1628P - Impact of COVID-19 pandemia on the diagnosis of breast cancer in one region of north of Portugal: One year experience

Background

The onset of COVID-19 pandemic forced lockdown and halted breast cancer screening programs. We aimed to investigate the impact of COVID-19 on the new diagnosis and staging of breast cancer.

Methods

In this cohort study, we included all patient with new diagnosis of breast cancer who were admitted to our Hospital (Hospital Pedro Hispano, Matosinhos, Portugal), between March 2019 and March 2021. We collected data on baseline clinical conditions such as age, stage at diagnosis and treatment. We created two different groups were created: 1^st group- before COVID-19 pandemia (March 1, 2019 to March 16, 2020); 2^nd group - COVID-19 pandemia (March 17, 2020 to March 31, 2021). A comparative assessment between groups was carried out.

Results

Were included 483 patients; n=289 in the 1^st group and n= 194 in the 2^nd group. The median age was 60 years old in the 1^st group and 59 years old in the 2^nd group. In the 1^st group, 13% patients were diagnosis with ductal in situ carcinoma (DCIS), 51% in stage I, 24% in stage II, 9.5% in stage III and 3% in stage IV. In 2^nd group, 9% had DCIS, 30% were in stage I, 40% in stage II, 11% in stage III and 10% in stage IV. Stage at diagnosis was significantly higher in the 2^nd group (p< 0.001) This situation was mainly due to tumour size (T). In the 1^st group, most patients (n=91; 38%) had tumour size between 10 e 20mm (T1c in TNM classification). One the other hand, 40% (n=78) of patients included in the 2^nd group had tumour size between 20 e 50mm (T2), with significant differences between them (p=0.004). No difference was found between groups in nodular involvement (p=0.189), with the majority of patients (∼50% in both groups) presenting without nodular involvement (N0 in TMN classification). 10% of patients in 2^nd group and 3% in 1^st group had metastatic disease at diagnosis, with differences between them (p=0.006). 49% (n=119) of patients in 1^st group and 52% (n=100) in the 2^nd group were treated with chemotherapy, without differences between those groups.

Conclusions

Our results show that during one year after COVID-19 pandemia the incidence of breast cancer decreased, and patients were diagnosis in more advanced stages. This situation could have been related to patient referral to non COVID-19 Hospitals or correspond to a true sub-diagnosis.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

M. Vilaça.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.