Severe complications of imported schistosomiasis, Spain: A retrospective observational study

Impact of species hybridization on the clinical management of schistosomiasis: A prospective study

BACKGROUND

Species hybridization represents a real concern in terms of parasite transmission, epidemiology and morbidity of schistosomiasis. It is greatly important to better understand the impact of species hybridization for the clinical management.

METHODS

A prospective observational study was carried out in sub-Saharan migrants who were diagnosed with confirmed genitourinary schistosomiasis. A tailored protocol was applied, including Schistosoma serology, a specific urine LAMP tests for schistosomiasis and an ultrasound examination before treatment with praziquantel. A scheduled follow-up was performed at 3, 6 and 12 months to monitor treatment response, comparing patients carriers of Schistosoma hybrids with carriers of only genetically pure forms.

RESULTS

A total of 31 male patients from West Africa were included in the study with a mean age of 26.5 years. Twelve (38.7 %) of the patients were carriers of Schistosoma hybrids. As compared with patients infected with S. haematobium alone, hybrid carriers had lower haemoglobin levels (13.8 g/dL [SD 1.8] vs 14.8 g/dL [SD 1.4], p = 0.04), a greater frequency of hematuria (100 % vs 52.6 %, p = 0.005), a higher ultrasound score (2.64, SD 2.20 vs 0.89, SD 0.99; p = 0.02). However, the presence of hybrids did not result in differences in clinical and analytical responses after treatment.

CONCLUSIONS

The presence of Schistosoma hybrids seems to cause increased morbidity in infected individuals. However, it does not appear to result in differences in diagnostic tests or in clinical and analytical responses after treatment.

A comprehensive exploration of schistosomiasis: Global impact, molecular characterization, drug discovery, artificial intelligence and future prospects

Schistosomiasis, one of the neglected tropical diseases which affects both humans and animals, is caused by trematode worms of the genus Schistosoma. The disease is caused by several species of Schistosoma which affect several organs such as urethra, liver, bladder, intestines, skin and bile ducts. The life cycle of the disease involves an intermediate host (snail) and a mammalian host. It affects people who are in close proximity to water bodies where the intermediate host is abundant. Common clinical manifestations of the disease at various stages include fever, chills, headache, cough, dysuria, hyperplasia and hydronephrosis. To date, most of the control strategies are dependent on effective diagnosis, chemotherapy and public health education on the biology of the vectors and parasites. Microscopy (Kato-Katz) is considered the golden standard for the detection of the parasite, while praziquantel is the drug of choice for the mass treatment of the disease since no vaccines have yet been developed. Most of the previous reviews on schistosomiasis have concentrated on epidemiology, life cycle, diagnosis, control and treatment. Thus, a comprehensive review that is in tune with modern developments is needed. Here, we extend this domain to cover historical perspectives, global impact, symptoms and detection, biochemical and molecular characterization, gene therapy, current drugs and vaccine status. We also discuss the prospects of using plants as potential and alternative sources of novel anti-schistosomal agents. Furthermore, we highlight advanced molecular techniques, imaging and artificial intelligence that may be useful in the future detection and treatment of the disease. Overall, the proper detection of schistosomiasis using state-of-the-art tools and techniques, as well as development of vaccines or new anti-schistosomal drugs may aid in the elimination of the disease.

Diagnosis and management of complicated urogenital schistosomiasis: a systematic review of the literature

BACKGROUND

Currently, there are no standardized guidelines for the diagnosis or management of the complications of urogenital schistosomiasis (UGS). This systematic review of the literature aims to investigate the state of the art in reference to diagnostic approaches and the clinical management of this condition.

METHODS

A systematic review of literature published between January 1990 and January 2021 was conducted in the MEDLINE database, scoping for articles regarding diagnostic means or therapeutic options for the complications of UGS, namely obstructive uropathy, bladder cancer, abortion, ectopic pregnancy, infertility, kidney failure, urolithiasis and the need for invasive procedures. Relevant data were then extracted from the articles deemed eligible according to the inclusion criteria.

MAIN RESULTS

In total, 3052 articles were identified by the research query, of which 167 articles fulfilling inclusion criteria after title/abstract screening and full-text evaluation were included, 35% on both diagnostic and therapeutic aspects, and 51% on diagnosis and 14% on therapy. Ultrasound was the most frequently tool employed for the diagnosis of UGS complications showing a good performance. Concerning the management of hydronephrosis, the majority of available evidences came from community-based studies where universal treatment with praziquantel was used leading to decrease of prevalence of obstructive uropathy. Concerning studies on surgical procedures, laser endoureterotomy followed by stenting was mostly employed in adult patients leading to a crude cure rate of 60% (43 of 71 patients). In the case of severe hydronephrosis, surgery consisting of ureteral re-implantation showed excellent results with a crude cure rate of 98% (157 cured patients of 160 treated). Concerning bladder cancer, data on 93 patients with a clear diagnosis of UGS-related bladder were available reporting a variable and sometime combined approach based on disease stage. Available data on diagnosis and management of abortion, ectopic pregnancy, infertility, kidney failure, urolithiasis and the need for invasive procedures due to UGS are also presented.

CONCLUSIONS

The review produced a complete picture of the diagnostic and therapeutic options currently available for complicated UGS. These results can be useful both for guiding clinicians towards correct management and for tracing the direction of future research.

Schistosoma haematobium urinary tract complications in African migrants attending primary care facilities in Paris, France: A retrospective cohort study (2004-2018)

OBJECTIVES

Little is known about the burden of urogenital schistosomiasis (UGS) outside endemic areas. This study was aimed at describing urinary complications of UGS detected among African migrants in French primary care facilities.

PATIENTS AND METHODS

A retrospective cohort study included patients with UGS diagnosed from 2004 to 2018 in 5 primary health centers in Paris. Cases were defined by the presence of typical Schistosoma haematobium eggs at urine microscopy. Demographic, clinical, biological and imaging data were collected. Ultrasonography (U-S) findings were classified in accordance with the WHO guidelines.

RESULTS

U-S was prescribed for all patients and performed in 100/118. Sex ratio (F/M) was 2/98, and mean age 24.4 years. Patients were from West Africa (73% from Mali) and consulted 8 months (median) after their arrival. Among the 95 patients with interpretable findings, 32 (33.7%) had abnormalities related to UGS, considered as major in 6 cases (6.3%), and mostly localized at the bladder (31/32) without detection of cancer. No sociodemographic, clinical, or biological factors were found to be associated with U-S abnormalities. All 100 patients were treated by praziquantel (PZQ). Among those with abnormalities, 20/32 received two to four doses at various time intervals. Post-cure imaging control performed in 19/32 showed persistent abnormalities in 6 patients, on average 5 months after the last PZQ uptake.

CONCLUSION

Urinary tract abnormalities associated with UGS were common and predominated at the bladder. U-S should be prescribed to any patient with positive urine microscopy. Schedules for PZQ uptake and U-S monitoring for patients with complications remain to be determined.

Geographical Influence on Morphometric Variability of Genetically “Pure” Schistosoma haematobium Eggs from Sub-Saharan Migrants in Spain

Schistosome eggs play a key role in schistosomiasis diagnosis and research. The aim of this work is to morphogenetically study the eggs of Schistosoma haematobium found in sub-Saharan migrants present in Spain, analyzing their morphometric variation in relation to the geographical origin of the parasite (Mali, Mauritania and Senegal). Only eggs considered “pure” S. haematobium by genetic characterization (rDNA ITS-2 and mtDNA cox1) have been used. A total of 162 eggs obtained from 20 migrants from Mali, Mauritania and Senegal were included in the study. Analyses were made by the Computer Image Analysis System (CIAS). Following a previously standardized methodology, seventeen measurements were carried out on each egg. The morphometric analysis of the three morphotypes detected (round, elongated and spindle) and the biometric variations in relation to the country of origin of the parasite on the egg phenotype were carried out by canonical variate analysis. Mahalanobis distances, when all egg measurements were analyzed, showed differences between: (i) Mali-Mauritania, Mali-Senegal and Mauritania-Senegal in the round morphotype; (ii) Mali-Mauritania and Mauritania-Senegal in the elongated morphotype; and (iii) Mauritania-Senegal in the spindle morphotype. Mahalanobis distances, when spine variables were analyzed, showed differences between Mali-Senegal in the round morphotype. In conclusion, this is the first phenotypic study performed on individually genotyped “pure” S. haematobium eggs, allowing the assessment of the intraspecific morphological variations associated with the geographical origin of the schistosome eggs.

Evaluation of Two Different Strategies for Schistosomiasis Screening in High-Risk Groups in a Non-Endemic Setting

A consensus on the recommended screening algorithms for schistosomiasis in asymptomatic high-risk subjects in non-endemic areas is lacking. The objective of this study was to evaluate the real-life performance of direct microscopy and ELISA serology for schistosomiasis screening in a high-risk population in a non-endemic setting. A retrospective cohort study was conducted in two out-patient Tropical Medicine units in Barcelona (Spain) from 2014 to 2017. Asymptomatic adults arriving from the Sub-Saharan region were included. Schistosomiasis screening was conducted according to clinical practice following a different strategy in each setting: (A) feces and urine direct examination plus S. mansoni serology if non-explained eosinophilia was present and (B) S. mansoni serology plus uroparasitological examination as the second step in case of a positive serology. Demographic, clinical and laboratory features were collected. Schistosomiasis cases, clinical management and a 24 month follow-up were recorded for each group. Four-hundred forty individuals were included. The patients were mainly from West African countries. Fifty schistosomiasis cases were detected (11.5% group A vs. 4 % group B, p = 0.733). When both microscopic and serological techniques were performed, discordant results were recorded in 18.4% (16/88). Schistosomiasis cases were younger (p < 0.001) and presented eosinophilia and elevated IgE (p < 0.001) more frequently. Schistosomiasis is a frequent diagnosis among high-risk populations. Serology achieves a similar performance to direct diagnosis for the screening of schistosomiasis in a high-risk population.

[Consensus document for the management of schistosomiasis in Primary Care]

La esquistosomiasis humana es la enfermedad parasitaria con mayor morbimortalidad a nivel mundial después de la malaria. Es endémica en más de 78 países tropicales y subtropicales, sobre todo de África Subsahariana, estimándose que 236 millones de personas están infectadas. Puede causar graves complicaciones de salud a nivel genitourinario y hepatoesplénico, llegando a ocasionar la muerte de 300.000 personas cada año. El número de casos importados en los países occidentales se ha ido incrementado en los últimos años debido a la llegada de un importante número de migrantes procedentes de regiones endémicas y de un creciente número de viajeros que han visitado las mismas. Por otro lado, recientemente se han comunicado brotes de transmisión autóctona en Córcega (Francia) y Almería (España). Por todos estos aspectos, las autoridades sanitarias europeas han recomendado el cribado serológico de la enfermedad en todas las personas migrantes procedentes de zonas endémicas y que lleven menos de 5 años en Europa. Dado que atención primaria es habitualmente el primer punto de contacto de estas personas con el sistema sanitario, los médicos deben conocer los principales aspectos de la enfermedad, y ser dotados de los medios necesarios para su diagnóstico y tratamiento. Este documento ha sido elaborado por profesionales pertenecientes a 5 sociedades científicas de atención primaria (SEMFyC, SEMG, SEMERGEN), Pediatría (SEIP) y Medicina Tropical y Salud Internacional (SEMTSI), con objeto de establecer unas recomendaciones claras para el diagnóstico y el manejo de la esquistosomiasis en atención primaria.

Schistosomiasis at the Crossroad to Elimination: Review of Eclipsed Research with Emphasis on the Post-Transmission Agenda

While chronic schistosomiasis is pathologically well defined, the acute form of the disease is less well understood. It is generally agreed that early lesions, such as lung nodules and bladder polyps, are reversible, which impedes identification of the time elapsed since exposure. The intermediate stage between the acute and the chronic forms of schistosomiasis requires further investigation, as does the clinical stage due to lesions remaining after treatment. With current schistosomiasis control efforts gradually progressing to elimination, there is a need to focus on post-transmission schistosomiasis, which not only refers to remaining lesions from previous infections, but also accounts for the potential presence of surviving worms after treatment. This issue is particularly salient for migrants from endemic to non-endemic countries and should be kept in mind for returning expatriates from schistosomiasis-endemic countries. Negative stool examination or urine filtration are generally taken as indicative of cure since rectoscopy for Schistosoma mansoni infection, or cystoscopy for S. haematobium infection, are rarely performed. However, pathology of affected organs may persist indefinitely, while potentially remaining live worms could produce additional pathology. Hence, post-transmission schistosomiasis can prevail for years after elimination of the disease, and thus, warrant further attention.

Schistosomiasis Among Female Migrants in Non-endemic Countries: Neglected Among the Neglected? A Pilot Study

Background

Schistosomiasis among migrant populations in Europe is an underdiagnosed infection, yet delayed treatment may have serious long-term consequences. In this study we aimed to characterize the clinical manifestations of Schistosoma infection among migrant women, and the degree of underdiagnosis.

Methods

We carried out a prospective cross-sectional study among a migrant population living in the North Metropolitan Barcelona area and coming from schistosomiasis-endemic countries. We obtained clinical, laboratory and socio-demographic data from electronic clinical records, as well as information about years of residence and previous attendance at health services. Blood sample was obtained and schistosomiasis exposure was assessed using a specific ELISA serological test.

Results

Four hundred and five patients from schistosomiasis-endemic regions were screened, of whom 51 (12.6%) were female. Seropositivity prevalence was 54.8%, but considering women alone we found a prevalence of 58.8% (30 out of 51). The median age of the 51 women was 41.0 years [IQR (35–48)] and the median period of residence in the European Union was 13 years [IQR (10–16)]. Schistosoma-positive women (N = 30) showed a higher prevalence of gynecological signs and symptoms compared to the seronegative women (96.4 vs. 66.6%, p = 0.005). Among seropositive women, the median number of visits to Sexual and Reproductive Health unit prior to diagnosis of schistosomiasis was 41 [IQR (18–65)].

Conclusion

The high prevalence of signs and symptoms among seropositive women and number of previous visits suggest a high rate of underdiagnosis and/or delayed diagnosis of Schistosoma infection, particularly female genital schistosomiasis, among migrant females.

Clinical Spectrum of Schistosomiasis: An Update

Schistosomiasis is a helminthic infection and one of the neglected tropical diseases (NTDs). It is caused by blood flukes of the genus Schistosoma. It is an important public health problem, particularly in poverty-stricken areas, especially those within the tropics and subtropics. It is estimated that at least 236 million people worldwide are infected, 90% of them in sub-Saharan Africa, and that this disease causes approximately 300,000 deaths annually. The clinical manifestations are varied and affect practically all organs. There are substantial differences in the clinical presentation, depending on the phase and clinical form of schistosomiasis in which it occurs. Schistosomiasis can remain undiagnosed for a long period of time, with secondary clinical lesion. Here, we review the clinical profile of schistosomiasis. This information may aid in the development of more efficacious treatments and improved disease prognosis.

First morphogenetic analysis of parasite eggs from Schistosomiasis haematobium infected sub-Saharan migrants in Spain and proposal for a new standardised study methodology

Schistosomiasis is a Neglected Tropical Disease caused by trematode species of the genus Schistosoma. Both, autochthonous and imported cases of urogenital schistosomiasis have been described in Europe. The present study focuses on eggs, considered pure S. haematobium by genetic characterisation (intergenic ITS region of the rDNA and cox1 mtDNA). A phenotypic characterisation of S. haematobium eggs was made by morphometric comparison with experimental populations of S. bovis and S. mansoni, to help in the diagnosis of S. haematobium populations infecting sub-Saharan migrants in Spain. Analyses were made by Computer Image Analysis System (CIAS) applied on the basis of new standardised measurements and geometric morphometric tools. The principal component analysis (PCA), including seventeen non-redundant measurements, showed three phenotypic patterns in eggs of S. haematobium, S. bovis and S. mansoni. PCA showed that the S. bovis population presented a large egg size range with a pronouncedly larger maximum size. Similarly, S. bovis shows bigger spine values than S. haematobium. Mahalanobis distances between each pair of groups were calculated for each discriminant analysis performed. In general, S. mansoni and S. bovis present larger distances between them than with S. haematobium, i.e. they present the greatest differences. Regarding the spine, S. haematobium and S. mansoni are the most distant species. Results show the usefulness of this methodology for the phenotypic differentiation between eggs from these Schistosoma species, capable of discerning morphologically close eggs, as is the case of the haematobium group. Schistosoma egg phenotyping approaches may be applied to assess not only hybrid forms but also potential influences of a variety of other factors.

Evidence of autochthonous transmission of urinary schistosomiasis in Almeria (southeast Spain): An outbreak analysis

BACKGROUND

Schistosomiasis is endemic in 78 countries belonging to tropical and subtropical areas. However, autochthonous transmission of urogenital schistosomiasis was reported in Corsica (France) in 2013. We present evidence of autochthonous transmission of urogenital schistosomiasis in Almería (Spain) in 2003.

METHODS

Description of the outbreak in farmers and subsequent epidemiological studies aimed at searching for Bulinus snails and their genotypic characteristics.

RESULTS

The outbreak affected 4 farmers out of a group of 5 people who repeatedly bathed that summer in an irrigation pool in the area. Two of them presented macroscopic hematuria with bilharziomas, showing the presence of Schistosoma eggs in bladder biopsies. Two others were asymptomatic but the serology for schistosomiasis was positive. In 2015, the presence of the vector Bulinus truncatus was demonstrated in Almería in water collections of appropriate characteristics. DNA sequencing proving that local B. truncatus species were base-to-base identical to B. truncatus from Senegal.

CONCLUSIONS

We present a new outbreak of autochthonous transmission of urogenital schistosomiasis in Europe. Although no new cases of autochthonous transmission have been reported, some other cases may have occurred at that time or later on and be unnoticed as many cases of schistosomiasis are asymptomatic or present mild and unspecific symptoms.

Usefulness of ultrasound in sub-Saharan patients with a serological diagnosis of schistosomiasis

OBJECTIVE

To evaluate the usefulness of ultrasound examination in patients with just a serological diagnosis of schistosomiasis but no other evidence of active infection.

METHODS

346 sub-Saharan patients with possible schistosomiasis that presented at a Tropical Medicine Unit between 2008 and 2019 were retrospectively selected. Possible schistosomiasis was considered in those patients with a positive serology for schistosomasis in the absence of direct microbiological isolates, hematuria and/or eosinophilia. Data from ultrasound examinations before and after treatment with praziquantel were collected and categorized following the World Health Organization-Niamey score to standardize the use of ultrasonography for the assessment of schistosomiasis-related morbidity.

RESULTS

Ultrasound examinations were abnormal in only ten patients (2.89%). Main findings were focal thickening of the bladder wall (n = 6), ureteral dilatation (n = 3) and grade I hydronephrosis (n = 1). No malignant lesions, hepatic lesions nor hepatobiliary related disorders were found. After treatment, the S. haematobium global score (5 vs 3.4, p = 0.06) and the urinary bladder score (2 vs 1, p = 0.059) showed a trend towards improvement after treatment. In three patients the score after treatment dropped to 0, and in another three it remained the same although with signs of improvement. No worsening of the score was observed in any case.

CONCLUSION

For those patients with a diagnosis of schistosomiasis based solely in a positive serology, the ultrasound examination could safely be spared due to the low prevalence of pathological findings and its response to treatment anyway.

Urological management and surgical procedures in migrants from Sub-Saharan Africa with urogenital schistosomiasis

INTRODUCTION AND OBJECTIVES

An increasing number of urogenital schistosomiasis (UGS) is being diagnosed in Europe following the unprecedented migratory flux from Sub-Saharan Africa (SSA). This phenomenon represent a challenge for urologists working in a non-endemic area. The aim of this study is to describe the urological management and the surgical procedures of patients with UGS in a tertiary referral centre.

PATIENTS

All subjects from SAA diagnosed with UGS from January 2011 to November 2018 were enrolled retrospectively. Detailed data of patients with UGS undergoing to urological procedures were collected and analysed.

RESULTS

Thirty patients were diagnosed with UGS, among them 12 (42.8%) were submitted to surgery. The most common surgical procedure was trans urethral resection of bladder (TURB) for suspected lesions persisted after praziquantel treatment performed in 7cases (58%). Other surgical procedure were TURB and concomitant ureteroscopy with laser fragmentation for suspected bladder neoplasm with renal stone, endoscopic lithotripsy and percutaneous nephrolithotomy for bladder and renal stones, laparoscopic nephrectomy for end-stage kidney disease, placement of bilateral nephrostomy for hydroureteronephrosis, explorative testicular surgery for a suspected testicular torsion in one case each. Four patients (33%) were lost at the follow up.

CONCLUSION

An increasing number of migrants from SSA diagnosed with UGS has been observed. Some patients required a surgical intervention for suspected neoplastic lesions or end-stage organ damage. It was particularly difficult to perform a regular follow-up in several patients. Further multicentric studies are needed to reach a proper standard in diagnosis, treatment and follow-up of subjects with UGS.

Evaluation of a duplex real-time PCR in human serum for simultaneous detection and differentiation of Schistosoma mansoni and Schistosoma haematobium infections - cross-sectional study

BACKGROUND

We evaluated a one-tube multiplex real-time PCR targeting DNA of Schistosoma haematobium complex and S. mansoni complex in serum samples obtained at different German diagnostic centers.

METHODS

Simplex real-time PCR protocols for the detection of the multi-copy DNA-repeats Dra1 of S. haematobium complex and Sm1-7 of S. mansoni complex in serum were combined to a new one-tube multiplex format. The new PCR was subjected to full validation including evaluation in a diagnostic real-life setting with travelers and migrants. PCR results were compared with those of stool and urine microscopy, serology, and circulating cathodic antigen (CCA) rapid diagnostic tests in urine. Sensitivity and specificity of the diagnostic approaches were analyzed using latent class analysis (LCA).

RESULTS

LCA assessment indicated sensitivity and specificity of 94.9% and 98.4%, respectively, for serum PCR if serology was included in the calculation, and 100% and 95.6%, respectively, if serology was not included as a parameter not necessarily associated with active infection. Agreement between the compared diagnostic procedures at genus level was fair (kappa 0.273) if serology was included and moderate (kappa 0.420) if serology was not included.

DISCUSSION

The PCR assay proved to be highly reliable for the diagnosis of schistosomiasis in travelers and migrants.

Emerging Infectious Diseases in Pregnant Women in a Non-Endemic Area: Almost One Out of Four Is at Risk

We report the results of a targeted testing strategy for five emerging infectious diseases (Chagas disease, human T-lymphotropic virus 1 infection, malaria, schistosomiasis, and Zika virus infection) in pregnant women accessing an Italian referral centre for infectious diseases in pregnancy for unrelated reasons. The strategy is based on a quick five-question questionnaire which allows the identification of pregnant women at risk who should be tested for a specific disease. One hundred and three (24%) out of 429 pregnant women evaluated in a 20 month period were at risk for at least one emerging infectious disease. Three (2.9%, all from sub-Saharan Africa) out of 103 at-risk women resulted in being affected (one case of Plasmodium falciparum malaria, two cases of schistosomiasis) and were appropriately managed. Prevalence of emerging infectious disease was particularly high in pregnant women from Africa (three out of 25 pregnant women tested, 12%). The proposed strategy could be used by health care professionals managing pregnant women in non-endemic setting, to identify those at risk for one of the five infection which could benefit for a targeted test and treatment.

Urinary schistosomiasis and the associated bladder cancer: update

Background

Urinary schistosomiasis and its severe complications, mainly bladder cancer, are scarce in non-endemic areas. The deficiency in knowledge and clinical experience of schistosomiasis may lead to inadequate management. Highlighting these topics may be of value, especially with the increased immigration from endemic low-/middle-income countries (LMIC) to non-endemic high-income countries (HIC). Schistosomiasis is a parasitic infection endemic in many low- and middle-income countries. It can affect various systems but is best known for its effect on the urinary system.

Main Body

PubMed, Scopus, Google Scholar, and the Cochrane Library databases were searched for urinary schistosomiasis and its related bladder cancer published from 1980 till 2020.

Schistosoma haematobium (SH) infecting the urinary bladder was considered by the IARC as group 1 definitive biological carcinogenic agent. Several carcinogenic pathways have been postulated but the exact mechanism(s) are not defined yet. A more thorough understanding of the parasite life cycle was explored to help eradicate the infection especially for the immigrants from endemic areas. This may prevent or slow down the process of carcinogenesis that leads to Schistosoma-associated bladder cancer (SA-BC), which is usually, but not conclusively, squamous cell carcinoma. Treatment of SA-BC generally follows the same guidelines as urothelial Schistosoma-non-associated bladder cancer (SNA-BC) management; however, prospective trials to confirm and refine the treatment approach for SA-BC have been relatively limited.

Conclusion

The available data showed that despite some etiologic and carcinogenic differences, the oncologic outcomes are generally comparable for SA-BC and NSA-BC when adjusting for stage, risk status, and comorbidities.