Prediction of the presence of invasive disease from the measurement of extent of malignant microcalcification on mammography and ductal carcinoma in situ grade at core biopsy.
OBJECTIVE
To determine whether the extent of microcalcification and ductal carcinoma in situ (DCIS) grade can be used to accurately predict the presence and size of invasive cancer in cases of malignant microcalcification.


METHODS
Over a 10-year period, 402 cases of malignant microcalcification from an NHS screening programme were analysed. For each case, measurement of mammographic microcalcification extent, DCIS grade, and the presence and size of invasive carcinoma from the excised surgical specimen were recorded.


RESULTS
The final histological diagnosis was DCIS only in 71% (284/402) and DCIS with a focus of invasive disease in 29% (118/402). The risk of invasive disease increased with increasing size of microcalcification from 20% (27/136) for cluster size less than 11mm, to 45% (18/40) for cluster size more than 60mm. The risk of invasive disease also increased with increasing histological grade of DCIS from 13% (4/31) with low-grade DCIS to 36% (86/239) with high-grade DCIS. There were significant associations with the presence of invasive disease for cluster size (p=0.0001) and DCIS grade (p=0.003), and when using univariate analysis with simple [cluster size (p=0.01) and grade (p=0.01)] and multiple [cluster size (p=0.02) and grade (p=0.02)] logistic regression, respectively. The Hosmer-Lemeshow goodness-of-fit test suggests that the multiple logistic regression model has a good fit (p=0.99).


CONCLUSIONS
The multidisciplinary team can use these data in individual cases to estimate the risk of invasive cancer and decide whether to carry out an axillary staging procedure.
O'Flynn
E A M
EA
South East London Breast Screening Programme, National Breast Screening Training Centre, Kings College Hospital NHS, London, UK. lizoflynn@doctors.org.uk
Morel
J C
JC
Gonzalez
J
J
Dutt
N
N
Evans
D
D
Wasan
R
R
Michell
M J
MJ
D001706:Biopsy; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D002114:Calcinosis / Q000000981:diagnostic imaging*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008327:Mammography; D009361:Neoplasm Invasiveness; D011379:Prognosis