The study was conducted on 131 patients, including the control group (n=45)(34.4%), the pandemic group (n=39)(29.8%) and the vaccine group (n=47)(35.9%). It has been observed that the number of patients during the pandemic period decreased by 5% compared to the precovid period but increased again after vaccination. The mean age of the patients was 52.94±11.84 years, and their ages ranged from 25 to 80 years. Age medians did not differ significantly, being 52 (26-78) in the control group, 52 (36-80) in the pandemic group, and 51 (25-72) in the vaccine group; p=0.848. Table 1 summarizes the general characteristics of the continuous data of the study by groups.
In Table 2, the descriptive statistics of the groups according to the continuous variables of the study and the results of the Kruskal-Wallis test are given. Those with significant differences were compared between the groups and adjusted significance values were calculated.
Patient admission delay time varied significantly between groups; H(2) = 29.617, p < 0.001. Pairwise comparisons with adjusted p-values showed that patient admission delay times were significantly higher in the pandemic period than in the pre-pandemic period; H = -44.99, p < 0.001, r = -0.59. Patient admission delay during the vaccination period was significantly reduced compared to the pandemic period; H = 24,352, p = 0.009, r = 0.32. During the vaccination period, patient admission times increased significantly compared with the pre-pandemic period, although not as much as during the pandemic period; H = -20.64, p = 0.026, r = -0.27.
Diagnosis time varied significantly according to the groups. H(2) = 29,070, p < 0.001. Pairwise comparisons with adjusted p-values showed that diagnosis times were significantly higher in both the pandemic period and the vaccination period compared to the pre-vaccination period, respectively, H = -44.527, p < 0.001, r = -0.56 and H = -31.109, p < 0.001, r = -0.41. The mean time to diagnosis during the vaccination period decreased compared with the pandemic period, but it was not statistically significant; H = 11,418, p = 0.492, r = 0.15.
Tumor size varied significantly between groups; H(2) = 13,809, p = 0.001. Pairwise comparisons with adjusted p-values showed that tumor sizes significantly increased during the pandemic period compared to pre-covid and vaccination period, respectively H = -27.075 p = 0.003, r = -0.356, and H = 26.748, p = 0.001, r = 0.351. The mean of tumor sizes in the pre-pandemic period and the vaccination periods are close to each other and are not statistically significant; H = -0.327, p = 1,000, r = -0.004.
Tumor size varied significantly between groups in patients receiving neo-adjuvant chemotherapy; H(2) = 8.910, p = 0.012. Pairwise comparisons with adjusted p-values showed that during the pandemic period, tumor sizes significantly increased in patients receiving neo-adjuvant chemotherapy compared to the control group and vaccine group, respectively H = -11.227 p = 0.017, r = -0.302 and H = 9.909, p = 0.043, r = 0.264. The mean of tumor sizes in the pre-pandemic period and the vaccination periods are close to each other and are not statistically significant; H = -1.318, p = 1,000, r = -0.035.
Tumor size also varied significantly between groups in patients not receiving neo-adjuvant chemotherapy; H(2) = 7.908, p = 0.019. Pairwise comparisons with adjusted p-values showed that tumor sizes significantly decreased in the vaccination period compared to the pandemic period in patients who did not receive neo-adjuvant chemotherapy; H = -18,197 p = 0.033, r = 0. In patients who did not receive neo-adjuvant therapy, tumor sizes increased during the pandemic period compared to the control group, but not statistically significant, H = -17,301, p = 0.051, r = -0.260. There was no significant difference in tumor sizes between the control group and the vaccination group, H = 0.896, p = 1.000, r = 0.013.
The complaints of the patients are shown in Figure 1 and Table 3. The patients were applied with the most common complaint of breast lump in all 3 periods. Other application complaints; mastalgia, skin retraction, nipple discharge, and feeling of fullness, back pain complaints. The complaints of the patients did not differ significantly between the groups. (Lump (p=0.099), mastalgia (p=0.103), skin retraction (p=0.435), nipple discharge (p=0.075), other (p=0485))
In Table 4, the descriptive statistics of the patients in the control, pandemic and vaccination periods according to the categorical variables of the study and the Pearson chi-square test findings are given. The frequency distribution of groups receiving neo-adjuvant therapy (p= 0.988), preoperative staging methods ((mammograpy (p=0.848), breast usg (p=1), breast MRI (p=0.157), PET CT (p=0.494)), type of surgery (p=0.079), sentinel lymph node biopsy (p= 0.505), SLNB result (p=0.651), ALND (P=0.579), pathology result (p=0.169), T distribution of patients with NAC (p=0.150), N distribution of patients with or without NAC (p=0.905) or (p=0.40), M distribution of patients with or without NAC (p=0.391) or (p=0.308), pathological stage patients with or without NAC (p=0.542) or (p=0.188) and molecular subtype (p=0.082) did not differ significantly.
The frequency distribution of the groups differed significantly in the T values of the patients who did not receive neoadjuvant chemotherapy; χ2= 16,066, p=0.041. When the relationship between the meanings was examined, it was understood that the high number of T3 tumors in the pandemic group caused this meaning.
Figure 2 shows the vaccine types of 47 patients in the vaccine group. Accordingly, 4 (8.51%) patients received Sinovac CoronaVac, 10 (21.28%) patients received Pfizer-BioNTech, and the remaining 33 (70.21%) patients received at least one dose of both vaccines.