Patient Experiences With the COVID-19 Vaccination After Breast Cancer Treatment

The investigators expect 90% of participants to receive the COVID-19 vaccine on their contralateral (unaffected) arm. This outcome measure is looking at the number of participants who received the COVID-19 vaccine on the side of breast cancer treatment vs those who received the vaccine on the opposite side of breast cancer treatment. Patients with bilateral cancer were excluded from this analysis due to the nature of breast cancer laterality categorization.

Time frame: This was a survey study of patients with breast surgery for breast cancer. Participants replied to the online survey up to 361.5 months post their breast surgery (median 69.0 months). This was the study's reported timeframe in the published manuscript.

Population: The cohort of patients who received a non-mRNA vaccine was not included in the analysis, as only a small proportion of the population received this vaccine type. Consequently, data on this group were not collected.

The outcome measure will be analyzing the reported duration of lymph node swelling, categorized by the location at which lymph node swelling occurred (the axilla vs supraclavicular region) and which side of the body this swelling occurred in relation to the side of the body that received the vaccine injection (ipsilateral vs contralateral). The main aim of this paper was to report the side effects of the mRNA COVID-19 vaccines in patients treated for breast cancer.

Time frame: This was a survey study of patients with breast surgery for breast cancer. Participants replied to the online survey up to 361.5 months post their breast surgery (median 69.0 months). This was the study's reported timeframe in the published manuscript.

Population: The number analyzed reflects participants who experienced swelling at the specified location (axilla or supraclavicular) and the side relative to vaccine administration. For example, Duration of LN swelling - Supraclavicular, Contralateral to Vaccine: 24 hours or less for Dose 1 included 11 patients, as 11 of 61 reported swelling in the supraclavicular region contralateral to the side they received the vaccine.

Due to the inherent activity of mRNA vaccines and the immune system, as well as the role of the lymph nodes in breast cancer (BC) and in breast cancer-related lymphedema (BCRL), this study analyzed the side effect profile in patients treated for BC and who received up to three doses of the COVID-19 vaccinations \[Moderna, Pfizer\]. A separate analysis is presented on results from participants who received the Johnson & Johnson (J&J) vaccine as lymph node swelling is not a listed side effect of this non-mRNA vaccine and only a small proportion of the population received this vaccine. This outcome analyzes the duration of side effects associated with each dose of the vaccine.

Time frame: This was a survey study of patients with breast surgery for breast cancer. Participants replied to the online survey up to 361.5 months post their breast surgery (median 69.0 months). This was the study's reported timeframe in the published manuscript.

Population: Participants are represented in multiple rows for the duration of separate side effects, so they can be accounted for in more than one row. The discrepancy for the \[mRNA vaccine Dose 1 - Moderna, Pfizer\] reported side effects Arm/Group is due to three participants who did not respond to the side effects question for Dose 1, resulting in a total of 529 responses out of 532 participants.

The investigators expect 10-15% of participants to experience lymph node swelling after receiving the Pfizer or Moderna vaccines. The outcome measure analyzes the number of participants who experienced LN swelling after receiving each dose of their COVID-19 vaccines. The analysis looked at what location on the body lymph node swelling occurred (axilla vs supraclavicular region), which side of the body this swelling occurred in relation to the side of the body that received the vaccine (ipsilateral vs contralateral), and which side of the body this swelling occurred in relation to the side of the body the patient has/had breast cancer (ipsilateral vs contralateral). Patients with bilateral cancer were excluded from the analysis of LN swelling in relation to both the vaccine and breast cancer laterality due to the nature of BC laterality categorization. Analysis on breast cancer laterality and LN swelling was not conducted for the non-mRNA vaccine (Johnson & Johnson) group.

Time frame: This was a survey study of patients with breast surgery for breast cancer. Participants replied to the online survey up to 361.5 months post their breast surgery (median 69.0 months). This was the study's reported timeframe in the published manuscript.

Population: The first row, 'Lymph node (LN) swelling, general', reports the number of subjects who reported LN swelling. We then analyzed, of the subjects who indicated that they experienced LN swelling, the laterality in which this swelling occurred. These data are represented in rows 2 through 5.~In the analysis of LN swelling laterality related to both vaccine and BC laterality, the population size was the number of participants vaccinated on the specified side (only conducted for mRNA vaccines).

Due to the inherent activity of mRNA vaccines and the immune system, as well as the role of the lymph nodes in breast cancer (BC) and in breast cancer-related lymphedema (BCRL), this study analyzed the side effect profile in patients treated for BC and who received up to three doses of the COVID-19 vaccinations \[Moderna, Pfizer\]. A separate analysis is presented on results from participants who received the Johnson & Johnson (J&J) vaccine as lymph node swelling is not a listed side effect of this non-mRNA vaccine and only a small proportion of the population received this vaccine.

Time frame: This was a survey study of patients with breast surgery for breast cancer. Participants replied to the online survey up to 361.5 months post their breast surgery (median 69.0 months). This was the study's reported timeframe in the published manuscript.