The relationship between late phase PET/CT findings and clinical and/or immunohistochemical prognostic factors in patients with breast cancer

OBJECTIVE: For staging and therapy monitoring, 18F-FDG PET / CT performed total of 82 women (mean age 50.0 ± 1.5 years, age range 26-82) who have new diagnosed of breast cancer were included in this study. Some patients who received chemotherapy or radiotherapy or had as the secondary malignancy were excluded. Patients were divided three groups as invasive ductal cancers, mixt types and the others. MATERIALS AND METHODS: Descriptive parameters, pathological diagnosis, grades, receptor values (ER, PR , Cerb-B2), cancer antigen values (CA- 15-3 and CEA), the presence of axillary lymph node metastasis, values of tumor area and quantitative parameters which calculated from early and late PET / CT were obtained from all patients. İmage acquisition was performed from head base to upper femoral region, up to 8-9 bed position by using 20 slice multidetector spiral CT integrated PET/CT which have LSO crystals, TOFF and HD features. RESULTS: Tumor area and CA 15-3 values were significantly different between invasive ductal carcinoma and others (p= 0.01 and p= 0.008). Among tumor area and 18F-FDG uptake parameters (early SUVmax and late SUVmax values), while there was lower correlation in the group of invasive ductal cancer (R = 0.158 to 0.2, p> 0.05), there was higher correlation in the group of others (R= 0.724 and 0.818, p= 0.002 and p< 0.0001). There was a significant correlation between early SUVmax and CEA values in others (R=0.850, p< 0.0001). Between Cerb-B2 positive and negative groups, CA 15-3 levels was significantly different (p= 0.043). Ages, tumor area values and CA 15-3 levels were significantly differences between axillary lymph node positive and negative groups (p= 0.023, p= 0.007 and p= 0.043). Between early SUVmax and late SUVmax values, there were significantly higher correlation in the invasive ductal cancer group (RR = 0.965, p <0.001) and other cancers (R= 0.929, p <0.001) but there were no significant correlation among SUVmax values and SUVmax RI values (R = (-0.069) - 0.263 and p > 0.05). In the estrogen and progesterone receptor positive and negative groups, there were no significant differences for these quantitative parameters. 92 CONCLUSION: Tumor area and CA 15-3 values significantly differ between invasive ductal carcinoma and others. While there was lower correlation in the group of invasive ductal cancer, there was higher correlation in the group of others among tumor area and 18F-FDG uptake parameters (early SUVmax and late SUVmax values). We thought that retention indices might be less remarkable parameter than SUVmax values for monitoring.