Comparison of HPV-positive triage strategies combining extended genotyping with cytology or p16/ki67 dual staining in the Italian NTCC2 study.

BACKGROUND: Each high-risk HPV genotype has different oncogenic potential, and the risk of CIN3+ varies according to genotype. We evaluated the performance of different strategies of HPV-positivity triage combining cytology, p16/ki67 dual staining (DS), and extended genotyping. METHODS: Samples from 3180 consecutive women from the NTCC2 study (NCT01837693) positive for HPV DNA at primary screening, were retrospectively analyzed by the BD Onclarity HPV Assay, which allows extended genotyping. Genotypes were divided into three groups based on the risk of CIN3+. HPV DNA-positive women were followed up for 24 months or to clearance. FINDINGS: Combining the three groups of genotypes with cytology or DS results we identify a group of women who need immediate colposcopy (PPV for CIN3+ from 7.8 to 20.1%), a group that can be referred to 1-year HPV retesting (PPV in those HPV-positive at retesting from 2.2 to 3.8), and a group with a very low 24-month CIN3+ risk, i.e. 0.4%, composed by women cytology or DS negative and positive for HPV 56/59/66 or 35/39/68 or negative with the Onclarity test, who can be referred to 3-year retesting. INTERPRETATION: Among the baseline HPV DNA positive/cytology or DS negative women, the extended genotyping allows to stratify for risk of CIN3+, and to identify a group of women with a risk of CIN3+ so low in the next 24 months that they could be referred to a new screening round after 3 years. FUNDING: Italian Ministry of Health (grant number RF-2009-1536040). Hologic-Genprobe, Roche Diagnostics, and Becton & Dickinson provided financial and non-financial support.

Exploring conservative management for cervical intraepithelial neoplasia grade 2 in organised cervical cancer screening programmes: a multicentre study in Italy.

Cervical intraepithelial neoplasia grade 2 (CIN2) lesions may regress spontaneously, offering an alternative to immediate treatment, especially for women of childbearing age (15-45 years).We conducted a prospective multicentre study on conservative CIN2 management, with semiannual follow-up visits over 24 months, biomarkers' investigation and treatment for progression to CIN3+ or CIN2 persistence for more than 12 months. Here, we assess women's willingness to participate and adherence to the study protocol.The study was set in population-based organised cervical cancer screening.From April 2019 to October 2021, 640 CIN2 cases were diagnosed in women aged 25-64 participating in the screening programmes.According to our predefined inclusion and exclusion criteria, 228 (35.6%) women were not eligible; 93 (22.6%) of the 412 eligible refused, and 319 (77.4%) were enrolled. Refusal for personal reasons (ie, desire to become pregnant, anxiety, difficulty in complying with the study protocol) and external barriers (ie, residence elsewhere and language problems) accounted for 71% and 17%, respectively. Only 9% expressed a preference for treatment. The primary ineligibility factor was the upper age limit of 45 years. After enrolment, 12 (4%) women without evidence of progression requested treatment, 125 (39%) were lost to follow-up (mostly after 6-12 months) and 182 (57%) remained compliant. Remarkably, 40% of enrolees did not fully adhere to the protocol, whereas only 5% (20/412) of the eligible women desired treatment.Our study demonstrates a good acceptance of conservative management for CIN2 lesions by the women, supporting its implementation within cervical screening programmes.

Acceptability of deferring the start of cervical cancer screening to age 30 for women vaccinated against human papillomavirus.

HPV vaccination of girls younger than 15 is very effective in reducing their risk of cervical cancer. In Italy, for vaccinated women, the starting age for cervical cancer screening is set to change from 25 to 30. Adherence to a protocol change is crucial to assure efficacy. The aim of our study was to monitor women's reaction to the change and learn about their attitudes. In September 2022, an anonymous online questionnaire was proposed to 3122 women born in 1997, fully vaccinated before 15 years of age and afferent to an organized cervical cancer screening programme in the Veneto region (North-East Italy). The questionnaire included 30 items on knowledge of HPV infection and preventive measures for cervical cancer, gynaecological check-ups and reactions to the deferment of the start of screening. Overall, 147 questionnaires were completed (4.7% participation rate). Almost all women had some information on HPV and HPV vaccination, while one third were unaware of the existence of the screening programme. Over 66% expressed agreement with the rationale for the deferment of screening initiation, but 62% would have preferred to start screening at 25. There was a significant association between having had one or more Pap tests and the willingness to undergo additional testing outside the screening programme before the age of 30. Continued efforts are required to improve the effectiveness of communication to women, especially when implementing existing protocols, together with strategies to promote correct approaches.

Performance of HPV E6/E7 mRNA assay as primary screening test: Results from the NTCC2 trial.

As the primary screening test, E6/E7 mRNA has shown similar sensitivity for CIN3+ and lower positivity rate than the HPV DNA test. Nevertheless, the overall mRNA positivity is too high for immediate colposcopy, making a triage test necessary. The aim was to estimate the mRNA performance as a primary test with different triage strategies. All HPV DNA-positives were tested for mRNA, cytology and p16/ki67. A sample of HPV DNA-negatives was also tested for mRNA to estimate test specificity. We included all CIN3+ histologically diagnosed within 24 months since recruitment. Of the 41 127 participants, 7.7% were HPV DNA-positive, of which 66.4% were mRNA-positive. Among the HPV DNA-negatives, 10/1108 (0.9%) were mRNA-positive. Overall, 97 CIN3+ were found. If mRNA was used as the primary test, it would miss about 3% of all CIN3+ with a 22% reduction of positivity compared with HPV DNA. The weighted specificity estimate for

A Retrospective Cohort Study of Young Women Spontaneously Choosing to Be Vaccinated against HPV: Outcomes from Their First Cervical Cancer Screening Test.

BACKGROUND: Efficacy for cervical cancer prevention of opportunistic HPV vaccination in post-pubertal girls is lower than in 11-year-olds. METHODS: Women born between 1986 and 1992 vaccinated at 15-25 years of age (at least one dose of 4-valent HPV vaccine) and screened at 24-27 years of age were included. Frequency of opportunistic vaccination, overall and by birth cohort, was calculated; screening outcomes were compared between vaccinated and unvaccinated women. RESULTS: Overall, 4718 (4.9%) HPV-vaccinated, and 91,512 unvaccinated, women were studied. The frequency of vaccination increased by birth cohort, ranging between 1.8% and 9.8%; age at vaccination decreased progressively by birth cohort (p < 0.0001). Participation in screening was 60.8% among vaccinated, and 56.6% among unvaccinated, women (p < 0.0001). Detection rates (DR) for high-grade lesions were lower in vaccinated women (2.11‰ vs. 3.85‰ in unvaccinated, for CIN3+, p = 0.24; 0.0‰ vs. 0.22‰ for cancer). The DR of CIN3+ increased with age at vaccination, scoring respectively 0.0‰, 0.83‰, and 4.68‰ for women vaccinated when they were 15-16, 17-20, and 21-25 years old (p = 0.17). CONCLUSIONS: In comparison to unvaccinated women, higher compliance with cervical cancer screening invitation and lower CIN3+ DR among vaccinated women was observed. Age at vaccination was inversely correlated to vaccination efficacy.

Leptomeningeal Carcinomatosis of a Poorly Differentiated Cervical Carcinoma Caused by Human Papillomavirus Type 18.

Cervical cancer is caused by a persistent infection with high-risk types of Papillomaviruses (hrHPV); HPV16 and HPV18 are associated with about 70% of the cases. In the last decades the introduction of a cervical cancer screening has allowed a decrease in cervical cancer incidence and mortality; regular adhesion to the screening procedures, by pap test or HPV test, and colposcopy, according to the international guidelines, prevents cancer development and allows for diagnosis at the early stages. Nowadays, in industrialized countries, it is not common to diagnose this pathology in advanced stages, and this occurrence is frequently associated with patient's unattendance of cervical screening programs. We describe a case of delayed diagnosis of cervical cancer, posed only after the onset of the neurological symptoms caused by leptomeningeal metastases, despite a two-year history of abnormal cytology. The endocervical mass was analyzed by immunohistochemistry, and search and typing of HPV sequences was performed by PCR in the meningeal carcinomatous cells. A poorly differentiated squamous cell carcinoma was diagnosed, and HPV18 sequences were detected. This rapidly fatal case highlights the importance of following the evidence-based recommended protocols and the preventive role of the population-based cervical cancer screening programs.

p16/ki67 and E6/E7 mRNA Accuracy and Prognostic Value in Triaging HPV DNA-Positive Women.

BACKGROUND: The study presents cross-sectional accuracy of E6 and E7 (E6/E7) mRNA detection and p16/ki67 dual staining, alone or in combination with cytology and human papillomavirus (HPV)16/18 genotyping, as a triage test in HPV DNA-positive women and their impact on cervical intraepithelial neoplasia (CIN2+) overdiagnosis. METHODS: Women aged 25-64 years were recruited. HPV DNA-positive women were triaged with cytology and tested for E6/E7 mRNA and p16/ki67. Cytology positive women were referred to colposcopy, and negatives were randomly assigned to immediate colposcopy or to 1-year HPV retesting. Lesions found within 24 months since recruitment were included. All P values were 2-sided. RESULTS: 40 509 women were recruited, and 3147 (7.8%) tested HPV DNA positive; 174 CIN2+ were found: sensitivity was 61.0% (95% confidence interval [CI] = 53.6 to 68.0), 94.4% (95% CI = 89.1 to 97.3), and 75.2% (95% CI = 68.1 to 81.6) for cytology, E6/E7 mRNA, and p16/ki67, respectively. Immediate referral was 25.6%, 66.8%, and 28.3%, respectively. Overall referral was 65.3%, 78.3%, and 63.3%, respectively. Cytology or p16/ki67, when combined with HPV16/18 typing, reached higher sensitivity with a small impact on referral. Among the 2306 HPV DNA-positive and cytology-negative women, relative CIN2+ detection in those randomly assigned at 1-year retesting vs immediate colposcopy suggests a -28% CIN2+ regression (95% CI = -57% to +20%); regression was higher in E6/E7 mRNA-negatives (Pinteraction = .29). HPV clearance at 1 year in E6/E7 mRNA and in p16/ki67 negative women was about 2 times higher than in positive women (Pinteraction < .001 for both). CONCLUSIONS: p16/ki67 showed good performance as a triage test. E6/E7 mRNA showed the highest sensitivity, at the price of too high a positivity rate to be efficient for triage. However, when negative, it showed a good prognostic value for clearance and CIN2+ regression.

Age-independent increasing prevalence of Human Papillomavirus-driven oropharyngeal carcinomas in North-East Italy.

HPV-driven oropharyngeal carcinomas (OPCs) show geographical variations with increasing temporal trends in several areas. We investigated their frequency and clinical outcomes within a prospective multicenter cohort study in North-East Italy. A tumor was defined as HPV-driven by using at least two different biomarkers, usually HPV-DNA positivity and p16INK4A overexpression. Different survival outcomes were compared among patients with HPV-driven and non-HPV-driven tumors. Overall, 42/130 (32.3%) patients with newly diagnosed OPC during the period 2000-2018 resulted HPV-driven; HPV16 was involved in 37 cases (88%), HPV33 in 3 cases (7%), HPV58 and HPV18 in 1 case each. Over time, HPV-driven cases raised from 16.7% (6/36) during 2000-2006 to 46.1% (24/52) during 2013-2018 (p < 0.001). The increase in HPV-driven OPCs was more marked in females than males (p = 0.010), and the frequency of HPV-driven cases was similar in the different age groups. In comparison to cases with non-HPV-driven tumors, a significantly (p < 0.001) better progression-free and overall survival were recorded among patients affected by HPV-driven OPC. The prevalence of HPV-driven OPC cases has been significantly increasing during the last two decades also in North-East Italy and was associated with favorable outcome. OPCs driven by non-HPV16 oncogenic types were restricted to patients older than 68-yrs.

Combined use of cytology, p16 immunostaining and genotyping for triage of women positive for high-risk human papillomavirus at primary screening.

Human papillomavirus (HPV) testing is very sensitive for primary cervical screening but has low specificity. Triage tests that improve specificity but maintain high sensitivity are needed. Women enrolled in the experimental arm of Phase 2 of the New Technologies for Cervical Cancer randomized controlled cervical screening trial were tested for high-risk HPV (hrHPV) and referred to colposcopy if positive. hrHPV-positive women also had HPV genotyping (by polymerase chain reaction with GP5+/GP6+ primers and reverse line blotting), immunostaining for p16 overexpression and cytology. We computed sensitivity, specificity and positive predictive value (PPV) for different combinations of tests and determined potential hierarchical ordering of triage tests. A number of 1,091 HPV-positive women had valid tests for cytology, p16 and genotyping. Ninety-two of them had cervical intraepithelial neoplasia grade 2+ (CIN2+) histology and 40 of them had CIN grade 3+ (CIN3+) histology. The PPV for CIN2+ was >10% in hrHPV-positive women with positive high-grade squamous intraepithelial lesion (61.3%), positive low-grade squamous intraepithelial lesion (LSIL+) (18.3%) and positive atypical squamous cells of undetermined significance (14.8%) cytology, p16 positive (16.7%) and, hierarchically, for infections by HPV33, 16, 35, 59, 31 and 52 (in decreasing order). Referral of women positive for either p16 or LSIL+ cytology had 97.8% sensitivity for CIN2+ and women negative for both of these had a 3-year CIN3+ risk of 0.2%. Similar results were seen for women being either p16 or HPV16/33 positive. hrHPV-positive women who were negative for p16 and cytology (LSIL threshold) had a very low CIN3+ rate in the following 3 years. Recalling them after that interval and referring those positive for either test to immediate colposcopy seem to be an efficient triage strategy. The same applies to p16 and HPV16.

HPV testing for cervical cancer screening: technical improvement of laboratory logistics and good clinical performance of the cobas 6800 in comparison to the 4800 system.

BACKGROUND: European guidelines for cervical cancer screening now recommend the use of clinically validated assays for high-risk HPV-DNA sequences as primary test in women older than 30 years, performed in centralized laboratories, and run on systems providing automated solutions for all steps. METHODS: We conducted a comparison study, according to the international guidelines, nested within the organized population-based cervical screening program, between the cobas 4800 and 6800 systems (Roche Diagnostics), to evaluate accuracy and reproducibility of HPV test results and laboratory workflow. In Italy implementation of HPV cervical screening is under way on a regional basis; in Veneto it started in June 2015, following a piloting phase; the assay in use in the three centralized laboratories is the cobas 4800 HPV test, run on the cobas 4800 system. Comparison of HPV results with a new version of the assay (cobas 6800/8800 HPV) run on the cobas 6800 system, and intra- and inter-reproducibility analyses have been conducted in samples collected in PreservCyt medium (Hologic) from women without and with a subsequent diagnosis of high-grade lesion. RESULTS: Samples from women older than 30 years attending organized cervical cancer screening were used. Clinical sensitivity and specificity were evaluated on 60 cases and 925 controls, respectively; intra-laboratory reproducibility and inter-laboratory agreement by the 6800 system were evaluated on 593 and 460 specimens, respectively. Our results showed a very high agreement (> 98%) for overall qualitative results between the two systems; clinical sensitivity and specificity of the HPV assay run on 6800 were non-inferior to those of the HPV assay run on 4800 (p = 0,0157 and p = 0,0056, respectively, at the recommended thresholds of 90 and 98%); kappa values of 0.967 and 0.969 were obtained for intra- and inter-laboratory reproducibility analyses in the 6800 system. The 6800 platform displayed several technological improvements over the 4800 system, with higher throughput and laboratory productivity, and lower operator's hands-on time. CONCLUSIONS: The new cobas 6800/8800 HPV assay run on the 6800 instrument is suitable for use in large centralized laboratories included within population-based cervical cancer screening programs.

Human papilloma virus genotyping for the cross-sectional and longitudinal probability of developing cervical intraepithelial neoplasia grade 2 or more.

Human papilloma virus (HPV) testing is more sensitive but less specific than cytology. We evaluated stand-alone genotyping as a possible triage method. During a multicentre randomised controlled trial comparing HPV testing to conventional cytology, HPV-positive women were referred to colposcopy and followed up if no high-grade lesion was detected. HPV-positive samples were genotyped by GP5+/GP6+ primed polymerase chain reaction followed by reverse line blot. Genotypes were hierarchically ordered by positive predictive value (PPV) for CIN grade 2 or more (CIN2+), and grouped by cluster analysis into three groups (A, B and C in decreasing order). Receiver operating characteristic curves were computed. Among 2,255 HPV-positive women with genotyping, 239 CIN2+ (including 113 CIN3+) were detected at baseline or during a 3-year follow-up. HPV33 had the highest PPV with CIN2+ and CIN3+ as the endpoint and when considering lesions detected at baseline or also during follow-up. HPV16 and HPV35 were the second and third, respectively. Cross-sectional sensitivity for CIN2+ at baseline was 67.3% (95% CI 59.7-74.2), 91.8% (95% CI 86.6-95.5) and 94.7% (95% CI 90.2-97.6), respectively, when considering as "positive" any of the HPV types in group A (33, 16 and 35), A or B (31, 52, 18, 59 and 58) and A or B or C (39, 51, 56, 45 and 68). The corresponding cross-sectional PPVs for CIN2+ were 15.8% 95% (CI 13.2-18.7), 12.0% (95% CI 10.3-13.9) and 9.6% (95% CI 8.2-11.1), respectively. HPV33, 16 and 35 confer a high probability of CIN2+ but this rapidly decreases when adding other genotypes.

Methylation analysis and HPV genotyping of self-collected cervical samples from women not responding to screening invitation and review of the literature.

AIM OF THE STUDY: To assess the feasibility of partial HPV genotyping and methylation analysis of CADM1, MAL, and miR124-2 genes as triage tests in assaying self-collected cervical samples positive for high-risk HPV on primary screening, and to review the literature regarding host cellular gene methylation analysis of self-collected cervical samples. MATERIAL AND METHODS: Women residing in North-East Italy who had failed to respond to the invitation to participate in an organized population-based program were invited to provide a self-sample. Their stored baseline (self-collected) and follow-up (clinician-collected) cervical samples were included in the study. DNA was extracted from HPV-positive (Qiagen's Hybrid Capture 2, HC2) samples. Partial genotyping with separate detection of HPV types 16 and 18 was performed with a hybrid capture-based method and a quantitative PCR assay. Methylation was assayed with a quantitative methylation-specific PCR. RESULTS: High-risk HPV infection was detected in 48% of baseline and 71% of follow-up HC2-positive samples. Methylation was demonstrated respectively in 15% and 23.5% of baseline and follow-up samples and chiefly involved a single gene (miR124-2). Invalid quantitative PCR results were recorded in 5% of self-collected samples. The specificity of miR124-1, MAL, and CADM1 methylation was 84%, 94%, and 98%, respectively, and the specificity of the three markers combined was 84%. Sensitivity was not estimated due to the lack of CIN2+ samples. The systematic review showed that different methylation assays yield different accuracy values. CONCLUSION: Self-collected samples are suitable for methylation assays included in reflex triage testing. The reproducibility and accuracy of the methylation tests described in the literature should be improved.

Determinants of Viral Oncogene E6-E7 mRNA Overexpression in a Population-Based Large Sample of Women Infected by High-Risk Human Papillomavirus Types.

Cervical cancer screening by human papillomavirus (HPV) DNA testing with cytology triage is more effective than cytology testing. Compared to cytology, the HPV DNA test's higher sensitivity, which allows better protection with longer intervals, makes it necessary to triage the women with a positive result to compensate its lower specificity. We are conducting a large randomized clinical trial (New Technologies for Cervical Cancer 2 [NTCC2]) within organized population-based screening programs in Italy using HPV DNA as the primary screening test to evaluate, by the Aptima HPV assay (Hologic), the use of HPV E6-E7 mRNA in a triage test in comparison to cytology. By the end of June 2016, data were available for 35,877 of 38,535 enrolled women, 2,651 (7.4%) of whom were HPV DNA positive. Among the samples obtained, 2,453 samples were tested also by Aptima, and 1,649 (67.2%) gave a positive result. The proportion of mRNA positivity was slightly higher among samples tested for HPV DNA by the Cobas 4800 HPV assay (Roche) than by the Hybrid Capture 2 (HC2) assay (Qiagen). In our setting, the observed E6-E7 mRNA positivity rate, if used as a triage test, would bring a rate of immediate referral to colposcopy of about 4 to 5%. This value is higher than that observed with cytology triage for both immediate and delayed referrals to colposcopy. By showing only a very high sensitivity and thus allowing a longer interval for HPV DNA-positive/HPV mRNA-negative women, a triage by this test might be more efficient than by cytology.

Efficacy of self-sampling in promoting participation to cervical cancer screening also in subsequent round.

Offering self-sampling devices improves participation of under-screened women. We evaluated participation in routine screening following the self-sampling intervention in two organized population-based screening programmes located in North-East Italy. Data on participation at 3-years-interval after a randomized clinical trial assessing the response to two strategies offering self-samplers (sent at home or offered free at local pharmacy) with a control action (sending reminders for a cervical specimen taken at the clinic) in 30-64 yr-old women non-respondent to the regular call-recall invitation were analyzed. Up to April 2016, 2300 women out of the 2995 recruited in the trial in 2011 were re-invited to perform a screening test at clinic; overall, 698 women adhered. Participation was similar in the three arms (29-32%), and highest (47-68%) among those who participated in the previous round. Over the two rounds, 44.6%, 32.3% and 30.3% women had at least one test in the self-sampling at home, self-sampling at pharmacy and test at the clinic arms, respectively. Our data indicate that the beneficial effect of offering self-sampling devices to nonparticipating women is maintained over time. Self-samplers are useful to increase overall coverage; their sporadic use does not seem to increase the proportion of women regularly repeating the test.

HPV testing for primary cervical screening: Laboratory issues and evolving requirements for robust quality assurance.

This review aims to highlight the importance of Quality Assurance for Laboratories performing HPV test for Cervical Cancer Screening. An HPV test, to be used as primary screening test, must be validated according to international criteria, based on comparison of its clinical accuracy to HC2 or GP5+/6+ PCR-EIA tests. The number of validated platforms is increasing and appropriate Quality Assurance Programs (QAPs) which can interrogate longitudinal robustness and quality are paramount. This document describes the following topics: (1) the characteristics of an HPV laboratory and the personnel training needs, to ensure an elevated quality of the entire process and the optimal use of the resources; (2) the Quality Assurance, as both internal (IQA) and external quality assessment (EQA) systems, to be implemented and performed, and the description of the existing EQAs, including limitations; (3) general considerations for an optimal EQA program for hrHPV primary screening Due to the importance of Quality Assurance for this field, international efforts are necessary to improve QA International Collaboration.

Cervical cancer screening by high risk HPV testing in routine practice: results at one year recall of high risk HPV-positive and cytology-negative women.

OBJECTIVE: Cervical cancer screening by human papillomavirus (HPV) testing requires the use of additional triage and follow-up analyses. We evaluated women's compliance with and the performance of this strategy in a routine setting. SETTING: Five cervical service screening programmes in North-East Italy. METHODS: Eligible women aged 25-64 invited for a new screening episode underwent HPV testing for high risk types (hrHPV by Hybrid Capture 2) and cytology triage. Women with positive HPV and cytology results were referred for colposcopy; women with positive HPV but negative cytology results were referred to 1-year repeat hrHPV testing. RESULTS: Of 46,694 women screened by HPV testing up to December 2011, 3,211 (6.9%) tested hrHPV positive; 45% of these had a positive triage cytology. Those with negative cytology were invited for 1-yr repeat testing. Compliance with invitation was 61.6% at baseline and 85.3% at 1-yr repeat. Rate of persistent hrHPV positivity was 58% (830/1,435). Colposcopy performed in women with a positive hrHPV test at 1-yr repeat accounted for 36% of all colposcopies performed within the screening programmes. Cumulatively, a histological high-grade lesion was detected in 276 women (5.9‰ detection rate), 234 at baseline (85%), and 42 (15%) at 1-yr repeat. CONCLUSIONS: Compliance with hrHPV-based screening programmes was high both at baseline and at 1-yr repeat. Compared with the randomized trials, a higher proportion of triage cytology was read as positive, and only a small number of high-grade lesions were detected among the group of hrHPV positive cytology negative women who repeated testing 1-yr after baseline.

[Molecular diagnosis of retinoblastoma: molecular epidemiology and genetic counseling]. / Diagnóstico molecular del retinoblastoma: epidemiología molecular y consejo genético.

BACKGROUND AND OBJECTIVE: Retinoblastoma, a prototype of hereditary cancer, is the most common intraocular tumor in children and a potential cause of blindness from therapeutic eye ablation, second tumors in germ line mutation carriers, and even death when untreated. The molecular scanning of RB1 in search of germ line mutations in 213 retinoblastoma patients from Spain, Cuba, Colombia and Serbia, has led to the detection of 106 mutations whose knowledge is important for genetic counselling and characterization of phenotypic-genotypic relations. PATIENTS AND METHOD: Mutational study (PCR-sequentiation and microsatellites analysis) in patients with retinoblastoma, from Spain, Cuba, Colombia and Serbia. RESULTS: 45% of mutations, including most of the frame shift (FS), missense (MS) and splicing (SP), were new, while all nonsense mutations (NS) corresponded to hypermutable sites in RB1. Germ line mutations were found in 22% of unilateral sporadic patients. The incidence of SP plus MS mutations in this group of patients was greater (p = 0.018) than in bilateral patients. The frequency of SP mutations was higher (p = 0.0003) in Spain and France than in Germany and United Kingdom, while the incidence of NS mutations was lower (p = 0.0006). SP mutations were associated with the low penetrance phenotype and were also overrepresented (p = 0.018) in patients with delayed retinoblastoma onset. CONCLUSIONS: Mutational scanning of unilateral patients is important for genetic counselling and may help decipher the molecular mechanisms leading to low penetrance or expressivity. The functional characterization of mutations associated with low-penetrance or expressivity phenotypes and the molecular classification of tumors using multiple expression profiling is important for a better understanding of the retinoblastoma pathogenesis.

Diagnóstico molecular del retinoblastoma: epidemiología molecular y consejo genético / Molecular diagnosis of retinoblastoma: molecular epidemiology and genetic counseling

Fundamento y objetivo: El retinoblastoma, prototipo de cáncer hereditario, puede causar ceguera, por enucleación terapéutica, segundos tumores en pacientes con mutación germinal e incluso muerte si no se trata. El diagnóstico molecular de 213 pacientes a lo largo de 5 años ha conducido a la detección de 106 mutaciones que se analizan desde la perspectiva de la epidemiología molecular y consejo genético. Pacientes y método: Estudio mutacional (reacción en cadena de la polimerasa, secuenciación y análisis de microsatélites) en pacientes con retinoblastoma procedentes de España, Cuba, Colombia y Serbia. Resultados: Un 45% de las mutaciones analizadas son nuevas y corresponden a mutaciones de tipo de corrimiento de pauta de lectura, cambio de aminoácido o procesado del ácido ribonucleico. Todas las mutaciones sin sentido corresponden a sitios de alta mutabilidad. La tasa de detección de mutaciones en pacientes unilaterales esporádicos es alta (22%). En este grupo de pacientes se detecta una mayor incidencia (p = 0,018) de mutaciones de cambio de aminoácido y procesamiento. España y Francia muestran una incidencia mayor de mutaciones del procesado (p = 0,0003) que Alemania y el Reino Unido, países en los que predominan las mutaciones sin sentido (p = 0,0006). Las mutaciones del procesado se asocian al fenotipo de baja penetración y retraso en la aparición de tumores (p = 0,018). Conclusiones: La incidencia de mutaciones germinales en pacientes unilaterales y las relaciones fenotipo/genotipo analizadas indican la necesidad del consejo genético basado en el diagnóstico molecular temprano. La mejora de las técnicas diagnósticas, la caracterización funcional de mutaciones asociadas a baja penetrancia o expresividad y el estudio del transcriptoma de los tumores son objetivos necesarios para definir mejor la patogenia del retinoblastoma

Background and objective: Retinoblastoma, a prototype of hereditary cancer, is the most common intraocular tumor in children and a potential cause of blindness from therapeutic eye ablation, second tumors in germ line mutation carriers, and even death when untreated. The molecular scanning of RB1 in search of germ line mutations in 213 retinoblastoma patients from Spain, Cuba, Colombia and Serbia, has led to the detection of 106 mutations whose knowledge is important for genetic counselling and characterization of phenotypic-genotypic relations. Patients and method: Mutational study (PCR-sequentiation and microsatellites analysis) in patients with retinoblastoma, from Spain, Cuba, Colombia and Serbia. Results: 45% of mutations, including most of the frame shift (FS), missense (MS) and splicing (SP), were new, while all nonsense mutations (NS) corresponded to hypermutable sites in RB1. Germ line mutations were found in 22% of unilateral sporadic patients. The incidence of SP plus MS mutations in this group of patients was greater (p = 0.018) than in bilateral patients. The frequency of SP mutations was higher (p = 0.0003) in Spain and France than in Germany and United Kingdom, while the incidence of NS mutations was lower (p = 0.0006). SP mutations were associated with the low penetrance phenotype and were also overrepresented (p = 0.018) in patients with delayed retinoblastoma onset. Conclusions: Mutational scanning of unilateral patients is important for genetic counselling and may help decipher the molecular mechanisms leading to low penetrance or expressivity. The functional characterization of mutations associated with low-penetrance or expressivity phenotypes and the molecular classification of tumors using multiple expression profiling is important for a better understanding of the retinoblastoma pathogenesis

Identification of 26 new constitutional RB1 gene mutations in Spanish, Colombian, and Cuban retinoblastoma patients.

Constitutional mutations in the RB1 gene predispose to retinoblastoma development. Hence genetic screening of retinoblastoma patients and relatives is important for genetic counseling purposes. In addition, RB1 gene mutation studies may help decipher the molecular mechanisms leading to tumors with different degrees of penetrance or expressivity. In the course of genetically screening of 107 hereditary and non-hereditary retinoblastoma patients (11 familiar bilateral, 4 familiar unilateral, 49 sporadic bilateral and 43 sporadic unilateral) and kindred from Spain, Colombia and Cuba, using direct PCR sequencing, we observed 45 distinct mutations and four RB1 deletions in 53 patients (9 familiar bilateral, 2 familiar unilateral, 31 sporadic bilateral and 11 sporadic unilateral). Most of these mutations (26/45, 57%) have not been reported before. In 32 patients, the predisposing mutations correspond to nonsense (mainly CpG transitions) and small insertions or deletions whose expected outcome is a truncated Rb protein that lacks the functional pockets and tail. Five single aminoacid replacements and seventeen mutations affecting splicing sites were also observed in retinoblastoma patients. Two of these sixteen mutations are of unclear pathogenic nature.

Two independent RB1-inactivating mutations in peripheral blood DNA of a hereditary retinoblastoma patient.

We report the presence of a hemizygous inactivating germ-line RB1 mutation (a recurrent g.78250C-->T transition, resulting in a stop codon in exon 17) in peripheral blood DNA from a patient with hereditary bilateral retinoblastoma. Hemizygosity was established by sequencing that showed no traces of the wild-type C nucleotide and by quantitative real-time PCR, which showed loss of one copy of exon 17. Genotyping of the RB1 locus with several polymorphic markers delineated a maximal deletion region between g.76875 and g.99426, including exons 15-17 and a large piece (21 kb) of intron 17. The heterozygosity for the mutation found in skin fibroblasts proves that the intragenic RB1 deletion probably took place in the definitive hematopoietic lineage of the patient. The presence of a null Rb-/- genotype in the hematopoietic cell lineage suggests that the white blood cells of the proband could be useful in the investigation of the role of complementary RBI family proteins in the control of the cell cycle.