Treatment delays may worsen survival in invasive breast cancer

Extended treatment delay for >90 days is associated with poor survival in patients with invasive nonmetastatic and metastatic breast cancer, according to a Singapore study.

However, in noninvasive breast cancer, slight delays in the initiation of first treatment do not seem to be detrimental to survival outlook and may even allow for a more extensive diagnostic workup and patient-doctor decision-making.

“Our study may not be generalizable to patients who received neoadjuvant chemotherapy,” said researchers. “It should [also] be noted that the impact of delayed adjuvant treatment postsurgery on survival and the association of endocrine treatment and survival may be confounded by the hormone receptor status of the patient.”

Of the 11,175 breast cancer patients included in this study, 20.7 percent (n=2,318) died due to any cause, with a median survival time of 7.9 years. [Cancer Med 2020;doi:10.1002/cam4.2830]

Delaying the treatment for >30 days was most common in those with noninvasive breast cancer (61.1 percent) and in those with invasive metastatic disease (49.5 percent). On the other hand, delaying surgery for >30 days was rarest in those with invasive, nonmetastatic breast cancer.

In patients with noninvasive breast cancer, delaying treatment initiation for >90 days does not seem to affect 5-year and 10-year survival rates (log-rank p=0.093). Conversely, getting treated earlier also does not significantly affect long-term survival.

In comparison, the timing of treatment appears to play an important role in more progressed diseases. In patients with invasive nonmetastatic breast cancer, for instance, delaying surgery for >90 days worsened overall survival relative to those who had the procedure within 30 days of diagnosis (hazard ratio [HR], 2.25, 95 percent confidence interval [CI], 1.55–3.28).

However, adjusting for cancer stage, radiotherapy, hormone therapy and adjuvant chemotherapy attenuated this effect (HR, 1.28, 95 percent CI, 0.87–1.87). Regardless, in the subset of patients who received adjuvant treatment after surgery, delays >90 days were independently detrimental to survival (HR, 1.50, 95 percent CI, 1.29–1.74).

In patients with metastatic disease, >90-day delays in treatment worsened survival (vs ≤30 days postdiagnosis; HR, 2.09, 95 percent CI, 1.66–2.64). However, restricting analysis to patients who survived for ≥6 months, the timing of treatment ceased to be a significant indicator of survival.

Overall, the present findings suggest that “extended treatment delay (>90 days postdiagnosis) resulted in worse survival in patients with invasive nonmetastatic and metastatic breast cancer, but not in patients with noninvasive breast cancer,” the researchers said.

This then affords these patients a more extensive decision-making process, they added. “While patients’ preference and anxiety status need to be considered, spending more time on treatment options or to have higher considerations in cosmetic outcomes in patients with noninvasive breast cancer may be viable.”