Cancer incidence and mortality patterns in women with breast symptoms in the mammography screening programme: A matched cohort analysis

Abstract

Efforts to reduce mortality through early detection and diagnosis has intensified in the recent decade. An important risk factor, ‘breast symptoms’ reported by women during screening visit, remains overlooked. In this population based matched cohort study using Finnish National Breast Cancer Screening Program (FNBCSP), we assessed the association between breast symptoms reported at screening visit and the risk of cancer incidence and breast cancer mortality and all-cause mortality followed-up over a period of 24 years. For each visit with symptoms, non-symptomatic controls were matched (1:1 for lump and retraction; 1:2 for nipple discharge) based on age at screening visit, year of invitation, number of invited visits, and municipality of invitation. Women who reported lump or retraction had about two-fold risk of breast cancer incidence, three-fold risk of breast cancer mortality and all-cause mortality respectively as compared to women without respective symptoms (p-value<0.05). We found a substantial difference (p-value<0.05) in mortality rates throughout the follow-up period between symptomatic and asymptomatic group. In absolute terms, after the follow-up period for women who reported lump, 180 died from breast cancer as compared to 70 deaths in those without lump, per 10,000 person-years of follow-up, and 315 versus 160 all-cause deaths per 10,000 person-years in women with and without lump respectively. our study provides comprehensive evidence that women with breast symptoms remain in a higher risk of dying over a very long period. The findings indicate needs to develop improvements in the guidelines for screening and clinical services for women presenting with symptoms.