Inter-Institutional Pathology Consultations for Breast Cancer: Impact on Clinical Oncology Therapy Recommendations

Background: Despite recommendations favouring review of cancer pathology specimens for patients being treated at an institution other than the one that produced the initial pathology report, data regarding discordance rates and their potential clinical impact remain limited, particularly for breast cancer. At the QEII Health Sciences Centre in Halifax, Nova Scotia, it was routine practice to review histopathology when patients referred for adjuvant therapy had undergone their breast cancer surgery and pathology reporting at another institution. The aim of the present study was to determine the rate and clinical impact of discordance in inter-institutional pathology consultations for breast cancer in Nova Scotia. Methods: We conducted a retrospective review of 100 randomly selected inter-institutional pathology consultations for breast cancer patients referred to the QEII in 2004. Cases were categorized as having either no discordance, discordance with no clinical impact, or discordance with potential for clinical impact. Cases with potential clinical impact were independently reviewed by 2 medical oncologists and 2 radiation oncologists, and the discordances were rated as having high, medium, or no clinical impact. Results: The study cohort consisted of 93 cases that met the inclusion criteria. Of these 93 cases, 6 had no discordance, 7 had discordance with no clinical impact, and 80 had discordance with potential for clinical impact. Overall, 10 cases (11%) were rated as having either high or medium clinical impact, with agreement on the clinical impact ratings by oncologist reviewers in the same specialty. The remaining cases had either no clinical impact or disagreement on the clinical impact rating. Conclusions: Inter-institutional pathology consultations for breast cancer in Nova Scotia identified discordant findings with potential clinical impact as determined by oncologist reviewers. Further evaluation of inter-institutional pathology consultations and the impact on clinical decision-making is warranted.