Summary

Breast cancer in young women is the first national report to present key data specific to breast cancer in women in their 20s and 30s. While breast cancer occurs relatively rarely in young women, the number of young women diagnosed with the disease each year is not insignificant. Breast cancers in young women tend to have different characteristics and survival outcomes than those for older women. This report provides an overview of the condition, its risk factors, detection and diagnosis methods as well as key summary measures including incidence, hospitalisations, survival and mortality.

Breast cancer occurs in young women as well as in older women

In 2015, it is projected that 795 young women will be diagnosed with breast cancer and 65 will die from this disease. On average, this is more than 2 breast cancers diagnosed every day and more than 1 death every week. While these figures are small when compared with the equivalent figures for women aged 40 and over-namely, 40 new cases per day and 57 deaths per week-breast cancer is the most commonly diagnosed cancer for women aged 20 to 39 and is associated with poorer survival outcomes.

Overall, 5-year relative survival is significantly lower in younger women, who had an 88% chance of surviving for 5 years in 2007-2011 compared with the 5-year relative survival rate for women aged 40 and over of 90%. However, the 5-year relative survival rate has improved for young women, from 72% in 1982-1986 to 88% in 2007-2011.

Young women have lower survival rates for common types of breast cancer

Invasive ductal carcinoma is the most common breast cancer type for women of all ages. However, a higher proportion of young women are diagnosed with this type of breast cancer than older women (87% compared with 78%). Young women diagnosed with invasive ductal carcinoma have a significantly lower 5-year relative survival rate than women aged 40 and over (83% compared with 88%).

Young women have significantly lower survival rates than women aged 40 and over for invasive lobular carcinoma (84% compared with 91%). Invasive lobular carcinoma is the second most common breast cancer type. However, a lower proportion of young women are diagnosed with this type of breast cancer than older women (3% compared with 11%).

Young women have lower survival rates for small breast cancers

Young women are less likely to be diagnosed with small breast cancers (<15 mm) than women aged 40 and over (25% compared with 32%) and are slightly more likely to be diagnosed with very large breast cancers (≥50 mm) than women aged 40 and over (8% compared with 6%).

However, even for small breast cancers-which tend to be associated with more treatment options and improved survival-young women have lower survival (93%) than women aged 40 and over (99%).