Breast cancer survival rates are measured from the date of diagnosis. Research has shown that the risk of recurrence for triple-negative breast cancer is highest up to three years after diagnosis; at that point, it drops significantly.
In one study, published in Clinical Cancer Research, researchers followed 1,601 women for up to 8.1 years. 180 of these women (11.2%) had triple-negative breast cancer.
Compared with other women with breast cancer, those with triple-negative breast cancer had an increased likelihood of distant recurrence…within 5 years of diagnosis but not thereafter. The pattern of recurrence was also qualitatively different; among the triple-negative group, the risk of distant recurrence peaked at ∼3 years and declined rapidly thereafter.
And according to the National Cancer Institute, survival rates are measured from time of diagnosis. Some definitions:
Cancer-specific Survival: The period from diagnosis until death from the same cancer, whether the original lesion or to a second primary, same cancer or related causes. (Adapted from DJA Punt et. al., 2007)
Disease Free Survival, Disease Free Interval :The period from date of diagnosis until date of first recurrence, loco-regional or systemic. (RTOG)
Overall Survival :The period from date of diagnosis until death from any cause. (RTOG)
Progression Free Survival, Progression Free Interval : The period during and after treatment in which a participant is living with a disease that does not get worse. Typically it is the period from date of diagnosis until 1) loco-regional or systemic recurrence, 2) second malignancy, or 3) death from any cause; late deaths not related to cancer or its treatment are excluded. (RTOG)