To investigate the vaccination against COVID-19 in patients with early breast cancer and analyze the influencing factors.

According to the inclusion and exclusion criteria, 400 patients with early breast cancer treated in the breast outpatient clinic of Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from September 21, 2021 to January 6, 2022 were enrolled for a retrospective study. Anonymous questionnaires were used to collect the general data of patients and the data related to COVID-19 vaccination. Patients were divided into vaccination group and vaccine hesitancy group according to whether they received the vaccination or not. The questionnaires included basic information of patients, tumor status, vaccination status, and reasons for vaccination or hesitancy. The count data (age, fixed income, comorbidities, regional lymph node metastasis and antitumor therapy) were presented as cases (%) and compared between two groups by χ² test. The ranked data (education background and number of family members) were compared between two groups by the Mann-Whitney test. Logistic regression analysis was used for multivariate analysis.

Among 400 patients, 77 cases were vaccinated (vaccination group) and 323 cases were not vaccinated (vaccine hesitancy group). The vaccination rate was 19.3% (77/400). Univariate analysis showed that the vaccination group had a significantly lower rate of regional lymph node metastasis compared with the vaccine hesitancy group [15.6% (12/77) vs 27.6% (89/323), χ²=4.720, P=0.030], but with a significantly higher proportion of patients who did not receive antitumor therapy [31.2%(24/77) vs 17.3%(56/323), χ²=7.434, P=0.008]. Multivariate analysis showed that regional lymph node metastasis was an independent risk factor for vaccination hesitation(OR =2.160, 95%CI: 1.230-3.790, P=0.007). The reasons for vaccination willingness were as follow: national policy to encourage vaccination (56/77, 72.7%), belief in the safety of the vaccine (49/77, 63.6%, ) and fear of COVID-19 infection (46/77, 59.7%). The reasons for vaccination hesitation were as follow: concern about effect of vaccination on breast cancer progression (152/323, 47.1%), concern about adverse events of vaccination (96/323, 29.7%), no recommendation from the oncologists (61/323, 18.9%) and internet rumors about no vaccination within 2 years after operation (39/323, 12.1%).

The early breast cancer patients, especially the patients with regional lymph node metastasis, have a low COVID-19 vaccination rate, which is mainly due to patients’ concern about the effect of vaccination on breast cancer. Future intervention, which include timely and accurate information release by authoritative media and training for oncologists in order to enhance the confidence of patients in COVID-19 vaccination.