New Delhi: A new study by scientists at the Indian Council of Medical Research (ICMR) has identified key breast cancer risk factors among Indian women, offering critical insights to strengthen prevention and early screening strategies.

Breast cancer is among the three most common cancers affecting women in India, with incidence rates projected to rise by around 5.6 per cent annually, translating to an estimated 50,000 additional cases every year, according to researchers.

The study, conducted by the ICMR’s National Centre for Disease Informatics and Research (NCDIR), Bengaluru, involved a systematic review and meta-analysis of 31 studies, covering 27,925 participants, of whom 45 per cent had been diagnosed with breast cancer.

Published in the journal 'Cancer Epidemiology', the findings show that reproductive timing, hormonal exposure, central obesity and family history are the primary factors influencing breast cancer risk among Indian women.

Women who experience menopause after the age of 50, have their first pregnancy after 30, marry later, undergo multiple abortions, or exhibit central obesity, defined by a waist-to-hip ratio above 0.85, face a significantly higher risk, the researchers said.

Several lifestyle-related factors were also linked to increased risk in individual studies, including poor sleep quality, irregular sleep patterns, sleeping in illuminated environments and elevated stress levels. In contrast, higher levels of physical activity were associated with a reduced risk of breast cancer.

Age-specific analysis revealed that women above 50 years had a threefold higher risk, while those aged 35 to 50 years faced a 1.63-fold increase, underscoring the need for early screening, particularly for women in their forties.

The researchers noted that differences in age classifications across studies may explain some variability in results. In high-income countries, breast cancer incidence rises sharply after 50, with most cases occurring among postmenopausal women. In contrast, India shows a relatively higher burden among younger women, typically in their 40s and 50s.

“Genetic susceptibility, earlier reproductive transitions, and distinct lifestyle factors may contribute to this disparity. These findings highlight the importance of early screening programmes for women in this age group to enable timely detection and intervention,” said the research team led by Saravanan Vijayakumar of ICMR-NCDIR, stressing the importance of timely detection and intervention.

The study also highlighted the need to consider low body mass index (BMI) as a potential factor influencing breast cancer prognosis and treatment outcomes. Given India’s high prevalence of abdominal obesity, the researchers said lifestyle interventions aimed at reducing waist circumference could play a role in prevention.

The review further emphasised the urgent need for large-scale, population-based prospective cohort studies in India to more precisely define breast cancer prevention and early detection strategies.

IANS