Abstract
Theoretically, time from breast cancer diagnosis to therapeutic surgery should affect
survival. However, it is unclear whether this holds true in a modern healthcare setting
in which breast cancer surgery is carried out within weeks to months of diagnosis.
This is a population- and register-based study of all women diagnosed with invasive
breast cancer in the Stockholm-Gotland healthcare region in Sweden, 2001 - 2008,
and who were initially operated. Follow-up of vital status ended 2014. 7017 women
were included in analysis. Our main outcome was overall survival. Main analyses
were carried out using Cox proportional hazards models. We adjusted for likely
confounders and stratified on mode of detection, tumor size and lymph node
metastasis.
We found that a longer interval between date of morphological diagnosis and
therapeutic surgery was associated with a poorer prognosis. Assuming a linear
association, the hazard rate of death from all causes increased by 1.011 (95% CI
1.006 to 1.017) per day. Comparing, e.g., surgery 6 weeks after diagnosis to surgery
3 weeks after diagnosis, thereby confers a 1.26-fold increased hazard rate. The
increase in hazard rate associated with surgical delay was strongest in women with
largest tumors. Whilst there was a clear association between delays and survival in
women without lymph node metastasis, the association may be attenuated in
subgroups with increasing number of lymph node metastases. We found no evidence
of an interaction between time to surgery and mode of detection.
In conclusion, unwarranted delays to primary treatment of breast cancer should be
avoided.
