van Maaren MC, Ávila AO, van Manen JG, et al. - A rise in lobular carcinoma in situ (LCIS) incidence and reduction in surgical treatment was evident over a time frame 1989–2017 in the Netherlands, and consideration of active surveillance is supported by the observed low mortality risks.

• Total 1890 patients with classic LCIS, with median age 51 years, were included.

• 10- and 20-year relative survival rates exceeded 90 %, regardless of surgery.

• A diagnosis of ductal carcinoma in situ and invasive breast cancer (IBC) was received by 48 (2.5 %) and 270 (14.3 %) patients, respectively.

• Highest standardised incidence ratios (SIR) of ipsilateral IBC was reported after no surgery, whereas the lowest SIR was noted post-mastectomy.

• Careful monitoring is needed in view of increased IBC incidence observed.