Digital pathology enabling lean management of HER2/neu testing in breast Cancer

Invasive breast carcinomas with an equivocal result of HER2/neu on immunohistochemistry (IHC) are reflex tested by fluorescent in situ hybridisation (FISH). Molecular testing is often not available in rural laboratories, from where it is routinely outsourced to central laboratories. Histopathology review (HPR) and IHC analysis of the tissue sample is thus repeated at the central laboratory before molecular testing which increases the turnaround time (TAT) and cost incurred by both the patient and the hospital. We aimed to assess the reduction in TAT and the cost effectiveness after introducing Digital Pathology (DP).

The tumours with equivocal HER2/neu results were outsourced for FISH from HBCH, Sangrur (rural laboratory) to Molecular Pathology Laboratory, TMH, Mumbai (central laboratory). The Haematoxylin-Eosin (HE) and IHC slides of 47 cases were virtually shared after scanning by Philips SG 60 digital slide scanner. Paraffin blocks of these cases were sent for FISH testing only. TAT of these prospectively shared cases were compared with a retrospective cohort in which virtual slides were not available. The cost benefits were also assessed.

With the availability of DP, we were able to obviate repeat IHC testing. We were able to achieve a 43.9 % reduction in the TAT (15.65 days to 8.775 days). We also achieved a 30 % reduction in cost.

This is a prototype study highlighting the utility of DP in the lean management of HER2/neu testing. The integration of DP in the referral process reduces the TAT and expenditure optimizing resource utilisation.