Interval breast cancer rate in the first round of the German mammography screening program

Transcription

1 Interval breast cancer rate in the first round of the German mammography screening program Oliver Heidinger, MD 1 Wolf-Ulrich Batzler, MA 1 Stefanie Weigel, MD 2 Walter Heindel, Prof MD 2 Hans-Werner Hense, Prof MD 1,3 1) Epidemiological Cancer Register NorthRhine-Westphalia 2) Reference Center Mammography and 3) Institute of Epidemiology & Social Medicine of the University Münster, Germany

2 Overview The Mammography Screening Programme (MSP) The Epidemiological Cancer Registry in North Rhine-Westphalia (EKR NRW) Principles of the data flow and record linkage procedures Results Strength and limitations Summary and conclusions

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4 The MSP in the State of North Rhine- Westphalia Start: October 2005 (step-wise introduction) Eligible women years: 2,3 Million Biannual invitation 20 Screening units in NRW 6 3 Digital mammography

5 The MSP in the State of North Rhine- Westphalia Start: October 2005 (step-wise introduction) Eligible women years: 2,3 Million Biannual invitation 20 Screening units in NRW 6 3 Digital mammography out of 20 screening units had completed their first round of examinations by the end of 12/

6 The population-based CR NRW Major characteristics: Expanding Muenster county CR (2.6 million) to cover the entire state (18.2 million). Operation started in July Legal obligation to notify all incident cancer cases. Electronic data transfer obligatory (establishing/ using interfaces with existent information and documentation systems). Probabilistic record linkage using encrypted personal identifiers. No patient consent required.

7 Data Flow in EKR NRW = generic notification software of EKR NRW = personal identifiers (plain text) = medical data / screening data = packed one-way encrypted IDAT attributes = pseudonymisation server = packed asymmetric encrypted PID

8 Data sources MSP Screening Units (MaSC) Pathologists Reports Breast Cancer Centres (CDS) Screening detected cancers Hospitals treating breast cancer (HIS/CDS) Interval cancers

9 Surrogate Endpoints (EU-Guidelines) Previous results: Breast cancer detection rate 81 per screened women Recall rate 6.1% Proportion DCIS 19.1% Proportion invasive cancers 10 m: 29.1% Participation 53%. Biesheuvel C., Weigel S., Heindel W.: Mammography Screening: Evidence, History and Current Practice in Germany and Other European Countries. Breast Care 2011; Weigel S., Batzler W.U., Decker T., Hense H.W., Heindel W.: First epidemiological analysis of breast cancer incidence and tumor characteristics after implementation of population-based digital mammography screening. RoFo 2009; 18:

10 Surrogate Endpoints (EU-Guidelines) Present report: Numbers of incident cancers within 24 months after a negative screen Proportionate interval cancer rate (relative to background incidence ) Tumour size and stage of screen-detected and interval cancers Programme sensitivity

11 Time lines 1st round of digital mammography screening 10/ /2008 Follow-up interval of 24 months 12/2010 Registration lag 18 months 07/2012

12 Results Flow Chart of Data in Analyses complete data sets for first mammography screening examinations among MSP participants of the years 2005 to negative screening result (inc. recall and diagnostic work-up) positive screening results (invasive and in-situ carcinoma) Interval cancers within 24 Months Invasive cancers In-situ cancers

13 Results Interval cancer rate among women with negative screen results NRW Participants with negative result at 1st screening exam Interval cancers months 1-12 (per screened women) 7,4 Interval cancers months (per screened women) 15,7 Interval cancers months 1-24 (per screened women) 23,2

14 Results Proportionate interval cancer rate (relative to background risk) NRW Proportionate Interval Cancer Rate* 1st year 0,27 Proportionate Interval Cancer Rate* 2nd year 0,58 *[Interval cancer rate/background incidence rate]; Background incidence rate (C50 only!): 269,4/ EU guidelines: 0,30 0,50 European comparison**: 0,29 0,63 ** Törnberg S. et al.: A pooled analysis of intervall cancer rates in six European countries. European Journal of Cancer Prevention 2010; 19: 87-93

15 Results Age-specific rates of interval cancers Age group years Age group years MSP participants, negative result, 1st screening exam Numbers of interval cancers (1st and 2nd year) Interval cancer rate (per and 24 mths.) , ,8 Age-specific background rate 50 to 59 yrs. : 24,1/ women per year; Age-specific background rate 60 to 69 yrs. : 30,1/ women per year: 21,0/25,8 24,1/30,1 0,8

16 Results Proportions of T categories 1 Weigel S., Batzler W.U., Decker T., Hense H.W., Heindel W.: First epidemiological analysis of breast cancer incidence and tumor characteristics after implementation of population-based digital mammography screening. RoFo 2009; 18: Biesheuvel C., Weigel S., Heindel W.: Mammography Screening: Evidence, History and Current Practice in Germany and Other European Countries. Breast Care 2011; )

17 Results Proportions of T-categories in all breast cancers occurring within two years after first screening 2005 to 2008: comparison of screening detected and interval cancers. All (incl. TX) Tis and T1 T2 to T4 All breast cancers Screening detected breast cancers % % % Interval cancers % % %

18 Results Proportions of lymph node negative tumors (N -) in all invasive breast cancers occurring within two years after first screening 2005 to 2008: comparison of screening detected and interval cancers. Lymph node negative invasive breast cancer Screening detected breast cancers % Interval cancers %

19 Results Programme-Sensitivity MSP NRW Screening detected cancers 7176 Interval cancers Programme-Sensitivity: 78% Screening detected breast cancer Screening detected breast cancer + Interval cancers

20 Strengths and limitations large population completeness of registration >95% timely inclusion of notifications lack of IC classification (legal amendment required) limited ability to trace back cases 20

21 Summary & Conclusion Due to its innovative notification system, the EKR NRW was able to quickly and reliably assemble the data necessary for a timely and comprehensive analysis of interval cancer rates in a large population base. The results of the first round of the Mammography- Screening-Programme in North Rhine-Westphalia are in line with previously published results from other population-based screening programmes in Europe.

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23 Dissection, standardisation and encryption of personal identifiers Example: Johanna Paula Müller zu Fischeriß, weiblich, geb Johann-Wolfgang-von-Goethe-Platz 93, Düsseldorf Variable Dissection Standardization One-way encryption Symmetrical encryption Family Names Müller Fischeriß zu MUELLER FISCHERISS ZU mnfp7d7sd66a"8#.t"3q.u$n5?ei]i\dbpe9t9^: $j0^<=t)1h!)ffz4o#tt r^&-w$k%<;eou=^sbmxt s!s\6gbbzr=dl2uh:xs> Meler Feseris MELER LfM#$5)*`nh["\VXt%LF.V=h*HYiC$7.UGSTO2$1 Johanna JOHANNA Vc^2.">o:)27bLB`*WD] ^\]/3+-P;'[luts"_9I$ First Names Paula PAULA Gg5Gbm3(XQB$Va#-$:9H Eueme Bele EUEME BELE EO35omP^U"Ppe!G;o>G; )Y`gfTG`XI+Ifo-]D1?V Street Johann JOHANN Wolfgang WOLFGANG c39dskk%i/#llck<x#f0 0B_)m,pE3XZusiYq+_FY Goethe GOETHE (:;$fjt9kjr5m'k+c/p3 Platz PLATZ kjgie]k9;9m3;0a_!eu* VpsPA5e.`'FXFeMoB2+g von VON #Q8WLgPilu!h)^$dc5qq 24

24 Summary This is the first evaluation of interval cancer rates in the German Mammography-Screening-Programme (MSP). The evaluation was conducted in the most populated federal state NRW by electronic record linkage of pseudonymised MSP data. The Epidemiological Cancer Register NRW - newly established in 2005 and using concomitantly implemented structures of the MSP and breast care in the state - became rapidly capable of a complete identification of interval cancers. The 24-months absolute interval cancer rate was 23,2 per negatively screened women. Relative to the annual background incidence the proportionate interval cancer rates were 0.27 in the first and 0.58 in the second year. 40% of the advanced breast cancers (stage T2+) detected over the 2 years after screening participation occurred in the screening interval. The overall sensitivity of the MSP in NRW between 2005 and 2008 was 78%.