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).
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,
The global screened detected and...
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,...
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.
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,
JD Edward A.
Analysis of 172 Subtle Findings on Prior Normal Mammograms in Women with Breast Cancer Detected at Follow-up Screening.