Estimating Risk of Breast Cancer Occurrences at Different Ages: Application of Survival Techniques

Rajbongshi, Nijara; Nath, Dilip C; Mahanta, Lipi B

doi:10.31557/APJCP.2018.19.11.3033

Estimating Risk of Breast Cancer Occurrences at Different Ages: Application of Survival Techniques

Document Type : Research Articles

Authors

¹ Central Computational and Numerical Sciences Division (CCNS), Institute of Advanced Study in Science and Technology (IASST) (An Autonomous Institute under Department of Science and Technology), Guwahati, India.

² Assam University, Silchar, Assam, India.

10.31557/APJCP.2018.19.11.3033

Abstract

Background: Awareness is the primary means to control breast cancer occurrence. The purpose of the present work
is to study the risk of breast cancer occurrence in different age group, for the study area, Assam, India, by means of
survival analysis techniques. Methods: Survival and hazard functions are key concepts in survival analysis for describing
the distribution of event times. In the present research a new individialized model has been proposed for cumulative
hazard function, taking gamma probability distribution as probability distribution of breast cancer occurrences. Kaplan
Meier Survival method has been applied to find out the probability of diseases occurrence in the early menarche and
late menarche group. The data used for implementation were collected from the Record Department of a prime local
cancer institute, for the period 2010-2012. The information for the risk factor age at menarche were collected from the
patients registered during August 2011 to February 2012. Results: The study reveals that in the study area, cumulative
hazard of the women belonging to 35 to 50 years is higher than the early and late aged women. The cumulative hazard
plot with shape parameter 0.5, 1 and 10 shows that cumulative risk for early aged women are greater than the late age
women but when this values is increased from 10, the opposite trend is observed. Further, the median age of disease
occurrence among early menarche group is 52 years and for late menarche it is 54 years. Conclusion: The model
developed could successfully point out the age group for women lying at higher risk of breast cancer occurrence.
Additionally the important risk factor, age at menarche, was effectively applied to supplement to this calculation. It is
hoped that practical use of this method would enhance not only awareness but also early detection of the said disease.

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