Optimal Strategies For Mass Screening Of Breast Cancer In India Through Markov Model And Survival Analysis Induced From Multistage Models

Baban WAGH, Indian Institute of Science, India
PAL D. 2

1 Department of Physics, Indian Institute of Science, Bangalore, India
2 Supercomputing Education and Research Centre, Indian Institute of Science, Bangalore, India

Purpose: The aim is to evaluate and assess different strategies of mass screening for breast cancer (BC) using mathematical model, since BC has survival rates around 31-54% in India as compared to over 90% in developed countries like USA. Also to formulate optimal age window for “once in a lifetime” (OL) and “twice in a lifetime” (TL) individual policies for resource limited setting in India.        
Methods: Natural history of BC with inter-stage transition was simulated using a mathematical model to evaluate various biennial and triennial screening policies that also had different age for initiating and terminating screening. Clinical Breast Examination (CBE) followed by clinical ultrasound, is the suitable screening method, recommended for Indian population where BC incidence peaks at a younger age was evaluated along with  standard mammography using specificity and sensitivity values reported for pilot screening programs in India.  Markov Chain transition model was used to model the natural history of BC progression through different clinical stages.           
Results: Initiating age of screening from 37 years for biennial policy increased average life expectancy by 30 days, and by 24 days, compared to average life expectancy at the age of 37 years, in triennial policies. For resource limited strategies such as “once in a lifetime” the optimal age window was 42 to 46 years and that for “twice in a lifetime” it was from 41 to 44 years and from 46 to 51 years, previously not investigated or recommended. False positive rates were 58% and 53% respectively for OL and TL. False positive rates declined after 45 years of age with use of mammography compared to CBE.           
Conclusions: The proposed optimal strategies can be considered for BC awareness and design and planning of mass screening programs in India.
Funding Source: Indian Institute of Science, Bangalore, India