Timing and Delays in Breast Cancer Evaluation and Treatment

Abstract

Background: Even small delays in the treatment of breast cancer are a frequently expressed concern of patients. Knowledge about this subject is important for clinicians to counsel patients appropriately and realistically, while also optimizing care. Although data and quality measures regarding time to chemotherapy and radiotherapy have been present for some time, data regarding surgical care are more recent and no standard exists. This review was written to discuss our current knowledge about the relationship of treatment times to outcomes.

Methods: The published medical literature addressing delays and optimal times to treatment was reviewed in the context of our current time-dependent standards for chemotherapy and radiotherapy. The surgical literature and the lack of a time-dependent surgical standard also were discussed, suggesting a possible standard.

Results: Risk factors for delay are numerous, and tumor doubling times are both difficult to determine and unhelpful to assess the impact of longer treatment times on outcomes. Evaluation components also have a time cost and are inextricable from the patient's workup. Although the published literature has lack of uniformity, optimal times to each modality are strongly suggested by emerging data, supporting the current quality measures. Times to surgery, chemotherapy, and radiotherapy all have a measurable impact on outcomes, including disease-free survival, disease-specific survival, and overall survival.

Conclusions: Delays have less of an impact than often thought but have a measurable impact on outcomes. Optimal times from diagnosis are < 90 days for surgery, < 120 days for chemotherapy, and, where chemotherapy is administered, < 365 days for radiotherapy.

Figure 1

Timing of treatments in breast cancer therapy, based upon current quality measures. Current standards specify time to chemotherapy within 120 days of diagnosis, while time to radiotherapy specifies administration within 365 days of diagnosis. With >98% of surgeries in the United States occurring within 90 days, and a drop in overall survival by an absolute 3.1–4.6%, this threshold seems appropriate as it allows one month to begin chemotherapy by the current quality measure. The 365-day quality measure for radiotherapy allows for sufficient time to undergo chemotherapy regimens of varying lengths, while allowing a short time to begin simulation and planning (panel 1a). When chemotherapy is not administered, however, the radiotherapy standard provides an excess of time, even when using 20 weeks postoperative, which is the longest interval found to not confer a survival decline (panel 1b). This suggests that a second standard, measured from time of surgery when chemotherapy is not administered, might optimize care. Dx = diagnosis; OS = Overall Survival; Sim = simulation; hypoFx = hypofractionation; WBXRT = whole breast radiotherapy; TC = taxotere and cyclophosphamide; DDAC = dose dense doxorubicin and cyclophosphamide; + T = paclitaxel; CMF = cyclophosphamide, methotrexate, and 5-fluorouracil.