Okay, I was looking at some studies. Some count t

Okay, I was looking at some studies. Some count time after surgery. So there could be some delay with that, but after, it looks starting chemo for tnbc within 61 days is best for overall survival., but the 90 day window seems important.

https://sciencebasedmedicine.org/you-have-bre...treatment/

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The effect of delayed TTC administration has been evaluated retrospectively with contradictory results. In a recent study, we reported that a delay of 61 or more days of adjuvant chemotherapy administration was associated with adverse outcomes among patients with stage II and III breast cancer and also among patients with triple-negative and human epidermal growth factor receptor 2 (ERBB2, formerly HER2 or HER2/neu)-positive tumors. Our findings suggest that among these specific patient subgroups, every effort should be made to avoid delayed adjuvant chemotherapy initiation.

This study didn’t use the SEER database or NCDB. Instead it examined a total of 24,843 patients from the California Cancer Registry diagnosed with stage I to III breast cancer between January 1, 2005 and December 31, 2010 treated with adjuvant chemotherapy. Time to chemotherapy was defined as the number of days between the last surgery for breast cancer and the first dose of chemotherapy, and delayed time to chemotherapy was defined as 91 or more days. Overall, the authors found no evidence of adverse effects when patients started chemotherapy between 31-60 or 61-90 days after their surgery as compared to patients who started their chemotherapy in 30 days. However, for patients who started their chemotherapy 91+ days after their surgery the results weren’t so good. These patients experienced worse overall survival (hazard ratio [HR], 1.34; 95% CI, 1.15-1.57) and worse breast cancer–specific survival (HR, 1.27; 95% CI, 1.05-1.53). The authors then did a subgroup analysis examining different subtypes of cancer to subtype, longer time-to-chemotherapy was associated with worse OS in the subgroups one would predict. Specifically patients with triple-negative breast cancer had worse overall survival (HR, 1.53; 95%CI, 1.17-2.00) and worse breast cancer–specific survival (HR, 1.53; 95%CI 1.17-2.07). This finding intuitively makes sense because it is patients whose tumors are estrogen receptor-negative for whom there is the greatest benefit due to adjuvant chemotherapy.

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