Background: If ductal carcinoma in situ (DCIS) is diagnosed by histological examination such as core needle biopsy or vacuum-assisted biopsy (VAB), invasion is often found by removing the entire tumor and performing pathological examination. According to a meta-analysis, the rate of invasion found by postoperative pathological examination is about 25%. Smoking is a risk factor for carcinogenesis in various carcinomas, including breast cancer. We examined the correlation between the risk of invasion found by postoperative pathology and smoking history in patients who were diagnosed with DCIS by preoperative biopsy.
Methods: In this study, we examined 128 patients who were diagnosed with DCIS by preoperative biopsy. Before the biopsy, all patients were asked about the duration of smoking, number of cigarettes smoked per day, and whether they were currently smoking. The data were used to calculate each patient’s tobacco exposure based on pack-years. The statistical analyses included the Pearson’s chi-square test and logistic analysis. Multivariate analysis was performed on the risk factors for invasion diagnosed by postoperative pathological examination in all cases diagnosed with DCIS by preoperative biopsy.
Results: Of all the patients included in this study, 107 (83.5%) never smoked, which represented the majority, while 8 patients (6.3%) smoked at diagnosis with DCIS, and 13 (10.2%) had quit smoking before diagnosis. Tobacco exposure was 10 or less pack-years for 11 patients (8.6%) and more than 10 pack-years for 10 patients (7.8%). Number of pack-years was not an independent factor (p=0.349, odds ratio [OR]=0.329), but current smoker status (p=0.006, OR=not calculable) was an independent factor with VAB (p=0.018, OR=0.327).
Conclusions: This study suggests that tobacco components may have an influence on the progression from DCIS to invasive ductal carcinoma.