity in 22%, and trunk in 10%. In studies with available information, most tumors were intermediate (27%, 46/169) or high grade (67%, 114/169) and 50% (79/158) were >10 cm. Two-year LC for the entire cohort was 96.9% (95% HPD: 0.9374-0.9889) and the rate of MWC was 30.6% (95% HPD: 0.2106-0.4149). Acute grade 2 and 3 dermatitis was seen in 12.7% and 2.2%, respectively. Late grade 2 toxicities included fibrosis (11.1%), stiffness (6.0%), and lymphedema (4.0%) and late grade 3 toxicities included fibrosis (1.8%) and stiffness (0.4%). Grade 4 toxicity was rare and included fibrosis (0.6%) and stiffness (0.6%). There was a trend toward improved LC with ≥ 30 Gy (95% HPD: 0.949-0.997 vs 0.838-0.986). There was no difference in MWC (95% HPD: 0.185-0.420 vs 0.172-0.553) or late toxicity between the two groups. Acute grade 3 dermatitis was seen less frequently with regimens <30 Gy (95% HPD: 0-0 vs 0.009-0.072), however rare overall.

CONCLUSION

Preoperative 5-fraction RT for STS demonstrates excellent 2-year LC with MWC and toxicity similar to standard fractionation preoperative RT. Multi-institutional trials with a universal RT protocol and larger sample size are warranted to assess this novel treatment paradigm.

Clinical Outcomes of Patients with Brain Metastases from Colorectal Cancer Treated with Stereotactic Radiosurgery

PURPOSE/OBJECTIVE(S)

Prior studies have demonstrated that brain metastases from gastrointestinal (GI) primary cancers have a poorer response to stereotactic radiosurgery (SRS) when compared to patients with other primary sites, with reported local control of 62-74%. We report our institutional outcomes for patients with colorectal primary cancer who were treated with SRS for brain metastases.

MATERIALS/METHODS

Patients with colorectal primary cancer who underwent SRS for brain metastases between 1989 and 2021 were retrospectively reviewed from a single institutional IRB-approved database. The primary endpoint was local failure (LF) and secondary endpoint was overall survival (OS). LF was estimated using the Cumulative Incidence Function with death as a competing risk. Survival analysis was performed using the Kaplan-Meier Method. Predictors of cumulative incidence of LF were assessed using competing risk regression.

RESULTS

The study population comprised of 109 patients with primary colorectal adenocarcinoma with 207 brain metastases. The median follow-up was 5.2 months (range: 0.4-124 months) and median OS was 5.8 months (range: 0.5-71.2 months). Fifty-two patients (48%) were male and median Karnofsky Performance Status at the time of treatment was 80 (range: 40-100). The median tumor diameter was 1.55 cm (range: 0.17-5.48 cm). The median prescription dose and number of fractions were 24 Gy (range: 11-36 Gy) and 1 fraction (range: 1-3 fractions), respectively. The cumulative incidence of LF at 3, 6, and 12 months was 9.7% (95% CI: 6.1-14%), 22% (95% CI: 16-28%), and 25% (95% CI: 20-31%), respectively. Overall survival at 3, 6, and 12 months was 81% (95% CI: 76-87%), 49% (95% CI: 42-56%) and 24% (95% CI: 18-31%), respectively. On univariate analysis, age was a significant predictor (HR = 0.96, 95% CI: 0.94-0.98), p < 0.001) of LF. Tumor size (HR = 0.80, p = 0.13) and prescription dose (HR = 1.02, p = 0.54) did not predict for LF.

CONCLUSION

To our knowledge, this is the largest series of patients with brain metastases from colorectal primary cancer treated with SRS. Compared to historical data, LF and OS in our cohort of patients was favorable. Our data confirms relatively higher rates of LF when compared to brain metastases from other primary disease sites. Further studies are warranted to identify factors that predict for LF following SRS and to develop models that predict which patients with colorectal brain metastases may be at higher risk of failure.

Disparities in prostate cancer diagnoses in persons experiencing homelessness

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Background: We previously reported that persons experiencing homelessness (PEH) are significantly less likely to undergo prostate specific antigen (PSA) testing compared to persons not experiencing homelessness (non-PEH). The purpose of this study was to determine if reduced PSA testing in PEH results in more advanced prostate cancer diagnoses. Methods: We identified PSA screening eligible PEH (men ages 50-69) from an institutional registry of all patients that presented to our healthcare system as homeless from 2014 to 2021. A matched cohort of non-PEH was generated for comparison. Institutional CPT and HCPCS billing codes for PSA testing were available beginning 01/01/2017 and cross-referenced to identify PEH and non-PEH who underwent PSA testing at least once between 01/01/2017 and 12/31/2021. In patients with ≥ 1 PSA test, we recorded screening, oncologic and treatment related variables. Patients with a history of prostate cancer diagnosed outside the study timeframe were excluded. Results: A total of 9,249 PEH were identified, with 1,597 meeting PSA screening criteria during the study timeframe; 3,370 screening eligible non-PEH were available for comparison. The median age was 59.0 for PEH and 60.0 for non-PEH. PEH were significantly less likely to have a primary care provider (58% vs 81%, p<0.001) or to have a PSA test (12% vs 33%, p<0.001). Among patients with a PSA test, PEH were significantly less likely to have multiple PSA tests compared to non-PEH (28% vs 61%, p<0.001) and significantly more likely to have a PSA ≥ 4.0 (18% vs 12%, p=0.028). In patients with a PSA ≥ 4.0, PEH were less likely to receive a prostate biopsy (37% vs 61%, p =0.009) and there was a trend towards decreased prostate MRI (11% vs 25%, p=0.085). A total of 6 PEH (0.4%) and 46 non-PEH (1.4%) were diagnosed with prostate cancer. The median PSA at diagnosis was 12.6 in PEH vs 7.0 in non-PEH (p=0.052). PEH were significantly more likely to present with high/very high risk disease (4/6 [66%] vs 9/46 [20%], p=0.019); no PEH had very low/low risk disease compared with 20 (43.5%) non-PEH. PEH were more likely to present with lymph node positive or metastatic disease (3/6 [50%] vs 3/46 [7%], p=0.016). The median time from biopsy to treatment was 119 days in PEH and 76 days in non-PEH (p=0.391). Conclusions: PEH are less likely to receive prostate cancer testing following an elevated PSA and more likely to present with high risk advanced prostate cancer. Interventions to increase prostate cancer awareness in PEH are needed to reduce disparities.

Cancer Diagnoses and Use of Radiation Therapy Among Persons Experiencing Homelessness

PURPOSE

Persons experiencing homelessness (PEH) have low rates of cancer screening and worse cancer mortality compared with persons not experiencing homelessness. Data regarding cancer diagnosis and treatment in PEH are limited. We investigated cancer prevalence and use of radiation therapy (RT) in PEH.

METHODS AND MATERIALS

Patients presenting between January 1, 2014, and September 27, 2021, at a large metropolitan hospital system were assessed for homelessness via intake screening or chart search. PEH data were cross-referenced with the institution's cancer database to identify PEH with cancer diagnoses. Demographic, clinical, and treatment variables were abstracted.

RESULTS

Of a total of 9654 (9250 evaluable) PEH with a median age of 42 years, 81 patients (0.88%) had at least 1 cancer diagnosis and 5 had multiple diagnoses, for a total of 87 PEH with at least 1 cancer diagnosis. The median age at diagnosis was 60 years. In total, 43% were female and 51% were Black, and 43% presented with advanced or metastatic disease. Lung (17%), prostate (15%), leukemia/lymphoma (13%), and head/neck (9%) were the most common diagnoses. In total, 17% of patients underwent surgery alone, 13% received chemotherapy alone, 14% received RT alone, and 6% received hormone therapy alone. A total of 8% of patients underwent no treatment, and 43% underwent multimodality therapy. In total, 58% of treated patients never achieved disease-free status. Of the 31 patients who received RT, 87% received external beam RT. Most patients (70%) received hypofractionated regimens. For patients who had multifraction treatment, the treatment completion rate was 85%, significantly lower than the departmental completion rate of 98% (P < .00001).

CONCLUSIONS

In a large cohort of PEH in a metropolitan setting, cancer diagnoses were uncommon and were frequently in advanced stages. Most patients underwent single-modality treatment or no treatment at all. Despite the use of hypofractionation, the RT completion rate was low, likely reflecting complex barriers to care. Further interventions to optimize cancer diagnosis and treatment in PEH are urgently needed.

Radiation necrosis or tumor progression? A review of the radiographic modalities used in the diagnosis of cerebral radiation necrosis

PURPOSE

Cerebral radiation necrosis is a complication of radiation therapy that can be seen months to years following radiation treatment. Differentiating radiation necrosis from tumor progression on standard magnetic resonance imaging (MRI) is often difficult and advanced imaging techniques may be needed to make an accurate diagnosis. The purpose of this article is to review the imaging modalities used in differentiating radiation necrosis from tumor progression following radiation therapy for brain metastases.

METHODS

We performed a review of the literature addressing the radiographic modalities used in the diagnosis of radiation necrosis.

RESULTS

Differentiating radiation necrosis from tumor progression remains a diagnostic challenge and advanced imaging modalities are often required to make a definitive diagnosis. If diagnostic uncertainty remains following conventional imaging, a multi-modality diagnostic approach with perfusion MRI, magnetic resonance spectroscopy (MRS), positron emission tomography (PET), single photon emission spectroscopy (SPECT), and radiomics may be used to improve diagnosis.

CONCLUSION

Several imaging modalities exist to aid in the diagnosis of radiation necrosis. Future studies developing advanced imaging techniques are needed.

Prostate Cancer Screening Disparities in Persons Experiencing Homelessness

PURPOSE

The purpose of this study was to assess prostate-specific antigen (PSA) testing rates in persons experiencing homelessness (PEH), identify factors associated with screening, and compare PSA screening rates in PEH with a matched cohort of persons not experiencing homelessness (non-PEH).

MATERIALS AND METHODS

We identified 9,249 potentially eligible PEH cared for at a large metropolitan hospital system from an institutional registry of all patients who presented to the health care system as homeless from 2014 to 2021. Homelessness was defined by the presence of the Z-code for homelessness (Z59), the listed address matching to the address of a homeless shelter or other transitional housing or a positive screen for homelessness. A matched cohort of 10,000 non-PEH was generated for comparison. Univariate chi-square analysis and multivariate logistic regression were performed to evaluate variables associated with PSA testing.

RESULTS

A total of 1,605 PEH and 3,413 non-PEH were eligible for PSA screening within the study timeframe. Half of PEH were Black (50%). Medicaid was the most common insurance (51%), followed by Medicare (18%). PEH were less likely to have a PCP (58% v 81%, P < .001) and had a significantly lower PSA testing rate (13% v 34%, P < .001) compared with non-PEH. Univariate analysis revealed that PSA testing was more common in PEH who were employed (P < .001), had private insurance or Medicare (P < .001), or had an established primary care provider (PCP; P < .001). Multivariate analysis confirmed that having a PCP (OR, 2.54; 95% CI, 1.62 to 4.00; P < .001) significantly increased the likelihood of PSA testing in PEH.

CONCLUSION

PEH experience low rates of prostate cancer screening. Interventions to increase screening in this population, including increased PCP access, are needed.

Breast cancer screening in persons experiencing homelessness

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Background: Persons experiencing homelessness (PEH) suffer from poor health outcomes, including worse cancer mortality, compared to persons not experiencing homelessness. A portion of the disparity in cancer outcomes is attributable to reduced access to cancer screening, leading to more advanced-stage disease and a higher risk of death compared to the general population. Data regarding cancer screening rates in PEH are scarce. We therefore sought to evaluate baseline rates of breast cancer screening in PEH. Methods: All patients presenting for care from January 1, 2014 onward at a hospital system spanning five counties in a populous Midwestern state were screened for homelessness. Homelessness was identified by two criteria: presence of the Z-code for homelessness (Z59) in the patient’s electronic medical record, and/or patient’s address on record listed as an address matching that of a regional homeless shelter, transitional housing, or “homeless.” Identified PEH were maintained in a prospective registry. For each female PEH in the screening age range, billing data for completed breast cancer screening mammography performed in the previous five years (1/1/17-12/31/21) were extracted (CPT codes 77063, 77067). Data were also extracted for a cohort of non-PEH patients eligible for screening. Demographic and clinical data were extracted for all patients. This study was approved by the hospital system’s IRB. Results: A total of 3,474 female (biological sex) PEH were identified, with 1,320 eligible for screening mammography (alive and between the ages of 40 and 79) in the study timeframe. The median age was 53.5 years old; 44% were Black, 48% White, 8.5% unknown/other race, and 3% Hispanic ethnicity. 28% of PEH were uninsured, and 67% had government insurance; 66% had an assigned primary care physician (PCP). Of PEH eligible for screening mammography, 237 (18%) had at least one screening mammogram during this five-year interval (2017, 2.2%; 2018, 4.3%; 2019, 3.6%; 2020, 3.7%; 2021, 4.3%). In a cohort of 6,240 non-PEH eligible for screening over the same timeframe, the screening mammography rate was 32%, which was significantly higher than the screening rate for PEH (p < 0.00001). Compared to PEH who did not undergo screening mammography, PEH who underwent screening mammography were more likely to have an assigned PCP (90% vs 38%, p < 0.00001), to be a non-current tobacco user (56% vs 35%, p < 0.00001), and to be a non-current illicit drug user (84 % vs 68%, p = 0.0015). PEH who underwent screening mammography were significantly less likely to be uninsured (12% vs 31%, p < 0.00001). Conclusions: In the largest study of its kind to date, we identified low rates of breast cancer screening in female PEH. Interventions to increase breast cancer screening in this vulnerable population are urgently needed and may include increased access to PCPs, tobacco and drug cessation programs, and provision of health insurance.