LCIS found on core needle biopsy
The appropriate management options for women with LCIS found on core needle biopsy will depend on whether LCIS is found alone, the subtype of LCIS and any associated pathological findings.
When classic LCIS is found on core needle biopsy (either conventional or vacuum-assisted) as an incidental finding, a multidisciplinary discussion is needed to determine further management. There is no strong evidence to guide whether to perform surgery (excision biopsy or other surgery) on these women. There are several studies that have attempted to correlate the results of core biopsy with subsequent excision, with widely varying upgrade rates (ranging from 2% to 26%). These variations reflect study design differences and in some cases, biases introduced due to the retrospective nature of the investigation.10
When classic LCIS is found on core needle biopsy, with radiological-pathological concordance and there are no other higher risk abnormalities that would impact management (e.g. DCIS or invasive carcinoma), it is the consensus of the Working Group that surveillance remains an appropriate option.
If classic LCIS is the only lesion found on core needle biopsy and it does not account for the radiological abnormality (i.e. it is not the index lesion and hence there is radiological-pathological discordance) the consensus of the Working Group is that a subsequent biopsy to obtain a larger tissue sample should be considered.
If there are other LCIS subtypes or proliferative lesions present that require investigation, the consensus of the Working Group is that an excision should be undertaken. Specific examples include:
- the presence of another lesion within the core biopsy that would itself trigger an excision (such as atypical ductal hyperplasia or DCIS)
- the LCIS is of pleomorphic subtype
- the LCIS is of the classic type with comedo-type necrosis
- the LCIS is of the florid/bulky subtype
LCIS found on excision biopsy
The appropriate management options for women with LCIS identified on excision biopsy will depend on whether LCIS is found in isolation, the subtype of LCIS and any associated pathological findings. When LCIS is found in the presence of DCIS or an invasive cancer, these will dictate further management. For LCIS found in isolation on excision biopsy, the management options for each subtype of LCIS are detailed below.
Classic LCIS
As LCIS is often a multifocal and multicentric process, the current WHO Classification: Tumours of the Breast2 does not recommend recording size and margin status for classic LCIS. Most institutions do not attempt clear surgical margins for classic LCIS found on excision biopsy. LCIS reflects a higher risk of developing invasive breast cancer, and surveillance will be dictated by any associated pathology, and personal or family history. Further risk-reducing strategies should be discussed, with consideration of the individual patient’s preferences.
Pleomorphic LCIS
There is a lack of follow-up data to inform the natural history of this subtype. However due to the high grade morphology and molecular profile of this variant, the consensus of the Working Group is that PLCIS be managed as for DCIS. If there is PLCIS at margins in the excisional biopsy, a further surgical procedure such as re-excision, wide-local excision or mastectomy should be considered. However, in order to avoid overtreatment, it is important for pathologists to make a diagnosis of PLCIS only when the nuclear atypia is of high grade (similar to high grade DCIS).
Classic LCIS with comedo-type necrosis, and Florid/Bulky LCIS
These entities have only been described very recently. Due to their rarity and lack of robust morphological criteria for classification, and lack of follow-up data, management decisions should be made as part of the multidisciplinary team discussion. The WHO Classification: Tumours of the Breast2 recommends that margin status should be recorded and a multidisciplinary team should plan further management, including the possibility of further excision or surgery, taking into consideration other risk factors and patient choice.