Factors Involved in Delaying Initiation of Adjuvant Chemotherapy After Breast Cancer Surgery

Factors delaying non-metastatic breast cancer adjuvant therapy and impact on prognosis in a cohort of Brazilian women

OBJECTIVE

To identify factors associated with delays in beginning adjuvant therapy and prognosis impacts on non-metastatic breast cancer patients.

METHODS

This assessment comprised a prospective cohort study concerning breast cancer patients treated at a public oncology centre. A time interval of ≥60 days between surgery and the beginning of the first adjuvant treatment was categorised as a delay. Factors associated with delays were evaluated through logistic regression analysis and the prognosis effects were assessed by a Cox regression analysis.

RESULTS

The median time interval between surgery and the first adjuvant treatment for the 401 women included in this study was of 57.0 days (37.0-93.0). Independent factors associated with delays comprised not presenting an overexpression of the HER-2 protein, not having undergone neoadjuvant chemotherapy, and having undergone chemotherapy or other therapeutic modalities other than hormone therapy and chemotherapy as the first adjuvant treatment. Delays did not affect recurrence, distant metastasis, or death risks. Factors associated with recurrence and distant metastasis risks comprised a clinical staging ≥2B, having undergone neoadjuvant chemotherapy, presenting the luminal molecular subtype B and triple-negative tumours, and having children. Factors associated with death comprised triple-negative molecular tumours and neoadjuvant chemotherapy.

CONCLUSION

Delays in beginning adjuvant treatment did not affect the prognosis of non-metastatic breast cancer patients. Clinical and treatment-related factors, on the other hand, were associated with delays, and recurrence, distant metastasis, and death risks.

Rate of residual tumor after repeat surgery for positive margins in ductal carcinoma in Situ, and predictive factors

AIMS

To evaluate the rate of residual tumor in re-excision specimen of patients with positive margins in ductal carcinoma in situ (DCIS) following breast-conservative surgery, and to identify predictive factors of residual tumor.

MATERIAL AND METHODS

We conducted a monocentric, retrospective study, from January 2010 to December 2020. All 103 patients who underwent re-excision for positive margins in DCIS following breast-conservative surgery for in situ or invasive breast carcinoma were included. Positive margins were defined as inferior to 2 mm from the DCIS component. Two groups were defined, depending on the presence of residual tumor or not, and were compared on their clinical and histopathological characteristics to identify predictive factors of residual tumor.

RESULTS

Residual tumor was found in re-excision specimen of 46 patients (44.7 %). The risk of residual tumor was increased in patients with more than 2 tumor foci (aOR: 12.4; 95 % CI: 1.2 -124.1; p = 0.032) and in those with extensive margin involvement (aOR: 3.2; 95 % CI: 1.3-8.2; p = 0.013). Finally, surgery performed after 2013 was associated with a lower risk of residual tumor (aOR: 0.23; 95 % CI: 0.09-0.058; p = 0.002).

CONCLUSION

The rate of residual tumor in re-excision specimen of patients with positive margins in DCIS is high. Both the number of tumor foci and the extension of positive margins were identified as risk factors. Finally, the surgical learning curve for this procedure seems to be significantly correlated with the risk of residual tumor and needs to be considered.

Development of a key performance indicator for breast cancer in Queensland, Australia

PURPOSE

Using population-based data for women diagnosed with stage I-III breast cancer, our aim was to examine the impact of time to treatment completion on survival and to identify factors associated with treatment delay.

METHODS

This retrospective study used clinical and treatment data from the Queensland Oncology Repository. Time from diagnosis to completing surgery, chemotherapy and radiation therapy identified a cut-off of 37 weeks as the optimal threshold for completing treatment. Logistic regression was used to identify factors associated with the likelihood of completing treatment > 37 weeks. Overall (OS) and breast cancer-specific survival (BCSS) were examined using Cox proportional hazards models.

RESULTS

Of 8279 women with stage I-III breast cancer, 31.9% completed treatment > 37 weeks. Apart from several clinical factors, being Indigenous (p = 0.002), living in a disadvantaged area (p = 0.003) and receiving ≥ two treatment modalities within the public sector (p < 0.001) were associated with an increased likelihood of completing treatment > 37 weeks. The risk of death from any cause was about 40% higher for women whose treatment went beyond 37 weeks (HR 1.37, 95%CI 1.16-1.61), a similar result was observed for BCSS. Using the surgery + chemotherapy + radiation pathway, a delay of > 6.9 weeks from surgery to starting chemotherapy was significantly associated with poorer survival (p = 0.001).

CONCLUSIONS

Several sociodemographic and system-related factors were associated with a greater likelihood of treatment completion > 37 weeks. We are proposing a key performance indicator for the management of early breast cancer where a facility should have > 90% of patients with a time from surgery to adjuvant chemotherapy < 6.9 weeks.

Preclinical toxicological study of long-circulating and fusogenic liposomes co-encapsulating paclitaxel and doxorubicin in synergic ratio

Combination therapy between paclitaxel (PTX) and doxorubicin (DXR) is applied as the first-line treatment of breast cancer. Co-administration of drugs at synergistic ratio for treatment is facilitated with the use of nanocarriers, such as liposomes. However, despite the high response rate of solid tumors to this combination, a synergism of cardiotoxicity may limit the use. Thus, the objective of this work was to investigate the toxicity of long-circulating and fusogenic liposomes co-encapsulating PTX and DXR at the synergistic molar ratio (1:10) (LCFL-PTX/DXR). For this, clinical chemistry, histopathological analysis and electrocardiographic exams were performed on female Balb/c mice that received a single intravenous dose of LCFL-PTX/DXR. The results of the study indicated that the LD50 dose range (lethal dose for 50% of animals) of the LCFL-PTX/DXR treatment (28.9-34.7 mg/kg) is much higher than that found for free PTX/DXR treatment (20.8-23.1 mg/kg). In addition, liposomes promoted cardiac protection by not raising CK-MB levels in animals, keeping cardiomyocytes without injury or electrocardiographic changes. After 14 days of treatment, free PTX/DXR caused prolongation of the QRS interval when compared to LCFL-PTX/DXR treatment at the same dose (37.0 ± 5.01 ms and 30.83 ± 2.62 ms, respectively, with p = 0.017). The survival rate of animals treated with LCFL-PTX/DXR was three times higher than that of those treated with free drugs. Thus, it was established that the toxicity of LCFL-PTX/DXR is reduced compared to the combination of free PTX/DXR and this platform has advantages for the clinical treatment of breast cancer.