The IHC4+C score: an affordable and reproducible non‐molecular decision‐aid in hormone receptor‐positive breast cancer. Does it still hold value for patients in 2020?

Abstract

Aim:The majority of women diagnosed with early breast cancer have hormonereceptor positive (HR+)/HER2-negative disease. Adjuvant endocrine therapy provides substantial risk reduction benefits in virtually all patients. The role of adjuvant chemotherapy in certain subsets of patients is equivocal. This paper sought to evaluate the role of the IHC4+C score to aid this clinical decision in addition to providing an overview of the current molecular and non-molecular tools available in the adjuvant setting.Methods: This prospective study included 53 post-operative HR+/HER2-negative early breast cancer patients selected from the multidiscipliniary team meeting between August 2017 and January 2020. IHC4+C testing was requested by clinicians for patients in whom the availability of the score may have impacted adjuvant decisionmaking. Adjuvant treatment decisions were recorded at three time points (prior and post IHC4+C scoring as well as the patient's final decision). The primary goal was the proportion of patients who were spared chemotherapy following the availability of IHC4+C scores to impact on clinicians' recommendations for adjuvant systemic therapy.Results: A total of 34 patients (64%) were initially recommended to undergo chemotherapy or to consider chemotherapy. With the availability of the IHC4+C score, only 17 patients (32%) underwent chemotherapy, demonstrating a substantial reduction in the frequency of chemotherapy prescribing. ConclusionThis study demonstrates that when utilized appropriately in a multidisciplinary setting, the IHC4+C algorithm is an alternative, reproducible and affordable tool with a proven capacity to stratify risk and to spare a large proportion of patients from undergoing chemotherapy.

The Role of Nodes and Nodal Assessment in Diagnosis, Treatment and Prediction in ER+, Node-Positive Breast Cancer

“…The IHC4 test uses the results of four IHC markers-ER, PR, HER2 and Ki67-to predict 10-year distant recurrence free survival and benefit from chemotherapy in women who have had 5 years of adjuvant ET [100][101][102][103][104]. Clinical and pathological features including the patient's age, tumour size, tumour grade, nodal status, and type of ET administered for 5 years (tamoxifen vs. AI) are also included in a revised version of the test (IHC4+C) [104]. If adequately sampled, a core biopsy can be used for the test if a whole FFPE section is not available [105].…”