Factors associated with the incidence of local recurrences of breast cancer in women who underwent conservative surgery

Estimating the incidence of breast cancer recurrence using administrative data

BACKGROUND

Breast cancer is the most common cancer among women, but most cancer registries do not capture recurrences. We estimated the incidence of local, regional, and distant recurrences using administrative data.

METHODS

Patients diagnosed with stage I-III primary breast cancer in Ontario, Canada from 2013 to 2017 were included. Patients were followed until 31/Dec/2021, death, or a new primary cancer diagnosis. We used hospital administrative data (diagnostic and intervention codes) to identify local recurrence, regional recurrence, and distant metastasis after primary diagnosis. We used logistic regression to explore factors associated with developing a distant metastasis.

RESULTS

With a median follow-up 67 months, 5,431/45,857 (11.8%) of patients developed a distant metastasis a median 23 (9, 42) months after diagnosis of the primary tumor. 1086 (2.4%) and 1069 (2.3%) patients developed an isolated regional or a local recurrence, respectively. Patients with distant metastatic disease had a median overall survival of 15.4 months (95% CI 14.4-16.4 months) from the time recurrence/metastasis was identified. In contrast, the median survival for all other patients was not reached. Patients were more likely to develop a distant metastasis if they had more advanced stage, greater comorbidity, and presented with symptoms (p < 0.0001). Trastuzumab halved the risk of recurrence [OR 0.53 (0.45-0.63), p < 0.0001].

CONCLUSION

Distant metastasis is not a rare outcome for patients diagnosed with breast cancer, translating to an annual incidence of 2132 new cases (17.8% of all breast cancer diagnoses). Overall survival remains high for patients with locoregional recurrences, but was poor following a diagnosis of a distant metastasis.

The association of young age with local recurrence in women with early-stage breast cancer after breast-conserving therapy: a meta-analysis

The aim of this meta-analysis is to determine the relationship between young age and local recurrence in patients with early-stage breast cancer after breast-conserving therapy. Eligible studies were retrieved from various electronic databases. Among the 19 studies included, 14 studies were analyzed for 5-year local recurrence rate and 8 studies for 10-year local recurrence rate using random effects models. Both results showed that young patients were at higher risk of local recurrence compared to old patients (5-year: RR = 2.64, 95% CI (1.94–3.60); 10-year: RR = 2.37, 95% CI (1.57–3.58)). Harbord’s modified test showed the presence of publication bias in both 5- and 10-year local recurrence rates (P = 0.019 and P = 0.01, respectively). While the Trim and Fill analysis showed that the presence of publication bias did not affect the overall outcome of the 5-year local recurrence rate (RR = 2.21, 95% CI (1.62, 3.02)), it significantly affected the effect size of the 10-year local recurrence rate (RR = 1.47, 95% CI (0.96, 2.27)). Young age is a significant risk factor for local recurrence developed within 5 years of breast-conserving therapy in patients with early-stage breast cancer. Further high-quality studies are needed to elucidate the relationship between young age and the risk of local recurrence developed within 10 years.