Aims and objectives
The goal of a mammography screening program is to identify breast cancers in an early stage,
prior to their dissemination.
Although mammography has been shown to be a very useful screening method for the detection of breast cancer,
there remains a group of tumors detected in the interval between screening examinations,
called interval cancers (IC).
There are at least three types of problems that lead to failure of detection by mammography: 1) Technical or interpretive errors,
2) Characteristics of the breast or tumor (increased mammographic...
Methods and materials
Between January 2007 through December 2012,
a total of 151,567 women aged 50-69 participated in the Screening Program in Cantabria.
In this period a total of 610 breast cancers were diagnosed through a screening mammogram (489 invasive and 121 intraductal cancers).
Besides this,
111 interval cancers were detected (cases diagnosed after a negative screening mammogram within the two year screening interval).
For our purpose,
we only considered those screened detected and interval cancers that were invasive: 489 and 97,
respectively.
The global screened detected and...
Results
We classified the invasive cancers according to their size:
T1 a/b: < 1 cm
T1c: 1-2 cm
T2: > 2cm but no larger than 5cm
T3: > 5cm
T4: any size with thoracic wall or skin infiltration
The percentage of invasive screened detected cancers,
according to their size was 35.7% for T1a/b,
46.6% for T1c,
15.7% for T2,
0.8% for T3 and 1% for T4.
The percentage of invasive interval cancers according to their size was 9.2% for T1a/b,
28.9% for T1c,
48.8% for T2,...
Conclusion
This study confirms that interval cancers displays a more advanced stage at diagnosis compared to screened cancers.
Although IC are inevitable in a screening program,
it is recommended that their frequency should kept very small,
since a high proportion would decrease screening effectiveness.
References
Gemma Renart-Vicens,
Montserrat Puig-Vives,
Joan Albanell,
Francesc Castañer,
Joana Ferrer,
Miquel Carreras,
Joan Tarradas,
Maria Sala and Rafael Marcos-Gragera.
Evaluation of the interval cancer rate and its determinants on the Girona health region’s early breast cancer detection program.
Renart-Vicens et al.
BMC Cancer 2014,
14:558.
Debra M.
Ikeda,
MD,
Robyn L.
Birdwell,
MD,
Kathryn F.
O’Shaughnessy,
PhD R.
James Brenner,
MD,
JD Edward A.
Sickles,
MD.
Analysis of 172 Subtle Findings on Prior Normal Mammograms in Women with Breast Cancer Detected at Follow-up Screening.
Radiology...