Objective: To identify the correlation between the OncotypeDx Recurrence score, Nottingham Prognostic Index (NPI), and Ki67.
Material & Methods: A retrospective study was conducted at Liaquat National Hospital where medical records of early-stage
breast cancer patients, who had OncotypeDx RS done were reviewed from 2008-2019. The patient’s age, Histopathology type,
tumor grade, size, No. of nodes involved, ER, PR, Her neu and Ki67 were collected. OncotypeDx RS, NPI, and Ki67 were
categorized into 3 groups and statistical analysis was done to find a correlation between OncotypeDx RS, NPI and Ki67.
Result: Total 76 patient’s records were reviewed. The average age of study participants was 56.40 ± 10.32 years. Oncotype-Dx
method categorized 34 (44.74%), 26 (34.21%) and 16 (21.05%) patients as low, moderate and high risk respectively. 18(23.68%),
56(73.68) and 2(2.63%) were classified as low, moderate and high-risk patients by the NPI method correspondingly. According
to Ki67, 26(40.63%), 21(32.81%) and 17(26.56%) patients were low, moderate and high risk respectively. Statistically significant
fair agreement was only observed between Oncotype-Dx& Ki67 (k=0.33, p<0.001) with weak positive correlation (r=0.44,
p<0.001). Further on age-stratification, it was observed that significant fair agreement (k=0.36, p<0.001) and weak positive
correlation (r=0.45, p<0.001) between Oncotype-Dx& Ki67 risk assessment categories was for age group >50 years. On age
stratification, moderate agreement (k=0.45, 0.002) and moderate correlation (r=0.57, p=0.005) were also observed between
OncotypeDx& NPI risk categories for age group ≤50 years.
Conclusion: No statistically significant strong agreement and correlation were observed among three risk assessment methods.
Further investigations should be conducted with a larger sample size to assess agreement among these risk classification methods.
